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280 |
jeremybenn |
/* If-conversion support.
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Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2010
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Free Software Foundation, Inc.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3, or (at your option)
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any later version.
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GCC is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
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License for more details.
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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING3. If not see
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<http://www.gnu.org/licenses/>. */
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#include "config.h"
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#include "system.h"
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#include "coretypes.h"
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#include "tm.h"
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#include "rtl.h"
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#include "regs.h"
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#include "function.h"
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#include "flags.h"
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#include "insn-config.h"
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#include "recog.h"
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#include "except.h"
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#include "hard-reg-set.h"
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#include "basic-block.h"
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#include "expr.h"
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#include "real.h"
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37 |
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#include "output.h"
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38 |
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#include "optabs.h"
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39 |
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#include "toplev.h"
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#include "tm_p.h"
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41 |
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#include "cfgloop.h"
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#include "target.h"
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#include "timevar.h"
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44 |
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#include "tree-pass.h"
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#include "df.h"
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46 |
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#include "vec.h"
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#include "vecprim.h"
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48 |
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#include "dbgcnt.h"
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49 |
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50 |
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#ifndef HAVE_conditional_move
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#define HAVE_conditional_move 0
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52 |
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#endif
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53 |
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#ifndef HAVE_incscc
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54 |
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#define HAVE_incscc 0
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55 |
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#endif
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56 |
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#ifndef HAVE_decscc
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57 |
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#define HAVE_decscc 0
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58 |
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#endif
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59 |
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#ifndef HAVE_trap
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#define HAVE_trap 0
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61 |
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#endif
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63 |
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#ifndef MAX_CONDITIONAL_EXECUTE
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#define MAX_CONDITIONAL_EXECUTE \
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(BRANCH_COST (optimize_function_for_speed_p (cfun), false) \
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+ 1)
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#endif
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68 |
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69 |
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#define IFCVT_MULTIPLE_DUMPS 1
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70 |
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71 |
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#define NULL_BLOCK ((basic_block) NULL)
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72 |
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73 |
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/* # of IF-THEN or IF-THEN-ELSE blocks we looked at */
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74 |
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static int num_possible_if_blocks;
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75 |
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76 |
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/* # of IF-THEN or IF-THEN-ELSE blocks were converted to conditional
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77 |
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execution. */
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78 |
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static int num_updated_if_blocks;
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79 |
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80 |
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/* # of changes made. */
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81 |
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static int num_true_changes;
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82 |
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83 |
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/* Whether conditional execution changes were made. */
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84 |
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static int cond_exec_changed_p;
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85 |
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86 |
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/* Forward references. */
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87 |
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static int count_bb_insns (const_basic_block);
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88 |
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static bool cheap_bb_rtx_cost_p (const_basic_block, int);
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89 |
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static rtx first_active_insn (basic_block);
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90 |
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static rtx last_active_insn (basic_block, int);
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91 |
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static basic_block block_fallthru (basic_block);
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92 |
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static int cond_exec_process_insns (ce_if_block_t *, rtx, rtx, rtx, rtx, int);
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93 |
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static rtx cond_exec_get_condition (rtx);
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94 |
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static rtx noce_get_condition (rtx, rtx *, bool);
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95 |
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static int noce_operand_ok (const_rtx);
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96 |
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static void merge_if_block (ce_if_block_t *);
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97 |
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static int find_cond_trap (basic_block, edge, edge);
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98 |
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static basic_block find_if_header (basic_block, int);
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99 |
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static int block_jumps_and_fallthru_p (basic_block, basic_block);
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100 |
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static int noce_find_if_block (basic_block, edge, edge, int);
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101 |
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static int cond_exec_find_if_block (ce_if_block_t *);
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102 |
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static int find_if_case_1 (basic_block, edge, edge);
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103 |
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static int find_if_case_2 (basic_block, edge, edge);
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104 |
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static int find_memory (rtx *, void *);
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static int dead_or_predicable (basic_block, basic_block, basic_block,
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106 |
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basic_block, int);
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107 |
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static void noce_emit_move_insn (rtx, rtx);
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108 |
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static rtx block_has_only_trap (basic_block);
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109 |
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110 |
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/* Count the number of non-jump active insns in BB. */
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111 |
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112 |
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static int
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113 |
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count_bb_insns (const_basic_block bb)
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114 |
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{
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115 |
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int count = 0;
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116 |
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rtx insn = BB_HEAD (bb);
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118 |
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while (1)
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119 |
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{
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120 |
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if (CALL_P (insn) || NONJUMP_INSN_P (insn))
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count++;
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122 |
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123 |
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if (insn == BB_END (bb))
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break;
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125 |
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insn = NEXT_INSN (insn);
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126 |
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}
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127 |
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128 |
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return count;
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129 |
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}
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130 |
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131 |
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/* Determine whether the total insn_rtx_cost on non-jump insns in
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132 |
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basic block BB is less than MAX_COST. This function returns
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133 |
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false if the cost of any instruction could not be estimated. */
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134 |
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135 |
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static bool
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136 |
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cheap_bb_rtx_cost_p (const_basic_block bb, int max_cost)
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137 |
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{
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138 |
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int count = 0;
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139 |
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rtx insn = BB_HEAD (bb);
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140 |
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bool speed = optimize_bb_for_speed_p (bb);
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141 |
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142 |
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while (1)
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143 |
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{
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144 |
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if (NONJUMP_INSN_P (insn))
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145 |
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{
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146 |
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int cost = insn_rtx_cost (PATTERN (insn), speed);
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147 |
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if (cost == 0)
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return false;
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149 |
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150 |
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/* If this instruction is the load or set of a "stack" register,
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such as a floating point register on x87, then the cost of
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152 |
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speculatively executing this insn may need to include
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the additional cost of popping its result off of the
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register stack. Unfortunately, correctly recognizing and
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accounting for this additional overhead is tricky, so for
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now we simply prohibit such speculative execution. */
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#ifdef STACK_REGS
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{
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159 |
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rtx set = single_set (insn);
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if (set && STACK_REG_P (SET_DEST (set)))
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return false;
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}
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#endif
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count += cost;
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if (count >= max_cost)
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return false;
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}
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else if (CALL_P (insn))
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return false;
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if (insn == BB_END (bb))
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break;
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insn = NEXT_INSN (insn);
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}
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return true;
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}
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/* Return the first non-jump active insn in the basic block. */
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static rtx
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first_active_insn (basic_block bb)
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{
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rtx insn = BB_HEAD (bb);
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if (LABEL_P (insn))
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{
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if (insn == BB_END (bb))
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return NULL_RTX;
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insn = NEXT_INSN (insn);
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}
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while (NOTE_P (insn) || DEBUG_INSN_P (insn))
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{
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if (insn == BB_END (bb))
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return NULL_RTX;
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insn = NEXT_INSN (insn);
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}
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if (JUMP_P (insn))
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return NULL_RTX;
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return insn;
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}
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/* Return the last non-jump active (non-jump) insn in the basic block. */
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static rtx
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last_active_insn (basic_block bb, int skip_use_p)
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{
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rtx insn = BB_END (bb);
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rtx head = BB_HEAD (bb);
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215 |
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while (NOTE_P (insn)
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216 |
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|| JUMP_P (insn)
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217 |
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|| DEBUG_INSN_P (insn)
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218 |
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|| (skip_use_p
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219 |
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&& NONJUMP_INSN_P (insn)
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&& GET_CODE (PATTERN (insn)) == USE))
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221 |
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{
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222 |
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if (insn == head)
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223 |
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return NULL_RTX;
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224 |
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insn = PREV_INSN (insn);
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225 |
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}
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226 |
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227 |
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if (LABEL_P (insn))
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return NULL_RTX;
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229 |
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230 |
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return insn;
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231 |
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}
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232 |
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233 |
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/* Return the basic block reached by falling though the basic block BB. */
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234 |
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235 |
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static basic_block
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236 |
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block_fallthru (basic_block bb)
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237 |
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{
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238 |
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edge e;
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239 |
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edge_iterator ei;
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240 |
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241 |
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FOR_EACH_EDGE (e, ei, bb->succs)
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242 |
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if (e->flags & EDGE_FALLTHRU)
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243 |
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break;
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244 |
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245 |
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return (e) ? e->dest : NULL_BLOCK;
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246 |
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}
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247 |
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248 |
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/* Go through a bunch of insns, converting them to conditional
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249 |
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execution format if possible. Return TRUE if all of the non-note
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250 |
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insns were processed. */
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251 |
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252 |
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static int
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253 |
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cond_exec_process_insns (ce_if_block_t *ce_info ATTRIBUTE_UNUSED,
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254 |
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/* if block information */rtx start,
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255 |
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/* first insn to look at */rtx end,
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256 |
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/* last insn to look at */rtx test,
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257 |
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/* conditional execution test */rtx prob_val,
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258 |
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/* probability of branch taken. */int mod_ok)
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259 |
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{
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260 |
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int must_be_last = FALSE;
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261 |
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rtx insn;
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262 |
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rtx xtest;
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263 |
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rtx pattern;
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264 |
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265 |
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if (!start || !end)
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266 |
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return FALSE;
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267 |
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268 |
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for (insn = start; ; insn = NEXT_INSN (insn))
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269 |
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{
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270 |
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if (NOTE_P (insn) || DEBUG_INSN_P (insn))
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271 |
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goto insn_done;
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272 |
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|
273 |
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gcc_assert(NONJUMP_INSN_P (insn) || CALL_P (insn));
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274 |
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|
275 |
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/* Remove USE insns that get in the way. */
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276 |
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if (reload_completed && GET_CODE (PATTERN (insn)) == USE)
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277 |
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{
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278 |
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/* ??? Ug. Actually unlinking the thing is problematic,
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279 |
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given what we'd have to coordinate with our callers. */
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280 |
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SET_INSN_DELETED (insn);
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281 |
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goto insn_done;
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282 |
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}
|
283 |
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|
284 |
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/* Last insn wasn't last? */
|
285 |
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if (must_be_last)
|
286 |
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return FALSE;
|
287 |
|
|
|
288 |
|
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if (modified_in_p (test, insn))
|
289 |
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{
|
290 |
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if (!mod_ok)
|
291 |
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return FALSE;
|
292 |
|
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must_be_last = TRUE;
|
293 |
|
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}
|
294 |
|
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|
295 |
|
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/* Now build the conditional form of the instruction. */
|
296 |
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pattern = PATTERN (insn);
|
297 |
|
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xtest = copy_rtx (test);
|
298 |
|
|
|
299 |
|
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/* If this is already a COND_EXEC, rewrite the test to be an AND of the
|
300 |
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two conditions. */
|
301 |
|
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if (GET_CODE (pattern) == COND_EXEC)
|
302 |
|
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{
|
303 |
|
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if (GET_MODE (xtest) != GET_MODE (COND_EXEC_TEST (pattern)))
|
304 |
|
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return FALSE;
|
305 |
|
|
|
306 |
|
|
xtest = gen_rtx_AND (GET_MODE (xtest), xtest,
|
307 |
|
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COND_EXEC_TEST (pattern));
|
308 |
|
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pattern = COND_EXEC_CODE (pattern);
|
309 |
|
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}
|
310 |
|
|
|
311 |
|
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pattern = gen_rtx_COND_EXEC (VOIDmode, xtest, pattern);
|
312 |
|
|
|
313 |
|
|
/* If the machine needs to modify the insn being conditionally executed,
|
314 |
|
|
say for example to force a constant integer operand into a temp
|
315 |
|
|
register, do so here. */
|
316 |
|
|
#ifdef IFCVT_MODIFY_INSN
|
317 |
|
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IFCVT_MODIFY_INSN (ce_info, pattern, insn);
|
318 |
|
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if (! pattern)
|
319 |
|
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return FALSE;
|
320 |
|
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#endif
|
321 |
|
|
|
322 |
|
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validate_change (insn, &PATTERN (insn), pattern, 1);
|
323 |
|
|
|
324 |
|
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if (CALL_P (insn) && prob_val)
|
325 |
|
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validate_change (insn, ®_NOTES (insn),
|
326 |
|
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alloc_EXPR_LIST (REG_BR_PROB, prob_val,
|
327 |
|
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REG_NOTES (insn)), 1);
|
328 |
|
|
|
329 |
|
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insn_done:
|
330 |
|
|
if (insn == end)
|
331 |
|
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break;
|
332 |
|
|
}
|
333 |
|
|
|
334 |
|
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return TRUE;
|
335 |
|
|
}
|
336 |
|
|
|
337 |
|
|
/* Return the condition for a jump. Do not do any special processing. */
|
338 |
|
|
|
339 |
|
|
static rtx
|
340 |
|
|
cond_exec_get_condition (rtx jump)
|
341 |
|
|
{
|
342 |
|
|
rtx test_if, cond;
|
343 |
|
|
|
344 |
|
|
if (any_condjump_p (jump))
|
345 |
|
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test_if = SET_SRC (pc_set (jump));
|
346 |
|
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else
|
347 |
|
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return NULL_RTX;
|
348 |
|
|
cond = XEXP (test_if, 0);
|
349 |
|
|
|
350 |
|
|
/* If this branches to JUMP_LABEL when the condition is false,
|
351 |
|
|
reverse the condition. */
|
352 |
|
|
if (GET_CODE (XEXP (test_if, 2)) == LABEL_REF
|
353 |
|
|
&& XEXP (XEXP (test_if, 2), 0) == JUMP_LABEL (jump))
|
354 |
|
|
{
|
355 |
|
|
enum rtx_code rev = reversed_comparison_code (cond, jump);
|
356 |
|
|
if (rev == UNKNOWN)
|
357 |
|
|
return NULL_RTX;
|
358 |
|
|
|
359 |
|
|
cond = gen_rtx_fmt_ee (rev, GET_MODE (cond), XEXP (cond, 0),
|
360 |
|
|
XEXP (cond, 1));
|
361 |
|
|
}
|
362 |
|
|
|
363 |
|
|
return cond;
|
364 |
|
|
}
|
365 |
|
|
|
366 |
|
|
/* Given a simple IF-THEN or IF-THEN-ELSE block, attempt to convert it
|
367 |
|
|
to conditional execution. Return TRUE if we were successful at
|
368 |
|
|
converting the block. */
|
369 |
|
|
|
370 |
|
|
static int
|
371 |
|
|
cond_exec_process_if_block (ce_if_block_t * ce_info,
|
372 |
|
|
/* if block information */int do_multiple_p)
|
373 |
|
|
{
|
374 |
|
|
basic_block test_bb = ce_info->test_bb; /* last test block */
|
375 |
|
|
basic_block then_bb = ce_info->then_bb; /* THEN */
|
376 |
|
|
basic_block else_bb = ce_info->else_bb; /* ELSE or NULL */
|
377 |
|
|
rtx test_expr; /* expression in IF_THEN_ELSE that is tested */
|
378 |
|
|
rtx then_start; /* first insn in THEN block */
|
379 |
|
|
rtx then_end; /* last insn + 1 in THEN block */
|
380 |
|
|
rtx else_start = NULL_RTX; /* first insn in ELSE block or NULL */
|
381 |
|
|
rtx else_end = NULL_RTX; /* last insn + 1 in ELSE block */
|
382 |
|
|
int max; /* max # of insns to convert. */
|
383 |
|
|
int then_mod_ok; /* whether conditional mods are ok in THEN */
|
384 |
|
|
rtx true_expr; /* test for else block insns */
|
385 |
|
|
rtx false_expr; /* test for then block insns */
|
386 |
|
|
rtx true_prob_val; /* probability of else block */
|
387 |
|
|
rtx false_prob_val; /* probability of then block */
|
388 |
|
|
int n_insns;
|
389 |
|
|
enum rtx_code false_code;
|
390 |
|
|
|
391 |
|
|
/* If test is comprised of && or || elements, and we've failed at handling
|
392 |
|
|
all of them together, just use the last test if it is the special case of
|
393 |
|
|
&& elements without an ELSE block. */
|
394 |
|
|
if (!do_multiple_p && ce_info->num_multiple_test_blocks)
|
395 |
|
|
{
|
396 |
|
|
if (else_bb || ! ce_info->and_and_p)
|
397 |
|
|
return FALSE;
|
398 |
|
|
|
399 |
|
|
ce_info->test_bb = test_bb = ce_info->last_test_bb;
|
400 |
|
|
ce_info->num_multiple_test_blocks = 0;
|
401 |
|
|
ce_info->num_and_and_blocks = 0;
|
402 |
|
|
ce_info->num_or_or_blocks = 0;
|
403 |
|
|
}
|
404 |
|
|
|
405 |
|
|
/* Find the conditional jump to the ELSE or JOIN part, and isolate
|
406 |
|
|
the test. */
|
407 |
|
|
test_expr = cond_exec_get_condition (BB_END (test_bb));
|
408 |
|
|
if (! test_expr)
|
409 |
|
|
return FALSE;
|
410 |
|
|
|
411 |
|
|
/* If the conditional jump is more than just a conditional jump,
|
412 |
|
|
then we can not do conditional execution conversion on this block. */
|
413 |
|
|
if (! onlyjump_p (BB_END (test_bb)))
|
414 |
|
|
return FALSE;
|
415 |
|
|
|
416 |
|
|
/* Collect the bounds of where we're to search, skipping any labels, jumps
|
417 |
|
|
and notes at the beginning and end of the block. Then count the total
|
418 |
|
|
number of insns and see if it is small enough to convert. */
|
419 |
|
|
then_start = first_active_insn (then_bb);
|
420 |
|
|
then_end = last_active_insn (then_bb, TRUE);
|
421 |
|
|
n_insns = ce_info->num_then_insns = count_bb_insns (then_bb);
|
422 |
|
|
max = MAX_CONDITIONAL_EXECUTE;
|
423 |
|
|
|
424 |
|
|
if (else_bb)
|
425 |
|
|
{
|
426 |
|
|
max *= 2;
|
427 |
|
|
else_start = first_active_insn (else_bb);
|
428 |
|
|
else_end = last_active_insn (else_bb, TRUE);
|
429 |
|
|
n_insns += ce_info->num_else_insns = count_bb_insns (else_bb);
|
430 |
|
|
}
|
431 |
|
|
|
432 |
|
|
if (n_insns > max)
|
433 |
|
|
return FALSE;
|
434 |
|
|
|
435 |
|
|
/* Map test_expr/test_jump into the appropriate MD tests to use on
|
436 |
|
|
the conditionally executed code. */
|
437 |
|
|
|
438 |
|
|
true_expr = test_expr;
|
439 |
|
|
|
440 |
|
|
false_code = reversed_comparison_code (true_expr, BB_END (test_bb));
|
441 |
|
|
if (false_code != UNKNOWN)
|
442 |
|
|
false_expr = gen_rtx_fmt_ee (false_code, GET_MODE (true_expr),
|
443 |
|
|
XEXP (true_expr, 0), XEXP (true_expr, 1));
|
444 |
|
|
else
|
445 |
|
|
false_expr = NULL_RTX;
|
446 |
|
|
|
447 |
|
|
#ifdef IFCVT_MODIFY_TESTS
|
448 |
|
|
/* If the machine description needs to modify the tests, such as setting a
|
449 |
|
|
conditional execution register from a comparison, it can do so here. */
|
450 |
|
|
IFCVT_MODIFY_TESTS (ce_info, true_expr, false_expr);
|
451 |
|
|
|
452 |
|
|
/* See if the conversion failed. */
|
453 |
|
|
if (!true_expr || !false_expr)
|
454 |
|
|
goto fail;
|
455 |
|
|
#endif
|
456 |
|
|
|
457 |
|
|
true_prob_val = find_reg_note (BB_END (test_bb), REG_BR_PROB, NULL_RTX);
|
458 |
|
|
if (true_prob_val)
|
459 |
|
|
{
|
460 |
|
|
true_prob_val = XEXP (true_prob_val, 0);
|
461 |
|
|
false_prob_val = GEN_INT (REG_BR_PROB_BASE - INTVAL (true_prob_val));
|
462 |
|
|
}
|
463 |
|
|
else
|
464 |
|
|
false_prob_val = NULL_RTX;
|
465 |
|
|
|
466 |
|
|
/* If we have && or || tests, do them here. These tests are in the adjacent
|
467 |
|
|
blocks after the first block containing the test. */
|
468 |
|
|
if (ce_info->num_multiple_test_blocks > 0)
|
469 |
|
|
{
|
470 |
|
|
basic_block bb = test_bb;
|
471 |
|
|
basic_block last_test_bb = ce_info->last_test_bb;
|
472 |
|
|
|
473 |
|
|
if (! false_expr)
|
474 |
|
|
goto fail;
|
475 |
|
|
|
476 |
|
|
do
|
477 |
|
|
{
|
478 |
|
|
rtx start, end;
|
479 |
|
|
rtx t, f;
|
480 |
|
|
enum rtx_code f_code;
|
481 |
|
|
|
482 |
|
|
bb = block_fallthru (bb);
|
483 |
|
|
start = first_active_insn (bb);
|
484 |
|
|
end = last_active_insn (bb, TRUE);
|
485 |
|
|
if (start
|
486 |
|
|
&& ! cond_exec_process_insns (ce_info, start, end, false_expr,
|
487 |
|
|
false_prob_val, FALSE))
|
488 |
|
|
goto fail;
|
489 |
|
|
|
490 |
|
|
/* If the conditional jump is more than just a conditional jump, then
|
491 |
|
|
we can not do conditional execution conversion on this block. */
|
492 |
|
|
if (! onlyjump_p (BB_END (bb)))
|
493 |
|
|
goto fail;
|
494 |
|
|
|
495 |
|
|
/* Find the conditional jump and isolate the test. */
|
496 |
|
|
t = cond_exec_get_condition (BB_END (bb));
|
497 |
|
|
if (! t)
|
498 |
|
|
goto fail;
|
499 |
|
|
|
500 |
|
|
f_code = reversed_comparison_code (t, BB_END (bb));
|
501 |
|
|
if (f_code == UNKNOWN)
|
502 |
|
|
goto fail;
|
503 |
|
|
|
504 |
|
|
f = gen_rtx_fmt_ee (f_code, GET_MODE (t), XEXP (t, 0), XEXP (t, 1));
|
505 |
|
|
if (ce_info->and_and_p)
|
506 |
|
|
{
|
507 |
|
|
t = gen_rtx_AND (GET_MODE (t), true_expr, t);
|
508 |
|
|
f = gen_rtx_IOR (GET_MODE (t), false_expr, f);
|
509 |
|
|
}
|
510 |
|
|
else
|
511 |
|
|
{
|
512 |
|
|
t = gen_rtx_IOR (GET_MODE (t), true_expr, t);
|
513 |
|
|
f = gen_rtx_AND (GET_MODE (t), false_expr, f);
|
514 |
|
|
}
|
515 |
|
|
|
516 |
|
|
/* If the machine description needs to modify the tests, such as
|
517 |
|
|
setting a conditional execution register from a comparison, it can
|
518 |
|
|
do so here. */
|
519 |
|
|
#ifdef IFCVT_MODIFY_MULTIPLE_TESTS
|
520 |
|
|
IFCVT_MODIFY_MULTIPLE_TESTS (ce_info, bb, t, f);
|
521 |
|
|
|
522 |
|
|
/* See if the conversion failed. */
|
523 |
|
|
if (!t || !f)
|
524 |
|
|
goto fail;
|
525 |
|
|
#endif
|
526 |
|
|
|
527 |
|
|
true_expr = t;
|
528 |
|
|
false_expr = f;
|
529 |
|
|
}
|
530 |
|
|
while (bb != last_test_bb);
|
531 |
|
|
}
|
532 |
|
|
|
533 |
|
|
/* For IF-THEN-ELSE blocks, we don't allow modifications of the test
|
534 |
|
|
on then THEN block. */
|
535 |
|
|
then_mod_ok = (else_bb == NULL_BLOCK);
|
536 |
|
|
|
537 |
|
|
/* Go through the THEN and ELSE blocks converting the insns if possible
|
538 |
|
|
to conditional execution. */
|
539 |
|
|
|
540 |
|
|
if (then_end
|
541 |
|
|
&& (! false_expr
|
542 |
|
|
|| ! cond_exec_process_insns (ce_info, then_start, then_end,
|
543 |
|
|
false_expr, false_prob_val,
|
544 |
|
|
then_mod_ok)))
|
545 |
|
|
goto fail;
|
546 |
|
|
|
547 |
|
|
if (else_bb && else_end
|
548 |
|
|
&& ! cond_exec_process_insns (ce_info, else_start, else_end,
|
549 |
|
|
true_expr, true_prob_val, TRUE))
|
550 |
|
|
goto fail;
|
551 |
|
|
|
552 |
|
|
/* If we cannot apply the changes, fail. Do not go through the normal fail
|
553 |
|
|
processing, since apply_change_group will call cancel_changes. */
|
554 |
|
|
if (! apply_change_group ())
|
555 |
|
|
{
|
556 |
|
|
#ifdef IFCVT_MODIFY_CANCEL
|
557 |
|
|
/* Cancel any machine dependent changes. */
|
558 |
|
|
IFCVT_MODIFY_CANCEL (ce_info);
|
559 |
|
|
#endif
|
560 |
|
|
return FALSE;
|
561 |
|
|
}
|
562 |
|
|
|
563 |
|
|
#ifdef IFCVT_MODIFY_FINAL
|
564 |
|
|
/* Do any machine dependent final modifications. */
|
565 |
|
|
IFCVT_MODIFY_FINAL (ce_info);
|
566 |
|
|
#endif
|
567 |
|
|
|
568 |
|
|
/* Conversion succeeded. */
|
569 |
|
|
if (dump_file)
|
570 |
|
|
fprintf (dump_file, "%d insn%s converted to conditional execution.\n",
|
571 |
|
|
n_insns, (n_insns == 1) ? " was" : "s were");
|
572 |
|
|
|
573 |
|
|
/* Merge the blocks! */
|
574 |
|
|
merge_if_block (ce_info);
|
575 |
|
|
cond_exec_changed_p = TRUE;
|
576 |
|
|
return TRUE;
|
577 |
|
|
|
578 |
|
|
fail:
|
579 |
|
|
#ifdef IFCVT_MODIFY_CANCEL
|
580 |
|
|
/* Cancel any machine dependent changes. */
|
581 |
|
|
IFCVT_MODIFY_CANCEL (ce_info);
|
582 |
|
|
#endif
|
583 |
|
|
|
584 |
|
|
cancel_changes (0);
|
585 |
|
|
return FALSE;
|
586 |
|
|
}
|
587 |
|
|
|
588 |
|
|
/* Used by noce_process_if_block to communicate with its subroutines.
|
589 |
|
|
|
590 |
|
|
The subroutines know that A and B may be evaluated freely. They
|
591 |
|
|
know that X is a register. They should insert new instructions
|
592 |
|
|
before cond_earliest. */
|
593 |
|
|
|
594 |
|
|
struct noce_if_info
|
595 |
|
|
{
|
596 |
|
|
/* The basic blocks that make up the IF-THEN-{ELSE-,}JOIN block. */
|
597 |
|
|
basic_block test_bb, then_bb, else_bb, join_bb;
|
598 |
|
|
|
599 |
|
|
/* The jump that ends TEST_BB. */
|
600 |
|
|
rtx jump;
|
601 |
|
|
|
602 |
|
|
/* The jump condition. */
|
603 |
|
|
rtx cond;
|
604 |
|
|
|
605 |
|
|
/* New insns should be inserted before this one. */
|
606 |
|
|
rtx cond_earliest;
|
607 |
|
|
|
608 |
|
|
/* Insns in the THEN and ELSE block. There is always just this
|
609 |
|
|
one insns in those blocks. The insns are single_set insns.
|
610 |
|
|
If there was no ELSE block, INSN_B is the last insn before
|
611 |
|
|
COND_EARLIEST, or NULL_RTX. In the former case, the insn
|
612 |
|
|
operands are still valid, as if INSN_B was moved down below
|
613 |
|
|
the jump. */
|
614 |
|
|
rtx insn_a, insn_b;
|
615 |
|
|
|
616 |
|
|
/* The SET_SRC of INSN_A and INSN_B. */
|
617 |
|
|
rtx a, b;
|
618 |
|
|
|
619 |
|
|
/* The SET_DEST of INSN_A. */
|
620 |
|
|
rtx x;
|
621 |
|
|
|
622 |
|
|
/* True if this if block is not canonical. In the canonical form of
|
623 |
|
|
if blocks, the THEN_BB is the block reached via the fallthru edge
|
624 |
|
|
from TEST_BB. For the noce transformations, we allow the symmetric
|
625 |
|
|
form as well. */
|
626 |
|
|
bool then_else_reversed;
|
627 |
|
|
|
628 |
|
|
/* Estimated cost of the particular branch instruction. */
|
629 |
|
|
int branch_cost;
|
630 |
|
|
};
|
631 |
|
|
|
632 |
|
|
static rtx noce_emit_store_flag (struct noce_if_info *, rtx, int, int);
|
633 |
|
|
static int noce_try_move (struct noce_if_info *);
|
634 |
|
|
static int noce_try_store_flag (struct noce_if_info *);
|
635 |
|
|
static int noce_try_addcc (struct noce_if_info *);
|
636 |
|
|
static int noce_try_store_flag_constants (struct noce_if_info *);
|
637 |
|
|
static int noce_try_store_flag_mask (struct noce_if_info *);
|
638 |
|
|
static rtx noce_emit_cmove (struct noce_if_info *, rtx, enum rtx_code, rtx,
|
639 |
|
|
rtx, rtx, rtx);
|
640 |
|
|
static int noce_try_cmove (struct noce_if_info *);
|
641 |
|
|
static int noce_try_cmove_arith (struct noce_if_info *);
|
642 |
|
|
static rtx noce_get_alt_condition (struct noce_if_info *, rtx, rtx *);
|
643 |
|
|
static int noce_try_minmax (struct noce_if_info *);
|
644 |
|
|
static int noce_try_abs (struct noce_if_info *);
|
645 |
|
|
static int noce_try_sign_mask (struct noce_if_info *);
|
646 |
|
|
|
647 |
|
|
/* Helper function for noce_try_store_flag*. */
|
648 |
|
|
|
649 |
|
|
static rtx
|
650 |
|
|
noce_emit_store_flag (struct noce_if_info *if_info, rtx x, int reversep,
|
651 |
|
|
int normalize)
|
652 |
|
|
{
|
653 |
|
|
rtx cond = if_info->cond;
|
654 |
|
|
int cond_complex;
|
655 |
|
|
enum rtx_code code;
|
656 |
|
|
|
657 |
|
|
cond_complex = (! general_operand (XEXP (cond, 0), VOIDmode)
|
658 |
|
|
|| ! general_operand (XEXP (cond, 1), VOIDmode));
|
659 |
|
|
|
660 |
|
|
/* If earliest == jump, or when the condition is complex, try to
|
661 |
|
|
build the store_flag insn directly. */
|
662 |
|
|
|
663 |
|
|
if (cond_complex)
|
664 |
|
|
{
|
665 |
|
|
rtx set = pc_set (if_info->jump);
|
666 |
|
|
cond = XEXP (SET_SRC (set), 0);
|
667 |
|
|
if (GET_CODE (XEXP (SET_SRC (set), 2)) == LABEL_REF
|
668 |
|
|
&& XEXP (XEXP (SET_SRC (set), 2), 0) == JUMP_LABEL (if_info->jump))
|
669 |
|
|
reversep = !reversep;
|
670 |
|
|
if (if_info->then_else_reversed)
|
671 |
|
|
reversep = !reversep;
|
672 |
|
|
}
|
673 |
|
|
|
674 |
|
|
if (reversep)
|
675 |
|
|
code = reversed_comparison_code (cond, if_info->jump);
|
676 |
|
|
else
|
677 |
|
|
code = GET_CODE (cond);
|
678 |
|
|
|
679 |
|
|
if ((if_info->cond_earliest == if_info->jump || cond_complex)
|
680 |
|
|
&& (normalize == 0 || STORE_FLAG_VALUE == normalize))
|
681 |
|
|
{
|
682 |
|
|
rtx tmp;
|
683 |
|
|
|
684 |
|
|
tmp = gen_rtx_fmt_ee (code, GET_MODE (x), XEXP (cond, 0),
|
685 |
|
|
XEXP (cond, 1));
|
686 |
|
|
tmp = gen_rtx_SET (VOIDmode, x, tmp);
|
687 |
|
|
|
688 |
|
|
start_sequence ();
|
689 |
|
|
tmp = emit_insn (tmp);
|
690 |
|
|
|
691 |
|
|
if (recog_memoized (tmp) >= 0)
|
692 |
|
|
{
|
693 |
|
|
tmp = get_insns ();
|
694 |
|
|
end_sequence ();
|
695 |
|
|
emit_insn (tmp);
|
696 |
|
|
|
697 |
|
|
if_info->cond_earliest = if_info->jump;
|
698 |
|
|
|
699 |
|
|
return x;
|
700 |
|
|
}
|
701 |
|
|
|
702 |
|
|
end_sequence ();
|
703 |
|
|
}
|
704 |
|
|
|
705 |
|
|
/* Don't even try if the comparison operands or the mode of X are weird. */
|
706 |
|
|
if (cond_complex || !SCALAR_INT_MODE_P (GET_MODE (x)))
|
707 |
|
|
return NULL_RTX;
|
708 |
|
|
|
709 |
|
|
return emit_store_flag (x, code, XEXP (cond, 0),
|
710 |
|
|
XEXP (cond, 1), VOIDmode,
|
711 |
|
|
(code == LTU || code == LEU
|
712 |
|
|
|| code == GEU || code == GTU), normalize);
|
713 |
|
|
}
|
714 |
|
|
|
715 |
|
|
/* Emit instruction to move an rtx, possibly into STRICT_LOW_PART.
|
716 |
|
|
X is the destination/target and Y is the value to copy. */
|
717 |
|
|
|
718 |
|
|
static void
|
719 |
|
|
noce_emit_move_insn (rtx x, rtx y)
|
720 |
|
|
{
|
721 |
|
|
enum machine_mode outmode;
|
722 |
|
|
rtx outer, inner;
|
723 |
|
|
int bitpos;
|
724 |
|
|
|
725 |
|
|
if (GET_CODE (x) != STRICT_LOW_PART)
|
726 |
|
|
{
|
727 |
|
|
rtx seq, insn, target;
|
728 |
|
|
optab ot;
|
729 |
|
|
|
730 |
|
|
start_sequence ();
|
731 |
|
|
/* Check that the SET_SRC is reasonable before calling emit_move_insn,
|
732 |
|
|
otherwise construct a suitable SET pattern ourselves. */
|
733 |
|
|
insn = (OBJECT_P (y) || CONSTANT_P (y) || GET_CODE (y) == SUBREG)
|
734 |
|
|
? emit_move_insn (x, y)
|
735 |
|
|
: emit_insn (gen_rtx_SET (VOIDmode, x, y));
|
736 |
|
|
seq = get_insns ();
|
737 |
|
|
end_sequence ();
|
738 |
|
|
|
739 |
|
|
if (recog_memoized (insn) <= 0)
|
740 |
|
|
{
|
741 |
|
|
if (GET_CODE (x) == ZERO_EXTRACT)
|
742 |
|
|
{
|
743 |
|
|
rtx op = XEXP (x, 0);
|
744 |
|
|
unsigned HOST_WIDE_INT size = INTVAL (XEXP (x, 1));
|
745 |
|
|
unsigned HOST_WIDE_INT start = INTVAL (XEXP (x, 2));
|
746 |
|
|
|
747 |
|
|
/* store_bit_field expects START to be relative to
|
748 |
|
|
BYTES_BIG_ENDIAN and adjusts this value for machines with
|
749 |
|
|
BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN. In order to be able to
|
750 |
|
|
invoke store_bit_field again it is necessary to have the START
|
751 |
|
|
value from the first call. */
|
752 |
|
|
if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN)
|
753 |
|
|
{
|
754 |
|
|
if (MEM_P (op))
|
755 |
|
|
start = BITS_PER_UNIT - start - size;
|
756 |
|
|
else
|
757 |
|
|
{
|
758 |
|
|
gcc_assert (REG_P (op));
|
759 |
|
|
start = BITS_PER_WORD - start - size;
|
760 |
|
|
}
|
761 |
|
|
}
|
762 |
|
|
|
763 |
|
|
gcc_assert (start < (MEM_P (op) ? BITS_PER_UNIT : BITS_PER_WORD));
|
764 |
|
|
store_bit_field (op, size, start, GET_MODE (x), y);
|
765 |
|
|
return;
|
766 |
|
|
}
|
767 |
|
|
|
768 |
|
|
switch (GET_RTX_CLASS (GET_CODE (y)))
|
769 |
|
|
{
|
770 |
|
|
case RTX_UNARY:
|
771 |
|
|
ot = code_to_optab[GET_CODE (y)];
|
772 |
|
|
if (ot)
|
773 |
|
|
{
|
774 |
|
|
start_sequence ();
|
775 |
|
|
target = expand_unop (GET_MODE (y), ot, XEXP (y, 0), x, 0);
|
776 |
|
|
if (target != NULL_RTX)
|
777 |
|
|
{
|
778 |
|
|
if (target != x)
|
779 |
|
|
emit_move_insn (x, target);
|
780 |
|
|
seq = get_insns ();
|
781 |
|
|
}
|
782 |
|
|
end_sequence ();
|
783 |
|
|
}
|
784 |
|
|
break;
|
785 |
|
|
|
786 |
|
|
case RTX_BIN_ARITH:
|
787 |
|
|
case RTX_COMM_ARITH:
|
788 |
|
|
ot = code_to_optab[GET_CODE (y)];
|
789 |
|
|
if (ot)
|
790 |
|
|
{
|
791 |
|
|
start_sequence ();
|
792 |
|
|
target = expand_binop (GET_MODE (y), ot,
|
793 |
|
|
XEXP (y, 0), XEXP (y, 1),
|
794 |
|
|
x, 0, OPTAB_DIRECT);
|
795 |
|
|
if (target != NULL_RTX)
|
796 |
|
|
{
|
797 |
|
|
if (target != x)
|
798 |
|
|
emit_move_insn (x, target);
|
799 |
|
|
seq = get_insns ();
|
800 |
|
|
}
|
801 |
|
|
end_sequence ();
|
802 |
|
|
}
|
803 |
|
|
break;
|
804 |
|
|
|
805 |
|
|
default:
|
806 |
|
|
break;
|
807 |
|
|
}
|
808 |
|
|
}
|
809 |
|
|
|
810 |
|
|
emit_insn (seq);
|
811 |
|
|
return;
|
812 |
|
|
}
|
813 |
|
|
|
814 |
|
|
outer = XEXP (x, 0);
|
815 |
|
|
inner = XEXP (outer, 0);
|
816 |
|
|
outmode = GET_MODE (outer);
|
817 |
|
|
bitpos = SUBREG_BYTE (outer) * BITS_PER_UNIT;
|
818 |
|
|
store_bit_field (inner, GET_MODE_BITSIZE (outmode), bitpos, outmode, y);
|
819 |
|
|
}
|
820 |
|
|
|
821 |
|
|
/* Return sequence of instructions generated by if conversion. This
|
822 |
|
|
function calls end_sequence() to end the current stream, ensures
|
823 |
|
|
that are instructions are unshared, recognizable non-jump insns.
|
824 |
|
|
On failure, this function returns a NULL_RTX. */
|
825 |
|
|
|
826 |
|
|
static rtx
|
827 |
|
|
end_ifcvt_sequence (struct noce_if_info *if_info)
|
828 |
|
|
{
|
829 |
|
|
rtx insn;
|
830 |
|
|
rtx seq = get_insns ();
|
831 |
|
|
|
832 |
|
|
set_used_flags (if_info->x);
|
833 |
|
|
set_used_flags (if_info->cond);
|
834 |
|
|
unshare_all_rtl_in_chain (seq);
|
835 |
|
|
end_sequence ();
|
836 |
|
|
|
837 |
|
|
/* Make sure that all of the instructions emitted are recognizable,
|
838 |
|
|
and that we haven't introduced a new jump instruction.
|
839 |
|
|
As an exercise for the reader, build a general mechanism that
|
840 |
|
|
allows proper placement of required clobbers. */
|
841 |
|
|
for (insn = seq; insn; insn = NEXT_INSN (insn))
|
842 |
|
|
if (JUMP_P (insn)
|
843 |
|
|
|| recog_memoized (insn) == -1)
|
844 |
|
|
return NULL_RTX;
|
845 |
|
|
|
846 |
|
|
return seq;
|
847 |
|
|
}
|
848 |
|
|
|
849 |
|
|
/* Convert "if (a != b) x = a; else x = b" into "x = a" and
|
850 |
|
|
"if (a == b) x = a; else x = b" into "x = b". */
|
851 |
|
|
|
852 |
|
|
static int
|
853 |
|
|
noce_try_move (struct noce_if_info *if_info)
|
854 |
|
|
{
|
855 |
|
|
rtx cond = if_info->cond;
|
856 |
|
|
enum rtx_code code = GET_CODE (cond);
|
857 |
|
|
rtx y, seq;
|
858 |
|
|
|
859 |
|
|
if (code != NE && code != EQ)
|
860 |
|
|
return FALSE;
|
861 |
|
|
|
862 |
|
|
/* This optimization isn't valid if either A or B could be a NaN
|
863 |
|
|
or a signed zero. */
|
864 |
|
|
if (HONOR_NANS (GET_MODE (if_info->x))
|
865 |
|
|
|| HONOR_SIGNED_ZEROS (GET_MODE (if_info->x)))
|
866 |
|
|
return FALSE;
|
867 |
|
|
|
868 |
|
|
/* Check whether the operands of the comparison are A and in
|
869 |
|
|
either order. */
|
870 |
|
|
if ((rtx_equal_p (if_info->a, XEXP (cond, 0))
|
871 |
|
|
&& rtx_equal_p (if_info->b, XEXP (cond, 1)))
|
872 |
|
|
|| (rtx_equal_p (if_info->a, XEXP (cond, 1))
|
873 |
|
|
&& rtx_equal_p (if_info->b, XEXP (cond, 0))))
|
874 |
|
|
{
|
875 |
|
|
y = (code == EQ) ? if_info->a : if_info->b;
|
876 |
|
|
|
877 |
|
|
/* Avoid generating the move if the source is the destination. */
|
878 |
|
|
if (! rtx_equal_p (if_info->x, y))
|
879 |
|
|
{
|
880 |
|
|
start_sequence ();
|
881 |
|
|
noce_emit_move_insn (if_info->x, y);
|
882 |
|
|
seq = end_ifcvt_sequence (if_info);
|
883 |
|
|
if (!seq)
|
884 |
|
|
return FALSE;
|
885 |
|
|
|
886 |
|
|
emit_insn_before_setloc (seq, if_info->jump,
|
887 |
|
|
INSN_LOCATOR (if_info->insn_a));
|
888 |
|
|
}
|
889 |
|
|
return TRUE;
|
890 |
|
|
}
|
891 |
|
|
return FALSE;
|
892 |
|
|
}
|
893 |
|
|
|
894 |
|
|
/* Convert "if (test) x = 1; else x = 0".
|
895 |
|
|
|
896 |
|
|
Only try 0 and STORE_FLAG_VALUE here. Other combinations will be
|
897 |
|
|
tried in noce_try_store_flag_constants after noce_try_cmove has had
|
898 |
|
|
a go at the conversion. */
|
899 |
|
|
|
900 |
|
|
static int
|
901 |
|
|
noce_try_store_flag (struct noce_if_info *if_info)
|
902 |
|
|
{
|
903 |
|
|
int reversep;
|
904 |
|
|
rtx target, seq;
|
905 |
|
|
|
906 |
|
|
if (CONST_INT_P (if_info->b)
|
907 |
|
|
&& INTVAL (if_info->b) == STORE_FLAG_VALUE
|
908 |
|
|
&& if_info->a == const0_rtx)
|
909 |
|
|
reversep = 0;
|
910 |
|
|
else if (if_info->b == const0_rtx
|
911 |
|
|
&& CONST_INT_P (if_info->a)
|
912 |
|
|
&& INTVAL (if_info->a) == STORE_FLAG_VALUE
|
913 |
|
|
&& (reversed_comparison_code (if_info->cond, if_info->jump)
|
914 |
|
|
!= UNKNOWN))
|
915 |
|
|
reversep = 1;
|
916 |
|
|
else
|
917 |
|
|
return FALSE;
|
918 |
|
|
|
919 |
|
|
start_sequence ();
|
920 |
|
|
|
921 |
|
|
target = noce_emit_store_flag (if_info, if_info->x, reversep, 0);
|
922 |
|
|
if (target)
|
923 |
|
|
{
|
924 |
|
|
if (target != if_info->x)
|
925 |
|
|
noce_emit_move_insn (if_info->x, target);
|
926 |
|
|
|
927 |
|
|
seq = end_ifcvt_sequence (if_info);
|
928 |
|
|
if (! seq)
|
929 |
|
|
return FALSE;
|
930 |
|
|
|
931 |
|
|
emit_insn_before_setloc (seq, if_info->jump,
|
932 |
|
|
INSN_LOCATOR (if_info->insn_a));
|
933 |
|
|
return TRUE;
|
934 |
|
|
}
|
935 |
|
|
else
|
936 |
|
|
{
|
937 |
|
|
end_sequence ();
|
938 |
|
|
return FALSE;
|
939 |
|
|
}
|
940 |
|
|
}
|
941 |
|
|
|
942 |
|
|
/* Convert "if (test) x = a; else x = b", for A and B constant. */
|
943 |
|
|
|
944 |
|
|
static int
|
945 |
|
|
noce_try_store_flag_constants (struct noce_if_info *if_info)
|
946 |
|
|
{
|
947 |
|
|
rtx target, seq;
|
948 |
|
|
int reversep;
|
949 |
|
|
HOST_WIDE_INT itrue, ifalse, diff, tmp;
|
950 |
|
|
int normalize, can_reverse;
|
951 |
|
|
enum machine_mode mode;
|
952 |
|
|
|
953 |
|
|
if (CONST_INT_P (if_info->a)
|
954 |
|
|
&& CONST_INT_P (if_info->b))
|
955 |
|
|
{
|
956 |
|
|
mode = GET_MODE (if_info->x);
|
957 |
|
|
ifalse = INTVAL (if_info->a);
|
958 |
|
|
itrue = INTVAL (if_info->b);
|
959 |
|
|
|
960 |
|
|
/* Make sure we can represent the difference between the two values. */
|
961 |
|
|
if ((itrue - ifalse > 0)
|
962 |
|
|
!= ((ifalse < 0) != (itrue < 0) ? ifalse < 0 : ifalse < itrue))
|
963 |
|
|
return FALSE;
|
964 |
|
|
|
965 |
|
|
diff = trunc_int_for_mode (itrue - ifalse, mode);
|
966 |
|
|
|
967 |
|
|
can_reverse = (reversed_comparison_code (if_info->cond, if_info->jump)
|
968 |
|
|
!= UNKNOWN);
|
969 |
|
|
|
970 |
|
|
reversep = 0;
|
971 |
|
|
if (diff == STORE_FLAG_VALUE || diff == -STORE_FLAG_VALUE)
|
972 |
|
|
normalize = 0;
|
973 |
|
|
else if (ifalse == 0 && exact_log2 (itrue) >= 0
|
974 |
|
|
&& (STORE_FLAG_VALUE == 1
|
975 |
|
|
|| if_info->branch_cost >= 2))
|
976 |
|
|
normalize = 1;
|
977 |
|
|
else if (itrue == 0 && exact_log2 (ifalse) >= 0 && can_reverse
|
978 |
|
|
&& (STORE_FLAG_VALUE == 1 || if_info->branch_cost >= 2))
|
979 |
|
|
normalize = 1, reversep = 1;
|
980 |
|
|
else if (itrue == -1
|
981 |
|
|
&& (STORE_FLAG_VALUE == -1
|
982 |
|
|
|| if_info->branch_cost >= 2))
|
983 |
|
|
normalize = -1;
|
984 |
|
|
else if (ifalse == -1 && can_reverse
|
985 |
|
|
&& (STORE_FLAG_VALUE == -1 || if_info->branch_cost >= 2))
|
986 |
|
|
normalize = -1, reversep = 1;
|
987 |
|
|
else if ((if_info->branch_cost >= 2 && STORE_FLAG_VALUE == -1)
|
988 |
|
|
|| if_info->branch_cost >= 3)
|
989 |
|
|
normalize = -1;
|
990 |
|
|
else
|
991 |
|
|
return FALSE;
|
992 |
|
|
|
993 |
|
|
if (reversep)
|
994 |
|
|
{
|
995 |
|
|
tmp = itrue; itrue = ifalse; ifalse = tmp;
|
996 |
|
|
diff = trunc_int_for_mode (-diff, mode);
|
997 |
|
|
}
|
998 |
|
|
|
999 |
|
|
start_sequence ();
|
1000 |
|
|
target = noce_emit_store_flag (if_info, if_info->x, reversep, normalize);
|
1001 |
|
|
if (! target)
|
1002 |
|
|
{
|
1003 |
|
|
end_sequence ();
|
1004 |
|
|
return FALSE;
|
1005 |
|
|
}
|
1006 |
|
|
|
1007 |
|
|
/* if (test) x = 3; else x = 4;
|
1008 |
|
|
=> x = 3 + (test == 0); */
|
1009 |
|
|
if (diff == STORE_FLAG_VALUE || diff == -STORE_FLAG_VALUE)
|
1010 |
|
|
{
|
1011 |
|
|
target = expand_simple_binop (mode,
|
1012 |
|
|
(diff == STORE_FLAG_VALUE
|
1013 |
|
|
? PLUS : MINUS),
|
1014 |
|
|
GEN_INT (ifalse), target, if_info->x, 0,
|
1015 |
|
|
OPTAB_WIDEN);
|
1016 |
|
|
}
|
1017 |
|
|
|
1018 |
|
|
/* if (test) x = 8; else x = 0;
|
1019 |
|
|
=> x = (test != 0) << 3; */
|
1020 |
|
|
else if (ifalse == 0 && (tmp = exact_log2 (itrue)) >= 0)
|
1021 |
|
|
{
|
1022 |
|
|
target = expand_simple_binop (mode, ASHIFT,
|
1023 |
|
|
target, GEN_INT (tmp), if_info->x, 0,
|
1024 |
|
|
OPTAB_WIDEN);
|
1025 |
|
|
}
|
1026 |
|
|
|
1027 |
|
|
/* if (test) x = -1; else x = b;
|
1028 |
|
|
=> x = -(test != 0) | b; */
|
1029 |
|
|
else if (itrue == -1)
|
1030 |
|
|
{
|
1031 |
|
|
target = expand_simple_binop (mode, IOR,
|
1032 |
|
|
target, GEN_INT (ifalse), if_info->x, 0,
|
1033 |
|
|
OPTAB_WIDEN);
|
1034 |
|
|
}
|
1035 |
|
|
|
1036 |
|
|
/* if (test) x = a; else x = b;
|
1037 |
|
|
=> x = (-(test != 0) & (b - a)) + a; */
|
1038 |
|
|
else
|
1039 |
|
|
{
|
1040 |
|
|
target = expand_simple_binop (mode, AND,
|
1041 |
|
|
target, GEN_INT (diff), if_info->x, 0,
|
1042 |
|
|
OPTAB_WIDEN);
|
1043 |
|
|
if (target)
|
1044 |
|
|
target = expand_simple_binop (mode, PLUS,
|
1045 |
|
|
target, GEN_INT (ifalse),
|
1046 |
|
|
if_info->x, 0, OPTAB_WIDEN);
|
1047 |
|
|
}
|
1048 |
|
|
|
1049 |
|
|
if (! target)
|
1050 |
|
|
{
|
1051 |
|
|
end_sequence ();
|
1052 |
|
|
return FALSE;
|
1053 |
|
|
}
|
1054 |
|
|
|
1055 |
|
|
if (target != if_info->x)
|
1056 |
|
|
noce_emit_move_insn (if_info->x, target);
|
1057 |
|
|
|
1058 |
|
|
seq = end_ifcvt_sequence (if_info);
|
1059 |
|
|
if (!seq)
|
1060 |
|
|
return FALSE;
|
1061 |
|
|
|
1062 |
|
|
emit_insn_before_setloc (seq, if_info->jump,
|
1063 |
|
|
INSN_LOCATOR (if_info->insn_a));
|
1064 |
|
|
return TRUE;
|
1065 |
|
|
}
|
1066 |
|
|
|
1067 |
|
|
return FALSE;
|
1068 |
|
|
}
|
1069 |
|
|
|
1070 |
|
|
/* Convert "if (test) foo++" into "foo += (test != 0)", and
|
1071 |
|
|
similarly for "foo--". */
|
1072 |
|
|
|
1073 |
|
|
static int
|
1074 |
|
|
noce_try_addcc (struct noce_if_info *if_info)
|
1075 |
|
|
{
|
1076 |
|
|
rtx target, seq;
|
1077 |
|
|
int subtract, normalize;
|
1078 |
|
|
|
1079 |
|
|
if (GET_CODE (if_info->a) == PLUS
|
1080 |
|
|
&& rtx_equal_p (XEXP (if_info->a, 0), if_info->b)
|
1081 |
|
|
&& (reversed_comparison_code (if_info->cond, if_info->jump)
|
1082 |
|
|
!= UNKNOWN))
|
1083 |
|
|
{
|
1084 |
|
|
rtx cond = if_info->cond;
|
1085 |
|
|
enum rtx_code code = reversed_comparison_code (cond, if_info->jump);
|
1086 |
|
|
|
1087 |
|
|
/* First try to use addcc pattern. */
|
1088 |
|
|
if (general_operand (XEXP (cond, 0), VOIDmode)
|
1089 |
|
|
&& general_operand (XEXP (cond, 1), VOIDmode))
|
1090 |
|
|
{
|
1091 |
|
|
start_sequence ();
|
1092 |
|
|
target = emit_conditional_add (if_info->x, code,
|
1093 |
|
|
XEXP (cond, 0),
|
1094 |
|
|
XEXP (cond, 1),
|
1095 |
|
|
VOIDmode,
|
1096 |
|
|
if_info->b,
|
1097 |
|
|
XEXP (if_info->a, 1),
|
1098 |
|
|
GET_MODE (if_info->x),
|
1099 |
|
|
(code == LTU || code == GEU
|
1100 |
|
|
|| code == LEU || code == GTU));
|
1101 |
|
|
if (target)
|
1102 |
|
|
{
|
1103 |
|
|
if (target != if_info->x)
|
1104 |
|
|
noce_emit_move_insn (if_info->x, target);
|
1105 |
|
|
|
1106 |
|
|
seq = end_ifcvt_sequence (if_info);
|
1107 |
|
|
if (!seq)
|
1108 |
|
|
return FALSE;
|
1109 |
|
|
|
1110 |
|
|
emit_insn_before_setloc (seq, if_info->jump,
|
1111 |
|
|
INSN_LOCATOR (if_info->insn_a));
|
1112 |
|
|
return TRUE;
|
1113 |
|
|
}
|
1114 |
|
|
end_sequence ();
|
1115 |
|
|
}
|
1116 |
|
|
|
1117 |
|
|
/* If that fails, construct conditional increment or decrement using
|
1118 |
|
|
setcc. */
|
1119 |
|
|
if (if_info->branch_cost >= 2
|
1120 |
|
|
&& (XEXP (if_info->a, 1) == const1_rtx
|
1121 |
|
|
|| XEXP (if_info->a, 1) == constm1_rtx))
|
1122 |
|
|
{
|
1123 |
|
|
start_sequence ();
|
1124 |
|
|
if (STORE_FLAG_VALUE == INTVAL (XEXP (if_info->a, 1)))
|
1125 |
|
|
subtract = 0, normalize = 0;
|
1126 |
|
|
else if (-STORE_FLAG_VALUE == INTVAL (XEXP (if_info->a, 1)))
|
1127 |
|
|
subtract = 1, normalize = 0;
|
1128 |
|
|
else
|
1129 |
|
|
subtract = 0, normalize = INTVAL (XEXP (if_info->a, 1));
|
1130 |
|
|
|
1131 |
|
|
|
1132 |
|
|
target = noce_emit_store_flag (if_info,
|
1133 |
|
|
gen_reg_rtx (GET_MODE (if_info->x)),
|
1134 |
|
|
1, normalize);
|
1135 |
|
|
|
1136 |
|
|
if (target)
|
1137 |
|
|
target = expand_simple_binop (GET_MODE (if_info->x),
|
1138 |
|
|
subtract ? MINUS : PLUS,
|
1139 |
|
|
if_info->b, target, if_info->x,
|
1140 |
|
|
0, OPTAB_WIDEN);
|
1141 |
|
|
if (target)
|
1142 |
|
|
{
|
1143 |
|
|
if (target != if_info->x)
|
1144 |
|
|
noce_emit_move_insn (if_info->x, target);
|
1145 |
|
|
|
1146 |
|
|
seq = end_ifcvt_sequence (if_info);
|
1147 |
|
|
if (!seq)
|
1148 |
|
|
return FALSE;
|
1149 |
|
|
|
1150 |
|
|
emit_insn_before_setloc (seq, if_info->jump,
|
1151 |
|
|
INSN_LOCATOR (if_info->insn_a));
|
1152 |
|
|
return TRUE;
|
1153 |
|
|
}
|
1154 |
|
|
end_sequence ();
|
1155 |
|
|
}
|
1156 |
|
|
}
|
1157 |
|
|
|
1158 |
|
|
return FALSE;
|
1159 |
|
|
}
|
1160 |
|
|
|
1161 |
|
|
/* Convert "if (test) x = 0;" to "x &= -(test == 0);" */
|
1162 |
|
|
|
1163 |
|
|
static int
|
1164 |
|
|
noce_try_store_flag_mask (struct noce_if_info *if_info)
|
1165 |
|
|
{
|
1166 |
|
|
rtx target, seq;
|
1167 |
|
|
int reversep;
|
1168 |
|
|
|
1169 |
|
|
reversep = 0;
|
1170 |
|
|
if ((if_info->branch_cost >= 2
|
1171 |
|
|
|| STORE_FLAG_VALUE == -1)
|
1172 |
|
|
&& ((if_info->a == const0_rtx
|
1173 |
|
|
&& rtx_equal_p (if_info->b, if_info->x))
|
1174 |
|
|
|| ((reversep = (reversed_comparison_code (if_info->cond,
|
1175 |
|
|
if_info->jump)
|
1176 |
|
|
!= UNKNOWN))
|
1177 |
|
|
&& if_info->b == const0_rtx
|
1178 |
|
|
&& rtx_equal_p (if_info->a, if_info->x))))
|
1179 |
|
|
{
|
1180 |
|
|
start_sequence ();
|
1181 |
|
|
target = noce_emit_store_flag (if_info,
|
1182 |
|
|
gen_reg_rtx (GET_MODE (if_info->x)),
|
1183 |
|
|
reversep, -1);
|
1184 |
|
|
if (target)
|
1185 |
|
|
target = expand_simple_binop (GET_MODE (if_info->x), AND,
|
1186 |
|
|
if_info->x,
|
1187 |
|
|
target, if_info->x, 0,
|
1188 |
|
|
OPTAB_WIDEN);
|
1189 |
|
|
|
1190 |
|
|
if (target)
|
1191 |
|
|
{
|
1192 |
|
|
if (target != if_info->x)
|
1193 |
|
|
noce_emit_move_insn (if_info->x, target);
|
1194 |
|
|
|
1195 |
|
|
seq = end_ifcvt_sequence (if_info);
|
1196 |
|
|
if (!seq)
|
1197 |
|
|
return FALSE;
|
1198 |
|
|
|
1199 |
|
|
emit_insn_before_setloc (seq, if_info->jump,
|
1200 |
|
|
INSN_LOCATOR (if_info->insn_a));
|
1201 |
|
|
return TRUE;
|
1202 |
|
|
}
|
1203 |
|
|
|
1204 |
|
|
end_sequence ();
|
1205 |
|
|
}
|
1206 |
|
|
|
1207 |
|
|
return FALSE;
|
1208 |
|
|
}
|
1209 |
|
|
|
1210 |
|
|
/* Helper function for noce_try_cmove and noce_try_cmove_arith. */
|
1211 |
|
|
|
1212 |
|
|
static rtx
|
1213 |
|
|
noce_emit_cmove (struct noce_if_info *if_info, rtx x, enum rtx_code code,
|
1214 |
|
|
rtx cmp_a, rtx cmp_b, rtx vfalse, rtx vtrue)
|
1215 |
|
|
{
|
1216 |
|
|
/* If earliest == jump, try to build the cmove insn directly.
|
1217 |
|
|
This is helpful when combine has created some complex condition
|
1218 |
|
|
(like for alpha's cmovlbs) that we can't hope to regenerate
|
1219 |
|
|
through the normal interface. */
|
1220 |
|
|
|
1221 |
|
|
if (if_info->cond_earliest == if_info->jump)
|
1222 |
|
|
{
|
1223 |
|
|
rtx tmp;
|
1224 |
|
|
|
1225 |
|
|
tmp = gen_rtx_fmt_ee (code, GET_MODE (if_info->cond), cmp_a, cmp_b);
|
1226 |
|
|
tmp = gen_rtx_IF_THEN_ELSE (GET_MODE (x), tmp, vtrue, vfalse);
|
1227 |
|
|
tmp = gen_rtx_SET (VOIDmode, x, tmp);
|
1228 |
|
|
|
1229 |
|
|
start_sequence ();
|
1230 |
|
|
tmp = emit_insn (tmp);
|
1231 |
|
|
|
1232 |
|
|
if (recog_memoized (tmp) >= 0)
|
1233 |
|
|
{
|
1234 |
|
|
tmp = get_insns ();
|
1235 |
|
|
end_sequence ();
|
1236 |
|
|
emit_insn (tmp);
|
1237 |
|
|
|
1238 |
|
|
return x;
|
1239 |
|
|
}
|
1240 |
|
|
|
1241 |
|
|
end_sequence ();
|
1242 |
|
|
}
|
1243 |
|
|
|
1244 |
|
|
/* Don't even try if the comparison operands are weird. */
|
1245 |
|
|
if (! general_operand (cmp_a, GET_MODE (cmp_a))
|
1246 |
|
|
|| ! general_operand (cmp_b, GET_MODE (cmp_b)))
|
1247 |
|
|
return NULL_RTX;
|
1248 |
|
|
|
1249 |
|
|
#if HAVE_conditional_move
|
1250 |
|
|
return emit_conditional_move (x, code, cmp_a, cmp_b, VOIDmode,
|
1251 |
|
|
vtrue, vfalse, GET_MODE (x),
|
1252 |
|
|
(code == LTU || code == GEU
|
1253 |
|
|
|| code == LEU || code == GTU));
|
1254 |
|
|
#else
|
1255 |
|
|
/* We'll never get here, as noce_process_if_block doesn't call the
|
1256 |
|
|
functions involved. Ifdef code, however, should be discouraged
|
1257 |
|
|
because it leads to typos in the code not selected. However,
|
1258 |
|
|
emit_conditional_move won't exist either. */
|
1259 |
|
|
return NULL_RTX;
|
1260 |
|
|
#endif
|
1261 |
|
|
}
|
1262 |
|
|
|
1263 |
|
|
/* Try only simple constants and registers here. More complex cases
|
1264 |
|
|
are handled in noce_try_cmove_arith after noce_try_store_flag_arith
|
1265 |
|
|
has had a go at it. */
|
1266 |
|
|
|
1267 |
|
|
static int
|
1268 |
|
|
noce_try_cmove (struct noce_if_info *if_info)
|
1269 |
|
|
{
|
1270 |
|
|
enum rtx_code code;
|
1271 |
|
|
rtx target, seq;
|
1272 |
|
|
|
1273 |
|
|
if ((CONSTANT_P (if_info->a) || register_operand (if_info->a, VOIDmode))
|
1274 |
|
|
&& (CONSTANT_P (if_info->b) || register_operand (if_info->b, VOIDmode)))
|
1275 |
|
|
{
|
1276 |
|
|
start_sequence ();
|
1277 |
|
|
|
1278 |
|
|
code = GET_CODE (if_info->cond);
|
1279 |
|
|
target = noce_emit_cmove (if_info, if_info->x, code,
|
1280 |
|
|
XEXP (if_info->cond, 0),
|
1281 |
|
|
XEXP (if_info->cond, 1),
|
1282 |
|
|
if_info->a, if_info->b);
|
1283 |
|
|
|
1284 |
|
|
if (target)
|
1285 |
|
|
{
|
1286 |
|
|
if (target != if_info->x)
|
1287 |
|
|
noce_emit_move_insn (if_info->x, target);
|
1288 |
|
|
|
1289 |
|
|
seq = end_ifcvt_sequence (if_info);
|
1290 |
|
|
if (!seq)
|
1291 |
|
|
return FALSE;
|
1292 |
|
|
|
1293 |
|
|
emit_insn_before_setloc (seq, if_info->jump,
|
1294 |
|
|
INSN_LOCATOR (if_info->insn_a));
|
1295 |
|
|
return TRUE;
|
1296 |
|
|
}
|
1297 |
|
|
else
|
1298 |
|
|
{
|
1299 |
|
|
end_sequence ();
|
1300 |
|
|
return FALSE;
|
1301 |
|
|
}
|
1302 |
|
|
}
|
1303 |
|
|
|
1304 |
|
|
return FALSE;
|
1305 |
|
|
}
|
1306 |
|
|
|
1307 |
|
|
/* Try more complex cases involving conditional_move. */
|
1308 |
|
|
|
1309 |
|
|
static int
|
1310 |
|
|
noce_try_cmove_arith (struct noce_if_info *if_info)
|
1311 |
|
|
{
|
1312 |
|
|
rtx a = if_info->a;
|
1313 |
|
|
rtx b = if_info->b;
|
1314 |
|
|
rtx x = if_info->x;
|
1315 |
|
|
rtx orig_a, orig_b;
|
1316 |
|
|
rtx insn_a, insn_b;
|
1317 |
|
|
rtx tmp, target;
|
1318 |
|
|
int is_mem = 0;
|
1319 |
|
|
int insn_cost;
|
1320 |
|
|
enum rtx_code code;
|
1321 |
|
|
|
1322 |
|
|
/* A conditional move from two memory sources is equivalent to a
|
1323 |
|
|
conditional on their addresses followed by a load. Don't do this
|
1324 |
|
|
early because it'll screw alias analysis. Note that we've
|
1325 |
|
|
already checked for no side effects. */
|
1326 |
|
|
/* ??? FIXME: Magic number 5. */
|
1327 |
|
|
if (cse_not_expected
|
1328 |
|
|
&& MEM_P (a) && MEM_P (b)
|
1329 |
|
|
&& MEM_ADDR_SPACE (a) == MEM_ADDR_SPACE (b)
|
1330 |
|
|
&& if_info->branch_cost >= 5)
|
1331 |
|
|
{
|
1332 |
|
|
enum machine_mode address_mode
|
1333 |
|
|
= targetm.addr_space.address_mode (MEM_ADDR_SPACE (a));
|
1334 |
|
|
|
1335 |
|
|
a = XEXP (a, 0);
|
1336 |
|
|
b = XEXP (b, 0);
|
1337 |
|
|
x = gen_reg_rtx (address_mode);
|
1338 |
|
|
is_mem = 1;
|
1339 |
|
|
}
|
1340 |
|
|
|
1341 |
|
|
/* ??? We could handle this if we knew that a load from A or B could
|
1342 |
|
|
not fault. This is also true if we've already loaded
|
1343 |
|
|
from the address along the path from ENTRY. */
|
1344 |
|
|
else if (may_trap_p (a) || may_trap_p (b))
|
1345 |
|
|
return FALSE;
|
1346 |
|
|
|
1347 |
|
|
/* if (test) x = a + b; else x = c - d;
|
1348 |
|
|
=> y = a + b;
|
1349 |
|
|
x = c - d;
|
1350 |
|
|
if (test)
|
1351 |
|
|
x = y;
|
1352 |
|
|
*/
|
1353 |
|
|
|
1354 |
|
|
code = GET_CODE (if_info->cond);
|
1355 |
|
|
insn_a = if_info->insn_a;
|
1356 |
|
|
insn_b = if_info->insn_b;
|
1357 |
|
|
|
1358 |
|
|
/* Total insn_rtx_cost should be smaller than branch cost. Exit
|
1359 |
|
|
if insn_rtx_cost can't be estimated. */
|
1360 |
|
|
if (insn_a)
|
1361 |
|
|
{
|
1362 |
|
|
insn_cost = insn_rtx_cost (PATTERN (insn_a),
|
1363 |
|
|
optimize_bb_for_speed_p (BLOCK_FOR_INSN (insn_a)));
|
1364 |
|
|
if (insn_cost == 0 || insn_cost > COSTS_N_INSNS (if_info->branch_cost))
|
1365 |
|
|
return FALSE;
|
1366 |
|
|
}
|
1367 |
|
|
else
|
1368 |
|
|
insn_cost = 0;
|
1369 |
|
|
|
1370 |
|
|
if (insn_b)
|
1371 |
|
|
{
|
1372 |
|
|
insn_cost += insn_rtx_cost (PATTERN (insn_b),
|
1373 |
|
|
optimize_bb_for_speed_p (BLOCK_FOR_INSN (insn_b)));
|
1374 |
|
|
if (insn_cost == 0 || insn_cost > COSTS_N_INSNS (if_info->branch_cost))
|
1375 |
|
|
return FALSE;
|
1376 |
|
|
}
|
1377 |
|
|
|
1378 |
|
|
/* Possibly rearrange operands to make things come out more natural. */
|
1379 |
|
|
if (reversed_comparison_code (if_info->cond, if_info->jump) != UNKNOWN)
|
1380 |
|
|
{
|
1381 |
|
|
int reversep = 0;
|
1382 |
|
|
if (rtx_equal_p (b, x))
|
1383 |
|
|
reversep = 1;
|
1384 |
|
|
else if (general_operand (b, GET_MODE (b)))
|
1385 |
|
|
reversep = 1;
|
1386 |
|
|
|
1387 |
|
|
if (reversep)
|
1388 |
|
|
{
|
1389 |
|
|
code = reversed_comparison_code (if_info->cond, if_info->jump);
|
1390 |
|
|
tmp = a, a = b, b = tmp;
|
1391 |
|
|
tmp = insn_a, insn_a = insn_b, insn_b = tmp;
|
1392 |
|
|
}
|
1393 |
|
|
}
|
1394 |
|
|
|
1395 |
|
|
start_sequence ();
|
1396 |
|
|
|
1397 |
|
|
orig_a = a;
|
1398 |
|
|
orig_b = b;
|
1399 |
|
|
|
1400 |
|
|
/* If either operand is complex, load it into a register first.
|
1401 |
|
|
The best way to do this is to copy the original insn. In this
|
1402 |
|
|
way we preserve any clobbers etc that the insn may have had.
|
1403 |
|
|
This is of course not possible in the IS_MEM case. */
|
1404 |
|
|
if (! general_operand (a, GET_MODE (a)))
|
1405 |
|
|
{
|
1406 |
|
|
rtx set;
|
1407 |
|
|
|
1408 |
|
|
if (is_mem)
|
1409 |
|
|
{
|
1410 |
|
|
tmp = gen_reg_rtx (GET_MODE (a));
|
1411 |
|
|
tmp = emit_insn (gen_rtx_SET (VOIDmode, tmp, a));
|
1412 |
|
|
}
|
1413 |
|
|
else if (! insn_a)
|
1414 |
|
|
goto end_seq_and_fail;
|
1415 |
|
|
else
|
1416 |
|
|
{
|
1417 |
|
|
a = gen_reg_rtx (GET_MODE (a));
|
1418 |
|
|
tmp = copy_rtx (insn_a);
|
1419 |
|
|
set = single_set (tmp);
|
1420 |
|
|
SET_DEST (set) = a;
|
1421 |
|
|
tmp = emit_insn (PATTERN (tmp));
|
1422 |
|
|
}
|
1423 |
|
|
if (recog_memoized (tmp) < 0)
|
1424 |
|
|
goto end_seq_and_fail;
|
1425 |
|
|
}
|
1426 |
|
|
if (! general_operand (b, GET_MODE (b)))
|
1427 |
|
|
{
|
1428 |
|
|
rtx set, last;
|
1429 |
|
|
|
1430 |
|
|
if (is_mem)
|
1431 |
|
|
{
|
1432 |
|
|
tmp = gen_reg_rtx (GET_MODE (b));
|
1433 |
|
|
tmp = gen_rtx_SET (VOIDmode, tmp, b);
|
1434 |
|
|
}
|
1435 |
|
|
else if (! insn_b)
|
1436 |
|
|
goto end_seq_and_fail;
|
1437 |
|
|
else
|
1438 |
|
|
{
|
1439 |
|
|
b = gen_reg_rtx (GET_MODE (b));
|
1440 |
|
|
tmp = copy_rtx (insn_b);
|
1441 |
|
|
set = single_set (tmp);
|
1442 |
|
|
SET_DEST (set) = b;
|
1443 |
|
|
tmp = PATTERN (tmp);
|
1444 |
|
|
}
|
1445 |
|
|
|
1446 |
|
|
/* If insn to set up A clobbers any registers B depends on, try to
|
1447 |
|
|
swap insn that sets up A with the one that sets up B. If even
|
1448 |
|
|
that doesn't help, punt. */
|
1449 |
|
|
last = get_last_insn ();
|
1450 |
|
|
if (last && modified_in_p (orig_b, last))
|
1451 |
|
|
{
|
1452 |
|
|
tmp = emit_insn_before (tmp, get_insns ());
|
1453 |
|
|
if (modified_in_p (orig_a, tmp))
|
1454 |
|
|
goto end_seq_and_fail;
|
1455 |
|
|
}
|
1456 |
|
|
else
|
1457 |
|
|
tmp = emit_insn (tmp);
|
1458 |
|
|
|
1459 |
|
|
if (recog_memoized (tmp) < 0)
|
1460 |
|
|
goto end_seq_and_fail;
|
1461 |
|
|
}
|
1462 |
|
|
|
1463 |
|
|
target = noce_emit_cmove (if_info, x, code, XEXP (if_info->cond, 0),
|
1464 |
|
|
XEXP (if_info->cond, 1), a, b);
|
1465 |
|
|
|
1466 |
|
|
if (! target)
|
1467 |
|
|
goto end_seq_and_fail;
|
1468 |
|
|
|
1469 |
|
|
/* If we're handling a memory for above, emit the load now. */
|
1470 |
|
|
if (is_mem)
|
1471 |
|
|
{
|
1472 |
|
|
tmp = gen_rtx_MEM (GET_MODE (if_info->x), target);
|
1473 |
|
|
|
1474 |
|
|
/* Copy over flags as appropriate. */
|
1475 |
|
|
if (MEM_VOLATILE_P (if_info->a) || MEM_VOLATILE_P (if_info->b))
|
1476 |
|
|
MEM_VOLATILE_P (tmp) = 1;
|
1477 |
|
|
if (MEM_IN_STRUCT_P (if_info->a) && MEM_IN_STRUCT_P (if_info->b))
|
1478 |
|
|
MEM_IN_STRUCT_P (tmp) = 1;
|
1479 |
|
|
if (MEM_SCALAR_P (if_info->a) && MEM_SCALAR_P (if_info->b))
|
1480 |
|
|
MEM_SCALAR_P (tmp) = 1;
|
1481 |
|
|
if (MEM_ALIAS_SET (if_info->a) == MEM_ALIAS_SET (if_info->b))
|
1482 |
|
|
set_mem_alias_set (tmp, MEM_ALIAS_SET (if_info->a));
|
1483 |
|
|
set_mem_align (tmp,
|
1484 |
|
|
MIN (MEM_ALIGN (if_info->a), MEM_ALIGN (if_info->b)));
|
1485 |
|
|
|
1486 |
|
|
gcc_assert (MEM_ADDR_SPACE (if_info->a) == MEM_ADDR_SPACE (if_info->b));
|
1487 |
|
|
set_mem_addr_space (tmp, MEM_ADDR_SPACE (if_info->a));
|
1488 |
|
|
|
1489 |
|
|
noce_emit_move_insn (if_info->x, tmp);
|
1490 |
|
|
}
|
1491 |
|
|
else if (target != x)
|
1492 |
|
|
noce_emit_move_insn (x, target);
|
1493 |
|
|
|
1494 |
|
|
tmp = end_ifcvt_sequence (if_info);
|
1495 |
|
|
if (!tmp)
|
1496 |
|
|
return FALSE;
|
1497 |
|
|
|
1498 |
|
|
emit_insn_before_setloc (tmp, if_info->jump, INSN_LOCATOR (if_info->insn_a));
|
1499 |
|
|
return TRUE;
|
1500 |
|
|
|
1501 |
|
|
end_seq_and_fail:
|
1502 |
|
|
end_sequence ();
|
1503 |
|
|
return FALSE;
|
1504 |
|
|
}
|
1505 |
|
|
|
1506 |
|
|
/* For most cases, the simplified condition we found is the best
|
1507 |
|
|
choice, but this is not the case for the min/max/abs transforms.
|
1508 |
|
|
For these we wish to know that it is A or B in the condition. */
|
1509 |
|
|
|
1510 |
|
|
static rtx
|
1511 |
|
|
noce_get_alt_condition (struct noce_if_info *if_info, rtx target,
|
1512 |
|
|
rtx *earliest)
|
1513 |
|
|
{
|
1514 |
|
|
rtx cond, set, insn;
|
1515 |
|
|
int reverse;
|
1516 |
|
|
|
1517 |
|
|
/* If target is already mentioned in the known condition, return it. */
|
1518 |
|
|
if (reg_mentioned_p (target, if_info->cond))
|
1519 |
|
|
{
|
1520 |
|
|
*earliest = if_info->cond_earliest;
|
1521 |
|
|
return if_info->cond;
|
1522 |
|
|
}
|
1523 |
|
|
|
1524 |
|
|
set = pc_set (if_info->jump);
|
1525 |
|
|
cond = XEXP (SET_SRC (set), 0);
|
1526 |
|
|
reverse
|
1527 |
|
|
= GET_CODE (XEXP (SET_SRC (set), 2)) == LABEL_REF
|
1528 |
|
|
&& XEXP (XEXP (SET_SRC (set), 2), 0) == JUMP_LABEL (if_info->jump);
|
1529 |
|
|
if (if_info->then_else_reversed)
|
1530 |
|
|
reverse = !reverse;
|
1531 |
|
|
|
1532 |
|
|
/* If we're looking for a constant, try to make the conditional
|
1533 |
|
|
have that constant in it. There are two reasons why it may
|
1534 |
|
|
not have the constant we want:
|
1535 |
|
|
|
1536 |
|
|
1. GCC may have needed to put the constant in a register, because
|
1537 |
|
|
the target can't compare directly against that constant. For
|
1538 |
|
|
this case, we look for a SET immediately before the comparison
|
1539 |
|
|
that puts a constant in that register.
|
1540 |
|
|
|
1541 |
|
|
2. GCC may have canonicalized the conditional, for example
|
1542 |
|
|
replacing "if x < 4" with "if x <= 3". We can undo that (or
|
1543 |
|
|
make equivalent types of changes) to get the constants we need
|
1544 |
|
|
if they're off by one in the right direction. */
|
1545 |
|
|
|
1546 |
|
|
if (CONST_INT_P (target))
|
1547 |
|
|
{
|
1548 |
|
|
enum rtx_code code = GET_CODE (if_info->cond);
|
1549 |
|
|
rtx op_a = XEXP (if_info->cond, 0);
|
1550 |
|
|
rtx op_b = XEXP (if_info->cond, 1);
|
1551 |
|
|
rtx prev_insn;
|
1552 |
|
|
|
1553 |
|
|
/* First, look to see if we put a constant in a register. */
|
1554 |
|
|
prev_insn = prev_nonnote_insn (if_info->cond_earliest);
|
1555 |
|
|
if (prev_insn
|
1556 |
|
|
&& BLOCK_FOR_INSN (prev_insn)
|
1557 |
|
|
== BLOCK_FOR_INSN (if_info->cond_earliest)
|
1558 |
|
|
&& INSN_P (prev_insn)
|
1559 |
|
|
&& GET_CODE (PATTERN (prev_insn)) == SET)
|
1560 |
|
|
{
|
1561 |
|
|
rtx src = find_reg_equal_equiv_note (prev_insn);
|
1562 |
|
|
if (!src)
|
1563 |
|
|
src = SET_SRC (PATTERN (prev_insn));
|
1564 |
|
|
if (CONST_INT_P (src))
|
1565 |
|
|
{
|
1566 |
|
|
if (rtx_equal_p (op_a, SET_DEST (PATTERN (prev_insn))))
|
1567 |
|
|
op_a = src;
|
1568 |
|
|
else if (rtx_equal_p (op_b, SET_DEST (PATTERN (prev_insn))))
|
1569 |
|
|
op_b = src;
|
1570 |
|
|
|
1571 |
|
|
if (CONST_INT_P (op_a))
|
1572 |
|
|
{
|
1573 |
|
|
rtx tmp = op_a;
|
1574 |
|
|
op_a = op_b;
|
1575 |
|
|
op_b = tmp;
|
1576 |
|
|
code = swap_condition (code);
|
1577 |
|
|
}
|
1578 |
|
|
}
|
1579 |
|
|
}
|
1580 |
|
|
|
1581 |
|
|
/* Now, look to see if we can get the right constant by
|
1582 |
|
|
adjusting the conditional. */
|
1583 |
|
|
if (CONST_INT_P (op_b))
|
1584 |
|
|
{
|
1585 |
|
|
HOST_WIDE_INT desired_val = INTVAL (target);
|
1586 |
|
|
HOST_WIDE_INT actual_val = INTVAL (op_b);
|
1587 |
|
|
|
1588 |
|
|
switch (code)
|
1589 |
|
|
{
|
1590 |
|
|
case LT:
|
1591 |
|
|
if (actual_val == desired_val + 1)
|
1592 |
|
|
{
|
1593 |
|
|
code = LE;
|
1594 |
|
|
op_b = GEN_INT (desired_val);
|
1595 |
|
|
}
|
1596 |
|
|
break;
|
1597 |
|
|
case LE:
|
1598 |
|
|
if (actual_val == desired_val - 1)
|
1599 |
|
|
{
|
1600 |
|
|
code = LT;
|
1601 |
|
|
op_b = GEN_INT (desired_val);
|
1602 |
|
|
}
|
1603 |
|
|
break;
|
1604 |
|
|
case GT:
|
1605 |
|
|
if (actual_val == desired_val - 1)
|
1606 |
|
|
{
|
1607 |
|
|
code = GE;
|
1608 |
|
|
op_b = GEN_INT (desired_val);
|
1609 |
|
|
}
|
1610 |
|
|
break;
|
1611 |
|
|
case GE:
|
1612 |
|
|
if (actual_val == desired_val + 1)
|
1613 |
|
|
{
|
1614 |
|
|
code = GT;
|
1615 |
|
|
op_b = GEN_INT (desired_val);
|
1616 |
|
|
}
|
1617 |
|
|
break;
|
1618 |
|
|
default:
|
1619 |
|
|
break;
|
1620 |
|
|
}
|
1621 |
|
|
}
|
1622 |
|
|
|
1623 |
|
|
/* If we made any changes, generate a new conditional that is
|
1624 |
|
|
equivalent to what we started with, but has the right
|
1625 |
|
|
constants in it. */
|
1626 |
|
|
if (code != GET_CODE (if_info->cond)
|
1627 |
|
|
|| op_a != XEXP (if_info->cond, 0)
|
1628 |
|
|
|| op_b != XEXP (if_info->cond, 1))
|
1629 |
|
|
{
|
1630 |
|
|
cond = gen_rtx_fmt_ee (code, GET_MODE (cond), op_a, op_b);
|
1631 |
|
|
*earliest = if_info->cond_earliest;
|
1632 |
|
|
return cond;
|
1633 |
|
|
}
|
1634 |
|
|
}
|
1635 |
|
|
|
1636 |
|
|
cond = canonicalize_condition (if_info->jump, cond, reverse,
|
1637 |
|
|
earliest, target, false, true);
|
1638 |
|
|
if (! cond || ! reg_mentioned_p (target, cond))
|
1639 |
|
|
return NULL;
|
1640 |
|
|
|
1641 |
|
|
/* We almost certainly searched back to a different place.
|
1642 |
|
|
Need to re-verify correct lifetimes. */
|
1643 |
|
|
|
1644 |
|
|
/* X may not be mentioned in the range (cond_earliest, jump]. */
|
1645 |
|
|
for (insn = if_info->jump; insn != *earliest; insn = PREV_INSN (insn))
|
1646 |
|
|
if (INSN_P (insn) && reg_overlap_mentioned_p (if_info->x, PATTERN (insn)))
|
1647 |
|
|
return NULL;
|
1648 |
|
|
|
1649 |
|
|
/* A and B may not be modified in the range [cond_earliest, jump). */
|
1650 |
|
|
for (insn = *earliest; insn != if_info->jump; insn = NEXT_INSN (insn))
|
1651 |
|
|
if (INSN_P (insn)
|
1652 |
|
|
&& (modified_in_p (if_info->a, insn)
|
1653 |
|
|
|| modified_in_p (if_info->b, insn)))
|
1654 |
|
|
return NULL;
|
1655 |
|
|
|
1656 |
|
|
return cond;
|
1657 |
|
|
}
|
1658 |
|
|
|
1659 |
|
|
/* Convert "if (a < b) x = a; else x = b;" to "x = min(a, b);", etc. */
|
1660 |
|
|
|
1661 |
|
|
static int
|
1662 |
|
|
noce_try_minmax (struct noce_if_info *if_info)
|
1663 |
|
|
{
|
1664 |
|
|
rtx cond, earliest, target, seq;
|
1665 |
|
|
enum rtx_code code, op;
|
1666 |
|
|
int unsignedp;
|
1667 |
|
|
|
1668 |
|
|
/* ??? Reject modes with NaNs or signed zeros since we don't know how
|
1669 |
|
|
they will be resolved with an SMIN/SMAX. It wouldn't be too hard
|
1670 |
|
|
to get the target to tell us... */
|
1671 |
|
|
if (HONOR_SIGNED_ZEROS (GET_MODE (if_info->x))
|
1672 |
|
|
|| HONOR_NANS (GET_MODE (if_info->x)))
|
1673 |
|
|
return FALSE;
|
1674 |
|
|
|
1675 |
|
|
cond = noce_get_alt_condition (if_info, if_info->a, &earliest);
|
1676 |
|
|
if (!cond)
|
1677 |
|
|
return FALSE;
|
1678 |
|
|
|
1679 |
|
|
/* Verify the condition is of the form we expect, and canonicalize
|
1680 |
|
|
the comparison code. */
|
1681 |
|
|
code = GET_CODE (cond);
|
1682 |
|
|
if (rtx_equal_p (XEXP (cond, 0), if_info->a))
|
1683 |
|
|
{
|
1684 |
|
|
if (! rtx_equal_p (XEXP (cond, 1), if_info->b))
|
1685 |
|
|
return FALSE;
|
1686 |
|
|
}
|
1687 |
|
|
else if (rtx_equal_p (XEXP (cond, 1), if_info->a))
|
1688 |
|
|
{
|
1689 |
|
|
if (! rtx_equal_p (XEXP (cond, 0), if_info->b))
|
1690 |
|
|
return FALSE;
|
1691 |
|
|
code = swap_condition (code);
|
1692 |
|
|
}
|
1693 |
|
|
else
|
1694 |
|
|
return FALSE;
|
1695 |
|
|
|
1696 |
|
|
/* Determine what sort of operation this is. Note that the code is for
|
1697 |
|
|
a taken branch, so the code->operation mapping appears backwards. */
|
1698 |
|
|
switch (code)
|
1699 |
|
|
{
|
1700 |
|
|
case LT:
|
1701 |
|
|
case LE:
|
1702 |
|
|
case UNLT:
|
1703 |
|
|
case UNLE:
|
1704 |
|
|
op = SMAX;
|
1705 |
|
|
unsignedp = 0;
|
1706 |
|
|
break;
|
1707 |
|
|
case GT:
|
1708 |
|
|
case GE:
|
1709 |
|
|
case UNGT:
|
1710 |
|
|
case UNGE:
|
1711 |
|
|
op = SMIN;
|
1712 |
|
|
unsignedp = 0;
|
1713 |
|
|
break;
|
1714 |
|
|
case LTU:
|
1715 |
|
|
case LEU:
|
1716 |
|
|
op = UMAX;
|
1717 |
|
|
unsignedp = 1;
|
1718 |
|
|
break;
|
1719 |
|
|
case GTU:
|
1720 |
|
|
case GEU:
|
1721 |
|
|
op = UMIN;
|
1722 |
|
|
unsignedp = 1;
|
1723 |
|
|
break;
|
1724 |
|
|
default:
|
1725 |
|
|
return FALSE;
|
1726 |
|
|
}
|
1727 |
|
|
|
1728 |
|
|
start_sequence ();
|
1729 |
|
|
|
1730 |
|
|
target = expand_simple_binop (GET_MODE (if_info->x), op,
|
1731 |
|
|
if_info->a, if_info->b,
|
1732 |
|
|
if_info->x, unsignedp, OPTAB_WIDEN);
|
1733 |
|
|
if (! target)
|
1734 |
|
|
{
|
1735 |
|
|
end_sequence ();
|
1736 |
|
|
return FALSE;
|
1737 |
|
|
}
|
1738 |
|
|
if (target != if_info->x)
|
1739 |
|
|
noce_emit_move_insn (if_info->x, target);
|
1740 |
|
|
|
1741 |
|
|
seq = end_ifcvt_sequence (if_info);
|
1742 |
|
|
if (!seq)
|
1743 |
|
|
return FALSE;
|
1744 |
|
|
|
1745 |
|
|
emit_insn_before_setloc (seq, if_info->jump, INSN_LOCATOR (if_info->insn_a));
|
1746 |
|
|
if_info->cond = cond;
|
1747 |
|
|
if_info->cond_earliest = earliest;
|
1748 |
|
|
|
1749 |
|
|
return TRUE;
|
1750 |
|
|
}
|
1751 |
|
|
|
1752 |
|
|
/* Convert "if (a < 0) x = -a; else x = a;" to "x = abs(a);",
|
1753 |
|
|
"if (a < 0) x = ~a; else x = a;" to "x = one_cmpl_abs(a);",
|
1754 |
|
|
etc. */
|
1755 |
|
|
|
1756 |
|
|
static int
|
1757 |
|
|
noce_try_abs (struct noce_if_info *if_info)
|
1758 |
|
|
{
|
1759 |
|
|
rtx cond, earliest, target, seq, a, b, c;
|
1760 |
|
|
int negate;
|
1761 |
|
|
bool one_cmpl = false;
|
1762 |
|
|
|
1763 |
|
|
/* Reject modes with signed zeros. */
|
1764 |
|
|
if (HONOR_SIGNED_ZEROS (GET_MODE (if_info->x)))
|
1765 |
|
|
return FALSE;
|
1766 |
|
|
|
1767 |
|
|
/* Recognize A and B as constituting an ABS or NABS. The canonical
|
1768 |
|
|
form is a branch around the negation, taken when the object is the
|
1769 |
|
|
first operand of a comparison against 0 that evaluates to true. */
|
1770 |
|
|
a = if_info->a;
|
1771 |
|
|
b = if_info->b;
|
1772 |
|
|
if (GET_CODE (a) == NEG && rtx_equal_p (XEXP (a, 0), b))
|
1773 |
|
|
negate = 0;
|
1774 |
|
|
else if (GET_CODE (b) == NEG && rtx_equal_p (XEXP (b, 0), a))
|
1775 |
|
|
{
|
1776 |
|
|
c = a; a = b; b = c;
|
1777 |
|
|
negate = 1;
|
1778 |
|
|
}
|
1779 |
|
|
else if (GET_CODE (a) == NOT && rtx_equal_p (XEXP (a, 0), b))
|
1780 |
|
|
{
|
1781 |
|
|
negate = 0;
|
1782 |
|
|
one_cmpl = true;
|
1783 |
|
|
}
|
1784 |
|
|
else if (GET_CODE (b) == NOT && rtx_equal_p (XEXP (b, 0), a))
|
1785 |
|
|
{
|
1786 |
|
|
c = a; a = b; b = c;
|
1787 |
|
|
negate = 1;
|
1788 |
|
|
one_cmpl = true;
|
1789 |
|
|
}
|
1790 |
|
|
else
|
1791 |
|
|
return FALSE;
|
1792 |
|
|
|
1793 |
|
|
cond = noce_get_alt_condition (if_info, b, &earliest);
|
1794 |
|
|
if (!cond)
|
1795 |
|
|
return FALSE;
|
1796 |
|
|
|
1797 |
|
|
/* Verify the condition is of the form we expect. */
|
1798 |
|
|
if (rtx_equal_p (XEXP (cond, 0), b))
|
1799 |
|
|
c = XEXP (cond, 1);
|
1800 |
|
|
else if (rtx_equal_p (XEXP (cond, 1), b))
|
1801 |
|
|
{
|
1802 |
|
|
c = XEXP (cond, 0);
|
1803 |
|
|
negate = !negate;
|
1804 |
|
|
}
|
1805 |
|
|
else
|
1806 |
|
|
return FALSE;
|
1807 |
|
|
|
1808 |
|
|
/* Verify that C is zero. Search one step backward for a
|
1809 |
|
|
REG_EQUAL note or a simple source if necessary. */
|
1810 |
|
|
if (REG_P (c))
|
1811 |
|
|
{
|
1812 |
|
|
rtx set, insn = prev_nonnote_insn (earliest);
|
1813 |
|
|
if (insn
|
1814 |
|
|
&& BLOCK_FOR_INSN (insn) == BLOCK_FOR_INSN (earliest)
|
1815 |
|
|
&& (set = single_set (insn))
|
1816 |
|
|
&& rtx_equal_p (SET_DEST (set), c))
|
1817 |
|
|
{
|
1818 |
|
|
rtx note = find_reg_equal_equiv_note (insn);
|
1819 |
|
|
if (note)
|
1820 |
|
|
c = XEXP (note, 0);
|
1821 |
|
|
else
|
1822 |
|
|
c = SET_SRC (set);
|
1823 |
|
|
}
|
1824 |
|
|
else
|
1825 |
|
|
return FALSE;
|
1826 |
|
|
}
|
1827 |
|
|
if (MEM_P (c)
|
1828 |
|
|
&& GET_CODE (XEXP (c, 0)) == SYMBOL_REF
|
1829 |
|
|
&& CONSTANT_POOL_ADDRESS_P (XEXP (c, 0)))
|
1830 |
|
|
c = get_pool_constant (XEXP (c, 0));
|
1831 |
|
|
|
1832 |
|
|
/* Work around funny ideas get_condition has wrt canonicalization.
|
1833 |
|
|
Note that these rtx constants are known to be CONST_INT, and
|
1834 |
|
|
therefore imply integer comparisons. */
|
1835 |
|
|
if (c == constm1_rtx && GET_CODE (cond) == GT)
|
1836 |
|
|
;
|
1837 |
|
|
else if (c == const1_rtx && GET_CODE (cond) == LT)
|
1838 |
|
|
;
|
1839 |
|
|
else if (c != CONST0_RTX (GET_MODE (b)))
|
1840 |
|
|
return FALSE;
|
1841 |
|
|
|
1842 |
|
|
/* Determine what sort of operation this is. */
|
1843 |
|
|
switch (GET_CODE (cond))
|
1844 |
|
|
{
|
1845 |
|
|
case LT:
|
1846 |
|
|
case LE:
|
1847 |
|
|
case UNLT:
|
1848 |
|
|
case UNLE:
|
1849 |
|
|
negate = !negate;
|
1850 |
|
|
break;
|
1851 |
|
|
case GT:
|
1852 |
|
|
case GE:
|
1853 |
|
|
case UNGT:
|
1854 |
|
|
case UNGE:
|
1855 |
|
|
break;
|
1856 |
|
|
default:
|
1857 |
|
|
return FALSE;
|
1858 |
|
|
}
|
1859 |
|
|
|
1860 |
|
|
start_sequence ();
|
1861 |
|
|
if (one_cmpl)
|
1862 |
|
|
target = expand_one_cmpl_abs_nojump (GET_MODE (if_info->x), b,
|
1863 |
|
|
if_info->x);
|
1864 |
|
|
else
|
1865 |
|
|
target = expand_abs_nojump (GET_MODE (if_info->x), b, if_info->x, 1);
|
1866 |
|
|
|
1867 |
|
|
/* ??? It's a quandary whether cmove would be better here, especially
|
1868 |
|
|
for integers. Perhaps combine will clean things up. */
|
1869 |
|
|
if (target && negate)
|
1870 |
|
|
{
|
1871 |
|
|
if (one_cmpl)
|
1872 |
|
|
target = expand_simple_unop (GET_MODE (target), NOT, target,
|
1873 |
|
|
if_info->x, 0);
|
1874 |
|
|
else
|
1875 |
|
|
target = expand_simple_unop (GET_MODE (target), NEG, target,
|
1876 |
|
|
if_info->x, 0);
|
1877 |
|
|
}
|
1878 |
|
|
|
1879 |
|
|
if (! target)
|
1880 |
|
|
{
|
1881 |
|
|
end_sequence ();
|
1882 |
|
|
return FALSE;
|
1883 |
|
|
}
|
1884 |
|
|
|
1885 |
|
|
if (target != if_info->x)
|
1886 |
|
|
noce_emit_move_insn (if_info->x, target);
|
1887 |
|
|
|
1888 |
|
|
seq = end_ifcvt_sequence (if_info);
|
1889 |
|
|
if (!seq)
|
1890 |
|
|
return FALSE;
|
1891 |
|
|
|
1892 |
|
|
emit_insn_before_setloc (seq, if_info->jump, INSN_LOCATOR (if_info->insn_a));
|
1893 |
|
|
if_info->cond = cond;
|
1894 |
|
|
if_info->cond_earliest = earliest;
|
1895 |
|
|
|
1896 |
|
|
return TRUE;
|
1897 |
|
|
}
|
1898 |
|
|
|
1899 |
|
|
/* Convert "if (m < 0) x = b; else x = 0;" to "x = (m >> C) & b;". */
|
1900 |
|
|
|
1901 |
|
|
static int
|
1902 |
|
|
noce_try_sign_mask (struct noce_if_info *if_info)
|
1903 |
|
|
{
|
1904 |
|
|
rtx cond, t, m, c, seq;
|
1905 |
|
|
enum machine_mode mode;
|
1906 |
|
|
enum rtx_code code;
|
1907 |
|
|
bool t_unconditional;
|
1908 |
|
|
|
1909 |
|
|
cond = if_info->cond;
|
1910 |
|
|
code = GET_CODE (cond);
|
1911 |
|
|
m = XEXP (cond, 0);
|
1912 |
|
|
c = XEXP (cond, 1);
|
1913 |
|
|
|
1914 |
|
|
t = NULL_RTX;
|
1915 |
|
|
if (if_info->a == const0_rtx)
|
1916 |
|
|
{
|
1917 |
|
|
if ((code == LT && c == const0_rtx)
|
1918 |
|
|
|| (code == LE && c == constm1_rtx))
|
1919 |
|
|
t = if_info->b;
|
1920 |
|
|
}
|
1921 |
|
|
else if (if_info->b == const0_rtx)
|
1922 |
|
|
{
|
1923 |
|
|
if ((code == GE && c == const0_rtx)
|
1924 |
|
|
|| (code == GT && c == constm1_rtx))
|
1925 |
|
|
t = if_info->a;
|
1926 |
|
|
}
|
1927 |
|
|
|
1928 |
|
|
if (! t || side_effects_p (t))
|
1929 |
|
|
return FALSE;
|
1930 |
|
|
|
1931 |
|
|
/* We currently don't handle different modes. */
|
1932 |
|
|
mode = GET_MODE (t);
|
1933 |
|
|
if (GET_MODE (m) != mode)
|
1934 |
|
|
return FALSE;
|
1935 |
|
|
|
1936 |
|
|
/* This is only profitable if T is unconditionally executed/evaluated in the
|
1937 |
|
|
original insn sequence or T is cheap. The former happens if B is the
|
1938 |
|
|
non-zero (T) value and if INSN_B was taken from TEST_BB, or there was no
|
1939 |
|
|
INSN_B which can happen for e.g. conditional stores to memory. For the
|
1940 |
|
|
cost computation use the block TEST_BB where the evaluation will end up
|
1941 |
|
|
after the transformation. */
|
1942 |
|
|
t_unconditional =
|
1943 |
|
|
(t == if_info->b
|
1944 |
|
|
&& (if_info->insn_b == NULL_RTX
|
1945 |
|
|
|| BLOCK_FOR_INSN (if_info->insn_b) == if_info->test_bb));
|
1946 |
|
|
if (!(t_unconditional
|
1947 |
|
|
|| (rtx_cost (t, SET, optimize_bb_for_speed_p (if_info->test_bb))
|
1948 |
|
|
< COSTS_N_INSNS (2))))
|
1949 |
|
|
return FALSE;
|
1950 |
|
|
|
1951 |
|
|
start_sequence ();
|
1952 |
|
|
/* Use emit_store_flag to generate "m < 0 ? -1 : 0" instead of expanding
|
1953 |
|
|
"(signed) m >> 31" directly. This benefits targets with specialized
|
1954 |
|
|
insns to obtain the signmask, but still uses ashr_optab otherwise. */
|
1955 |
|
|
m = emit_store_flag (gen_reg_rtx (mode), LT, m, const0_rtx, mode, 0, -1);
|
1956 |
|
|
t = m ? expand_binop (mode, and_optab, m, t, NULL_RTX, 0, OPTAB_DIRECT)
|
1957 |
|
|
: NULL_RTX;
|
1958 |
|
|
|
1959 |
|
|
if (!t)
|
1960 |
|
|
{
|
1961 |
|
|
end_sequence ();
|
1962 |
|
|
return FALSE;
|
1963 |
|
|
}
|
1964 |
|
|
|
1965 |
|
|
noce_emit_move_insn (if_info->x, t);
|
1966 |
|
|
|
1967 |
|
|
seq = end_ifcvt_sequence (if_info);
|
1968 |
|
|
if (!seq)
|
1969 |
|
|
return FALSE;
|
1970 |
|
|
|
1971 |
|
|
emit_insn_before_setloc (seq, if_info->jump, INSN_LOCATOR (if_info->insn_a));
|
1972 |
|
|
return TRUE;
|
1973 |
|
|
}
|
1974 |
|
|
|
1975 |
|
|
|
1976 |
|
|
/* Optimize away "if (x & C) x |= C" and similar bit manipulation
|
1977 |
|
|
transformations. */
|
1978 |
|
|
|
1979 |
|
|
static int
|
1980 |
|
|
noce_try_bitop (struct noce_if_info *if_info)
|
1981 |
|
|
{
|
1982 |
|
|
rtx cond, x, a, result, seq;
|
1983 |
|
|
enum machine_mode mode;
|
1984 |
|
|
enum rtx_code code;
|
1985 |
|
|
int bitnum;
|
1986 |
|
|
|
1987 |
|
|
x = if_info->x;
|
1988 |
|
|
cond = if_info->cond;
|
1989 |
|
|
code = GET_CODE (cond);
|
1990 |
|
|
|
1991 |
|
|
/* Check for no else condition. */
|
1992 |
|
|
if (! rtx_equal_p (x, if_info->b))
|
1993 |
|
|
return FALSE;
|
1994 |
|
|
|
1995 |
|
|
/* Check for a suitable condition. */
|
1996 |
|
|
if (code != NE && code != EQ)
|
1997 |
|
|
return FALSE;
|
1998 |
|
|
if (XEXP (cond, 1) != const0_rtx)
|
1999 |
|
|
return FALSE;
|
2000 |
|
|
cond = XEXP (cond, 0);
|
2001 |
|
|
|
2002 |
|
|
/* ??? We could also handle AND here. */
|
2003 |
|
|
if (GET_CODE (cond) == ZERO_EXTRACT)
|
2004 |
|
|
{
|
2005 |
|
|
if (XEXP (cond, 1) != const1_rtx
|
2006 |
|
|
|| !CONST_INT_P (XEXP (cond, 2))
|
2007 |
|
|
|| ! rtx_equal_p (x, XEXP (cond, 0)))
|
2008 |
|
|
return FALSE;
|
2009 |
|
|
bitnum = INTVAL (XEXP (cond, 2));
|
2010 |
|
|
mode = GET_MODE (x);
|
2011 |
|
|
if (BITS_BIG_ENDIAN)
|
2012 |
|
|
bitnum = GET_MODE_BITSIZE (mode) - 1 - bitnum;
|
2013 |
|
|
if (bitnum < 0 || bitnum >= HOST_BITS_PER_WIDE_INT)
|
2014 |
|
|
return FALSE;
|
2015 |
|
|
}
|
2016 |
|
|
else
|
2017 |
|
|
return FALSE;
|
2018 |
|
|
|
2019 |
|
|
a = if_info->a;
|
2020 |
|
|
if (GET_CODE (a) == IOR || GET_CODE (a) == XOR)
|
2021 |
|
|
{
|
2022 |
|
|
/* Check for "if (X & C) x = x op C". */
|
2023 |
|
|
if (! rtx_equal_p (x, XEXP (a, 0))
|
2024 |
|
|
|| !CONST_INT_P (XEXP (a, 1))
|
2025 |
|
|
|| (INTVAL (XEXP (a, 1)) & GET_MODE_MASK (mode))
|
2026 |
|
|
!= (unsigned HOST_WIDE_INT) 1 << bitnum)
|
2027 |
|
|
return FALSE;
|
2028 |
|
|
|
2029 |
|
|
/* if ((x & C) == 0) x |= C; is transformed to x |= C. */
|
2030 |
|
|
/* if ((x & C) != 0) x |= C; is transformed to nothing. */
|
2031 |
|
|
if (GET_CODE (a) == IOR)
|
2032 |
|
|
result = (code == NE) ? a : NULL_RTX;
|
2033 |
|
|
else if (code == NE)
|
2034 |
|
|
{
|
2035 |
|
|
/* if ((x & C) == 0) x ^= C; is transformed to x |= C. */
|
2036 |
|
|
result = gen_int_mode ((HOST_WIDE_INT) 1 << bitnum, mode);
|
2037 |
|
|
result = simplify_gen_binary (IOR, mode, x, result);
|
2038 |
|
|
}
|
2039 |
|
|
else
|
2040 |
|
|
{
|
2041 |
|
|
/* if ((x & C) != 0) x ^= C; is transformed to x &= ~C. */
|
2042 |
|
|
result = gen_int_mode (~((HOST_WIDE_INT) 1 << bitnum), mode);
|
2043 |
|
|
result = simplify_gen_binary (AND, mode, x, result);
|
2044 |
|
|
}
|
2045 |
|
|
}
|
2046 |
|
|
else if (GET_CODE (a) == AND)
|
2047 |
|
|
{
|
2048 |
|
|
/* Check for "if (X & C) x &= ~C". */
|
2049 |
|
|
if (! rtx_equal_p (x, XEXP (a, 0))
|
2050 |
|
|
|| !CONST_INT_P (XEXP (a, 1))
|
2051 |
|
|
|| (INTVAL (XEXP (a, 1)) & GET_MODE_MASK (mode))
|
2052 |
|
|
!= (~((HOST_WIDE_INT) 1 << bitnum) & GET_MODE_MASK (mode)))
|
2053 |
|
|
return FALSE;
|
2054 |
|
|
|
2055 |
|
|
/* if ((x & C) == 0) x &= ~C; is transformed to nothing. */
|
2056 |
|
|
/* if ((x & C) != 0) x &= ~C; is transformed to x &= ~C. */
|
2057 |
|
|
result = (code == EQ) ? a : NULL_RTX;
|
2058 |
|
|
}
|
2059 |
|
|
else
|
2060 |
|
|
return FALSE;
|
2061 |
|
|
|
2062 |
|
|
if (result)
|
2063 |
|
|
{
|
2064 |
|
|
start_sequence ();
|
2065 |
|
|
noce_emit_move_insn (x, result);
|
2066 |
|
|
seq = end_ifcvt_sequence (if_info);
|
2067 |
|
|
if (!seq)
|
2068 |
|
|
return FALSE;
|
2069 |
|
|
|
2070 |
|
|
emit_insn_before_setloc (seq, if_info->jump,
|
2071 |
|
|
INSN_LOCATOR (if_info->insn_a));
|
2072 |
|
|
}
|
2073 |
|
|
return TRUE;
|
2074 |
|
|
}
|
2075 |
|
|
|
2076 |
|
|
|
2077 |
|
|
/* Similar to get_condition, only the resulting condition must be
|
2078 |
|
|
valid at JUMP, instead of at EARLIEST.
|
2079 |
|
|
|
2080 |
|
|
If THEN_ELSE_REVERSED is true, the fallthrough does not go to the
|
2081 |
|
|
THEN block of the caller, and we have to reverse the condition. */
|
2082 |
|
|
|
2083 |
|
|
static rtx
|
2084 |
|
|
noce_get_condition (rtx jump, rtx *earliest, bool then_else_reversed)
|
2085 |
|
|
{
|
2086 |
|
|
rtx cond, set, tmp;
|
2087 |
|
|
bool reverse;
|
2088 |
|
|
|
2089 |
|
|
if (! any_condjump_p (jump))
|
2090 |
|
|
return NULL_RTX;
|
2091 |
|
|
|
2092 |
|
|
set = pc_set (jump);
|
2093 |
|
|
|
2094 |
|
|
/* If this branches to JUMP_LABEL when the condition is false,
|
2095 |
|
|
reverse the condition. */
|
2096 |
|
|
reverse = (GET_CODE (XEXP (SET_SRC (set), 2)) == LABEL_REF
|
2097 |
|
|
&& XEXP (XEXP (SET_SRC (set), 2), 0) == JUMP_LABEL (jump));
|
2098 |
|
|
|
2099 |
|
|
/* We may have to reverse because the caller's if block is not canonical,
|
2100 |
|
|
i.e. the THEN block isn't the fallthrough block for the TEST block
|
2101 |
|
|
(see find_if_header). */
|
2102 |
|
|
if (then_else_reversed)
|
2103 |
|
|
reverse = !reverse;
|
2104 |
|
|
|
2105 |
|
|
/* If the condition variable is a register and is MODE_INT, accept it. */
|
2106 |
|
|
|
2107 |
|
|
cond = XEXP (SET_SRC (set), 0);
|
2108 |
|
|
tmp = XEXP (cond, 0);
|
2109 |
|
|
if (REG_P (tmp) && GET_MODE_CLASS (GET_MODE (tmp)) == MODE_INT)
|
2110 |
|
|
{
|
2111 |
|
|
*earliest = jump;
|
2112 |
|
|
|
2113 |
|
|
if (reverse)
|
2114 |
|
|
cond = gen_rtx_fmt_ee (reverse_condition (GET_CODE (cond)),
|
2115 |
|
|
GET_MODE (cond), tmp, XEXP (cond, 1));
|
2116 |
|
|
return cond;
|
2117 |
|
|
}
|
2118 |
|
|
|
2119 |
|
|
/* Otherwise, fall back on canonicalize_condition to do the dirty
|
2120 |
|
|
work of manipulating MODE_CC values and COMPARE rtx codes. */
|
2121 |
|
|
return canonicalize_condition (jump, cond, reverse, earliest,
|
2122 |
|
|
NULL_RTX, false, true);
|
2123 |
|
|
}
|
2124 |
|
|
|
2125 |
|
|
/* Return true if OP is ok for if-then-else processing. */
|
2126 |
|
|
|
2127 |
|
|
static int
|
2128 |
|
|
noce_operand_ok (const_rtx op)
|
2129 |
|
|
{
|
2130 |
|
|
/* We special-case memories, so handle any of them with
|
2131 |
|
|
no address side effects. */
|
2132 |
|
|
if (MEM_P (op))
|
2133 |
|
|
return ! side_effects_p (XEXP (op, 0));
|
2134 |
|
|
|
2135 |
|
|
if (side_effects_p (op))
|
2136 |
|
|
return FALSE;
|
2137 |
|
|
|
2138 |
|
|
return ! may_trap_p (op);
|
2139 |
|
|
}
|
2140 |
|
|
|
2141 |
|
|
/* Return true if a write into MEM may trap or fault. */
|
2142 |
|
|
|
2143 |
|
|
static bool
|
2144 |
|
|
noce_mem_write_may_trap_or_fault_p (const_rtx mem)
|
2145 |
|
|
{
|
2146 |
|
|
rtx addr;
|
2147 |
|
|
|
2148 |
|
|
if (MEM_READONLY_P (mem))
|
2149 |
|
|
return true;
|
2150 |
|
|
|
2151 |
|
|
if (may_trap_or_fault_p (mem))
|
2152 |
|
|
return true;
|
2153 |
|
|
|
2154 |
|
|
addr = XEXP (mem, 0);
|
2155 |
|
|
|
2156 |
|
|
/* Call target hook to avoid the effects of -fpic etc.... */
|
2157 |
|
|
addr = targetm.delegitimize_address (addr);
|
2158 |
|
|
|
2159 |
|
|
while (addr)
|
2160 |
|
|
switch (GET_CODE (addr))
|
2161 |
|
|
{
|
2162 |
|
|
case CONST:
|
2163 |
|
|
case PRE_DEC:
|
2164 |
|
|
case PRE_INC:
|
2165 |
|
|
case POST_DEC:
|
2166 |
|
|
case POST_INC:
|
2167 |
|
|
case POST_MODIFY:
|
2168 |
|
|
addr = XEXP (addr, 0);
|
2169 |
|
|
break;
|
2170 |
|
|
case LO_SUM:
|
2171 |
|
|
case PRE_MODIFY:
|
2172 |
|
|
addr = XEXP (addr, 1);
|
2173 |
|
|
break;
|
2174 |
|
|
case PLUS:
|
2175 |
|
|
if (CONST_INT_P (XEXP (addr, 1)))
|
2176 |
|
|
addr = XEXP (addr, 0);
|
2177 |
|
|
else
|
2178 |
|
|
return false;
|
2179 |
|
|
break;
|
2180 |
|
|
case LABEL_REF:
|
2181 |
|
|
return true;
|
2182 |
|
|
case SYMBOL_REF:
|
2183 |
|
|
if (SYMBOL_REF_DECL (addr)
|
2184 |
|
|
&& decl_readonly_section (SYMBOL_REF_DECL (addr), 0))
|
2185 |
|
|
return true;
|
2186 |
|
|
return false;
|
2187 |
|
|
default:
|
2188 |
|
|
return false;
|
2189 |
|
|
}
|
2190 |
|
|
|
2191 |
|
|
return false;
|
2192 |
|
|
}
|
2193 |
|
|
|
2194 |
|
|
/* Return whether we can use store speculation for MEM. TOP_BB is the
|
2195 |
|
|
basic block above the conditional block where we are considering
|
2196 |
|
|
doing the speculative store. We look for whether MEM is set
|
2197 |
|
|
unconditionally later in the function. */
|
2198 |
|
|
|
2199 |
|
|
static bool
|
2200 |
|
|
noce_can_store_speculate_p (basic_block top_bb, const_rtx mem)
|
2201 |
|
|
{
|
2202 |
|
|
basic_block dominator;
|
2203 |
|
|
|
2204 |
|
|
for (dominator = get_immediate_dominator (CDI_POST_DOMINATORS, top_bb);
|
2205 |
|
|
dominator != NULL;
|
2206 |
|
|
dominator = get_immediate_dominator (CDI_POST_DOMINATORS, dominator))
|
2207 |
|
|
{
|
2208 |
|
|
rtx insn;
|
2209 |
|
|
|
2210 |
|
|
FOR_BB_INSNS (dominator, insn)
|
2211 |
|
|
{
|
2212 |
|
|
/* If we see something that might be a memory barrier, we
|
2213 |
|
|
have to stop looking. Even if the MEM is set later in
|
2214 |
|
|
the function, we still don't want to set it
|
2215 |
|
|
unconditionally before the barrier. */
|
2216 |
|
|
if (INSN_P (insn)
|
2217 |
|
|
&& (volatile_insn_p (PATTERN (insn))
|
2218 |
|
|
|| (CALL_P (insn) && (!RTL_CONST_CALL_P (insn)))))
|
2219 |
|
|
return false;
|
2220 |
|
|
|
2221 |
|
|
if (memory_modified_in_insn_p (mem, insn))
|
2222 |
|
|
return true;
|
2223 |
|
|
if (modified_in_p (XEXP (mem, 0), insn))
|
2224 |
|
|
return false;
|
2225 |
|
|
|
2226 |
|
|
}
|
2227 |
|
|
}
|
2228 |
|
|
|
2229 |
|
|
return false;
|
2230 |
|
|
}
|
2231 |
|
|
|
2232 |
|
|
/* Given a simple IF-THEN-JOIN or IF-THEN-ELSE-JOIN block, attempt to convert
|
2233 |
|
|
it without using conditional execution. Return TRUE if we were successful
|
2234 |
|
|
at converting the block. */
|
2235 |
|
|
|
2236 |
|
|
static int
|
2237 |
|
|
noce_process_if_block (struct noce_if_info *if_info)
|
2238 |
|
|
{
|
2239 |
|
|
basic_block test_bb = if_info->test_bb; /* test block */
|
2240 |
|
|
basic_block then_bb = if_info->then_bb; /* THEN */
|
2241 |
|
|
basic_block else_bb = if_info->else_bb; /* ELSE or NULL */
|
2242 |
|
|
basic_block join_bb = if_info->join_bb; /* JOIN */
|
2243 |
|
|
rtx jump = if_info->jump;
|
2244 |
|
|
rtx cond = if_info->cond;
|
2245 |
|
|
rtx insn_a, insn_b;
|
2246 |
|
|
rtx set_a, set_b;
|
2247 |
|
|
rtx orig_x, x, a, b;
|
2248 |
|
|
|
2249 |
|
|
/* We're looking for patterns of the form
|
2250 |
|
|
|
2251 |
|
|
(1) if (...) x = a; else x = b;
|
2252 |
|
|
(2) x = b; if (...) x = a;
|
2253 |
|
|
(3) if (...) x = a; // as if with an initial x = x.
|
2254 |
|
|
|
2255 |
|
|
The later patterns require jumps to be more expensive.
|
2256 |
|
|
|
2257 |
|
|
??? For future expansion, look for multiple X in such patterns. */
|
2258 |
|
|
|
2259 |
|
|
/* Look for one of the potential sets. */
|
2260 |
|
|
insn_a = first_active_insn (then_bb);
|
2261 |
|
|
if (! insn_a
|
2262 |
|
|
|| insn_a != last_active_insn (then_bb, FALSE)
|
2263 |
|
|
|| (set_a = single_set (insn_a)) == NULL_RTX)
|
2264 |
|
|
return FALSE;
|
2265 |
|
|
|
2266 |
|
|
x = SET_DEST (set_a);
|
2267 |
|
|
a = SET_SRC (set_a);
|
2268 |
|
|
|
2269 |
|
|
/* Look for the other potential set. Make sure we've got equivalent
|
2270 |
|
|
destinations. */
|
2271 |
|
|
/* ??? This is overconservative. Storing to two different mems is
|
2272 |
|
|
as easy as conditionally computing the address. Storing to a
|
2273 |
|
|
single mem merely requires a scratch memory to use as one of the
|
2274 |
|
|
destination addresses; often the memory immediately below the
|
2275 |
|
|
stack pointer is available for this. */
|
2276 |
|
|
set_b = NULL_RTX;
|
2277 |
|
|
if (else_bb)
|
2278 |
|
|
{
|
2279 |
|
|
insn_b = first_active_insn (else_bb);
|
2280 |
|
|
if (! insn_b
|
2281 |
|
|
|| insn_b != last_active_insn (else_bb, FALSE)
|
2282 |
|
|
|| (set_b = single_set (insn_b)) == NULL_RTX
|
2283 |
|
|
|| ! rtx_equal_p (x, SET_DEST (set_b)))
|
2284 |
|
|
return FALSE;
|
2285 |
|
|
}
|
2286 |
|
|
else
|
2287 |
|
|
{
|
2288 |
|
|
insn_b = prev_nonnote_insn (if_info->cond_earliest);
|
2289 |
|
|
while (insn_b && DEBUG_INSN_P (insn_b))
|
2290 |
|
|
insn_b = prev_nonnote_insn (insn_b);
|
2291 |
|
|
/* We're going to be moving the evaluation of B down from above
|
2292 |
|
|
COND_EARLIEST to JUMP. Make sure the relevant data is still
|
2293 |
|
|
intact. */
|
2294 |
|
|
if (! insn_b
|
2295 |
|
|
|| BLOCK_FOR_INSN (insn_b) != BLOCK_FOR_INSN (if_info->cond_earliest)
|
2296 |
|
|
|| !NONJUMP_INSN_P (insn_b)
|
2297 |
|
|
|| (set_b = single_set (insn_b)) == NULL_RTX
|
2298 |
|
|
|| ! rtx_equal_p (x, SET_DEST (set_b))
|
2299 |
|
|
|| ! noce_operand_ok (SET_SRC (set_b))
|
2300 |
|
|
|| reg_overlap_mentioned_p (x, SET_SRC (set_b))
|
2301 |
|
|
|| modified_between_p (SET_SRC (set_b), insn_b, jump)
|
2302 |
|
|
/* Likewise with X. In particular this can happen when
|
2303 |
|
|
noce_get_condition looks farther back in the instruction
|
2304 |
|
|
stream than one might expect. */
|
2305 |
|
|
|| reg_overlap_mentioned_p (x, cond)
|
2306 |
|
|
|| reg_overlap_mentioned_p (x, a)
|
2307 |
|
|
|| modified_between_p (x, insn_b, jump))
|
2308 |
|
|
insn_b = set_b = NULL_RTX;
|
2309 |
|
|
}
|
2310 |
|
|
|
2311 |
|
|
/* If x has side effects then only the if-then-else form is safe to
|
2312 |
|
|
convert. But even in that case we would need to restore any notes
|
2313 |
|
|
(such as REG_INC) at then end. That can be tricky if
|
2314 |
|
|
noce_emit_move_insn expands to more than one insn, so disable the
|
2315 |
|
|
optimization entirely for now if there are side effects. */
|
2316 |
|
|
if (side_effects_p (x))
|
2317 |
|
|
return FALSE;
|
2318 |
|
|
|
2319 |
|
|
b = (set_b ? SET_SRC (set_b) : x);
|
2320 |
|
|
|
2321 |
|
|
/* Only operate on register destinations, and even then avoid extending
|
2322 |
|
|
the lifetime of hard registers on small register class machines. */
|
2323 |
|
|
orig_x = x;
|
2324 |
|
|
if (!REG_P (x)
|
2325 |
|
|
|| (SMALL_REGISTER_CLASSES
|
2326 |
|
|
&& REGNO (x) < FIRST_PSEUDO_REGISTER))
|
2327 |
|
|
{
|
2328 |
|
|
if (GET_MODE (x) == BLKmode)
|
2329 |
|
|
return FALSE;
|
2330 |
|
|
|
2331 |
|
|
if (GET_CODE (x) == ZERO_EXTRACT
|
2332 |
|
|
&& (!CONST_INT_P (XEXP (x, 1))
|
2333 |
|
|
|| !CONST_INT_P (XEXP (x, 2))))
|
2334 |
|
|
return FALSE;
|
2335 |
|
|
|
2336 |
|
|
x = gen_reg_rtx (GET_MODE (GET_CODE (x) == STRICT_LOW_PART
|
2337 |
|
|
? XEXP (x, 0) : x));
|
2338 |
|
|
}
|
2339 |
|
|
|
2340 |
|
|
/* Don't operate on sources that may trap or are volatile. */
|
2341 |
|
|
if (! noce_operand_ok (a) || ! noce_operand_ok (b))
|
2342 |
|
|
return FALSE;
|
2343 |
|
|
|
2344 |
|
|
retry:
|
2345 |
|
|
/* Set up the info block for our subroutines. */
|
2346 |
|
|
if_info->insn_a = insn_a;
|
2347 |
|
|
if_info->insn_b = insn_b;
|
2348 |
|
|
if_info->x = x;
|
2349 |
|
|
if_info->a = a;
|
2350 |
|
|
if_info->b = b;
|
2351 |
|
|
|
2352 |
|
|
/* Try optimizations in some approximation of a useful order. */
|
2353 |
|
|
/* ??? Should first look to see if X is live incoming at all. If it
|
2354 |
|
|
isn't, we don't need anything but an unconditional set. */
|
2355 |
|
|
|
2356 |
|
|
/* Look and see if A and B are really the same. Avoid creating silly
|
2357 |
|
|
cmove constructs that no one will fix up later. */
|
2358 |
|
|
if (rtx_equal_p (a, b))
|
2359 |
|
|
{
|
2360 |
|
|
/* If we have an INSN_B, we don't have to create any new rtl. Just
|
2361 |
|
|
move the instruction that we already have. If we don't have an
|
2362 |
|
|
INSN_B, that means that A == X, and we've got a noop move. In
|
2363 |
|
|
that case don't do anything and let the code below delete INSN_A. */
|
2364 |
|
|
if (insn_b && else_bb)
|
2365 |
|
|
{
|
2366 |
|
|
rtx note;
|
2367 |
|
|
|
2368 |
|
|
if (else_bb && insn_b == BB_END (else_bb))
|
2369 |
|
|
BB_END (else_bb) = PREV_INSN (insn_b);
|
2370 |
|
|
reorder_insns (insn_b, insn_b, PREV_INSN (jump));
|
2371 |
|
|
|
2372 |
|
|
/* If there was a REG_EQUAL note, delete it since it may have been
|
2373 |
|
|
true due to this insn being after a jump. */
|
2374 |
|
|
if ((note = find_reg_note (insn_b, REG_EQUAL, NULL_RTX)) != 0)
|
2375 |
|
|
remove_note (insn_b, note);
|
2376 |
|
|
|
2377 |
|
|
insn_b = NULL_RTX;
|
2378 |
|
|
}
|
2379 |
|
|
/* If we have "x = b; if (...) x = a;", and x has side-effects, then
|
2380 |
|
|
x must be executed twice. */
|
2381 |
|
|
else if (insn_b && side_effects_p (orig_x))
|
2382 |
|
|
return FALSE;
|
2383 |
|
|
|
2384 |
|
|
x = orig_x;
|
2385 |
|
|
goto success;
|
2386 |
|
|
}
|
2387 |
|
|
|
2388 |
|
|
if (!set_b && MEM_P (orig_x))
|
2389 |
|
|
{
|
2390 |
|
|
/* Disallow the "if (...) x = a;" form (implicit "else x = x;")
|
2391 |
|
|
for optimizations if writing to x may trap or fault,
|
2392 |
|
|
i.e. it's a memory other than a static var or a stack slot,
|
2393 |
|
|
is misaligned on strict aligned machines or is read-only. If
|
2394 |
|
|
x is a read-only memory, then the program is valid only if we
|
2395 |
|
|
avoid the store into it. If there are stores on both the
|
2396 |
|
|
THEN and ELSE arms, then we can go ahead with the conversion;
|
2397 |
|
|
either the program is broken, or the condition is always
|
2398 |
|
|
false such that the other memory is selected. */
|
2399 |
|
|
if (noce_mem_write_may_trap_or_fault_p (orig_x))
|
2400 |
|
|
return FALSE;
|
2401 |
|
|
|
2402 |
|
|
/* Avoid store speculation: given "if (...) x = a" where x is a
|
2403 |
|
|
MEM, we only want to do the store if x is always set
|
2404 |
|
|
somewhere in the function. This avoids cases like
|
2405 |
|
|
if (pthread_mutex_trylock(mutex))
|
2406 |
|
|
++global_variable;
|
2407 |
|
|
where we only want global_variable to be changed if the mutex
|
2408 |
|
|
is held. FIXME: This should ideally be expressed directly in
|
2409 |
|
|
RTL somehow. */
|
2410 |
|
|
if (!noce_can_store_speculate_p (test_bb, orig_x))
|
2411 |
|
|
return FALSE;
|
2412 |
|
|
}
|
2413 |
|
|
|
2414 |
|
|
if (noce_try_move (if_info))
|
2415 |
|
|
goto success;
|
2416 |
|
|
if (noce_try_store_flag (if_info))
|
2417 |
|
|
goto success;
|
2418 |
|
|
if (noce_try_bitop (if_info))
|
2419 |
|
|
goto success;
|
2420 |
|
|
if (noce_try_minmax (if_info))
|
2421 |
|
|
goto success;
|
2422 |
|
|
if (noce_try_abs (if_info))
|
2423 |
|
|
goto success;
|
2424 |
|
|
if (HAVE_conditional_move
|
2425 |
|
|
&& noce_try_cmove (if_info))
|
2426 |
|
|
goto success;
|
2427 |
|
|
if (! targetm.have_conditional_execution ())
|
2428 |
|
|
{
|
2429 |
|
|
if (noce_try_store_flag_constants (if_info))
|
2430 |
|
|
goto success;
|
2431 |
|
|
if (noce_try_addcc (if_info))
|
2432 |
|
|
goto success;
|
2433 |
|
|
if (noce_try_store_flag_mask (if_info))
|
2434 |
|
|
goto success;
|
2435 |
|
|
if (HAVE_conditional_move
|
2436 |
|
|
&& noce_try_cmove_arith (if_info))
|
2437 |
|
|
goto success;
|
2438 |
|
|
if (noce_try_sign_mask (if_info))
|
2439 |
|
|
goto success;
|
2440 |
|
|
}
|
2441 |
|
|
|
2442 |
|
|
if (!else_bb && set_b)
|
2443 |
|
|
{
|
2444 |
|
|
insn_b = set_b = NULL_RTX;
|
2445 |
|
|
b = orig_x;
|
2446 |
|
|
goto retry;
|
2447 |
|
|
}
|
2448 |
|
|
|
2449 |
|
|
return FALSE;
|
2450 |
|
|
|
2451 |
|
|
success:
|
2452 |
|
|
|
2453 |
|
|
/* If we used a temporary, fix it up now. */
|
2454 |
|
|
if (orig_x != x)
|
2455 |
|
|
{
|
2456 |
|
|
rtx seq;
|
2457 |
|
|
|
2458 |
|
|
start_sequence ();
|
2459 |
|
|
noce_emit_move_insn (orig_x, x);
|
2460 |
|
|
seq = get_insns ();
|
2461 |
|
|
set_used_flags (orig_x);
|
2462 |
|
|
unshare_all_rtl_in_chain (seq);
|
2463 |
|
|
end_sequence ();
|
2464 |
|
|
|
2465 |
|
|
emit_insn_before_setloc (seq, BB_END (test_bb), INSN_LOCATOR (insn_a));
|
2466 |
|
|
}
|
2467 |
|
|
|
2468 |
|
|
/* The original THEN and ELSE blocks may now be removed. The test block
|
2469 |
|
|
must now jump to the join block. If the test block and the join block
|
2470 |
|
|
can be merged, do so. */
|
2471 |
|
|
if (else_bb)
|
2472 |
|
|
{
|
2473 |
|
|
delete_basic_block (else_bb);
|
2474 |
|
|
num_true_changes++;
|
2475 |
|
|
}
|
2476 |
|
|
else
|
2477 |
|
|
remove_edge (find_edge (test_bb, join_bb));
|
2478 |
|
|
|
2479 |
|
|
remove_edge (find_edge (then_bb, join_bb));
|
2480 |
|
|
redirect_edge_and_branch_force (single_succ_edge (test_bb), join_bb);
|
2481 |
|
|
delete_basic_block (then_bb);
|
2482 |
|
|
num_true_changes++;
|
2483 |
|
|
|
2484 |
|
|
if (can_merge_blocks_p (test_bb, join_bb))
|
2485 |
|
|
{
|
2486 |
|
|
merge_blocks (test_bb, join_bb);
|
2487 |
|
|
num_true_changes++;
|
2488 |
|
|
}
|
2489 |
|
|
|
2490 |
|
|
num_updated_if_blocks++;
|
2491 |
|
|
return TRUE;
|
2492 |
|
|
}
|
2493 |
|
|
|
2494 |
|
|
/* Check whether a block is suitable for conditional move conversion.
|
2495 |
|
|
Every insn must be a simple set of a register to a constant or a
|
2496 |
|
|
register. For each assignment, store the value in the array VALS,
|
2497 |
|
|
indexed by register number, then store the register number in
|
2498 |
|
|
REGS. COND is the condition we will test. */
|
2499 |
|
|
|
2500 |
|
|
static int
|
2501 |
|
|
check_cond_move_block (basic_block bb, rtx *vals, VEC (int, heap) **regs, rtx cond)
|
2502 |
|
|
{
|
2503 |
|
|
rtx insn;
|
2504 |
|
|
|
2505 |
|
|
/* We can only handle simple jumps at the end of the basic block.
|
2506 |
|
|
It is almost impossible to update the CFG otherwise. */
|
2507 |
|
|
insn = BB_END (bb);
|
2508 |
|
|
if (JUMP_P (insn) && !onlyjump_p (insn))
|
2509 |
|
|
return FALSE;
|
2510 |
|
|
|
2511 |
|
|
FOR_BB_INSNS (bb, insn)
|
2512 |
|
|
{
|
2513 |
|
|
rtx set, dest, src;
|
2514 |
|
|
|
2515 |
|
|
if (!NONDEBUG_INSN_P (insn) || JUMP_P (insn))
|
2516 |
|
|
continue;
|
2517 |
|
|
set = single_set (insn);
|
2518 |
|
|
if (!set)
|
2519 |
|
|
return FALSE;
|
2520 |
|
|
|
2521 |
|
|
dest = SET_DEST (set);
|
2522 |
|
|
src = SET_SRC (set);
|
2523 |
|
|
if (!REG_P (dest)
|
2524 |
|
|
|| (SMALL_REGISTER_CLASSES && HARD_REGISTER_P (dest)))
|
2525 |
|
|
return FALSE;
|
2526 |
|
|
|
2527 |
|
|
if (!CONSTANT_P (src) && !register_operand (src, VOIDmode))
|
2528 |
|
|
return FALSE;
|
2529 |
|
|
|
2530 |
|
|
if (side_effects_p (src) || side_effects_p (dest))
|
2531 |
|
|
return FALSE;
|
2532 |
|
|
|
2533 |
|
|
if (may_trap_p (src) || may_trap_p (dest))
|
2534 |
|
|
return FALSE;
|
2535 |
|
|
|
2536 |
|
|
/* Don't try to handle this if the source register was
|
2537 |
|
|
modified earlier in the block. */
|
2538 |
|
|
if ((REG_P (src)
|
2539 |
|
|
&& vals[REGNO (src)] != NULL)
|
2540 |
|
|
|| (GET_CODE (src) == SUBREG && REG_P (SUBREG_REG (src))
|
2541 |
|
|
&& vals[REGNO (SUBREG_REG (src))] != NULL))
|
2542 |
|
|
return FALSE;
|
2543 |
|
|
|
2544 |
|
|
/* Don't try to handle this if the destination register was
|
2545 |
|
|
modified earlier in the block. */
|
2546 |
|
|
if (vals[REGNO (dest)] != NULL)
|
2547 |
|
|
return FALSE;
|
2548 |
|
|
|
2549 |
|
|
/* Don't try to handle this if the condition uses the
|
2550 |
|
|
destination register. */
|
2551 |
|
|
if (reg_overlap_mentioned_p (dest, cond))
|
2552 |
|
|
return FALSE;
|
2553 |
|
|
|
2554 |
|
|
/* Don't try to handle this if the source register is modified
|
2555 |
|
|
later in the block. */
|
2556 |
|
|
if (!CONSTANT_P (src)
|
2557 |
|
|
&& modified_between_p (src, insn, NEXT_INSN (BB_END (bb))))
|
2558 |
|
|
return FALSE;
|
2559 |
|
|
|
2560 |
|
|
vals[REGNO (dest)] = src;
|
2561 |
|
|
|
2562 |
|
|
VEC_safe_push (int, heap, *regs, REGNO (dest));
|
2563 |
|
|
}
|
2564 |
|
|
|
2565 |
|
|
return TRUE;
|
2566 |
|
|
}
|
2567 |
|
|
|
2568 |
|
|
/* Given a basic block BB suitable for conditional move conversion,
|
2569 |
|
|
a condition COND, and arrays THEN_VALS and ELSE_VALS containing the
|
2570 |
|
|
register values depending on COND, emit the insns in the block as
|
2571 |
|
|
conditional moves. If ELSE_BLOCK is true, THEN_BB was already
|
2572 |
|
|
processed. The caller has started a sequence for the conversion.
|
2573 |
|
|
Return true if successful, false if something goes wrong. */
|
2574 |
|
|
|
2575 |
|
|
static bool
|
2576 |
|
|
cond_move_convert_if_block (struct noce_if_info *if_infop,
|
2577 |
|
|
basic_block bb, rtx cond,
|
2578 |
|
|
rtx *then_vals, rtx *else_vals,
|
2579 |
|
|
bool else_block_p)
|
2580 |
|
|
{
|
2581 |
|
|
enum rtx_code code;
|
2582 |
|
|
rtx insn, cond_arg0, cond_arg1;
|
2583 |
|
|
|
2584 |
|
|
code = GET_CODE (cond);
|
2585 |
|
|
cond_arg0 = XEXP (cond, 0);
|
2586 |
|
|
cond_arg1 = XEXP (cond, 1);
|
2587 |
|
|
|
2588 |
|
|
FOR_BB_INSNS (bb, insn)
|
2589 |
|
|
{
|
2590 |
|
|
rtx set, target, dest, t, e;
|
2591 |
|
|
unsigned int regno;
|
2592 |
|
|
|
2593 |
|
|
/* ??? Maybe emit conditional debug insn? */
|
2594 |
|
|
if (!NONDEBUG_INSN_P (insn) || JUMP_P (insn))
|
2595 |
|
|
continue;
|
2596 |
|
|
set = single_set (insn);
|
2597 |
|
|
gcc_assert (set && REG_P (SET_DEST (set)));
|
2598 |
|
|
|
2599 |
|
|
dest = SET_DEST (set);
|
2600 |
|
|
regno = REGNO (dest);
|
2601 |
|
|
|
2602 |
|
|
t = then_vals[regno];
|
2603 |
|
|
e = else_vals[regno];
|
2604 |
|
|
|
2605 |
|
|
if (else_block_p)
|
2606 |
|
|
{
|
2607 |
|
|
/* If this register was set in the then block, we already
|
2608 |
|
|
handled this case there. */
|
2609 |
|
|
if (t)
|
2610 |
|
|
continue;
|
2611 |
|
|
t = dest;
|
2612 |
|
|
gcc_assert (e);
|
2613 |
|
|
}
|
2614 |
|
|
else
|
2615 |
|
|
{
|
2616 |
|
|
gcc_assert (t);
|
2617 |
|
|
if (!e)
|
2618 |
|
|
e = dest;
|
2619 |
|
|
}
|
2620 |
|
|
|
2621 |
|
|
target = noce_emit_cmove (if_infop, dest, code, cond_arg0, cond_arg1,
|
2622 |
|
|
t, e);
|
2623 |
|
|
if (!target)
|
2624 |
|
|
return false;
|
2625 |
|
|
|
2626 |
|
|
if (target != dest)
|
2627 |
|
|
noce_emit_move_insn (dest, target);
|
2628 |
|
|
}
|
2629 |
|
|
|
2630 |
|
|
return true;
|
2631 |
|
|
}
|
2632 |
|
|
|
2633 |
|
|
/* Given a simple IF-THEN-JOIN or IF-THEN-ELSE-JOIN block, attempt to convert
|
2634 |
|
|
it using only conditional moves. Return TRUE if we were successful at
|
2635 |
|
|
converting the block. */
|
2636 |
|
|
|
2637 |
|
|
static int
|
2638 |
|
|
cond_move_process_if_block (struct noce_if_info *if_info)
|
2639 |
|
|
{
|
2640 |
|
|
basic_block test_bb = if_info->test_bb;
|
2641 |
|
|
basic_block then_bb = if_info->then_bb;
|
2642 |
|
|
basic_block else_bb = if_info->else_bb;
|
2643 |
|
|
basic_block join_bb = if_info->join_bb;
|
2644 |
|
|
rtx jump = if_info->jump;
|
2645 |
|
|
rtx cond = if_info->cond;
|
2646 |
|
|
rtx seq, loc_insn;
|
2647 |
|
|
int max_reg, size, c, reg;
|
2648 |
|
|
rtx *then_vals;
|
2649 |
|
|
rtx *else_vals;
|
2650 |
|
|
VEC (int, heap) *then_regs = NULL;
|
2651 |
|
|
VEC (int, heap) *else_regs = NULL;
|
2652 |
|
|
unsigned int i;
|
2653 |
|
|
|
2654 |
|
|
/* Build a mapping for each block to the value used for each
|
2655 |
|
|
register. */
|
2656 |
|
|
max_reg = max_reg_num ();
|
2657 |
|
|
size = (max_reg + 1) * sizeof (rtx);
|
2658 |
|
|
then_vals = (rtx *) alloca (size);
|
2659 |
|
|
else_vals = (rtx *) alloca (size);
|
2660 |
|
|
memset (then_vals, 0, size);
|
2661 |
|
|
memset (else_vals, 0, size);
|
2662 |
|
|
|
2663 |
|
|
/* Make sure the blocks are suitable. */
|
2664 |
|
|
if (!check_cond_move_block (then_bb, then_vals, &then_regs, cond)
|
2665 |
|
|
|| (else_bb && !check_cond_move_block (else_bb, else_vals, &else_regs, cond)))
|
2666 |
|
|
{
|
2667 |
|
|
VEC_free (int, heap, then_regs);
|
2668 |
|
|
VEC_free (int, heap, else_regs);
|
2669 |
|
|
return FALSE;
|
2670 |
|
|
}
|
2671 |
|
|
|
2672 |
|
|
/* Make sure the blocks can be used together. If the same register
|
2673 |
|
|
is set in both blocks, and is not set to a constant in both
|
2674 |
|
|
cases, then both blocks must set it to the same register. We
|
2675 |
|
|
have already verified that if it is set to a register, that the
|
2676 |
|
|
source register does not change after the assignment. Also count
|
2677 |
|
|
the number of registers set in only one of the blocks. */
|
2678 |
|
|
c = 0;
|
2679 |
|
|
for (i = 0; VEC_iterate (int, then_regs, i, reg); i++)
|
2680 |
|
|
{
|
2681 |
|
|
if (!then_vals[reg] && !else_vals[reg])
|
2682 |
|
|
continue;
|
2683 |
|
|
|
2684 |
|
|
if (!else_vals[reg])
|
2685 |
|
|
++c;
|
2686 |
|
|
else
|
2687 |
|
|
{
|
2688 |
|
|
if (!CONSTANT_P (then_vals[reg])
|
2689 |
|
|
&& !CONSTANT_P (else_vals[reg])
|
2690 |
|
|
&& !rtx_equal_p (then_vals[reg], else_vals[reg]))
|
2691 |
|
|
{
|
2692 |
|
|
VEC_free (int, heap, then_regs);
|
2693 |
|
|
VEC_free (int, heap, else_regs);
|
2694 |
|
|
return FALSE;
|
2695 |
|
|
}
|
2696 |
|
|
}
|
2697 |
|
|
}
|
2698 |
|
|
|
2699 |
|
|
/* Finish off c for MAX_CONDITIONAL_EXECUTE. */
|
2700 |
|
|
for (i = 0; VEC_iterate (int, else_regs, i, reg); ++i)
|
2701 |
|
|
if (!then_vals[reg])
|
2702 |
|
|
++c;
|
2703 |
|
|
|
2704 |
|
|
/* Make sure it is reasonable to convert this block. What matters
|
2705 |
|
|
is the number of assignments currently made in only one of the
|
2706 |
|
|
branches, since if we convert we are going to always execute
|
2707 |
|
|
them. */
|
2708 |
|
|
if (c > MAX_CONDITIONAL_EXECUTE)
|
2709 |
|
|
{
|
2710 |
|
|
VEC_free (int, heap, then_regs);
|
2711 |
|
|
VEC_free (int, heap, else_regs);
|
2712 |
|
|
return FALSE;
|
2713 |
|
|
}
|
2714 |
|
|
|
2715 |
|
|
/* Try to emit the conditional moves. First do the then block,
|
2716 |
|
|
then do anything left in the else blocks. */
|
2717 |
|
|
start_sequence ();
|
2718 |
|
|
if (!cond_move_convert_if_block (if_info, then_bb, cond,
|
2719 |
|
|
then_vals, else_vals, false)
|
2720 |
|
|
|| (else_bb
|
2721 |
|
|
&& !cond_move_convert_if_block (if_info, else_bb, cond,
|
2722 |
|
|
then_vals, else_vals, true)))
|
2723 |
|
|
{
|
2724 |
|
|
end_sequence ();
|
2725 |
|
|
VEC_free (int, heap, then_regs);
|
2726 |
|
|
VEC_free (int, heap, else_regs);
|
2727 |
|
|
return FALSE;
|
2728 |
|
|
}
|
2729 |
|
|
seq = end_ifcvt_sequence (if_info);
|
2730 |
|
|
if (!seq)
|
2731 |
|
|
{
|
2732 |
|
|
VEC_free (int, heap, then_regs);
|
2733 |
|
|
VEC_free (int, heap, else_regs);
|
2734 |
|
|
return FALSE;
|
2735 |
|
|
}
|
2736 |
|
|
|
2737 |
|
|
loc_insn = first_active_insn (then_bb);
|
2738 |
|
|
if (!loc_insn)
|
2739 |
|
|
{
|
2740 |
|
|
loc_insn = first_active_insn (else_bb);
|
2741 |
|
|
gcc_assert (loc_insn);
|
2742 |
|
|
}
|
2743 |
|
|
emit_insn_before_setloc (seq, jump, INSN_LOCATOR (loc_insn));
|
2744 |
|
|
|
2745 |
|
|
if (else_bb)
|
2746 |
|
|
{
|
2747 |
|
|
delete_basic_block (else_bb);
|
2748 |
|
|
num_true_changes++;
|
2749 |
|
|
}
|
2750 |
|
|
else
|
2751 |
|
|
remove_edge (find_edge (test_bb, join_bb));
|
2752 |
|
|
|
2753 |
|
|
remove_edge (find_edge (then_bb, join_bb));
|
2754 |
|
|
redirect_edge_and_branch_force (single_succ_edge (test_bb), join_bb);
|
2755 |
|
|
delete_basic_block (then_bb);
|
2756 |
|
|
num_true_changes++;
|
2757 |
|
|
|
2758 |
|
|
if (can_merge_blocks_p (test_bb, join_bb))
|
2759 |
|
|
{
|
2760 |
|
|
merge_blocks (test_bb, join_bb);
|
2761 |
|
|
num_true_changes++;
|
2762 |
|
|
}
|
2763 |
|
|
|
2764 |
|
|
num_updated_if_blocks++;
|
2765 |
|
|
|
2766 |
|
|
VEC_free (int, heap, then_regs);
|
2767 |
|
|
VEC_free (int, heap, else_regs);
|
2768 |
|
|
return TRUE;
|
2769 |
|
|
}
|
2770 |
|
|
|
2771 |
|
|
|
2772 |
|
|
/* Determine if a given basic block heads a simple IF-THEN-JOIN or an
|
2773 |
|
|
IF-THEN-ELSE-JOIN block.
|
2774 |
|
|
|
2775 |
|
|
If so, we'll try to convert the insns to not require the branch,
|
2776 |
|
|
using only transformations that do not require conditional execution.
|
2777 |
|
|
|
2778 |
|
|
Return TRUE if we were successful at converting the block. */
|
2779 |
|
|
|
2780 |
|
|
static int
|
2781 |
|
|
noce_find_if_block (basic_block test_bb,
|
2782 |
|
|
edge then_edge, edge else_edge,
|
2783 |
|
|
int pass)
|
2784 |
|
|
{
|
2785 |
|
|
basic_block then_bb, else_bb, join_bb;
|
2786 |
|
|
bool then_else_reversed = false;
|
2787 |
|
|
rtx jump, cond;
|
2788 |
|
|
rtx cond_earliest;
|
2789 |
|
|
struct noce_if_info if_info;
|
2790 |
|
|
|
2791 |
|
|
/* We only ever should get here before reload. */
|
2792 |
|
|
gcc_assert (!reload_completed);
|
2793 |
|
|
|
2794 |
|
|
/* Recognize an IF-THEN-ELSE-JOIN block. */
|
2795 |
|
|
if (single_pred_p (then_edge->dest)
|
2796 |
|
|
&& single_succ_p (then_edge->dest)
|
2797 |
|
|
&& single_pred_p (else_edge->dest)
|
2798 |
|
|
&& single_succ_p (else_edge->dest)
|
2799 |
|
|
&& single_succ (then_edge->dest) == single_succ (else_edge->dest))
|
2800 |
|
|
{
|
2801 |
|
|
then_bb = then_edge->dest;
|
2802 |
|
|
else_bb = else_edge->dest;
|
2803 |
|
|
join_bb = single_succ (then_bb);
|
2804 |
|
|
}
|
2805 |
|
|
/* Recognize an IF-THEN-JOIN block. */
|
2806 |
|
|
else if (single_pred_p (then_edge->dest)
|
2807 |
|
|
&& single_succ_p (then_edge->dest)
|
2808 |
|
|
&& single_succ (then_edge->dest) == else_edge->dest)
|
2809 |
|
|
{
|
2810 |
|
|
then_bb = then_edge->dest;
|
2811 |
|
|
else_bb = NULL_BLOCK;
|
2812 |
|
|
join_bb = else_edge->dest;
|
2813 |
|
|
}
|
2814 |
|
|
/* Recognize an IF-ELSE-JOIN block. We can have those because the order
|
2815 |
|
|
of basic blocks in cfglayout mode does not matter, so the fallthrough
|
2816 |
|
|
edge can go to any basic block (and not just to bb->next_bb, like in
|
2817 |
|
|
cfgrtl mode). */
|
2818 |
|
|
else if (single_pred_p (else_edge->dest)
|
2819 |
|
|
&& single_succ_p (else_edge->dest)
|
2820 |
|
|
&& single_succ (else_edge->dest) == then_edge->dest)
|
2821 |
|
|
{
|
2822 |
|
|
/* The noce transformations do not apply to IF-ELSE-JOIN blocks.
|
2823 |
|
|
To make this work, we have to invert the THEN and ELSE blocks
|
2824 |
|
|
and reverse the jump condition. */
|
2825 |
|
|
then_bb = else_edge->dest;
|
2826 |
|
|
else_bb = NULL_BLOCK;
|
2827 |
|
|
join_bb = single_succ (then_bb);
|
2828 |
|
|
then_else_reversed = true;
|
2829 |
|
|
}
|
2830 |
|
|
else
|
2831 |
|
|
/* Not a form we can handle. */
|
2832 |
|
|
return FALSE;
|
2833 |
|
|
|
2834 |
|
|
/* The edges of the THEN and ELSE blocks cannot have complex edges. */
|
2835 |
|
|
if (single_succ_edge (then_bb)->flags & EDGE_COMPLEX)
|
2836 |
|
|
return FALSE;
|
2837 |
|
|
if (else_bb
|
2838 |
|
|
&& single_succ_edge (else_bb)->flags & EDGE_COMPLEX)
|
2839 |
|
|
return FALSE;
|
2840 |
|
|
|
2841 |
|
|
num_possible_if_blocks++;
|
2842 |
|
|
|
2843 |
|
|
if (dump_file)
|
2844 |
|
|
{
|
2845 |
|
|
fprintf (dump_file,
|
2846 |
|
|
"\nIF-THEN%s-JOIN block found, pass %d, test %d, then %d",
|
2847 |
|
|
(else_bb) ? "-ELSE" : "",
|
2848 |
|
|
pass, test_bb->index, then_bb->index);
|
2849 |
|
|
|
2850 |
|
|
if (else_bb)
|
2851 |
|
|
fprintf (dump_file, ", else %d", else_bb->index);
|
2852 |
|
|
|
2853 |
|
|
fprintf (dump_file, ", join %d\n", join_bb->index);
|
2854 |
|
|
}
|
2855 |
|
|
|
2856 |
|
|
/* If the conditional jump is more than just a conditional
|
2857 |
|
|
jump, then we can not do if-conversion on this block. */
|
2858 |
|
|
jump = BB_END (test_bb);
|
2859 |
|
|
if (! onlyjump_p (jump))
|
2860 |
|
|
return FALSE;
|
2861 |
|
|
|
2862 |
|
|
/* If this is not a standard conditional jump, we can't parse it. */
|
2863 |
|
|
cond = noce_get_condition (jump,
|
2864 |
|
|
&cond_earliest,
|
2865 |
|
|
then_else_reversed);
|
2866 |
|
|
if (!cond)
|
2867 |
|
|
return FALSE;
|
2868 |
|
|
|
2869 |
|
|
/* We must be comparing objects whose modes imply the size. */
|
2870 |
|
|
if (GET_MODE (XEXP (cond, 0)) == BLKmode)
|
2871 |
|
|
return FALSE;
|
2872 |
|
|
|
2873 |
|
|
/* Initialize an IF_INFO struct to pass around. */
|
2874 |
|
|
memset (&if_info, 0, sizeof if_info);
|
2875 |
|
|
if_info.test_bb = test_bb;
|
2876 |
|
|
if_info.then_bb = then_bb;
|
2877 |
|
|
if_info.else_bb = else_bb;
|
2878 |
|
|
if_info.join_bb = join_bb;
|
2879 |
|
|
if_info.cond = cond;
|
2880 |
|
|
if_info.cond_earliest = cond_earliest;
|
2881 |
|
|
if_info.jump = jump;
|
2882 |
|
|
if_info.then_else_reversed = then_else_reversed;
|
2883 |
|
|
if_info.branch_cost = BRANCH_COST (optimize_bb_for_speed_p (test_bb),
|
2884 |
|
|
predictable_edge_p (then_edge));
|
2885 |
|
|
|
2886 |
|
|
/* Do the real work. */
|
2887 |
|
|
|
2888 |
|
|
if (noce_process_if_block (&if_info))
|
2889 |
|
|
return TRUE;
|
2890 |
|
|
|
2891 |
|
|
if (HAVE_conditional_move
|
2892 |
|
|
&& cond_move_process_if_block (&if_info))
|
2893 |
|
|
return TRUE;
|
2894 |
|
|
|
2895 |
|
|
return FALSE;
|
2896 |
|
|
}
|
2897 |
|
|
|
2898 |
|
|
|
2899 |
|
|
/* Merge the blocks and mark for local life update. */
|
2900 |
|
|
|
2901 |
|
|
static void
|
2902 |
|
|
merge_if_block (struct ce_if_block * ce_info)
|
2903 |
|
|
{
|
2904 |
|
|
basic_block test_bb = ce_info->test_bb; /* last test block */
|
2905 |
|
|
basic_block then_bb = ce_info->then_bb; /* THEN */
|
2906 |
|
|
basic_block else_bb = ce_info->else_bb; /* ELSE or NULL */
|
2907 |
|
|
basic_block join_bb = ce_info->join_bb; /* join block */
|
2908 |
|
|
basic_block combo_bb;
|
2909 |
|
|
|
2910 |
|
|
/* All block merging is done into the lower block numbers. */
|
2911 |
|
|
|
2912 |
|
|
combo_bb = test_bb;
|
2913 |
|
|
df_set_bb_dirty (test_bb);
|
2914 |
|
|
|
2915 |
|
|
/* Merge any basic blocks to handle && and || subtests. Each of
|
2916 |
|
|
the blocks are on the fallthru path from the predecessor block. */
|
2917 |
|
|
if (ce_info->num_multiple_test_blocks > 0)
|
2918 |
|
|
{
|
2919 |
|
|
basic_block bb = test_bb;
|
2920 |
|
|
basic_block last_test_bb = ce_info->last_test_bb;
|
2921 |
|
|
basic_block fallthru = block_fallthru (bb);
|
2922 |
|
|
|
2923 |
|
|
do
|
2924 |
|
|
{
|
2925 |
|
|
bb = fallthru;
|
2926 |
|
|
fallthru = block_fallthru (bb);
|
2927 |
|
|
merge_blocks (combo_bb, bb);
|
2928 |
|
|
num_true_changes++;
|
2929 |
|
|
}
|
2930 |
|
|
while (bb != last_test_bb);
|
2931 |
|
|
}
|
2932 |
|
|
|
2933 |
|
|
/* Merge TEST block into THEN block. Normally the THEN block won't have a
|
2934 |
|
|
label, but it might if there were || tests. That label's count should be
|
2935 |
|
|
zero, and it normally should be removed. */
|
2936 |
|
|
|
2937 |
|
|
if (then_bb)
|
2938 |
|
|
{
|
2939 |
|
|
merge_blocks (combo_bb, then_bb);
|
2940 |
|
|
num_true_changes++;
|
2941 |
|
|
}
|
2942 |
|
|
|
2943 |
|
|
/* The ELSE block, if it existed, had a label. That label count
|
2944 |
|
|
will almost always be zero, but odd things can happen when labels
|
2945 |
|
|
get their addresses taken. */
|
2946 |
|
|
if (else_bb)
|
2947 |
|
|
{
|
2948 |
|
|
merge_blocks (combo_bb, else_bb);
|
2949 |
|
|
num_true_changes++;
|
2950 |
|
|
}
|
2951 |
|
|
|
2952 |
|
|
/* If there was no join block reported, that means it was not adjacent
|
2953 |
|
|
to the others, and so we cannot merge them. */
|
2954 |
|
|
|
2955 |
|
|
if (! join_bb)
|
2956 |
|
|
{
|
2957 |
|
|
rtx last = BB_END (combo_bb);
|
2958 |
|
|
|
2959 |
|
|
/* The outgoing edge for the current COMBO block should already
|
2960 |
|
|
be correct. Verify this. */
|
2961 |
|
|
if (EDGE_COUNT (combo_bb->succs) == 0)
|
2962 |
|
|
gcc_assert (find_reg_note (last, REG_NORETURN, NULL)
|
2963 |
|
|
|| (NONJUMP_INSN_P (last)
|
2964 |
|
|
&& GET_CODE (PATTERN (last)) == TRAP_IF
|
2965 |
|
|
&& (TRAP_CONDITION (PATTERN (last))
|
2966 |
|
|
== const_true_rtx)));
|
2967 |
|
|
|
2968 |
|
|
else
|
2969 |
|
|
/* There should still be something at the end of the THEN or ELSE
|
2970 |
|
|
blocks taking us to our final destination. */
|
2971 |
|
|
gcc_assert (JUMP_P (last)
|
2972 |
|
|
|| (EDGE_SUCC (combo_bb, 0)->dest == EXIT_BLOCK_PTR
|
2973 |
|
|
&& CALL_P (last)
|
2974 |
|
|
&& SIBLING_CALL_P (last))
|
2975 |
|
|
|| ((EDGE_SUCC (combo_bb, 0)->flags & EDGE_EH)
|
2976 |
|
|
&& can_throw_internal (last)));
|
2977 |
|
|
}
|
2978 |
|
|
|
2979 |
|
|
/* The JOIN block may have had quite a number of other predecessors too.
|
2980 |
|
|
Since we've already merged the TEST, THEN and ELSE blocks, we should
|
2981 |
|
|
have only one remaining edge from our if-then-else diamond. If there
|
2982 |
|
|
is more than one remaining edge, it must come from elsewhere. There
|
2983 |
|
|
may be zero incoming edges if the THEN block didn't actually join
|
2984 |
|
|
back up (as with a call to a non-return function). */
|
2985 |
|
|
else if (EDGE_COUNT (join_bb->preds) < 2
|
2986 |
|
|
&& join_bb != EXIT_BLOCK_PTR)
|
2987 |
|
|
{
|
2988 |
|
|
/* We can merge the JOIN cleanly and update the dataflow try
|
2989 |
|
|
again on this pass.*/
|
2990 |
|
|
merge_blocks (combo_bb, join_bb);
|
2991 |
|
|
num_true_changes++;
|
2992 |
|
|
}
|
2993 |
|
|
else
|
2994 |
|
|
{
|
2995 |
|
|
/* We cannot merge the JOIN. */
|
2996 |
|
|
|
2997 |
|
|
/* The outgoing edge for the current COMBO block should already
|
2998 |
|
|
be correct. Verify this. */
|
2999 |
|
|
gcc_assert (single_succ_p (combo_bb)
|
3000 |
|
|
&& single_succ (combo_bb) == join_bb);
|
3001 |
|
|
|
3002 |
|
|
/* Remove the jump and cruft from the end of the COMBO block. */
|
3003 |
|
|
if (join_bb != EXIT_BLOCK_PTR)
|
3004 |
|
|
tidy_fallthru_edge (single_succ_edge (combo_bb));
|
3005 |
|
|
}
|
3006 |
|
|
|
3007 |
|
|
num_updated_if_blocks++;
|
3008 |
|
|
}
|
3009 |
|
|
|
3010 |
|
|
/* Find a block ending in a simple IF condition and try to transform it
|
3011 |
|
|
in some way. When converting a multi-block condition, put the new code
|
3012 |
|
|
in the first such block and delete the rest. Return a pointer to this
|
3013 |
|
|
first block if some transformation was done. Return NULL otherwise. */
|
3014 |
|
|
|
3015 |
|
|
static basic_block
|
3016 |
|
|
find_if_header (basic_block test_bb, int pass)
|
3017 |
|
|
{
|
3018 |
|
|
ce_if_block_t ce_info;
|
3019 |
|
|
edge then_edge;
|
3020 |
|
|
edge else_edge;
|
3021 |
|
|
|
3022 |
|
|
/* The kind of block we're looking for has exactly two successors. */
|
3023 |
|
|
if (EDGE_COUNT (test_bb->succs) != 2)
|
3024 |
|
|
return NULL;
|
3025 |
|
|
|
3026 |
|
|
then_edge = EDGE_SUCC (test_bb, 0);
|
3027 |
|
|
else_edge = EDGE_SUCC (test_bb, 1);
|
3028 |
|
|
|
3029 |
|
|
if (df_get_bb_dirty (then_edge->dest))
|
3030 |
|
|
return NULL;
|
3031 |
|
|
if (df_get_bb_dirty (else_edge->dest))
|
3032 |
|
|
return NULL;
|
3033 |
|
|
|
3034 |
|
|
/* Neither edge should be abnormal. */
|
3035 |
|
|
if ((then_edge->flags & EDGE_COMPLEX)
|
3036 |
|
|
|| (else_edge->flags & EDGE_COMPLEX))
|
3037 |
|
|
return NULL;
|
3038 |
|
|
|
3039 |
|
|
/* Nor exit the loop. */
|
3040 |
|
|
if ((then_edge->flags & EDGE_LOOP_EXIT)
|
3041 |
|
|
|| (else_edge->flags & EDGE_LOOP_EXIT))
|
3042 |
|
|
return NULL;
|
3043 |
|
|
|
3044 |
|
|
/* The THEN edge is canonically the one that falls through. */
|
3045 |
|
|
if (then_edge->flags & EDGE_FALLTHRU)
|
3046 |
|
|
;
|
3047 |
|
|
else if (else_edge->flags & EDGE_FALLTHRU)
|
3048 |
|
|
{
|
3049 |
|
|
edge e = else_edge;
|
3050 |
|
|
else_edge = then_edge;
|
3051 |
|
|
then_edge = e;
|
3052 |
|
|
}
|
3053 |
|
|
else
|
3054 |
|
|
/* Otherwise this must be a multiway branch of some sort. */
|
3055 |
|
|
return NULL;
|
3056 |
|
|
|
3057 |
|
|
memset (&ce_info, '\0', sizeof (ce_info));
|
3058 |
|
|
ce_info.test_bb = test_bb;
|
3059 |
|
|
ce_info.then_bb = then_edge->dest;
|
3060 |
|
|
ce_info.else_bb = else_edge->dest;
|
3061 |
|
|
ce_info.pass = pass;
|
3062 |
|
|
|
3063 |
|
|
#ifdef IFCVT_INIT_EXTRA_FIELDS
|
3064 |
|
|
IFCVT_INIT_EXTRA_FIELDS (&ce_info);
|
3065 |
|
|
#endif
|
3066 |
|
|
|
3067 |
|
|
if (! reload_completed
|
3068 |
|
|
&& noce_find_if_block (test_bb, then_edge, else_edge, pass))
|
3069 |
|
|
goto success;
|
3070 |
|
|
|
3071 |
|
|
if (targetm.have_conditional_execution () && reload_completed
|
3072 |
|
|
&& cond_exec_find_if_block (&ce_info))
|
3073 |
|
|
goto success;
|
3074 |
|
|
|
3075 |
|
|
if (HAVE_trap
|
3076 |
|
|
&& optab_handler (ctrap_optab, word_mode)->insn_code != CODE_FOR_nothing
|
3077 |
|
|
&& find_cond_trap (test_bb, then_edge, else_edge))
|
3078 |
|
|
goto success;
|
3079 |
|
|
|
3080 |
|
|
if (dom_info_state (CDI_POST_DOMINATORS) >= DOM_NO_FAST_QUERY
|
3081 |
|
|
&& (! targetm.have_conditional_execution () || reload_completed))
|
3082 |
|
|
{
|
3083 |
|
|
if (find_if_case_1 (test_bb, then_edge, else_edge))
|
3084 |
|
|
goto success;
|
3085 |
|
|
if (find_if_case_2 (test_bb, then_edge, else_edge))
|
3086 |
|
|
goto success;
|
3087 |
|
|
}
|
3088 |
|
|
|
3089 |
|
|
return NULL;
|
3090 |
|
|
|
3091 |
|
|
success:
|
3092 |
|
|
if (dump_file)
|
3093 |
|
|
fprintf (dump_file, "Conversion succeeded on pass %d.\n", pass);
|
3094 |
|
|
/* Set this so we continue looking. */
|
3095 |
|
|
cond_exec_changed_p = TRUE;
|
3096 |
|
|
return ce_info.test_bb;
|
3097 |
|
|
}
|
3098 |
|
|
|
3099 |
|
|
/* Return true if a block has two edges, one of which falls through to the next
|
3100 |
|
|
block, and the other jumps to a specific block, so that we can tell if the
|
3101 |
|
|
block is part of an && test or an || test. Returns either -1 or the number
|
3102 |
|
|
of non-note, non-jump, non-USE/CLOBBER insns in the block. */
|
3103 |
|
|
|
3104 |
|
|
static int
|
3105 |
|
|
block_jumps_and_fallthru_p (basic_block cur_bb, basic_block target_bb)
|
3106 |
|
|
{
|
3107 |
|
|
edge cur_edge;
|
3108 |
|
|
int fallthru_p = FALSE;
|
3109 |
|
|
int jump_p = FALSE;
|
3110 |
|
|
rtx insn;
|
3111 |
|
|
rtx end;
|
3112 |
|
|
int n_insns = 0;
|
3113 |
|
|
edge_iterator ei;
|
3114 |
|
|
|
3115 |
|
|
if (!cur_bb || !target_bb)
|
3116 |
|
|
return -1;
|
3117 |
|
|
|
3118 |
|
|
/* If no edges, obviously it doesn't jump or fallthru. */
|
3119 |
|
|
if (EDGE_COUNT (cur_bb->succs) == 0)
|
3120 |
|
|
return FALSE;
|
3121 |
|
|
|
3122 |
|
|
FOR_EACH_EDGE (cur_edge, ei, cur_bb->succs)
|
3123 |
|
|
{
|
3124 |
|
|
if (cur_edge->flags & EDGE_COMPLEX)
|
3125 |
|
|
/* Anything complex isn't what we want. */
|
3126 |
|
|
return -1;
|
3127 |
|
|
|
3128 |
|
|
else if (cur_edge->flags & EDGE_FALLTHRU)
|
3129 |
|
|
fallthru_p = TRUE;
|
3130 |
|
|
|
3131 |
|
|
else if (cur_edge->dest == target_bb)
|
3132 |
|
|
jump_p = TRUE;
|
3133 |
|
|
|
3134 |
|
|
else
|
3135 |
|
|
return -1;
|
3136 |
|
|
}
|
3137 |
|
|
|
3138 |
|
|
if ((jump_p & fallthru_p) == 0)
|
3139 |
|
|
return -1;
|
3140 |
|
|
|
3141 |
|
|
/* Don't allow calls in the block, since this is used to group && and ||
|
3142 |
|
|
together for conditional execution support. ??? we should support
|
3143 |
|
|
conditional execution support across calls for IA-64 some day, but
|
3144 |
|
|
for now it makes the code simpler. */
|
3145 |
|
|
end = BB_END (cur_bb);
|
3146 |
|
|
insn = BB_HEAD (cur_bb);
|
3147 |
|
|
|
3148 |
|
|
while (insn != NULL_RTX)
|
3149 |
|
|
{
|
3150 |
|
|
if (CALL_P (insn))
|
3151 |
|
|
return -1;
|
3152 |
|
|
|
3153 |
|
|
if (INSN_P (insn)
|
3154 |
|
|
&& !JUMP_P (insn)
|
3155 |
|
|
&& !DEBUG_INSN_P (insn)
|
3156 |
|
|
&& GET_CODE (PATTERN (insn)) != USE
|
3157 |
|
|
&& GET_CODE (PATTERN (insn)) != CLOBBER)
|
3158 |
|
|
n_insns++;
|
3159 |
|
|
|
3160 |
|
|
if (insn == end)
|
3161 |
|
|
break;
|
3162 |
|
|
|
3163 |
|
|
insn = NEXT_INSN (insn);
|
3164 |
|
|
}
|
3165 |
|
|
|
3166 |
|
|
return n_insns;
|
3167 |
|
|
}
|
3168 |
|
|
|
3169 |
|
|
/* Determine if a given basic block heads a simple IF-THEN or IF-THEN-ELSE
|
3170 |
|
|
block. If so, we'll try to convert the insns to not require the branch.
|
3171 |
|
|
Return TRUE if we were successful at converting the block. */
|
3172 |
|
|
|
3173 |
|
|
static int
|
3174 |
|
|
cond_exec_find_if_block (struct ce_if_block * ce_info)
|
3175 |
|
|
{
|
3176 |
|
|
basic_block test_bb = ce_info->test_bb;
|
3177 |
|
|
basic_block then_bb = ce_info->then_bb;
|
3178 |
|
|
basic_block else_bb = ce_info->else_bb;
|
3179 |
|
|
basic_block join_bb = NULL_BLOCK;
|
3180 |
|
|
edge cur_edge;
|
3181 |
|
|
basic_block next;
|
3182 |
|
|
edge_iterator ei;
|
3183 |
|
|
|
3184 |
|
|
ce_info->last_test_bb = test_bb;
|
3185 |
|
|
|
3186 |
|
|
/* We only ever should get here after reload,
|
3187 |
|
|
and only if we have conditional execution. */
|
3188 |
|
|
gcc_assert (targetm.have_conditional_execution () && reload_completed);
|
3189 |
|
|
|
3190 |
|
|
/* Discover if any fall through predecessors of the current test basic block
|
3191 |
|
|
were && tests (which jump to the else block) or || tests (which jump to
|
3192 |
|
|
the then block). */
|
3193 |
|
|
if (single_pred_p (test_bb)
|
3194 |
|
|
&& single_pred_edge (test_bb)->flags == EDGE_FALLTHRU)
|
3195 |
|
|
{
|
3196 |
|
|
basic_block bb = single_pred (test_bb);
|
3197 |
|
|
basic_block target_bb;
|
3198 |
|
|
int max_insns = MAX_CONDITIONAL_EXECUTE;
|
3199 |
|
|
int n_insns;
|
3200 |
|
|
|
3201 |
|
|
/* Determine if the preceding block is an && or || block. */
|
3202 |
|
|
if ((n_insns = block_jumps_and_fallthru_p (bb, else_bb)) >= 0)
|
3203 |
|
|
{
|
3204 |
|
|
ce_info->and_and_p = TRUE;
|
3205 |
|
|
target_bb = else_bb;
|
3206 |
|
|
}
|
3207 |
|
|
else if ((n_insns = block_jumps_and_fallthru_p (bb, then_bb)) >= 0)
|
3208 |
|
|
{
|
3209 |
|
|
ce_info->and_and_p = FALSE;
|
3210 |
|
|
target_bb = then_bb;
|
3211 |
|
|
}
|
3212 |
|
|
else
|
3213 |
|
|
target_bb = NULL_BLOCK;
|
3214 |
|
|
|
3215 |
|
|
if (target_bb && n_insns <= max_insns)
|
3216 |
|
|
{
|
3217 |
|
|
int total_insns = 0;
|
3218 |
|
|
int blocks = 0;
|
3219 |
|
|
|
3220 |
|
|
ce_info->last_test_bb = test_bb;
|
3221 |
|
|
|
3222 |
|
|
/* Found at least one && or || block, look for more. */
|
3223 |
|
|
do
|
3224 |
|
|
{
|
3225 |
|
|
ce_info->test_bb = test_bb = bb;
|
3226 |
|
|
total_insns += n_insns;
|
3227 |
|
|
blocks++;
|
3228 |
|
|
|
3229 |
|
|
if (!single_pred_p (bb))
|
3230 |
|
|
break;
|
3231 |
|
|
|
3232 |
|
|
bb = single_pred (bb);
|
3233 |
|
|
n_insns = block_jumps_and_fallthru_p (bb, target_bb);
|
3234 |
|
|
}
|
3235 |
|
|
while (n_insns >= 0 && (total_insns + n_insns) <= max_insns);
|
3236 |
|
|
|
3237 |
|
|
ce_info->num_multiple_test_blocks = blocks;
|
3238 |
|
|
ce_info->num_multiple_test_insns = total_insns;
|
3239 |
|
|
|
3240 |
|
|
if (ce_info->and_and_p)
|
3241 |
|
|
ce_info->num_and_and_blocks = blocks;
|
3242 |
|
|
else
|
3243 |
|
|
ce_info->num_or_or_blocks = blocks;
|
3244 |
|
|
}
|
3245 |
|
|
}
|
3246 |
|
|
|
3247 |
|
|
/* The THEN block of an IF-THEN combo must have exactly one predecessor,
|
3248 |
|
|
other than any || blocks which jump to the THEN block. */
|
3249 |
|
|
if ((EDGE_COUNT (then_bb->preds) - ce_info->num_or_or_blocks) != 1)
|
3250 |
|
|
return FALSE;
|
3251 |
|
|
|
3252 |
|
|
/* The edges of the THEN and ELSE blocks cannot have complex edges. */
|
3253 |
|
|
FOR_EACH_EDGE (cur_edge, ei, then_bb->preds)
|
3254 |
|
|
{
|
3255 |
|
|
if (cur_edge->flags & EDGE_COMPLEX)
|
3256 |
|
|
return FALSE;
|
3257 |
|
|
}
|
3258 |
|
|
|
3259 |
|
|
FOR_EACH_EDGE (cur_edge, ei, else_bb->preds)
|
3260 |
|
|
{
|
3261 |
|
|
if (cur_edge->flags & EDGE_COMPLEX)
|
3262 |
|
|
return FALSE;
|
3263 |
|
|
}
|
3264 |
|
|
|
3265 |
|
|
/* The THEN block of an IF-THEN combo must have zero or one successors. */
|
3266 |
|
|
if (EDGE_COUNT (then_bb->succs) > 0
|
3267 |
|
|
&& (!single_succ_p (then_bb)
|
3268 |
|
|
|| (single_succ_edge (then_bb)->flags & EDGE_COMPLEX)
|
3269 |
|
|
|| (epilogue_completed && tablejump_p (BB_END (then_bb), NULL, NULL))))
|
3270 |
|
|
return FALSE;
|
3271 |
|
|
|
3272 |
|
|
/* If the THEN block has no successors, conditional execution can still
|
3273 |
|
|
make a conditional call. Don't do this unless the ELSE block has
|
3274 |
|
|
only one incoming edge -- the CFG manipulation is too ugly otherwise.
|
3275 |
|
|
Check for the last insn of the THEN block being an indirect jump, which
|
3276 |
|
|
is listed as not having any successors, but confuses the rest of the CE
|
3277 |
|
|
code processing. ??? we should fix this in the future. */
|
3278 |
|
|
if (EDGE_COUNT (then_bb->succs) == 0)
|
3279 |
|
|
{
|
3280 |
|
|
if (single_pred_p (else_bb))
|
3281 |
|
|
{
|
3282 |
|
|
rtx last_insn = BB_END (then_bb);
|
3283 |
|
|
|
3284 |
|
|
while (last_insn
|
3285 |
|
|
&& NOTE_P (last_insn)
|
3286 |
|
|
&& last_insn != BB_HEAD (then_bb))
|
3287 |
|
|
last_insn = PREV_INSN (last_insn);
|
3288 |
|
|
|
3289 |
|
|
if (last_insn
|
3290 |
|
|
&& JUMP_P (last_insn)
|
3291 |
|
|
&& ! simplejump_p (last_insn))
|
3292 |
|
|
return FALSE;
|
3293 |
|
|
|
3294 |
|
|
join_bb = else_bb;
|
3295 |
|
|
else_bb = NULL_BLOCK;
|
3296 |
|
|
}
|
3297 |
|
|
else
|
3298 |
|
|
return FALSE;
|
3299 |
|
|
}
|
3300 |
|
|
|
3301 |
|
|
/* If the THEN block's successor is the other edge out of the TEST block,
|
3302 |
|
|
then we have an IF-THEN combo without an ELSE. */
|
3303 |
|
|
else if (single_succ (then_bb) == else_bb)
|
3304 |
|
|
{
|
3305 |
|
|
join_bb = else_bb;
|
3306 |
|
|
else_bb = NULL_BLOCK;
|
3307 |
|
|
}
|
3308 |
|
|
|
3309 |
|
|
/* If the THEN and ELSE block meet in a subsequent block, and the ELSE
|
3310 |
|
|
has exactly one predecessor and one successor, and the outgoing edge
|
3311 |
|
|
is not complex, then we have an IF-THEN-ELSE combo. */
|
3312 |
|
|
else if (single_succ_p (else_bb)
|
3313 |
|
|
&& single_succ (then_bb) == single_succ (else_bb)
|
3314 |
|
|
&& single_pred_p (else_bb)
|
3315 |
|
|
&& ! (single_succ_edge (else_bb)->flags & EDGE_COMPLEX)
|
3316 |
|
|
&& ! (epilogue_completed && tablejump_p (BB_END (else_bb), NULL, NULL)))
|
3317 |
|
|
join_bb = single_succ (else_bb);
|
3318 |
|
|
|
3319 |
|
|
/* Otherwise it is not an IF-THEN or IF-THEN-ELSE combination. */
|
3320 |
|
|
else
|
3321 |
|
|
return FALSE;
|
3322 |
|
|
|
3323 |
|
|
num_possible_if_blocks++;
|
3324 |
|
|
|
3325 |
|
|
if (dump_file)
|
3326 |
|
|
{
|
3327 |
|
|
fprintf (dump_file,
|
3328 |
|
|
"\nIF-THEN%s block found, pass %d, start block %d "
|
3329 |
|
|
"[insn %d], then %d [%d]",
|
3330 |
|
|
(else_bb) ? "-ELSE" : "",
|
3331 |
|
|
ce_info->pass,
|
3332 |
|
|
test_bb->index,
|
3333 |
|
|
BB_HEAD (test_bb) ? (int)INSN_UID (BB_HEAD (test_bb)) : -1,
|
3334 |
|
|
then_bb->index,
|
3335 |
|
|
BB_HEAD (then_bb) ? (int)INSN_UID (BB_HEAD (then_bb)) : -1);
|
3336 |
|
|
|
3337 |
|
|
if (else_bb)
|
3338 |
|
|
fprintf (dump_file, ", else %d [%d]",
|
3339 |
|
|
else_bb->index,
|
3340 |
|
|
BB_HEAD (else_bb) ? (int)INSN_UID (BB_HEAD (else_bb)) : -1);
|
3341 |
|
|
|
3342 |
|
|
fprintf (dump_file, ", join %d [%d]",
|
3343 |
|
|
join_bb->index,
|
3344 |
|
|
BB_HEAD (join_bb) ? (int)INSN_UID (BB_HEAD (join_bb)) : -1);
|
3345 |
|
|
|
3346 |
|
|
if (ce_info->num_multiple_test_blocks > 0)
|
3347 |
|
|
fprintf (dump_file, ", %d %s block%s last test %d [%d]",
|
3348 |
|
|
ce_info->num_multiple_test_blocks,
|
3349 |
|
|
(ce_info->and_and_p) ? "&&" : "||",
|
3350 |
|
|
(ce_info->num_multiple_test_blocks == 1) ? "" : "s",
|
3351 |
|
|
ce_info->last_test_bb->index,
|
3352 |
|
|
((BB_HEAD (ce_info->last_test_bb))
|
3353 |
|
|
? (int)INSN_UID (BB_HEAD (ce_info->last_test_bb))
|
3354 |
|
|
: -1));
|
3355 |
|
|
|
3356 |
|
|
fputc ('\n', dump_file);
|
3357 |
|
|
}
|
3358 |
|
|
|
3359 |
|
|
/* Make sure IF, THEN, and ELSE, blocks are adjacent. Actually, we get the
|
3360 |
|
|
first condition for free, since we've already asserted that there's a
|
3361 |
|
|
fallthru edge from IF to THEN. Likewise for the && and || blocks, since
|
3362 |
|
|
we checked the FALLTHRU flag, those are already adjacent to the last IF
|
3363 |
|
|
block. */
|
3364 |
|
|
/* ??? As an enhancement, move the ELSE block. Have to deal with
|
3365 |
|
|
BLOCK notes, if by no other means than backing out the merge if they
|
3366 |
|
|
exist. Sticky enough I don't want to think about it now. */
|
3367 |
|
|
next = then_bb;
|
3368 |
|
|
if (else_bb && (next = next->next_bb) != else_bb)
|
3369 |
|
|
return FALSE;
|
3370 |
|
|
if ((next = next->next_bb) != join_bb && join_bb != EXIT_BLOCK_PTR)
|
3371 |
|
|
{
|
3372 |
|
|
if (else_bb)
|
3373 |
|
|
join_bb = NULL;
|
3374 |
|
|
else
|
3375 |
|
|
return FALSE;
|
3376 |
|
|
}
|
3377 |
|
|
|
3378 |
|
|
/* Do the real work. */
|
3379 |
|
|
|
3380 |
|
|
ce_info->else_bb = else_bb;
|
3381 |
|
|
ce_info->join_bb = join_bb;
|
3382 |
|
|
|
3383 |
|
|
/* If we have && and || tests, try to first handle combining the && and ||
|
3384 |
|
|
tests into the conditional code, and if that fails, go back and handle
|
3385 |
|
|
it without the && and ||, which at present handles the && case if there
|
3386 |
|
|
was no ELSE block. */
|
3387 |
|
|
if (cond_exec_process_if_block (ce_info, TRUE))
|
3388 |
|
|
return TRUE;
|
3389 |
|
|
|
3390 |
|
|
if (ce_info->num_multiple_test_blocks)
|
3391 |
|
|
{
|
3392 |
|
|
cancel_changes (0);
|
3393 |
|
|
|
3394 |
|
|
if (cond_exec_process_if_block (ce_info, FALSE))
|
3395 |
|
|
return TRUE;
|
3396 |
|
|
}
|
3397 |
|
|
|
3398 |
|
|
return FALSE;
|
3399 |
|
|
}
|
3400 |
|
|
|
3401 |
|
|
/* Convert a branch over a trap, or a branch
|
3402 |
|
|
to a trap, into a conditional trap. */
|
3403 |
|
|
|
3404 |
|
|
static int
|
3405 |
|
|
find_cond_trap (basic_block test_bb, edge then_edge, edge else_edge)
|
3406 |
|
|
{
|
3407 |
|
|
basic_block then_bb = then_edge->dest;
|
3408 |
|
|
basic_block else_bb = else_edge->dest;
|
3409 |
|
|
basic_block other_bb, trap_bb;
|
3410 |
|
|
rtx trap, jump, cond, cond_earliest, seq;
|
3411 |
|
|
enum rtx_code code;
|
3412 |
|
|
|
3413 |
|
|
/* Locate the block with the trap instruction. */
|
3414 |
|
|
/* ??? While we look for no successors, we really ought to allow
|
3415 |
|
|
EH successors. Need to fix merge_if_block for that to work. */
|
3416 |
|
|
if ((trap = block_has_only_trap (then_bb)) != NULL)
|
3417 |
|
|
trap_bb = then_bb, other_bb = else_bb;
|
3418 |
|
|
else if ((trap = block_has_only_trap (else_bb)) != NULL)
|
3419 |
|
|
trap_bb = else_bb, other_bb = then_bb;
|
3420 |
|
|
else
|
3421 |
|
|
return FALSE;
|
3422 |
|
|
|
3423 |
|
|
if (dump_file)
|
3424 |
|
|
{
|
3425 |
|
|
fprintf (dump_file, "\nTRAP-IF block found, start %d, trap %d\n",
|
3426 |
|
|
test_bb->index, trap_bb->index);
|
3427 |
|
|
}
|
3428 |
|
|
|
3429 |
|
|
/* If this is not a standard conditional jump, we can't parse it. */
|
3430 |
|
|
jump = BB_END (test_bb);
|
3431 |
|
|
cond = noce_get_condition (jump, &cond_earliest, false);
|
3432 |
|
|
if (! cond)
|
3433 |
|
|
return FALSE;
|
3434 |
|
|
|
3435 |
|
|
/* If the conditional jump is more than just a conditional jump, then
|
3436 |
|
|
we can not do if-conversion on this block. */
|
3437 |
|
|
if (! onlyjump_p (jump))
|
3438 |
|
|
return FALSE;
|
3439 |
|
|
|
3440 |
|
|
/* We must be comparing objects whose modes imply the size. */
|
3441 |
|
|
if (GET_MODE (XEXP (cond, 0)) == BLKmode)
|
3442 |
|
|
return FALSE;
|
3443 |
|
|
|
3444 |
|
|
/* Reverse the comparison code, if necessary. */
|
3445 |
|
|
code = GET_CODE (cond);
|
3446 |
|
|
if (then_bb == trap_bb)
|
3447 |
|
|
{
|
3448 |
|
|
code = reversed_comparison_code (cond, jump);
|
3449 |
|
|
if (code == UNKNOWN)
|
3450 |
|
|
return FALSE;
|
3451 |
|
|
}
|
3452 |
|
|
|
3453 |
|
|
/* Attempt to generate the conditional trap. */
|
3454 |
|
|
seq = gen_cond_trap (code, copy_rtx (XEXP (cond, 0)),
|
3455 |
|
|
copy_rtx (XEXP (cond, 1)),
|
3456 |
|
|
TRAP_CODE (PATTERN (trap)));
|
3457 |
|
|
if (seq == NULL)
|
3458 |
|
|
return FALSE;
|
3459 |
|
|
|
3460 |
|
|
/* Emit the new insns before cond_earliest. */
|
3461 |
|
|
emit_insn_before_setloc (seq, cond_earliest, INSN_LOCATOR (trap));
|
3462 |
|
|
|
3463 |
|
|
/* Delete the trap block if possible. */
|
3464 |
|
|
remove_edge (trap_bb == then_bb ? then_edge : else_edge);
|
3465 |
|
|
df_set_bb_dirty (test_bb);
|
3466 |
|
|
df_set_bb_dirty (then_bb);
|
3467 |
|
|
df_set_bb_dirty (else_bb);
|
3468 |
|
|
|
3469 |
|
|
if (EDGE_COUNT (trap_bb->preds) == 0)
|
3470 |
|
|
{
|
3471 |
|
|
delete_basic_block (trap_bb);
|
3472 |
|
|
num_true_changes++;
|
3473 |
|
|
}
|
3474 |
|
|
|
3475 |
|
|
/* Wire together the blocks again. */
|
3476 |
|
|
if (current_ir_type () == IR_RTL_CFGLAYOUT)
|
3477 |
|
|
single_succ_edge (test_bb)->flags |= EDGE_FALLTHRU;
|
3478 |
|
|
else
|
3479 |
|
|
{
|
3480 |
|
|
rtx lab, newjump;
|
3481 |
|
|
|
3482 |
|
|
lab = JUMP_LABEL (jump);
|
3483 |
|
|
newjump = emit_jump_insn_after (gen_jump (lab), jump);
|
3484 |
|
|
LABEL_NUSES (lab) += 1;
|
3485 |
|
|
JUMP_LABEL (newjump) = lab;
|
3486 |
|
|
emit_barrier_after (newjump);
|
3487 |
|
|
}
|
3488 |
|
|
delete_insn (jump);
|
3489 |
|
|
|
3490 |
|
|
if (can_merge_blocks_p (test_bb, other_bb))
|
3491 |
|
|
{
|
3492 |
|
|
merge_blocks (test_bb, other_bb);
|
3493 |
|
|
num_true_changes++;
|
3494 |
|
|
}
|
3495 |
|
|
|
3496 |
|
|
num_updated_if_blocks++;
|
3497 |
|
|
return TRUE;
|
3498 |
|
|
}
|
3499 |
|
|
|
3500 |
|
|
/* Subroutine of find_cond_trap: if BB contains only a trap insn,
|
3501 |
|
|
return it. */
|
3502 |
|
|
|
3503 |
|
|
static rtx
|
3504 |
|
|
block_has_only_trap (basic_block bb)
|
3505 |
|
|
{
|
3506 |
|
|
rtx trap;
|
3507 |
|
|
|
3508 |
|
|
/* We're not the exit block. */
|
3509 |
|
|
if (bb == EXIT_BLOCK_PTR)
|
3510 |
|
|
return NULL_RTX;
|
3511 |
|
|
|
3512 |
|
|
/* The block must have no successors. */
|
3513 |
|
|
if (EDGE_COUNT (bb->succs) > 0)
|
3514 |
|
|
return NULL_RTX;
|
3515 |
|
|
|
3516 |
|
|
/* The only instruction in the THEN block must be the trap. */
|
3517 |
|
|
trap = first_active_insn (bb);
|
3518 |
|
|
if (! (trap == BB_END (bb)
|
3519 |
|
|
&& GET_CODE (PATTERN (trap)) == TRAP_IF
|
3520 |
|
|
&& TRAP_CONDITION (PATTERN (trap)) == const_true_rtx))
|
3521 |
|
|
return NULL_RTX;
|
3522 |
|
|
|
3523 |
|
|
return trap;
|
3524 |
|
|
}
|
3525 |
|
|
|
3526 |
|
|
/* Look for IF-THEN-ELSE cases in which one of THEN or ELSE is
|
3527 |
|
|
transformable, but not necessarily the other. There need be no
|
3528 |
|
|
JOIN block.
|
3529 |
|
|
|
3530 |
|
|
Return TRUE if we were successful at converting the block.
|
3531 |
|
|
|
3532 |
|
|
Cases we'd like to look at:
|
3533 |
|
|
|
3534 |
|
|
(1)
|
3535 |
|
|
if (test) goto over; // x not live
|
3536 |
|
|
x = a;
|
3537 |
|
|
goto label;
|
3538 |
|
|
over:
|
3539 |
|
|
|
3540 |
|
|
becomes
|
3541 |
|
|
|
3542 |
|
|
x = a;
|
3543 |
|
|
if (! test) goto label;
|
3544 |
|
|
|
3545 |
|
|
(2)
|
3546 |
|
|
if (test) goto E; // x not live
|
3547 |
|
|
x = big();
|
3548 |
|
|
goto L;
|
3549 |
|
|
E:
|
3550 |
|
|
x = b;
|
3551 |
|
|
goto M;
|
3552 |
|
|
|
3553 |
|
|
becomes
|
3554 |
|
|
|
3555 |
|
|
x = b;
|
3556 |
|
|
if (test) goto M;
|
3557 |
|
|
x = big();
|
3558 |
|
|
goto L;
|
3559 |
|
|
|
3560 |
|
|
(3) // This one's really only interesting for targets that can do
|
3561 |
|
|
// multiway branching, e.g. IA-64 BBB bundles. For other targets
|
3562 |
|
|
// it results in multiple branches on a cache line, which often
|
3563 |
|
|
// does not sit well with predictors.
|
3564 |
|
|
|
3565 |
|
|
if (test1) goto E; // predicted not taken
|
3566 |
|
|
x = a;
|
3567 |
|
|
if (test2) goto F;
|
3568 |
|
|
...
|
3569 |
|
|
E:
|
3570 |
|
|
x = b;
|
3571 |
|
|
J:
|
3572 |
|
|
|
3573 |
|
|
becomes
|
3574 |
|
|
|
3575 |
|
|
x = a;
|
3576 |
|
|
if (test1) goto E;
|
3577 |
|
|
if (test2) goto F;
|
3578 |
|
|
|
3579 |
|
|
Notes:
|
3580 |
|
|
|
3581 |
|
|
(A) Don't do (2) if the branch is predicted against the block we're
|
3582 |
|
|
eliminating. Do it anyway if we can eliminate a branch; this requires
|
3583 |
|
|
that the sole successor of the eliminated block postdominate the other
|
3584 |
|
|
side of the if.
|
3585 |
|
|
|
3586 |
|
|
(B) With CE, on (3) we can steal from both sides of the if, creating
|
3587 |
|
|
|
3588 |
|
|
if (test1) x = a;
|
3589 |
|
|
if (!test1) x = b;
|
3590 |
|
|
if (test1) goto J;
|
3591 |
|
|
if (test2) goto F;
|
3592 |
|
|
...
|
3593 |
|
|
J:
|
3594 |
|
|
|
3595 |
|
|
Again, this is most useful if J postdominates.
|
3596 |
|
|
|
3597 |
|
|
(C) CE substitutes for helpful life information.
|
3598 |
|
|
|
3599 |
|
|
(D) These heuristics need a lot of work. */
|
3600 |
|
|
|
3601 |
|
|
/* Tests for case 1 above. */
|
3602 |
|
|
|
3603 |
|
|
static int
|
3604 |
|
|
find_if_case_1 (basic_block test_bb, edge then_edge, edge else_edge)
|
3605 |
|
|
{
|
3606 |
|
|
basic_block then_bb = then_edge->dest;
|
3607 |
|
|
basic_block else_bb = else_edge->dest;
|
3608 |
|
|
basic_block new_bb;
|
3609 |
|
|
int then_bb_index;
|
3610 |
|
|
|
3611 |
|
|
/* If we are partitioning hot/cold basic blocks, we don't want to
|
3612 |
|
|
mess up unconditional or indirect jumps that cross between hot
|
3613 |
|
|
and cold sections.
|
3614 |
|
|
|
3615 |
|
|
Basic block partitioning may result in some jumps that appear to
|
3616 |
|
|
be optimizable (or blocks that appear to be mergeable), but which really
|
3617 |
|
|
must be left untouched (they are required to make it safely across
|
3618 |
|
|
partition boundaries). See the comments at the top of
|
3619 |
|
|
bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
|
3620 |
|
|
|
3621 |
|
|
if ((BB_END (then_bb)
|
3622 |
|
|
&& find_reg_note (BB_END (then_bb), REG_CROSSING_JUMP, NULL_RTX))
|
3623 |
|
|
|| (BB_END (test_bb)
|
3624 |
|
|
&& find_reg_note (BB_END (test_bb), REG_CROSSING_JUMP, NULL_RTX))
|
3625 |
|
|
|| (BB_END (else_bb)
|
3626 |
|
|
&& find_reg_note (BB_END (else_bb), REG_CROSSING_JUMP,
|
3627 |
|
|
NULL_RTX)))
|
3628 |
|
|
return FALSE;
|
3629 |
|
|
|
3630 |
|
|
/* THEN has one successor. */
|
3631 |
|
|
if (!single_succ_p (then_bb))
|
3632 |
|
|
return FALSE;
|
3633 |
|
|
|
3634 |
|
|
/* THEN does not fall through, but is not strange either. */
|
3635 |
|
|
if (single_succ_edge (then_bb)->flags & (EDGE_COMPLEX | EDGE_FALLTHRU))
|
3636 |
|
|
return FALSE;
|
3637 |
|
|
|
3638 |
|
|
/* THEN has one predecessor. */
|
3639 |
|
|
if (!single_pred_p (then_bb))
|
3640 |
|
|
return FALSE;
|
3641 |
|
|
|
3642 |
|
|
/* THEN must do something. */
|
3643 |
|
|
if (forwarder_block_p (then_bb))
|
3644 |
|
|
return FALSE;
|
3645 |
|
|
|
3646 |
|
|
num_possible_if_blocks++;
|
3647 |
|
|
if (dump_file)
|
3648 |
|
|
fprintf (dump_file,
|
3649 |
|
|
"\nIF-CASE-1 found, start %d, then %d\n",
|
3650 |
|
|
test_bb->index, then_bb->index);
|
3651 |
|
|
|
3652 |
|
|
/* THEN is small. */
|
3653 |
|
|
if (! cheap_bb_rtx_cost_p (then_bb,
|
3654 |
|
|
COSTS_N_INSNS (BRANCH_COST (optimize_bb_for_speed_p (then_edge->src),
|
3655 |
|
|
predictable_edge_p (then_edge)))))
|
3656 |
|
|
return FALSE;
|
3657 |
|
|
|
3658 |
|
|
/* Registers set are dead, or are predicable. */
|
3659 |
|
|
if (! dead_or_predicable (test_bb, then_bb, else_bb,
|
3660 |
|
|
single_succ (then_bb), 1))
|
3661 |
|
|
return FALSE;
|
3662 |
|
|
|
3663 |
|
|
/* Conversion went ok, including moving the insns and fixing up the
|
3664 |
|
|
jump. Adjust the CFG to match. */
|
3665 |
|
|
|
3666 |
|
|
/* We can avoid creating a new basic block if then_bb is immediately
|
3667 |
|
|
followed by else_bb, i.e. deleting then_bb allows test_bb to fall
|
3668 |
|
|
thru to else_bb. */
|
3669 |
|
|
|
3670 |
|
|
if (then_bb->next_bb == else_bb
|
3671 |
|
|
&& then_bb->prev_bb == test_bb
|
3672 |
|
|
&& else_bb != EXIT_BLOCK_PTR)
|
3673 |
|
|
{
|
3674 |
|
|
redirect_edge_succ (FALLTHRU_EDGE (test_bb), else_bb);
|
3675 |
|
|
new_bb = 0;
|
3676 |
|
|
}
|
3677 |
|
|
else
|
3678 |
|
|
new_bb = redirect_edge_and_branch_force (FALLTHRU_EDGE (test_bb),
|
3679 |
|
|
else_bb);
|
3680 |
|
|
|
3681 |
|
|
df_set_bb_dirty (test_bb);
|
3682 |
|
|
df_set_bb_dirty (else_bb);
|
3683 |
|
|
|
3684 |
|
|
then_bb_index = then_bb->index;
|
3685 |
|
|
delete_basic_block (then_bb);
|
3686 |
|
|
|
3687 |
|
|
/* Make rest of code believe that the newly created block is the THEN_BB
|
3688 |
|
|
block we removed. */
|
3689 |
|
|
if (new_bb)
|
3690 |
|
|
{
|
3691 |
|
|
df_bb_replace (then_bb_index, new_bb);
|
3692 |
|
|
/* Since the fallthru edge was redirected from test_bb to new_bb,
|
3693 |
|
|
we need to ensure that new_bb is in the same partition as
|
3694 |
|
|
test bb (you can not fall through across section boundaries). */
|
3695 |
|
|
BB_COPY_PARTITION (new_bb, test_bb);
|
3696 |
|
|
}
|
3697 |
|
|
|
3698 |
|
|
num_true_changes++;
|
3699 |
|
|
num_updated_if_blocks++;
|
3700 |
|
|
|
3701 |
|
|
return TRUE;
|
3702 |
|
|
}
|
3703 |
|
|
|
3704 |
|
|
/* Test for case 2 above. */
|
3705 |
|
|
|
3706 |
|
|
static int
|
3707 |
|
|
find_if_case_2 (basic_block test_bb, edge then_edge, edge else_edge)
|
3708 |
|
|
{
|
3709 |
|
|
basic_block then_bb = then_edge->dest;
|
3710 |
|
|
basic_block else_bb = else_edge->dest;
|
3711 |
|
|
edge else_succ;
|
3712 |
|
|
rtx note;
|
3713 |
|
|
|
3714 |
|
|
/* If we are partitioning hot/cold basic blocks, we don't want to
|
3715 |
|
|
mess up unconditional or indirect jumps that cross between hot
|
3716 |
|
|
and cold sections.
|
3717 |
|
|
|
3718 |
|
|
Basic block partitioning may result in some jumps that appear to
|
3719 |
|
|
be optimizable (or blocks that appear to be mergeable), but which really
|
3720 |
|
|
must be left untouched (they are required to make it safely across
|
3721 |
|
|
partition boundaries). See the comments at the top of
|
3722 |
|
|
bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
|
3723 |
|
|
|
3724 |
|
|
if ((BB_END (then_bb)
|
3725 |
|
|
&& find_reg_note (BB_END (then_bb), REG_CROSSING_JUMP, NULL_RTX))
|
3726 |
|
|
|| (BB_END (test_bb)
|
3727 |
|
|
&& find_reg_note (BB_END (test_bb), REG_CROSSING_JUMP, NULL_RTX))
|
3728 |
|
|
|| (BB_END (else_bb)
|
3729 |
|
|
&& find_reg_note (BB_END (else_bb), REG_CROSSING_JUMP,
|
3730 |
|
|
NULL_RTX)))
|
3731 |
|
|
return FALSE;
|
3732 |
|
|
|
3733 |
|
|
/* ELSE has one successor. */
|
3734 |
|
|
if (!single_succ_p (else_bb))
|
3735 |
|
|
return FALSE;
|
3736 |
|
|
else
|
3737 |
|
|
else_succ = single_succ_edge (else_bb);
|
3738 |
|
|
|
3739 |
|
|
/* ELSE outgoing edge is not complex. */
|
3740 |
|
|
if (else_succ->flags & EDGE_COMPLEX)
|
3741 |
|
|
return FALSE;
|
3742 |
|
|
|
3743 |
|
|
/* ELSE has one predecessor. */
|
3744 |
|
|
if (!single_pred_p (else_bb))
|
3745 |
|
|
return FALSE;
|
3746 |
|
|
|
3747 |
|
|
/* THEN is not EXIT. */
|
3748 |
|
|
if (then_bb->index < NUM_FIXED_BLOCKS)
|
3749 |
|
|
return FALSE;
|
3750 |
|
|
|
3751 |
|
|
/* ELSE is predicted or SUCC(ELSE) postdominates THEN. */
|
3752 |
|
|
note = find_reg_note (BB_END (test_bb), REG_BR_PROB, NULL_RTX);
|
3753 |
|
|
if (note && INTVAL (XEXP (note, 0)) >= REG_BR_PROB_BASE / 2)
|
3754 |
|
|
;
|
3755 |
|
|
else if (else_succ->dest->index < NUM_FIXED_BLOCKS
|
3756 |
|
|
|| dominated_by_p (CDI_POST_DOMINATORS, then_bb,
|
3757 |
|
|
else_succ->dest))
|
3758 |
|
|
;
|
3759 |
|
|
else
|
3760 |
|
|
return FALSE;
|
3761 |
|
|
|
3762 |
|
|
num_possible_if_blocks++;
|
3763 |
|
|
if (dump_file)
|
3764 |
|
|
fprintf (dump_file,
|
3765 |
|
|
"\nIF-CASE-2 found, start %d, else %d\n",
|
3766 |
|
|
test_bb->index, else_bb->index);
|
3767 |
|
|
|
3768 |
|
|
/* ELSE is small. */
|
3769 |
|
|
if (! cheap_bb_rtx_cost_p (else_bb,
|
3770 |
|
|
COSTS_N_INSNS (BRANCH_COST (optimize_bb_for_speed_p (else_edge->src),
|
3771 |
|
|
predictable_edge_p (else_edge)))))
|
3772 |
|
|
return FALSE;
|
3773 |
|
|
|
3774 |
|
|
/* Registers set are dead, or are predicable. */
|
3775 |
|
|
if (! dead_or_predicable (test_bb, else_bb, then_bb, else_succ->dest, 0))
|
3776 |
|
|
return FALSE;
|
3777 |
|
|
|
3778 |
|
|
/* Conversion went ok, including moving the insns and fixing up the
|
3779 |
|
|
jump. Adjust the CFG to match. */
|
3780 |
|
|
|
3781 |
|
|
df_set_bb_dirty (test_bb);
|
3782 |
|
|
df_set_bb_dirty (then_bb);
|
3783 |
|
|
delete_basic_block (else_bb);
|
3784 |
|
|
|
3785 |
|
|
num_true_changes++;
|
3786 |
|
|
num_updated_if_blocks++;
|
3787 |
|
|
|
3788 |
|
|
/* ??? We may now fallthru from one of THEN's successors into a join
|
3789 |
|
|
block. Rerun cleanup_cfg? Examine things manually? Wait? */
|
3790 |
|
|
|
3791 |
|
|
return TRUE;
|
3792 |
|
|
}
|
3793 |
|
|
|
3794 |
|
|
/* A subroutine of dead_or_predicable called through for_each_rtx.
|
3795 |
|
|
Return 1 if a memory is found. */
|
3796 |
|
|
|
3797 |
|
|
static int
|
3798 |
|
|
find_memory (rtx *px, void *data ATTRIBUTE_UNUSED)
|
3799 |
|
|
{
|
3800 |
|
|
return MEM_P (*px);
|
3801 |
|
|
}
|
3802 |
|
|
|
3803 |
|
|
/* Used by the code above to perform the actual rtl transformations.
|
3804 |
|
|
Return TRUE if successful.
|
3805 |
|
|
|
3806 |
|
|
TEST_BB is the block containing the conditional branch. MERGE_BB
|
3807 |
|
|
is the block containing the code to manipulate. NEW_DEST is the
|
3808 |
|
|
label TEST_BB should be branching to after the conversion.
|
3809 |
|
|
REVERSEP is true if the sense of the branch should be reversed. */
|
3810 |
|
|
|
3811 |
|
|
static int
|
3812 |
|
|
dead_or_predicable (basic_block test_bb, basic_block merge_bb,
|
3813 |
|
|
basic_block other_bb, basic_block new_dest, int reversep)
|
3814 |
|
|
{
|
3815 |
|
|
rtx head, end, jump, earliest = NULL_RTX, old_dest, new_label = NULL_RTX;
|
3816 |
|
|
/* Number of pending changes. */
|
3817 |
|
|
int n_validated_changes = 0;
|
3818 |
|
|
|
3819 |
|
|
jump = BB_END (test_bb);
|
3820 |
|
|
|
3821 |
|
|
/* Find the extent of the real code in the merge block. */
|
3822 |
|
|
head = BB_HEAD (merge_bb);
|
3823 |
|
|
end = BB_END (merge_bb);
|
3824 |
|
|
|
3825 |
|
|
while (DEBUG_INSN_P (end) && end != head)
|
3826 |
|
|
end = PREV_INSN (end);
|
3827 |
|
|
|
3828 |
|
|
/* If merge_bb ends with a tablejump, predicating/moving insn's
|
3829 |
|
|
into test_bb and then deleting merge_bb will result in the jumptable
|
3830 |
|
|
that follows merge_bb being removed along with merge_bb and then we
|
3831 |
|
|
get an unresolved reference to the jumptable. */
|
3832 |
|
|
if (tablejump_p (end, NULL, NULL))
|
3833 |
|
|
return FALSE;
|
3834 |
|
|
|
3835 |
|
|
if (LABEL_P (head))
|
3836 |
|
|
head = NEXT_INSN (head);
|
3837 |
|
|
while (DEBUG_INSN_P (head) && head != end)
|
3838 |
|
|
head = NEXT_INSN (head);
|
3839 |
|
|
if (NOTE_P (head))
|
3840 |
|
|
{
|
3841 |
|
|
if (head == end)
|
3842 |
|
|
{
|
3843 |
|
|
head = end = NULL_RTX;
|
3844 |
|
|
goto no_body;
|
3845 |
|
|
}
|
3846 |
|
|
head = NEXT_INSN (head);
|
3847 |
|
|
while (DEBUG_INSN_P (head) && head != end)
|
3848 |
|
|
head = NEXT_INSN (head);
|
3849 |
|
|
}
|
3850 |
|
|
|
3851 |
|
|
if (JUMP_P (end))
|
3852 |
|
|
{
|
3853 |
|
|
if (head == end)
|
3854 |
|
|
{
|
3855 |
|
|
head = end = NULL_RTX;
|
3856 |
|
|
goto no_body;
|
3857 |
|
|
}
|
3858 |
|
|
end = PREV_INSN (end);
|
3859 |
|
|
while (DEBUG_INSN_P (end) && end != head)
|
3860 |
|
|
end = PREV_INSN (end);
|
3861 |
|
|
}
|
3862 |
|
|
|
3863 |
|
|
/* Disable handling dead code by conditional execution if the machine needs
|
3864 |
|
|
to do anything funny with the tests, etc. */
|
3865 |
|
|
#ifndef IFCVT_MODIFY_TESTS
|
3866 |
|
|
if (targetm.have_conditional_execution ())
|
3867 |
|
|
{
|
3868 |
|
|
/* In the conditional execution case, we have things easy. We know
|
3869 |
|
|
the condition is reversible. We don't have to check life info
|
3870 |
|
|
because we're going to conditionally execute the code anyway.
|
3871 |
|
|
All that's left is making sure the insns involved can actually
|
3872 |
|
|
be predicated. */
|
3873 |
|
|
|
3874 |
|
|
rtx cond, prob_val;
|
3875 |
|
|
|
3876 |
|
|
cond = cond_exec_get_condition (jump);
|
3877 |
|
|
if (! cond)
|
3878 |
|
|
return FALSE;
|
3879 |
|
|
|
3880 |
|
|
prob_val = find_reg_note (jump, REG_BR_PROB, NULL_RTX);
|
3881 |
|
|
if (prob_val)
|
3882 |
|
|
prob_val = XEXP (prob_val, 0);
|
3883 |
|
|
|
3884 |
|
|
if (reversep)
|
3885 |
|
|
{
|
3886 |
|
|
enum rtx_code rev = reversed_comparison_code (cond, jump);
|
3887 |
|
|
if (rev == UNKNOWN)
|
3888 |
|
|
return FALSE;
|
3889 |
|
|
cond = gen_rtx_fmt_ee (rev, GET_MODE (cond), XEXP (cond, 0),
|
3890 |
|
|
XEXP (cond, 1));
|
3891 |
|
|
if (prob_val)
|
3892 |
|
|
prob_val = GEN_INT (REG_BR_PROB_BASE - INTVAL (prob_val));
|
3893 |
|
|
}
|
3894 |
|
|
|
3895 |
|
|
if (cond_exec_process_insns (NULL, head, end, cond, prob_val, 0)
|
3896 |
|
|
&& verify_changes (0))
|
3897 |
|
|
n_validated_changes = num_validated_changes ();
|
3898 |
|
|
else
|
3899 |
|
|
cancel_changes (0);
|
3900 |
|
|
|
3901 |
|
|
earliest = jump;
|
3902 |
|
|
}
|
3903 |
|
|
#endif
|
3904 |
|
|
/* Try the NCE path if the CE path did not result in any changes. */
|
3905 |
|
|
if (n_validated_changes == 0)
|
3906 |
|
|
{
|
3907 |
|
|
/* In the non-conditional execution case, we have to verify that there
|
3908 |
|
|
are no trapping operations, no calls, no references to memory, and
|
3909 |
|
|
that any registers modified are dead at the branch site. */
|
3910 |
|
|
|
3911 |
|
|
rtx insn, cond, prev;
|
3912 |
|
|
bitmap merge_set, test_live, test_set;
|
3913 |
|
|
unsigned i, fail = 0;
|
3914 |
|
|
bitmap_iterator bi;
|
3915 |
|
|
|
3916 |
|
|
/* Check for no calls or trapping operations. */
|
3917 |
|
|
for (insn = head; ; insn = NEXT_INSN (insn))
|
3918 |
|
|
{
|
3919 |
|
|
if (CALL_P (insn))
|
3920 |
|
|
return FALSE;
|
3921 |
|
|
if (NONDEBUG_INSN_P (insn))
|
3922 |
|
|
{
|
3923 |
|
|
if (may_trap_p (PATTERN (insn)))
|
3924 |
|
|
return FALSE;
|
3925 |
|
|
|
3926 |
|
|
/* ??? Even non-trapping memories such as stack frame
|
3927 |
|
|
references must be avoided. For stores, we collect
|
3928 |
|
|
no lifetime info; for reads, we'd have to assert
|
3929 |
|
|
true_dependence false against every store in the
|
3930 |
|
|
TEST range. */
|
3931 |
|
|
if (for_each_rtx (&PATTERN (insn), find_memory, NULL))
|
3932 |
|
|
return FALSE;
|
3933 |
|
|
}
|
3934 |
|
|
if (insn == end)
|
3935 |
|
|
break;
|
3936 |
|
|
}
|
3937 |
|
|
|
3938 |
|
|
if (! any_condjump_p (jump))
|
3939 |
|
|
return FALSE;
|
3940 |
|
|
|
3941 |
|
|
/* Find the extent of the conditional. */
|
3942 |
|
|
cond = noce_get_condition (jump, &earliest, false);
|
3943 |
|
|
if (! cond)
|
3944 |
|
|
return FALSE;
|
3945 |
|
|
|
3946 |
|
|
/* Collect:
|
3947 |
|
|
MERGE_SET = set of registers set in MERGE_BB
|
3948 |
|
|
TEST_LIVE = set of registers live at EARLIEST
|
3949 |
|
|
TEST_SET = set of registers set between EARLIEST and the
|
3950 |
|
|
end of the block. */
|
3951 |
|
|
|
3952 |
|
|
merge_set = BITMAP_ALLOC (®_obstack);
|
3953 |
|
|
test_live = BITMAP_ALLOC (®_obstack);
|
3954 |
|
|
test_set = BITMAP_ALLOC (®_obstack);
|
3955 |
|
|
|
3956 |
|
|
/* ??? bb->local_set is only valid during calculate_global_regs_live,
|
3957 |
|
|
so we must recompute usage for MERGE_BB. Not so bad, I suppose,
|
3958 |
|
|
since we've already asserted that MERGE_BB is small. */
|
3959 |
|
|
/* If we allocated new pseudos (e.g. in the conditional move
|
3960 |
|
|
expander called from noce_emit_cmove), we must resize the
|
3961 |
|
|
array first. */
|
3962 |
|
|
if (max_regno < max_reg_num ())
|
3963 |
|
|
max_regno = max_reg_num ();
|
3964 |
|
|
|
3965 |
|
|
FOR_BB_INSNS (merge_bb, insn)
|
3966 |
|
|
{
|
3967 |
|
|
if (NONDEBUG_INSN_P (insn))
|
3968 |
|
|
{
|
3969 |
|
|
unsigned int uid = INSN_UID (insn);
|
3970 |
|
|
df_ref *def_rec;
|
3971 |
|
|
for (def_rec = DF_INSN_UID_DEFS (uid); *def_rec; def_rec++)
|
3972 |
|
|
{
|
3973 |
|
|
df_ref def = *def_rec;
|
3974 |
|
|
bitmap_set_bit (merge_set, DF_REF_REGNO (def));
|
3975 |
|
|
}
|
3976 |
|
|
}
|
3977 |
|
|
}
|
3978 |
|
|
|
3979 |
|
|
/* For small register class machines, don't lengthen lifetimes of
|
3980 |
|
|
hard registers before reload. */
|
3981 |
|
|
if (SMALL_REGISTER_CLASSES && ! reload_completed)
|
3982 |
|
|
{
|
3983 |
|
|
EXECUTE_IF_SET_IN_BITMAP (merge_set, 0, i, bi)
|
3984 |
|
|
{
|
3985 |
|
|
if (i < FIRST_PSEUDO_REGISTER
|
3986 |
|
|
&& ! fixed_regs[i]
|
3987 |
|
|
&& ! global_regs[i])
|
3988 |
|
|
fail = 1;
|
3989 |
|
|
}
|
3990 |
|
|
}
|
3991 |
|
|
|
3992 |
|
|
/* For TEST, we're interested in a range of insns, not a whole block.
|
3993 |
|
|
Moreover, we're interested in the insns live from OTHER_BB. */
|
3994 |
|
|
|
3995 |
|
|
/* The loop below takes the set of live registers
|
3996 |
|
|
after JUMP, and calculates the live set before EARLIEST. */
|
3997 |
|
|
bitmap_copy (test_live, df_get_live_in (other_bb));
|
3998 |
|
|
df_simulate_initialize_backwards (test_bb, test_live);
|
3999 |
|
|
for (insn = jump; ; insn = prev)
|
4000 |
|
|
{
|
4001 |
|
|
if (INSN_P (insn))
|
4002 |
|
|
{
|
4003 |
|
|
df_simulate_find_defs (insn, test_set);
|
4004 |
|
|
df_simulate_one_insn_backwards (test_bb, insn, test_live);
|
4005 |
|
|
}
|
4006 |
|
|
prev = PREV_INSN (insn);
|
4007 |
|
|
if (insn == earliest)
|
4008 |
|
|
break;
|
4009 |
|
|
}
|
4010 |
|
|
|
4011 |
|
|
/* We can perform the transformation if
|
4012 |
|
|
MERGE_SET & (TEST_SET | TEST_LIVE)
|
4013 |
|
|
and
|
4014 |
|
|
TEST_SET & DF_LIVE_IN (merge_bb)
|
4015 |
|
|
are empty. */
|
4016 |
|
|
|
4017 |
|
|
if (bitmap_intersect_p (test_set, merge_set)
|
4018 |
|
|
|| bitmap_intersect_p (test_live, merge_set)
|
4019 |
|
|
|| bitmap_intersect_p (test_set, df_get_live_in (merge_bb)))
|
4020 |
|
|
fail = 1;
|
4021 |
|
|
|
4022 |
|
|
BITMAP_FREE (merge_set);
|
4023 |
|
|
BITMAP_FREE (test_live);
|
4024 |
|
|
BITMAP_FREE (test_set);
|
4025 |
|
|
|
4026 |
|
|
if (fail)
|
4027 |
|
|
return FALSE;
|
4028 |
|
|
}
|
4029 |
|
|
|
4030 |
|
|
no_body:
|
4031 |
|
|
/* We don't want to use normal invert_jump or redirect_jump because
|
4032 |
|
|
we don't want to delete_insn called. Also, we want to do our own
|
4033 |
|
|
change group management. */
|
4034 |
|
|
|
4035 |
|
|
old_dest = JUMP_LABEL (jump);
|
4036 |
|
|
if (other_bb != new_dest)
|
4037 |
|
|
{
|
4038 |
|
|
new_label = block_label (new_dest);
|
4039 |
|
|
if (reversep
|
4040 |
|
|
? ! invert_jump_1 (jump, new_label)
|
4041 |
|
|
: ! redirect_jump_1 (jump, new_label))
|
4042 |
|
|
goto cancel;
|
4043 |
|
|
}
|
4044 |
|
|
|
4045 |
|
|
if (verify_changes (n_validated_changes))
|
4046 |
|
|
confirm_change_group ();
|
4047 |
|
|
else
|
4048 |
|
|
goto cancel;
|
4049 |
|
|
|
4050 |
|
|
if (other_bb != new_dest)
|
4051 |
|
|
{
|
4052 |
|
|
redirect_jump_2 (jump, old_dest, new_label, 0, reversep);
|
4053 |
|
|
|
4054 |
|
|
redirect_edge_succ (BRANCH_EDGE (test_bb), new_dest);
|
4055 |
|
|
if (reversep)
|
4056 |
|
|
{
|
4057 |
|
|
gcov_type count, probability;
|
4058 |
|
|
count = BRANCH_EDGE (test_bb)->count;
|
4059 |
|
|
BRANCH_EDGE (test_bb)->count = FALLTHRU_EDGE (test_bb)->count;
|
4060 |
|
|
FALLTHRU_EDGE (test_bb)->count = count;
|
4061 |
|
|
probability = BRANCH_EDGE (test_bb)->probability;
|
4062 |
|
|
BRANCH_EDGE (test_bb)->probability
|
4063 |
|
|
= FALLTHRU_EDGE (test_bb)->probability;
|
4064 |
|
|
FALLTHRU_EDGE (test_bb)->probability = probability;
|
4065 |
|
|
update_br_prob_note (test_bb);
|
4066 |
|
|
}
|
4067 |
|
|
}
|
4068 |
|
|
|
4069 |
|
|
/* Move the insns out of MERGE_BB to before the branch. */
|
4070 |
|
|
if (head != NULL)
|
4071 |
|
|
{
|
4072 |
|
|
rtx insn;
|
4073 |
|
|
|
4074 |
|
|
if (end == BB_END (merge_bb))
|
4075 |
|
|
BB_END (merge_bb) = PREV_INSN (head);
|
4076 |
|
|
|
4077 |
|
|
/* PR 21767: When moving insns above a conditional branch, REG_EQUAL
|
4078 |
|
|
notes might become invalid. */
|
4079 |
|
|
insn = head;
|
4080 |
|
|
do
|
4081 |
|
|
{
|
4082 |
|
|
rtx note, set;
|
4083 |
|
|
|
4084 |
|
|
if (! INSN_P (insn))
|
4085 |
|
|
continue;
|
4086 |
|
|
note = find_reg_note (insn, REG_EQUAL, NULL_RTX);
|
4087 |
|
|
if (! note)
|
4088 |
|
|
continue;
|
4089 |
|
|
set = single_set (insn);
|
4090 |
|
|
if (!set || !function_invariant_p (SET_SRC (set))
|
4091 |
|
|
|| !function_invariant_p (XEXP (note, 0)))
|
4092 |
|
|
remove_note (insn, note);
|
4093 |
|
|
} while (insn != end && (insn = NEXT_INSN (insn)));
|
4094 |
|
|
|
4095 |
|
|
reorder_insns (head, end, PREV_INSN (earliest));
|
4096 |
|
|
}
|
4097 |
|
|
|
4098 |
|
|
/* Remove the jump and edge if we can. */
|
4099 |
|
|
if (other_bb == new_dest)
|
4100 |
|
|
{
|
4101 |
|
|
delete_insn (jump);
|
4102 |
|
|
remove_edge (BRANCH_EDGE (test_bb));
|
4103 |
|
|
/* ??? Can't merge blocks here, as then_bb is still in use.
|
4104 |
|
|
At minimum, the merge will get done just before bb-reorder. */
|
4105 |
|
|
}
|
4106 |
|
|
|
4107 |
|
|
return TRUE;
|
4108 |
|
|
|
4109 |
|
|
cancel:
|
4110 |
|
|
cancel_changes (0);
|
4111 |
|
|
return FALSE;
|
4112 |
|
|
}
|
4113 |
|
|
|
4114 |
|
|
/* Main entry point for all if-conversion. */
|
4115 |
|
|
|
4116 |
|
|
static void
|
4117 |
|
|
if_convert (void)
|
4118 |
|
|
{
|
4119 |
|
|
basic_block bb;
|
4120 |
|
|
int pass;
|
4121 |
|
|
|
4122 |
|
|
if (optimize == 1)
|
4123 |
|
|
{
|
4124 |
|
|
df_live_add_problem ();
|
4125 |
|
|
df_live_set_all_dirty ();
|
4126 |
|
|
}
|
4127 |
|
|
|
4128 |
|
|
num_possible_if_blocks = 0;
|
4129 |
|
|
num_updated_if_blocks = 0;
|
4130 |
|
|
num_true_changes = 0;
|
4131 |
|
|
|
4132 |
|
|
loop_optimizer_init (AVOID_CFG_MODIFICATIONS);
|
4133 |
|
|
mark_loop_exit_edges ();
|
4134 |
|
|
loop_optimizer_finalize ();
|
4135 |
|
|
free_dominance_info (CDI_DOMINATORS);
|
4136 |
|
|
|
4137 |
|
|
/* Compute postdominators. */
|
4138 |
|
|
calculate_dominance_info (CDI_POST_DOMINATORS);
|
4139 |
|
|
|
4140 |
|
|
df_set_flags (DF_LR_RUN_DCE);
|
4141 |
|
|
|
4142 |
|
|
/* Go through each of the basic blocks looking for things to convert. If we
|
4143 |
|
|
have conditional execution, we make multiple passes to allow us to handle
|
4144 |
|
|
IF-THEN{-ELSE} blocks within other IF-THEN{-ELSE} blocks. */
|
4145 |
|
|
pass = 0;
|
4146 |
|
|
do
|
4147 |
|
|
{
|
4148 |
|
|
df_analyze ();
|
4149 |
|
|
/* Only need to do dce on the first pass. */
|
4150 |
|
|
df_clear_flags (DF_LR_RUN_DCE);
|
4151 |
|
|
cond_exec_changed_p = FALSE;
|
4152 |
|
|
pass++;
|
4153 |
|
|
|
4154 |
|
|
#ifdef IFCVT_MULTIPLE_DUMPS
|
4155 |
|
|
if (dump_file && pass > 1)
|
4156 |
|
|
fprintf (dump_file, "\n\n========== Pass %d ==========\n", pass);
|
4157 |
|
|
#endif
|
4158 |
|
|
|
4159 |
|
|
FOR_EACH_BB (bb)
|
4160 |
|
|
{
|
4161 |
|
|
basic_block new_bb;
|
4162 |
|
|
while (!df_get_bb_dirty (bb)
|
4163 |
|
|
&& (new_bb = find_if_header (bb, pass)) != NULL)
|
4164 |
|
|
bb = new_bb;
|
4165 |
|
|
}
|
4166 |
|
|
|
4167 |
|
|
#ifdef IFCVT_MULTIPLE_DUMPS
|
4168 |
|
|
if (dump_file && cond_exec_changed_p)
|
4169 |
|
|
{
|
4170 |
|
|
if (dump_flags & TDF_SLIM)
|
4171 |
|
|
print_rtl_slim_with_bb (dump_file, get_insns (), dump_flags);
|
4172 |
|
|
else
|
4173 |
|
|
print_rtl_with_bb (dump_file, get_insns ());
|
4174 |
|
|
}
|
4175 |
|
|
#endif
|
4176 |
|
|
}
|
4177 |
|
|
while (cond_exec_changed_p);
|
4178 |
|
|
|
4179 |
|
|
#ifdef IFCVT_MULTIPLE_DUMPS
|
4180 |
|
|
if (dump_file)
|
4181 |
|
|
fprintf (dump_file, "\n\n========== no more changes\n");
|
4182 |
|
|
#endif
|
4183 |
|
|
|
4184 |
|
|
free_dominance_info (CDI_POST_DOMINATORS);
|
4185 |
|
|
|
4186 |
|
|
if (dump_file)
|
4187 |
|
|
fflush (dump_file);
|
4188 |
|
|
|
4189 |
|
|
clear_aux_for_blocks ();
|
4190 |
|
|
|
4191 |
|
|
/* If we allocated new pseudos, we must resize the array for sched1. */
|
4192 |
|
|
if (max_regno < max_reg_num ())
|
4193 |
|
|
max_regno = max_reg_num ();
|
4194 |
|
|
|
4195 |
|
|
/* Write the final stats. */
|
4196 |
|
|
if (dump_file && num_possible_if_blocks > 0)
|
4197 |
|
|
{
|
4198 |
|
|
fprintf (dump_file,
|
4199 |
|
|
"\n%d possible IF blocks searched.\n",
|
4200 |
|
|
num_possible_if_blocks);
|
4201 |
|
|
fprintf (dump_file,
|
4202 |
|
|
"%d IF blocks converted.\n",
|
4203 |
|
|
num_updated_if_blocks);
|
4204 |
|
|
fprintf (dump_file,
|
4205 |
|
|
"%d true changes made.\n\n\n",
|
4206 |
|
|
num_true_changes);
|
4207 |
|
|
}
|
4208 |
|
|
|
4209 |
|
|
if (optimize == 1)
|
4210 |
|
|
df_remove_problem (df_live);
|
4211 |
|
|
|
4212 |
|
|
#ifdef ENABLE_CHECKING
|
4213 |
|
|
verify_flow_info ();
|
4214 |
|
|
#endif
|
4215 |
|
|
}
|
4216 |
|
|
|
4217 |
|
|
static bool
|
4218 |
|
|
gate_handle_if_conversion (void)
|
4219 |
|
|
{
|
4220 |
|
|
return (optimize > 0)
|
4221 |
|
|
&& dbg_cnt (if_conversion);
|
4222 |
|
|
}
|
4223 |
|
|
|
4224 |
|
|
/* If-conversion and CFG cleanup. */
|
4225 |
|
|
static unsigned int
|
4226 |
|
|
rest_of_handle_if_conversion (void)
|
4227 |
|
|
{
|
4228 |
|
|
if (flag_if_conversion)
|
4229 |
|
|
{
|
4230 |
|
|
if (dump_file)
|
4231 |
|
|
dump_flow_info (dump_file, dump_flags);
|
4232 |
|
|
cleanup_cfg (CLEANUP_EXPENSIVE);
|
4233 |
|
|
if_convert ();
|
4234 |
|
|
}
|
4235 |
|
|
|
4236 |
|
|
cleanup_cfg (0);
|
4237 |
|
|
return 0;
|
4238 |
|
|
}
|
4239 |
|
|
|
4240 |
|
|
struct rtl_opt_pass pass_rtl_ifcvt =
|
4241 |
|
|
{
|
4242 |
|
|
{
|
4243 |
|
|
RTL_PASS,
|
4244 |
|
|
"ce1", /* name */
|
4245 |
|
|
gate_handle_if_conversion, /* gate */
|
4246 |
|
|
rest_of_handle_if_conversion, /* execute */
|
4247 |
|
|
NULL, /* sub */
|
4248 |
|
|
NULL, /* next */
|
4249 |
|
|
0, /* static_pass_number */
|
4250 |
|
|
TV_IFCVT, /* tv_id */
|
4251 |
|
|
0, /* properties_required */
|
4252 |
|
|
0, /* properties_provided */
|
4253 |
|
|
0, /* properties_destroyed */
|
4254 |
|
|
0, /* todo_flags_start */
|
4255 |
|
|
TODO_df_finish | TODO_verify_rtl_sharing |
|
4256 |
|
|
TODO_dump_func /* todo_flags_finish */
|
4257 |
|
|
}
|
4258 |
|
|
};
|
4259 |
|
|
|
4260 |
|
|
static bool
|
4261 |
|
|
gate_handle_if_after_combine (void)
|
4262 |
|
|
{
|
4263 |
|
|
return optimize > 0 && flag_if_conversion
|
4264 |
|
|
&& dbg_cnt (if_after_combine);
|
4265 |
|
|
}
|
4266 |
|
|
|
4267 |
|
|
|
4268 |
|
|
/* Rerun if-conversion, as combine may have simplified things enough
|
4269 |
|
|
to now meet sequence length restrictions. */
|
4270 |
|
|
static unsigned int
|
4271 |
|
|
rest_of_handle_if_after_combine (void)
|
4272 |
|
|
{
|
4273 |
|
|
if_convert ();
|
4274 |
|
|
return 0;
|
4275 |
|
|
}
|
4276 |
|
|
|
4277 |
|
|
struct rtl_opt_pass pass_if_after_combine =
|
4278 |
|
|
{
|
4279 |
|
|
{
|
4280 |
|
|
RTL_PASS,
|
4281 |
|
|
"ce2", /* name */
|
4282 |
|
|
gate_handle_if_after_combine, /* gate */
|
4283 |
|
|
rest_of_handle_if_after_combine, /* execute */
|
4284 |
|
|
NULL, /* sub */
|
4285 |
|
|
NULL, /* next */
|
4286 |
|
|
0, /* static_pass_number */
|
4287 |
|
|
TV_IFCVT, /* tv_id */
|
4288 |
|
|
0, /* properties_required */
|
4289 |
|
|
0, /* properties_provided */
|
4290 |
|
|
0, /* properties_destroyed */
|
4291 |
|
|
0, /* todo_flags_start */
|
4292 |
|
|
TODO_df_finish | TODO_verify_rtl_sharing |
|
4293 |
|
|
TODO_dump_func |
|
4294 |
|
|
TODO_ggc_collect /* todo_flags_finish */
|
4295 |
|
|
}
|
4296 |
|
|
};
|
4297 |
|
|
|
4298 |
|
|
|
4299 |
|
|
static bool
|
4300 |
|
|
gate_handle_if_after_reload (void)
|
4301 |
|
|
{
|
4302 |
|
|
return optimize > 0 && flag_if_conversion2
|
4303 |
|
|
&& dbg_cnt (if_after_reload);
|
4304 |
|
|
}
|
4305 |
|
|
|
4306 |
|
|
static unsigned int
|
4307 |
|
|
rest_of_handle_if_after_reload (void)
|
4308 |
|
|
{
|
4309 |
|
|
if_convert ();
|
4310 |
|
|
return 0;
|
4311 |
|
|
}
|
4312 |
|
|
|
4313 |
|
|
|
4314 |
|
|
struct rtl_opt_pass pass_if_after_reload =
|
4315 |
|
|
{
|
4316 |
|
|
{
|
4317 |
|
|
RTL_PASS,
|
4318 |
|
|
"ce3", /* name */
|
4319 |
|
|
gate_handle_if_after_reload, /* gate */
|
4320 |
|
|
rest_of_handle_if_after_reload, /* execute */
|
4321 |
|
|
NULL, /* sub */
|
4322 |
|
|
NULL, /* next */
|
4323 |
|
|
0, /* static_pass_number */
|
4324 |
|
|
TV_IFCVT2, /* tv_id */
|
4325 |
|
|
0, /* properties_required */
|
4326 |
|
|
0, /* properties_provided */
|
4327 |
|
|
0, /* properties_destroyed */
|
4328 |
|
|
0, /* todo_flags_start */
|
4329 |
|
|
TODO_df_finish | TODO_verify_rtl_sharing |
|
4330 |
|
|
TODO_dump_func |
|
4331 |
|
|
TODO_ggc_collect /* todo_flags_finish */
|
4332 |
|
|
}
|
4333 |
|
|
};
|