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684 |
jeremybenn |
/* Convert a program in SSA form into Normal form.
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Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010
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Free Software Foundation, Inc.
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Contributed by Andrew Macleod <amacleod@redhat.com>
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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
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it 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,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public 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 "tree.h"
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#include "ggc.h"
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#include "basic-block.h"
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#include "tree-pretty-print.h"
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#include "gimple-pretty-print.h"
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#include "bitmap.h"
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#include "tree-flow.h"
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#include "timevar.h"
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#include "tree-dump.h"
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#include "tree-pass.h"
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#include "diagnostic-core.h"
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#include "ssaexpand.h"
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/* FIXME: A lot of code here deals with expanding to RTL. All that code
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should be in cfgexpand.c. */
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#include "expr.h"
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DEF_VEC_I(source_location);
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DEF_VEC_ALLOC_I(source_location,heap);
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/* Used to hold all the components required to do SSA PHI elimination.
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The node and pred/succ list is a simple linear list of nodes and
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edges represented as pairs of nodes.
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The predecessor and successor list: Nodes are entered in pairs, where
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[0] ->PRED, [1]->SUCC. All the even indexes in the array represent
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predecessors, all the odd elements are successors.
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Rationale:
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When implemented as bitmaps, very large programs SSA->Normal times were
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being dominated by clearing the interference graph.
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Typically this list of edges is extremely small since it only includes
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PHI results and uses from a single edge which have not coalesced with
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each other. This means that no virtual PHI nodes are included, and
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empirical evidence suggests that the number of edges rarely exceed
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3, and in a bootstrap of GCC, the maximum size encountered was 7.
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This also limits the number of possible nodes that are involved to
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rarely more than 6, and in the bootstrap of gcc, the maximum number
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of nodes encountered was 12. */
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typedef struct _elim_graph {
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/* Size of the elimination vectors. */
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int size;
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/* List of nodes in the elimination graph. */
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VEC(int,heap) *nodes;
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/* The predecessor and successor edge list. */
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VEC(int,heap) *edge_list;
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/* Source locus on each edge */
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VEC(source_location,heap) *edge_locus;
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/* Visited vector. */
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sbitmap visited;
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/* Stack for visited nodes. */
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VEC(int,heap) *stack;
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/* The variable partition map. */
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var_map map;
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/* Edge being eliminated by this graph. */
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edge e;
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/* List of constant copies to emit. These are pushed on in pairs. */
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VEC(int,heap) *const_dests;
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VEC(tree,heap) *const_copies;
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/* Source locations for any constant copies. */
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VEC(source_location,heap) *copy_locus;
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} *elim_graph;
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/* For an edge E find out a good source location to associate with
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instructions inserted on edge E. If E has an implicit goto set,
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use its location. Otherwise search instructions in predecessors
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of E for a location, and use that one. That makes sense because
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we insert on edges for PHI nodes, and effects of PHIs happen on
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the end of the predecessor conceptually. */
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static void
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set_location_for_edge (edge e)
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{
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if (e->goto_locus)
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{
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set_curr_insn_source_location (e->goto_locus);
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set_curr_insn_block (e->goto_block);
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}
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else
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{
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basic_block bb = e->src;
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gimple_stmt_iterator gsi;
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do
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{
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for (gsi = gsi_last_bb (bb); !gsi_end_p (gsi); gsi_prev (&gsi))
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{
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gimple stmt = gsi_stmt (gsi);
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if (is_gimple_debug (stmt))
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continue;
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if (gimple_has_location (stmt) || gimple_block (stmt))
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{
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set_curr_insn_source_location (gimple_location (stmt));
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set_curr_insn_block (gimple_block (stmt));
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return;
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}
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}
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/* Nothing found in this basic block. Make a half-assed attempt
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to continue with another block. */
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if (single_pred_p (bb))
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bb = single_pred (bb);
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else
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bb = e->src;
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}
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while (bb != e->src);
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}
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}
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/* Emit insns to copy SRC into DEST converting SRC if necessary. As
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SRC/DEST might be BLKmode memory locations SIZEEXP is a tree from
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which we deduce the size to copy in that case. */
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static inline rtx
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emit_partition_copy (rtx dest, rtx src, int unsignedsrcp, tree sizeexp)
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{
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rtx seq;
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start_sequence ();
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if (GET_MODE (src) != VOIDmode && GET_MODE (src) != GET_MODE (dest))
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src = convert_to_mode (GET_MODE (dest), src, unsignedsrcp);
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if (GET_MODE (src) == BLKmode)
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{
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gcc_assert (GET_MODE (dest) == BLKmode);
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emit_block_move (dest, src, expr_size (sizeexp), BLOCK_OP_NORMAL);
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}
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else
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emit_move_insn (dest, src);
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seq = get_insns ();
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end_sequence ();
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return seq;
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}
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/* Insert a copy instruction from partition SRC to DEST onto edge E. */
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static void
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insert_partition_copy_on_edge (edge e, int dest, int src, source_location locus)
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{
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tree var;
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rtx seq;
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if (dump_file && (dump_flags & TDF_DETAILS))
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{
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fprintf (dump_file,
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"Inserting a partition copy on edge BB%d->BB%d :"
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"PART.%d = PART.%d",
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e->src->index,
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e->dest->index, dest, src);
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fprintf (dump_file, "\n");
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}
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gcc_assert (SA.partition_to_pseudo[dest]);
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gcc_assert (SA.partition_to_pseudo[src]);
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set_location_for_edge (e);
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/* If a locus is provided, override the default. */
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if (locus)
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set_curr_insn_source_location (locus);
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var = partition_to_var (SA.map, src);
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seq = emit_partition_copy (SA.partition_to_pseudo[dest],
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SA.partition_to_pseudo[src],
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TYPE_UNSIGNED (TREE_TYPE (var)),
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var);
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insert_insn_on_edge (seq, e);
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}
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/* Insert a copy instruction from expression SRC to partition DEST
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onto edge E. */
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static void
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insert_value_copy_on_edge (edge e, int dest, tree src, source_location locus)
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{
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rtx seq, x;
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enum machine_mode dest_mode, src_mode;
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int unsignedp;
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tree var;
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if (dump_file && (dump_flags & TDF_DETAILS))
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{
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fprintf (dump_file,
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"Inserting a value copy on edge BB%d->BB%d : PART.%d = ",
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e->src->index,
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e->dest->index, dest);
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print_generic_expr (dump_file, src, TDF_SLIM);
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fprintf (dump_file, "\n");
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}
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gcc_assert (SA.partition_to_pseudo[dest]);
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set_location_for_edge (e);
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/* If a locus is provided, override the default. */
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if (locus)
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set_curr_insn_source_location (locus);
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start_sequence ();
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var = SSA_NAME_VAR (partition_to_var (SA.map, dest));
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src_mode = TYPE_MODE (TREE_TYPE (src));
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dest_mode = GET_MODE (SA.partition_to_pseudo[dest]);
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gcc_assert (src_mode == TYPE_MODE (TREE_TYPE (var)));
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gcc_assert (!REG_P (SA.partition_to_pseudo[dest])
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|| dest_mode == promote_decl_mode (var, &unsignedp));
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if (src_mode != dest_mode)
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{
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x = expand_expr (src, NULL, src_mode, EXPAND_NORMAL);
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x = convert_modes (dest_mode, src_mode, x, unsignedp);
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}
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else if (src_mode == BLKmode)
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{
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x = SA.partition_to_pseudo[dest];
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store_expr (src, x, 0, false);
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}
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else
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x = expand_expr (src, SA.partition_to_pseudo[dest],
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dest_mode, EXPAND_NORMAL);
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if (x != SA.partition_to_pseudo[dest])
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emit_move_insn (SA.partition_to_pseudo[dest], x);
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seq = get_insns ();
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end_sequence ();
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insert_insn_on_edge (seq, e);
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}
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/* Insert a copy instruction from RTL expression SRC to partition DEST
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onto edge E. */
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static void
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insert_rtx_to_part_on_edge (edge e, int dest, rtx src, int unsignedsrcp,
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source_location locus)
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{
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rtx seq;
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if (dump_file && (dump_flags & TDF_DETAILS))
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{
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fprintf (dump_file,
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"Inserting a temp copy on edge BB%d->BB%d : PART.%d = ",
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e->src->index,
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e->dest->index, dest);
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print_simple_rtl (dump_file, src);
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fprintf (dump_file, "\n");
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}
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gcc_assert (SA.partition_to_pseudo[dest]);
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set_location_for_edge (e);
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/* If a locus is provided, override the default. */
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if (locus)
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set_curr_insn_source_location (locus);
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/* We give the destination as sizeexp in case src/dest are BLKmode
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mems. Usually we give the source. As we result from SSA names
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the left and right size should be the same (and no WITH_SIZE_EXPR
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involved), so it doesn't matter. */
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seq = emit_partition_copy (SA.partition_to_pseudo[dest],
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src, unsignedsrcp,
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partition_to_var (SA.map, dest));
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299 |
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insert_insn_on_edge (seq, e);
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}
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302 |
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/* Insert a copy instruction from partition SRC to RTL lvalue DEST
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onto edge E. */
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305 |
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306 |
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static void
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307 |
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insert_part_to_rtx_on_edge (edge e, rtx dest, int src, source_location locus)
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308 |
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{
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309 |
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tree var;
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310 |
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rtx seq;
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311 |
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if (dump_file && (dump_flags & TDF_DETAILS))
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312 |
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{
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313 |
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fprintf (dump_file,
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"Inserting a temp copy on edge BB%d->BB%d : ",
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e->src->index,
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e->dest->index);
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print_simple_rtl (dump_file, dest);
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318 |
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fprintf (dump_file, "= PART.%d\n", src);
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319 |
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}
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320 |
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321 |
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gcc_assert (SA.partition_to_pseudo[src]);
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322 |
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323 |
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set_location_for_edge (e);
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324 |
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/* If a locus is provided, override the default. */
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325 |
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if (locus)
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326 |
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set_curr_insn_source_location (locus);
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327 |
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328 |
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var = partition_to_var (SA.map, src);
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329 |
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seq = emit_partition_copy (dest,
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330 |
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SA.partition_to_pseudo[src],
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331 |
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TYPE_UNSIGNED (TREE_TYPE (var)),
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332 |
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var);
|
333 |
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334 |
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insert_insn_on_edge (seq, e);
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335 |
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}
|
336 |
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337 |
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338 |
|
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/* Create an elimination graph with SIZE nodes and associated data
|
339 |
|
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structures. */
|
340 |
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|
341 |
|
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static elim_graph
|
342 |
|
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new_elim_graph (int size)
|
343 |
|
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{
|
344 |
|
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elim_graph g = (elim_graph) xmalloc (sizeof (struct _elim_graph));
|
345 |
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346 |
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g->nodes = VEC_alloc (int, heap, 30);
|
347 |
|
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g->const_dests = VEC_alloc (int, heap, 20);
|
348 |
|
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g->const_copies = VEC_alloc (tree, heap, 20);
|
349 |
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g->copy_locus = VEC_alloc (source_location, heap, 10);
|
350 |
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g->edge_list = VEC_alloc (int, heap, 20);
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351 |
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g->edge_locus = VEC_alloc (source_location, heap, 10);
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352 |
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g->stack = VEC_alloc (int, heap, 30);
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353 |
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354 |
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g->visited = sbitmap_alloc (size);
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355 |
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|
356 |
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return g;
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357 |
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}
|
358 |
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|
359 |
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|
360 |
|
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/* Empty elimination graph G. */
|
361 |
|
|
|
362 |
|
|
static inline void
|
363 |
|
|
clear_elim_graph (elim_graph g)
|
364 |
|
|
{
|
365 |
|
|
VEC_truncate (int, g->nodes, 0);
|
366 |
|
|
VEC_truncate (int, g->edge_list, 0);
|
367 |
|
|
VEC_truncate (source_location, g->edge_locus, 0);
|
368 |
|
|
}
|
369 |
|
|
|
370 |
|
|
|
371 |
|
|
/* Delete elimination graph G. */
|
372 |
|
|
|
373 |
|
|
static inline void
|
374 |
|
|
delete_elim_graph (elim_graph g)
|
375 |
|
|
{
|
376 |
|
|
sbitmap_free (g->visited);
|
377 |
|
|
VEC_free (int, heap, g->stack);
|
378 |
|
|
VEC_free (int, heap, g->edge_list);
|
379 |
|
|
VEC_free (tree, heap, g->const_copies);
|
380 |
|
|
VEC_free (int, heap, g->const_dests);
|
381 |
|
|
VEC_free (int, heap, g->nodes);
|
382 |
|
|
VEC_free (source_location, heap, g->copy_locus);
|
383 |
|
|
VEC_free (source_location, heap, g->edge_locus);
|
384 |
|
|
|
385 |
|
|
free (g);
|
386 |
|
|
}
|
387 |
|
|
|
388 |
|
|
|
389 |
|
|
/* Return the number of nodes in graph G. */
|
390 |
|
|
|
391 |
|
|
static inline int
|
392 |
|
|
elim_graph_size (elim_graph g)
|
393 |
|
|
{
|
394 |
|
|
return VEC_length (int, g->nodes);
|
395 |
|
|
}
|
396 |
|
|
|
397 |
|
|
|
398 |
|
|
/* Add NODE to graph G, if it doesn't exist already. */
|
399 |
|
|
|
400 |
|
|
static inline void
|
401 |
|
|
elim_graph_add_node (elim_graph g, int node)
|
402 |
|
|
{
|
403 |
|
|
int x;
|
404 |
|
|
int t;
|
405 |
|
|
|
406 |
|
|
FOR_EACH_VEC_ELT (int, g->nodes, x, t)
|
407 |
|
|
if (t == node)
|
408 |
|
|
return;
|
409 |
|
|
VEC_safe_push (int, heap, g->nodes, node);
|
410 |
|
|
}
|
411 |
|
|
|
412 |
|
|
|
413 |
|
|
/* Add the edge PRED->SUCC to graph G. */
|
414 |
|
|
|
415 |
|
|
static inline void
|
416 |
|
|
elim_graph_add_edge (elim_graph g, int pred, int succ, source_location locus)
|
417 |
|
|
{
|
418 |
|
|
VEC_safe_push (int, heap, g->edge_list, pred);
|
419 |
|
|
VEC_safe_push (int, heap, g->edge_list, succ);
|
420 |
|
|
VEC_safe_push (source_location, heap, g->edge_locus, locus);
|
421 |
|
|
}
|
422 |
|
|
|
423 |
|
|
|
424 |
|
|
/* Remove an edge from graph G for which NODE is the predecessor, and
|
425 |
|
|
return the successor node. -1 is returned if there is no such edge. */
|
426 |
|
|
|
427 |
|
|
static inline int
|
428 |
|
|
elim_graph_remove_succ_edge (elim_graph g, int node, source_location *locus)
|
429 |
|
|
{
|
430 |
|
|
int y;
|
431 |
|
|
unsigned x;
|
432 |
|
|
for (x = 0; x < VEC_length (int, g->edge_list); x += 2)
|
433 |
|
|
if (VEC_index (int, g->edge_list, x) == node)
|
434 |
|
|
{
|
435 |
|
|
VEC_replace (int, g->edge_list, x, -1);
|
436 |
|
|
y = VEC_index (int, g->edge_list, x + 1);
|
437 |
|
|
VEC_replace (int, g->edge_list, x + 1, -1);
|
438 |
|
|
*locus = VEC_index (source_location, g->edge_locus, x / 2);
|
439 |
|
|
VEC_replace (source_location, g->edge_locus, x / 2, UNKNOWN_LOCATION);
|
440 |
|
|
return y;
|
441 |
|
|
}
|
442 |
|
|
*locus = UNKNOWN_LOCATION;
|
443 |
|
|
return -1;
|
444 |
|
|
}
|
445 |
|
|
|
446 |
|
|
|
447 |
|
|
/* Find all the nodes in GRAPH which are successors to NODE in the
|
448 |
|
|
edge list. VAR will hold the partition number found. CODE is the
|
449 |
|
|
code fragment executed for every node found. */
|
450 |
|
|
|
451 |
|
|
#define FOR_EACH_ELIM_GRAPH_SUCC(GRAPH, NODE, VAR, LOCUS, CODE) \
|
452 |
|
|
do { \
|
453 |
|
|
unsigned x_; \
|
454 |
|
|
int y_; \
|
455 |
|
|
for (x_ = 0; x_ < VEC_length (int, (GRAPH)->edge_list); x_ += 2) \
|
456 |
|
|
{ \
|
457 |
|
|
y_ = VEC_index (int, (GRAPH)->edge_list, x_); \
|
458 |
|
|
if (y_ != (NODE)) \
|
459 |
|
|
continue; \
|
460 |
|
|
(void) ((VAR) = VEC_index (int, (GRAPH)->edge_list, x_ + 1)); \
|
461 |
|
|
(void) ((LOCUS) = VEC_index (source_location, \
|
462 |
|
|
(GRAPH)->edge_locus, x_ / 2)); \
|
463 |
|
|
CODE; \
|
464 |
|
|
} \
|
465 |
|
|
} while (0)
|
466 |
|
|
|
467 |
|
|
|
468 |
|
|
/* Find all the nodes which are predecessors of NODE in the edge list for
|
469 |
|
|
GRAPH. VAR will hold the partition number found. CODE is the
|
470 |
|
|
code fragment executed for every node found. */
|
471 |
|
|
|
472 |
|
|
#define FOR_EACH_ELIM_GRAPH_PRED(GRAPH, NODE, VAR, LOCUS, CODE) \
|
473 |
|
|
do { \
|
474 |
|
|
unsigned x_; \
|
475 |
|
|
int y_; \
|
476 |
|
|
for (x_ = 0; x_ < VEC_length (int, (GRAPH)->edge_list); x_ += 2) \
|
477 |
|
|
{ \
|
478 |
|
|
y_ = VEC_index (int, (GRAPH)->edge_list, x_ + 1); \
|
479 |
|
|
if (y_ != (NODE)) \
|
480 |
|
|
continue; \
|
481 |
|
|
(void) ((VAR) = VEC_index (int, (GRAPH)->edge_list, x_)); \
|
482 |
|
|
(void) ((LOCUS) = VEC_index (source_location, \
|
483 |
|
|
(GRAPH)->edge_locus, x_ / 2)); \
|
484 |
|
|
CODE; \
|
485 |
|
|
} \
|
486 |
|
|
} while (0)
|
487 |
|
|
|
488 |
|
|
|
489 |
|
|
/* Add T to elimination graph G. */
|
490 |
|
|
|
491 |
|
|
static inline void
|
492 |
|
|
eliminate_name (elim_graph g, int T)
|
493 |
|
|
{
|
494 |
|
|
elim_graph_add_node (g, T);
|
495 |
|
|
}
|
496 |
|
|
|
497 |
|
|
|
498 |
|
|
/* Build elimination graph G for basic block BB on incoming PHI edge
|
499 |
|
|
G->e. */
|
500 |
|
|
|
501 |
|
|
static void
|
502 |
|
|
eliminate_build (elim_graph g)
|
503 |
|
|
{
|
504 |
|
|
tree Ti;
|
505 |
|
|
int p0, pi;
|
506 |
|
|
gimple_stmt_iterator gsi;
|
507 |
|
|
|
508 |
|
|
clear_elim_graph (g);
|
509 |
|
|
|
510 |
|
|
for (gsi = gsi_start_phis (g->e->dest); !gsi_end_p (gsi); gsi_next (&gsi))
|
511 |
|
|
{
|
512 |
|
|
gimple phi = gsi_stmt (gsi);
|
513 |
|
|
source_location locus;
|
514 |
|
|
|
515 |
|
|
p0 = var_to_partition (g->map, gimple_phi_result (phi));
|
516 |
|
|
/* Ignore results which are not in partitions. */
|
517 |
|
|
if (p0 == NO_PARTITION)
|
518 |
|
|
continue;
|
519 |
|
|
|
520 |
|
|
Ti = PHI_ARG_DEF (phi, g->e->dest_idx);
|
521 |
|
|
locus = gimple_phi_arg_location_from_edge (phi, g->e);
|
522 |
|
|
|
523 |
|
|
/* If this argument is a constant, or a SSA_NAME which is being
|
524 |
|
|
left in SSA form, just queue a copy to be emitted on this
|
525 |
|
|
edge. */
|
526 |
|
|
if (!phi_ssa_name_p (Ti)
|
527 |
|
|
|| (TREE_CODE (Ti) == SSA_NAME
|
528 |
|
|
&& var_to_partition (g->map, Ti) == NO_PARTITION))
|
529 |
|
|
{
|
530 |
|
|
/* Save constant copies until all other copies have been emitted
|
531 |
|
|
on this edge. */
|
532 |
|
|
VEC_safe_push (int, heap, g->const_dests, p0);
|
533 |
|
|
VEC_safe_push (tree, heap, g->const_copies, Ti);
|
534 |
|
|
VEC_safe_push (source_location, heap, g->copy_locus, locus);
|
535 |
|
|
}
|
536 |
|
|
else
|
537 |
|
|
{
|
538 |
|
|
pi = var_to_partition (g->map, Ti);
|
539 |
|
|
if (p0 != pi)
|
540 |
|
|
{
|
541 |
|
|
eliminate_name (g, p0);
|
542 |
|
|
eliminate_name (g, pi);
|
543 |
|
|
elim_graph_add_edge (g, p0, pi, locus);
|
544 |
|
|
}
|
545 |
|
|
}
|
546 |
|
|
}
|
547 |
|
|
}
|
548 |
|
|
|
549 |
|
|
|
550 |
|
|
/* Push successors of T onto the elimination stack for G. */
|
551 |
|
|
|
552 |
|
|
static void
|
553 |
|
|
elim_forward (elim_graph g, int T)
|
554 |
|
|
{
|
555 |
|
|
int S;
|
556 |
|
|
source_location locus;
|
557 |
|
|
|
558 |
|
|
SET_BIT (g->visited, T);
|
559 |
|
|
FOR_EACH_ELIM_GRAPH_SUCC (g, T, S, locus,
|
560 |
|
|
{
|
561 |
|
|
if (!TEST_BIT (g->visited, S))
|
562 |
|
|
elim_forward (g, S);
|
563 |
|
|
});
|
564 |
|
|
VEC_safe_push (int, heap, g->stack, T);
|
565 |
|
|
}
|
566 |
|
|
|
567 |
|
|
|
568 |
|
|
/* Return 1 if there unvisited predecessors of T in graph G. */
|
569 |
|
|
|
570 |
|
|
static int
|
571 |
|
|
elim_unvisited_predecessor (elim_graph g, int T)
|
572 |
|
|
{
|
573 |
|
|
int P;
|
574 |
|
|
source_location locus;
|
575 |
|
|
|
576 |
|
|
FOR_EACH_ELIM_GRAPH_PRED (g, T, P, locus,
|
577 |
|
|
{
|
578 |
|
|
if (!TEST_BIT (g->visited, P))
|
579 |
|
|
return 1;
|
580 |
|
|
});
|
581 |
|
|
return 0;
|
582 |
|
|
}
|
583 |
|
|
|
584 |
|
|
/* Process predecessors first, and insert a copy. */
|
585 |
|
|
|
586 |
|
|
static void
|
587 |
|
|
elim_backward (elim_graph g, int T)
|
588 |
|
|
{
|
589 |
|
|
int P;
|
590 |
|
|
source_location locus;
|
591 |
|
|
|
592 |
|
|
SET_BIT (g->visited, T);
|
593 |
|
|
FOR_EACH_ELIM_GRAPH_PRED (g, T, P, locus,
|
594 |
|
|
{
|
595 |
|
|
if (!TEST_BIT (g->visited, P))
|
596 |
|
|
{
|
597 |
|
|
elim_backward (g, P);
|
598 |
|
|
insert_partition_copy_on_edge (g->e, P, T, locus);
|
599 |
|
|
}
|
600 |
|
|
});
|
601 |
|
|
}
|
602 |
|
|
|
603 |
|
|
/* Allocate a new pseudo register usable for storing values sitting
|
604 |
|
|
in NAME (a decl or SSA name), i.e. with matching mode and attributes. */
|
605 |
|
|
|
606 |
|
|
static rtx
|
607 |
|
|
get_temp_reg (tree name)
|
608 |
|
|
{
|
609 |
|
|
tree var = TREE_CODE (name) == SSA_NAME ? SSA_NAME_VAR (name) : name;
|
610 |
|
|
tree type = TREE_TYPE (var);
|
611 |
|
|
int unsignedp;
|
612 |
|
|
enum machine_mode reg_mode = promote_decl_mode (var, &unsignedp);
|
613 |
|
|
rtx x = gen_reg_rtx (reg_mode);
|
614 |
|
|
if (POINTER_TYPE_P (type))
|
615 |
|
|
mark_reg_pointer (x, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (var))));
|
616 |
|
|
return x;
|
617 |
|
|
}
|
618 |
|
|
|
619 |
|
|
/* Insert required copies for T in graph G. Check for a strongly connected
|
620 |
|
|
region, and create a temporary to break the cycle if one is found. */
|
621 |
|
|
|
622 |
|
|
static void
|
623 |
|
|
elim_create (elim_graph g, int T)
|
624 |
|
|
{
|
625 |
|
|
int P, S;
|
626 |
|
|
source_location locus;
|
627 |
|
|
|
628 |
|
|
if (elim_unvisited_predecessor (g, T))
|
629 |
|
|
{
|
630 |
|
|
tree var = partition_to_var (g->map, T);
|
631 |
|
|
rtx U = get_temp_reg (var);
|
632 |
|
|
int unsignedsrcp = TYPE_UNSIGNED (TREE_TYPE (var));
|
633 |
|
|
|
634 |
|
|
insert_part_to_rtx_on_edge (g->e, U, T, UNKNOWN_LOCATION);
|
635 |
|
|
FOR_EACH_ELIM_GRAPH_PRED (g, T, P, locus,
|
636 |
|
|
{
|
637 |
|
|
if (!TEST_BIT (g->visited, P))
|
638 |
|
|
{
|
639 |
|
|
elim_backward (g, P);
|
640 |
|
|
insert_rtx_to_part_on_edge (g->e, P, U, unsignedsrcp, locus);
|
641 |
|
|
}
|
642 |
|
|
});
|
643 |
|
|
}
|
644 |
|
|
else
|
645 |
|
|
{
|
646 |
|
|
S = elim_graph_remove_succ_edge (g, T, &locus);
|
647 |
|
|
if (S != -1)
|
648 |
|
|
{
|
649 |
|
|
SET_BIT (g->visited, T);
|
650 |
|
|
insert_partition_copy_on_edge (g->e, T, S, locus);
|
651 |
|
|
}
|
652 |
|
|
}
|
653 |
|
|
}
|
654 |
|
|
|
655 |
|
|
|
656 |
|
|
/* Eliminate all the phi nodes on edge E in graph G. */
|
657 |
|
|
|
658 |
|
|
static void
|
659 |
|
|
eliminate_phi (edge e, elim_graph g)
|
660 |
|
|
{
|
661 |
|
|
int x;
|
662 |
|
|
|
663 |
|
|
gcc_assert (VEC_length (tree, g->const_copies) == 0);
|
664 |
|
|
gcc_assert (VEC_length (source_location, g->copy_locus) == 0);
|
665 |
|
|
|
666 |
|
|
/* Abnormal edges already have everything coalesced. */
|
667 |
|
|
if (e->flags & EDGE_ABNORMAL)
|
668 |
|
|
return;
|
669 |
|
|
|
670 |
|
|
g->e = e;
|
671 |
|
|
|
672 |
|
|
eliminate_build (g);
|
673 |
|
|
|
674 |
|
|
if (elim_graph_size (g) != 0)
|
675 |
|
|
{
|
676 |
|
|
int part;
|
677 |
|
|
|
678 |
|
|
sbitmap_zero (g->visited);
|
679 |
|
|
VEC_truncate (int, g->stack, 0);
|
680 |
|
|
|
681 |
|
|
FOR_EACH_VEC_ELT (int, g->nodes, x, part)
|
682 |
|
|
{
|
683 |
|
|
if (!TEST_BIT (g->visited, part))
|
684 |
|
|
elim_forward (g, part);
|
685 |
|
|
}
|
686 |
|
|
|
687 |
|
|
sbitmap_zero (g->visited);
|
688 |
|
|
while (VEC_length (int, g->stack) > 0)
|
689 |
|
|
{
|
690 |
|
|
x = VEC_pop (int, g->stack);
|
691 |
|
|
if (!TEST_BIT (g->visited, x))
|
692 |
|
|
elim_create (g, x);
|
693 |
|
|
}
|
694 |
|
|
}
|
695 |
|
|
|
696 |
|
|
/* If there are any pending constant copies, issue them now. */
|
697 |
|
|
while (VEC_length (tree, g->const_copies) > 0)
|
698 |
|
|
{
|
699 |
|
|
int dest;
|
700 |
|
|
tree src;
|
701 |
|
|
source_location locus;
|
702 |
|
|
|
703 |
|
|
src = VEC_pop (tree, g->const_copies);
|
704 |
|
|
dest = VEC_pop (int, g->const_dests);
|
705 |
|
|
locus = VEC_pop (source_location, g->copy_locus);
|
706 |
|
|
insert_value_copy_on_edge (e, dest, src, locus);
|
707 |
|
|
}
|
708 |
|
|
}
|
709 |
|
|
|
710 |
|
|
|
711 |
|
|
/* Remove each argument from PHI. If an arg was the last use of an SSA_NAME,
|
712 |
|
|
check to see if this allows another PHI node to be removed. */
|
713 |
|
|
|
714 |
|
|
static void
|
715 |
|
|
remove_gimple_phi_args (gimple phi)
|
716 |
|
|
{
|
717 |
|
|
use_operand_p arg_p;
|
718 |
|
|
ssa_op_iter iter;
|
719 |
|
|
|
720 |
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
721 |
|
|
{
|
722 |
|
|
fprintf (dump_file, "Removing Dead PHI definition: ");
|
723 |
|
|
print_gimple_stmt (dump_file, phi, 0, TDF_SLIM);
|
724 |
|
|
}
|
725 |
|
|
|
726 |
|
|
FOR_EACH_PHI_ARG (arg_p, phi, iter, SSA_OP_USE)
|
727 |
|
|
{
|
728 |
|
|
tree arg = USE_FROM_PTR (arg_p);
|
729 |
|
|
if (TREE_CODE (arg) == SSA_NAME)
|
730 |
|
|
{
|
731 |
|
|
/* Remove the reference to the existing argument. */
|
732 |
|
|
SET_USE (arg_p, NULL_TREE);
|
733 |
|
|
if (has_zero_uses (arg))
|
734 |
|
|
{
|
735 |
|
|
gimple stmt;
|
736 |
|
|
gimple_stmt_iterator gsi;
|
737 |
|
|
|
738 |
|
|
stmt = SSA_NAME_DEF_STMT (arg);
|
739 |
|
|
|
740 |
|
|
/* Also remove the def if it is a PHI node. */
|
741 |
|
|
if (gimple_code (stmt) == GIMPLE_PHI)
|
742 |
|
|
{
|
743 |
|
|
remove_gimple_phi_args (stmt);
|
744 |
|
|
gsi = gsi_for_stmt (stmt);
|
745 |
|
|
remove_phi_node (&gsi, true);
|
746 |
|
|
}
|
747 |
|
|
|
748 |
|
|
}
|
749 |
|
|
}
|
750 |
|
|
}
|
751 |
|
|
}
|
752 |
|
|
|
753 |
|
|
/* Remove any PHI node which is a virtual PHI, or a PHI with no uses. */
|
754 |
|
|
|
755 |
|
|
static void
|
756 |
|
|
eliminate_useless_phis (void)
|
757 |
|
|
{
|
758 |
|
|
basic_block bb;
|
759 |
|
|
gimple_stmt_iterator gsi;
|
760 |
|
|
tree result;
|
761 |
|
|
|
762 |
|
|
FOR_EACH_BB (bb)
|
763 |
|
|
{
|
764 |
|
|
for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); )
|
765 |
|
|
{
|
766 |
|
|
gimple phi = gsi_stmt (gsi);
|
767 |
|
|
result = gimple_phi_result (phi);
|
768 |
|
|
if (!is_gimple_reg (SSA_NAME_VAR (result)))
|
769 |
|
|
{
|
770 |
|
|
#ifdef ENABLE_CHECKING
|
771 |
|
|
size_t i;
|
772 |
|
|
/* There should be no arguments which are not virtual, or the
|
773 |
|
|
results will be incorrect. */
|
774 |
|
|
for (i = 0; i < gimple_phi_num_args (phi); i++)
|
775 |
|
|
{
|
776 |
|
|
tree arg = PHI_ARG_DEF (phi, i);
|
777 |
|
|
if (TREE_CODE (arg) == SSA_NAME
|
778 |
|
|
&& is_gimple_reg (SSA_NAME_VAR (arg)))
|
779 |
|
|
{
|
780 |
|
|
fprintf (stderr, "Argument of PHI is not virtual (");
|
781 |
|
|
print_generic_expr (stderr, arg, TDF_SLIM);
|
782 |
|
|
fprintf (stderr, "), but the result is :");
|
783 |
|
|
print_gimple_stmt (stderr, phi, 0, TDF_SLIM);
|
784 |
|
|
internal_error ("SSA corruption");
|
785 |
|
|
}
|
786 |
|
|
}
|
787 |
|
|
#endif
|
788 |
|
|
remove_phi_node (&gsi, true);
|
789 |
|
|
}
|
790 |
|
|
else
|
791 |
|
|
{
|
792 |
|
|
/* Also remove real PHIs with no uses. */
|
793 |
|
|
if (has_zero_uses (result))
|
794 |
|
|
{
|
795 |
|
|
remove_gimple_phi_args (phi);
|
796 |
|
|
remove_phi_node (&gsi, true);
|
797 |
|
|
}
|
798 |
|
|
else
|
799 |
|
|
gsi_next (&gsi);
|
800 |
|
|
}
|
801 |
|
|
}
|
802 |
|
|
}
|
803 |
|
|
}
|
804 |
|
|
|
805 |
|
|
|
806 |
|
|
/* This function will rewrite the current program using the variable mapping
|
807 |
|
|
found in MAP. If the replacement vector VALUES is provided, any
|
808 |
|
|
occurrences of partitions with non-null entries in the vector will be
|
809 |
|
|
replaced with the expression in the vector instead of its mapped
|
810 |
|
|
variable. */
|
811 |
|
|
|
812 |
|
|
static void
|
813 |
|
|
rewrite_trees (var_map map ATTRIBUTE_UNUSED)
|
814 |
|
|
{
|
815 |
|
|
#ifdef ENABLE_CHECKING
|
816 |
|
|
basic_block bb;
|
817 |
|
|
/* Search for PHIs where the destination has no partition, but one
|
818 |
|
|
or more arguments has a partition. This should not happen and can
|
819 |
|
|
create incorrect code. */
|
820 |
|
|
FOR_EACH_BB (bb)
|
821 |
|
|
{
|
822 |
|
|
gimple_stmt_iterator gsi;
|
823 |
|
|
for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
|
824 |
|
|
{
|
825 |
|
|
gimple phi = gsi_stmt (gsi);
|
826 |
|
|
tree T0 = var_to_partition_to_var (map, gimple_phi_result (phi));
|
827 |
|
|
if (T0 == NULL_TREE)
|
828 |
|
|
{
|
829 |
|
|
size_t i;
|
830 |
|
|
for (i = 0; i < gimple_phi_num_args (phi); i++)
|
831 |
|
|
{
|
832 |
|
|
tree arg = PHI_ARG_DEF (phi, i);
|
833 |
|
|
|
834 |
|
|
if (TREE_CODE (arg) == SSA_NAME
|
835 |
|
|
&& var_to_partition (map, arg) != NO_PARTITION)
|
836 |
|
|
{
|
837 |
|
|
fprintf (stderr, "Argument of PHI is in a partition :(");
|
838 |
|
|
print_generic_expr (stderr, arg, TDF_SLIM);
|
839 |
|
|
fprintf (stderr, "), but the result is not :");
|
840 |
|
|
print_gimple_stmt (stderr, phi, 0, TDF_SLIM);
|
841 |
|
|
internal_error ("SSA corruption");
|
842 |
|
|
}
|
843 |
|
|
}
|
844 |
|
|
}
|
845 |
|
|
}
|
846 |
|
|
}
|
847 |
|
|
#endif
|
848 |
|
|
}
|
849 |
|
|
|
850 |
|
|
/* Given the out-of-ssa info object SA (with prepared partitions)
|
851 |
|
|
eliminate all phi nodes in all basic blocks. Afterwards no
|
852 |
|
|
basic block will have phi nodes anymore and there are possibly
|
853 |
|
|
some RTL instructions inserted on edges. */
|
854 |
|
|
|
855 |
|
|
void
|
856 |
|
|
expand_phi_nodes (struct ssaexpand *sa)
|
857 |
|
|
{
|
858 |
|
|
basic_block bb;
|
859 |
|
|
elim_graph g = new_elim_graph (sa->map->num_partitions);
|
860 |
|
|
g->map = sa->map;
|
861 |
|
|
|
862 |
|
|
FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR->next_bb, EXIT_BLOCK_PTR, next_bb)
|
863 |
|
|
if (!gimple_seq_empty_p (phi_nodes (bb)))
|
864 |
|
|
{
|
865 |
|
|
edge e;
|
866 |
|
|
edge_iterator ei;
|
867 |
|
|
FOR_EACH_EDGE (e, ei, bb->preds)
|
868 |
|
|
eliminate_phi (e, g);
|
869 |
|
|
set_phi_nodes (bb, NULL);
|
870 |
|
|
/* We can't redirect EH edges in RTL land, so we need to do this
|
871 |
|
|
here. Redirection happens only when splitting is necessary,
|
872 |
|
|
which it is only for critical edges, normally. For EH edges
|
873 |
|
|
it might also be necessary when the successor has more than
|
874 |
|
|
one predecessor. In that case the edge is either required to
|
875 |
|
|
be fallthru (which EH edges aren't), or the predecessor needs
|
876 |
|
|
to end with a jump (which again, isn't the case with EH edges).
|
877 |
|
|
Hence, split all EH edges on which we inserted instructions
|
878 |
|
|
and whose successor has multiple predecessors. */
|
879 |
|
|
for (ei = ei_start (bb->preds); (e = ei_safe_edge (ei)); )
|
880 |
|
|
{
|
881 |
|
|
if (e->insns.r && (e->flags & EDGE_EH)
|
882 |
|
|
&& !single_pred_p (e->dest))
|
883 |
|
|
{
|
884 |
|
|
rtx insns = e->insns.r;
|
885 |
|
|
basic_block bb;
|
886 |
|
|
e->insns.r = NULL_RTX;
|
887 |
|
|
bb = split_edge (e);
|
888 |
|
|
single_pred_edge (bb)->insns.r = insns;
|
889 |
|
|
}
|
890 |
|
|
else
|
891 |
|
|
ei_next (&ei);
|
892 |
|
|
}
|
893 |
|
|
}
|
894 |
|
|
|
895 |
|
|
delete_elim_graph (g);
|
896 |
|
|
}
|
897 |
|
|
|
898 |
|
|
|
899 |
|
|
/* Remove the ssa-names in the current function and translate them into normal
|
900 |
|
|
compiler variables. PERFORM_TER is true if Temporary Expression Replacement
|
901 |
|
|
should also be used. */
|
902 |
|
|
|
903 |
|
|
static void
|
904 |
|
|
remove_ssa_form (bool perform_ter, struct ssaexpand *sa)
|
905 |
|
|
{
|
906 |
|
|
bitmap values = NULL;
|
907 |
|
|
var_map map;
|
908 |
|
|
unsigned i;
|
909 |
|
|
|
910 |
|
|
map = coalesce_ssa_name ();
|
911 |
|
|
|
912 |
|
|
/* Return to viewing the variable list as just all reference variables after
|
913 |
|
|
coalescing has been performed. */
|
914 |
|
|
partition_view_normal (map, false);
|
915 |
|
|
|
916 |
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
917 |
|
|
{
|
918 |
|
|
fprintf (dump_file, "After Coalescing:\n");
|
919 |
|
|
dump_var_map (dump_file, map);
|
920 |
|
|
}
|
921 |
|
|
|
922 |
|
|
if (perform_ter)
|
923 |
|
|
{
|
924 |
|
|
values = find_replaceable_exprs (map);
|
925 |
|
|
if (values && dump_file && (dump_flags & TDF_DETAILS))
|
926 |
|
|
dump_replaceable_exprs (dump_file, values);
|
927 |
|
|
}
|
928 |
|
|
|
929 |
|
|
rewrite_trees (map);
|
930 |
|
|
|
931 |
|
|
sa->map = map;
|
932 |
|
|
sa->values = values;
|
933 |
|
|
sa->partition_has_default_def = BITMAP_ALLOC (NULL);
|
934 |
|
|
for (i = 1; i < num_ssa_names; i++)
|
935 |
|
|
{
|
936 |
|
|
tree t = ssa_name (i);
|
937 |
|
|
if (t && SSA_NAME_IS_DEFAULT_DEF (t))
|
938 |
|
|
{
|
939 |
|
|
int p = var_to_partition (map, t);
|
940 |
|
|
if (p != NO_PARTITION)
|
941 |
|
|
bitmap_set_bit (sa->partition_has_default_def, p);
|
942 |
|
|
}
|
943 |
|
|
}
|
944 |
|
|
}
|
945 |
|
|
|
946 |
|
|
|
947 |
|
|
/* If not already done so for basic block BB, assign increasing uids
|
948 |
|
|
to each of its instructions. */
|
949 |
|
|
|
950 |
|
|
static void
|
951 |
|
|
maybe_renumber_stmts_bb (basic_block bb)
|
952 |
|
|
{
|
953 |
|
|
unsigned i = 0;
|
954 |
|
|
gimple_stmt_iterator gsi;
|
955 |
|
|
|
956 |
|
|
if (!bb->aux)
|
957 |
|
|
return;
|
958 |
|
|
bb->aux = NULL;
|
959 |
|
|
for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
|
960 |
|
|
{
|
961 |
|
|
gimple stmt = gsi_stmt (gsi);
|
962 |
|
|
gimple_set_uid (stmt, i);
|
963 |
|
|
i++;
|
964 |
|
|
}
|
965 |
|
|
}
|
966 |
|
|
|
967 |
|
|
|
968 |
|
|
/* Return true if we can determine that the SSA_NAMEs RESULT (a result
|
969 |
|
|
of a PHI node) and ARG (one of its arguments) conflict. Return false
|
970 |
|
|
otherwise, also when we simply aren't sure. */
|
971 |
|
|
|
972 |
|
|
static bool
|
973 |
|
|
trivially_conflicts_p (basic_block bb, tree result, tree arg)
|
974 |
|
|
{
|
975 |
|
|
use_operand_p use;
|
976 |
|
|
imm_use_iterator imm_iter;
|
977 |
|
|
gimple defa = SSA_NAME_DEF_STMT (arg);
|
978 |
|
|
|
979 |
|
|
/* If ARG isn't defined in the same block it's too complicated for
|
980 |
|
|
our little mind. */
|
981 |
|
|
if (gimple_bb (defa) != bb)
|
982 |
|
|
return false;
|
983 |
|
|
|
984 |
|
|
FOR_EACH_IMM_USE_FAST (use, imm_iter, result)
|
985 |
|
|
{
|
986 |
|
|
gimple use_stmt = USE_STMT (use);
|
987 |
|
|
if (is_gimple_debug (use_stmt))
|
988 |
|
|
continue;
|
989 |
|
|
/* Now, if there's a use of RESULT that lies outside this basic block,
|
990 |
|
|
then there surely is a conflict with ARG. */
|
991 |
|
|
if (gimple_bb (use_stmt) != bb)
|
992 |
|
|
return true;
|
993 |
|
|
if (gimple_code (use_stmt) == GIMPLE_PHI)
|
994 |
|
|
continue;
|
995 |
|
|
/* The use now is in a real stmt of BB, so if ARG was defined
|
996 |
|
|
in a PHI node (like RESULT) both conflict. */
|
997 |
|
|
if (gimple_code (defa) == GIMPLE_PHI)
|
998 |
|
|
return true;
|
999 |
|
|
maybe_renumber_stmts_bb (bb);
|
1000 |
|
|
/* If the use of RESULT occurs after the definition of ARG,
|
1001 |
|
|
the two conflict too. */
|
1002 |
|
|
if (gimple_uid (defa) < gimple_uid (use_stmt))
|
1003 |
|
|
return true;
|
1004 |
|
|
}
|
1005 |
|
|
|
1006 |
|
|
return false;
|
1007 |
|
|
}
|
1008 |
|
|
|
1009 |
|
|
|
1010 |
|
|
/* Search every PHI node for arguments associated with backedges which
|
1011 |
|
|
we can trivially determine will need a copy (the argument is either
|
1012 |
|
|
not an SSA_NAME or the argument has a different underlying variable
|
1013 |
|
|
than the PHI result).
|
1014 |
|
|
|
1015 |
|
|
Insert a copy from the PHI argument to a new destination at the
|
1016 |
|
|
end of the block with the backedge to the top of the loop. Update
|
1017 |
|
|
the PHI argument to reference this new destination. */
|
1018 |
|
|
|
1019 |
|
|
static void
|
1020 |
|
|
insert_backedge_copies (void)
|
1021 |
|
|
{
|
1022 |
|
|
basic_block bb;
|
1023 |
|
|
gimple_stmt_iterator gsi;
|
1024 |
|
|
|
1025 |
|
|
mark_dfs_back_edges ();
|
1026 |
|
|
|
1027 |
|
|
FOR_EACH_BB (bb)
|
1028 |
|
|
{
|
1029 |
|
|
/* Mark block as possibly needing calculation of UIDs. */
|
1030 |
|
|
bb->aux = &bb->aux;
|
1031 |
|
|
|
1032 |
|
|
for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
|
1033 |
|
|
{
|
1034 |
|
|
gimple phi = gsi_stmt (gsi);
|
1035 |
|
|
tree result = gimple_phi_result (phi);
|
1036 |
|
|
tree result_var;
|
1037 |
|
|
size_t i;
|
1038 |
|
|
|
1039 |
|
|
if (!is_gimple_reg (result))
|
1040 |
|
|
continue;
|
1041 |
|
|
|
1042 |
|
|
result_var = SSA_NAME_VAR (result);
|
1043 |
|
|
for (i = 0; i < gimple_phi_num_args (phi); i++)
|
1044 |
|
|
{
|
1045 |
|
|
tree arg = gimple_phi_arg_def (phi, i);
|
1046 |
|
|
edge e = gimple_phi_arg_edge (phi, i);
|
1047 |
|
|
|
1048 |
|
|
/* If the argument is not an SSA_NAME, then we will need a
|
1049 |
|
|
constant initialization. If the argument is an SSA_NAME with
|
1050 |
|
|
a different underlying variable then a copy statement will be
|
1051 |
|
|
needed. */
|
1052 |
|
|
if ((e->flags & EDGE_DFS_BACK)
|
1053 |
|
|
&& (TREE_CODE (arg) != SSA_NAME
|
1054 |
|
|
|| SSA_NAME_VAR (arg) != result_var
|
1055 |
|
|
|| trivially_conflicts_p (bb, result, arg)))
|
1056 |
|
|
{
|
1057 |
|
|
tree name;
|
1058 |
|
|
gimple stmt, last = NULL;
|
1059 |
|
|
gimple_stmt_iterator gsi2;
|
1060 |
|
|
|
1061 |
|
|
gsi2 = gsi_last_bb (gimple_phi_arg_edge (phi, i)->src);
|
1062 |
|
|
if (!gsi_end_p (gsi2))
|
1063 |
|
|
last = gsi_stmt (gsi2);
|
1064 |
|
|
|
1065 |
|
|
/* In theory the only way we ought to get back to the
|
1066 |
|
|
start of a loop should be with a COND_EXPR or GOTO_EXPR.
|
1067 |
|
|
However, better safe than sorry.
|
1068 |
|
|
If the block ends with a control statement or
|
1069 |
|
|
something that might throw, then we have to
|
1070 |
|
|
insert this assignment before the last
|
1071 |
|
|
statement. Else insert it after the last statement. */
|
1072 |
|
|
if (last && stmt_ends_bb_p (last))
|
1073 |
|
|
{
|
1074 |
|
|
/* If the last statement in the block is the definition
|
1075 |
|
|
site of the PHI argument, then we can't insert
|
1076 |
|
|
anything after it. */
|
1077 |
|
|
if (TREE_CODE (arg) == SSA_NAME
|
1078 |
|
|
&& SSA_NAME_DEF_STMT (arg) == last)
|
1079 |
|
|
continue;
|
1080 |
|
|
}
|
1081 |
|
|
|
1082 |
|
|
/* Create a new instance of the underlying variable of the
|
1083 |
|
|
PHI result. */
|
1084 |
|
|
stmt = gimple_build_assign (result_var,
|
1085 |
|
|
gimple_phi_arg_def (phi, i));
|
1086 |
|
|
name = make_ssa_name (result_var, stmt);
|
1087 |
|
|
gimple_assign_set_lhs (stmt, name);
|
1088 |
|
|
|
1089 |
|
|
/* copy location if present. */
|
1090 |
|
|
if (gimple_phi_arg_has_location (phi, i))
|
1091 |
|
|
gimple_set_location (stmt,
|
1092 |
|
|
gimple_phi_arg_location (phi, i));
|
1093 |
|
|
|
1094 |
|
|
/* Insert the new statement into the block and update
|
1095 |
|
|
the PHI node. */
|
1096 |
|
|
if (last && stmt_ends_bb_p (last))
|
1097 |
|
|
gsi_insert_before (&gsi2, stmt, GSI_NEW_STMT);
|
1098 |
|
|
else
|
1099 |
|
|
gsi_insert_after (&gsi2, stmt, GSI_NEW_STMT);
|
1100 |
|
|
SET_PHI_ARG_DEF (phi, i, name);
|
1101 |
|
|
}
|
1102 |
|
|
}
|
1103 |
|
|
}
|
1104 |
|
|
|
1105 |
|
|
/* Unmark this block again. */
|
1106 |
|
|
bb->aux = NULL;
|
1107 |
|
|
}
|
1108 |
|
|
}
|
1109 |
|
|
|
1110 |
|
|
/* Free all memory associated with going out of SSA form. SA is
|
1111 |
|
|
the outof-SSA info object. */
|
1112 |
|
|
|
1113 |
|
|
void
|
1114 |
|
|
finish_out_of_ssa (struct ssaexpand *sa)
|
1115 |
|
|
{
|
1116 |
|
|
free (sa->partition_to_pseudo);
|
1117 |
|
|
if (sa->values)
|
1118 |
|
|
BITMAP_FREE (sa->values);
|
1119 |
|
|
delete_var_map (sa->map);
|
1120 |
|
|
BITMAP_FREE (sa->partition_has_default_def);
|
1121 |
|
|
memset (sa, 0, sizeof *sa);
|
1122 |
|
|
}
|
1123 |
|
|
|
1124 |
|
|
/* Take the current function out of SSA form, translating PHIs as described in
|
1125 |
|
|
R. Morgan, ``Building an Optimizing Compiler'',
|
1126 |
|
|
Butterworth-Heinemann, Boston, MA, 1998. pp 176-186. */
|
1127 |
|
|
|
1128 |
|
|
unsigned int
|
1129 |
|
|
rewrite_out_of_ssa (struct ssaexpand *sa)
|
1130 |
|
|
{
|
1131 |
|
|
/* If elimination of a PHI requires inserting a copy on a backedge,
|
1132 |
|
|
then we will have to split the backedge which has numerous
|
1133 |
|
|
undesirable performance effects.
|
1134 |
|
|
|
1135 |
|
|
A significant number of such cases can be handled here by inserting
|
1136 |
|
|
copies into the loop itself. */
|
1137 |
|
|
insert_backedge_copies ();
|
1138 |
|
|
|
1139 |
|
|
|
1140 |
|
|
/* Eliminate PHIs which are of no use, such as virtual or dead phis. */
|
1141 |
|
|
eliminate_useless_phis ();
|
1142 |
|
|
|
1143 |
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
1144 |
|
|
gimple_dump_cfg (dump_file, dump_flags & ~TDF_DETAILS);
|
1145 |
|
|
|
1146 |
|
|
remove_ssa_form (flag_tree_ter, sa);
|
1147 |
|
|
|
1148 |
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
1149 |
|
|
gimple_dump_cfg (dump_file, dump_flags & ~TDF_DETAILS);
|
1150 |
|
|
|
1151 |
|
|
return 0;
|
1152 |
|
|
}
|