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/* Convert function calls to rtl insns, for GNU C compiler. Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. This file is part of GCC. GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. GCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GCC; see the file COPYING3. If not see <http://www.gnu.org/licenses/>. */ #include "config.h" #include "system.h" #include "coretypes.h" #include "tm.h" #include "rtl.h" #include "tree.h" #include "gimple.h" #include "flags.h" #include "expr.h" #include "optabs.h" #include "libfuncs.h" #include "function.h" #include "regs.h" #include "toplev.h" #include "output.h" #include "tm_p.h" #include "timevar.h" #include "sbitmap.h" #include "langhooks.h" #include "target.h" #include "debug.h" #include "cgraph.h" #include "except.h" #include "dbgcnt.h" #include "tree-flow.h" /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */ #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT) /* Data structure and subroutines used within expand_call. */ struct arg_data { /* Tree node for this argument. */ tree tree_value; /* Mode for value; TYPE_MODE unless promoted. */ enum machine_mode mode; /* Current RTL value for argument, or 0 if it isn't precomputed. */ rtx value; /* Initially-compute RTL value for argument; only for const functions. */ rtx initial_value; /* Register to pass this argument in, 0 if passed on stack, or an PARALLEL if the arg is to be copied into multiple non-contiguous registers. */ rtx reg; /* Register to pass this argument in when generating tail call sequence. This is not the same register as for normal calls on machines with register windows. */ rtx tail_call_reg; /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct form for emit_group_move. */ rtx parallel_value; /* If REG was promoted from the actual mode of the argument expression, indicates whether the promotion is sign- or zero-extended. */ int unsignedp; /* Number of bytes to put in registers. 0 means put the whole arg in registers. Also 0 if not passed in registers. */ int partial; /* Nonzero if argument must be passed on stack. Note that some arguments may be passed on the stack even though pass_on_stack is zero, just because FUNCTION_ARG says so. pass_on_stack identifies arguments that *cannot* go in registers. */ int pass_on_stack; /* Some fields packaged up for locate_and_pad_parm. */ struct locate_and_pad_arg_data locate; /* Location on the stack at which parameter should be stored. The store has already been done if STACK == VALUE. */ rtx stack; /* Location on the stack of the start of this argument slot. This can differ from STACK if this arg pads downward. This location is known to be aligned to FUNCTION_ARG_BOUNDARY. */ rtx stack_slot; /* Place that this stack area has been saved, if needed. */ rtx save_area; /* If an argument's alignment does not permit direct copying into registers, copy in smaller-sized pieces into pseudos. These are stored in a block pointed to by this field. The next field says how many word-sized pseudos we made. */ rtx *aligned_regs; int n_aligned_regs; }; /* A vector of one char per byte of stack space. A byte if nonzero if the corresponding stack location has been used. This vector is used to prevent a function call within an argument from clobbering any stack already set up. */ static char *stack_usage_map; /* Size of STACK_USAGE_MAP. */ static int highest_outgoing_arg_in_use; /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding stack location's tail call argument has been already stored into the stack. This bitmap is used to prevent sibling call optimization if function tries to use parent's incoming argument slots when they have been already overwritten with tail call arguments. */ static sbitmap stored_args_map; /* stack_arg_under_construction is nonzero when an argument may be initialized with a constructor call (including a C function that returns a BLKmode struct) and expand_call must take special action to make sure the object being constructed does not overlap the argument list for the constructor call. */ static int stack_arg_under_construction; static void emit_call_1 (rtx, tree, tree, tree, HOST_WIDE_INT, HOST_WIDE_INT, HOST_WIDE_INT, rtx, rtx, int, rtx, int, CUMULATIVE_ARGS *); static void precompute_register_parameters (int, struct arg_data *, int *); static int store_one_arg (struct arg_data *, rtx, int, int, int); static void store_unaligned_arguments_into_pseudos (struct arg_data *, int); static int finalize_must_preallocate (int, int, struct arg_data *, struct args_size *); static void precompute_arguments (int, struct arg_data *); static int compute_argument_block_size (int, struct args_size *, tree, tree, int); static void initialize_argument_information (int, struct arg_data *, struct args_size *, int, tree, tree, tree, tree, CUMULATIVE_ARGS *, int, rtx *, int *, int *, int *, bool *, bool); static void compute_argument_addresses (struct arg_data *, rtx, int); static rtx rtx_for_function_call (tree, tree); static void load_register_parameters (struct arg_data *, int, rtx *, int, int, int *); static rtx emit_library_call_value_1 (int, rtx, rtx, enum libcall_type, enum machine_mode, int, va_list); static int special_function_p (const_tree, int); static int check_sibcall_argument_overlap_1 (rtx); static int check_sibcall_argument_overlap (rtx, struct arg_data *, int); static int combine_pending_stack_adjustment_and_call (int, struct args_size *, unsigned int); static tree split_complex_types (tree); #ifdef REG_PARM_STACK_SPACE static rtx save_fixed_argument_area (int, rtx, int *, int *); static void restore_fixed_argument_area (rtx, rtx, int, int); #endif /* Force FUNEXP into a form suitable for the address of a CALL, and return that as an rtx. Also load the static chain register if FNDECL is a nested function. CALL_FUSAGE points to a variable holding the prospective CALL_INSN_FUNCTION_USAGE information. */ rtx prepare_call_address (tree fndecl, rtx funexp, rtx static_chain_value, rtx *call_fusage, int reg_parm_seen, int sibcallp) { /* Make a valid memory address and copy constants through pseudo-regs, but not for a constant address if -fno-function-cse. */ if (GET_CODE (funexp) != SYMBOL_REF) /* If we are using registers for parameters, force the function address into a register now. */ funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen) ? force_not_mem (memory_address (FUNCTION_MODE, funexp)) : memory_address (FUNCTION_MODE, funexp)); else if (! sibcallp) { #ifndef NO_FUNCTION_CSE if (optimize && ! flag_no_function_cse) funexp = force_reg (Pmode, funexp); #endif } if (static_chain_value != 0) { rtx chain; gcc_assert (fndecl); chain = targetm.calls.static_chain (fndecl, false); static_chain_value = convert_memory_address (Pmode, static_chain_value); emit_move_insn (chain, static_chain_value); if (REG_P (chain)) use_reg (call_fusage, chain); } return funexp; } /* Generate instructions to call function FUNEXP, and optionally pop the results. The CALL_INSN is the first insn generated. FNDECL is the declaration node of the function. This is given to the macro RETURN_POPS_ARGS to determine whether this function pops its own args. FUNTYPE is the data type of the function. This is given to the macro RETURN_POPS_ARGS to determine whether this function pops its own args. We used to allow an identifier for library functions, but that doesn't work when the return type is an aggregate type and the calling convention says that the pointer to this aggregate is to be popped by the callee. STACK_SIZE is the number of bytes of arguments on the stack, ROUNDED_STACK_SIZE is that number rounded up to PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is both to put into the call insn and to generate explicit popping code if necessary. STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value. It is zero if this call doesn't want a structure value. NEXT_ARG_REG is the rtx that results from executing FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1) just after all the args have had their registers assigned. This could be whatever you like, but normally it is the first arg-register beyond those used for args in this call, or 0 if all the arg-registers are used in this call. It is passed on to `gen_call' so you can put this info in the call insn. VALREG is a hard register in which a value is returned, or 0 if the call does not return a value. OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before the args to this call were processed. We restore `inhibit_defer_pop' to that value. CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that denote registers used by the called function. */ static void emit_call_1 (rtx funexp, tree fntree ATTRIBUTE_UNUSED, tree fndecl ATTRIBUTE_UNUSED, tree funtype ATTRIBUTE_UNUSED, HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED, HOST_WIDE_INT rounded_stack_size, HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED, rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg, int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags, CUMULATIVE_ARGS *args_so_far ATTRIBUTE_UNUSED) { rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size); rtx call_insn; int already_popped = 0; HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size); #ifdef CALL_POPS_ARGS n_popped += CALL_POPS_ARGS (* args_so_far); #endif /* Ensure address is valid. SYMBOL_REF is already valid, so no need, and we don't want to load it into a register as an optimization, because prepare_call_address already did it if it should be done. */ if (GET_CODE (funexp) != SYMBOL_REF) funexp = memory_address (FUNCTION_MODE, funexp); #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop) if ((ecf_flags & ECF_SIBCALL) && HAVE_sibcall_pop && HAVE_sibcall_value_pop && (n_popped > 0 || stack_size == 0)) { rtx n_pop = GEN_INT (n_popped); rtx pat; /* If this subroutine pops its own args, record that in the call insn if possible, for the sake of frame pointer elimination. */ if (valreg) pat = GEN_SIBCALL_VALUE_POP (valreg, gen_rtx_MEM (FUNCTION_MODE, funexp), rounded_stack_size_rtx, next_arg_reg, n_pop); else pat = GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp), rounded_stack_size_rtx, next_arg_reg, n_pop); emit_call_insn (pat); already_popped = 1; } else #endif #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop) /* If the target has "call" or "call_value" insns, then prefer them if no arguments are actually popped. If the target does not have "call" or "call_value" insns, then we must use the popping versions even if the call has no arguments to pop. */ #if defined (HAVE_call) && defined (HAVE_call_value) if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop && n_popped > 0) #else if (HAVE_call_pop && HAVE_call_value_pop) #endif { rtx n_pop = GEN_INT (n_popped); rtx pat; /* If this subroutine pops its own args, record that in the call insn if possible, for the sake of frame pointer elimination. */ if (valreg) pat = GEN_CALL_VALUE_POP (valreg, gen_rtx_MEM (FUNCTION_MODE, funexp), rounded_stack_size_rtx, next_arg_reg, n_pop); else pat = GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp), rounded_stack_size_rtx, next_arg_reg, n_pop); emit_call_insn (pat); already_popped = 1; } else #endif #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value) if ((ecf_flags & ECF_SIBCALL) && HAVE_sibcall && HAVE_sibcall_value) { if (valreg) emit_call_insn (GEN_SIBCALL_VALUE (valreg, gen_rtx_MEM (FUNCTION_MODE, funexp), rounded_stack_size_rtx, next_arg_reg, NULL_RTX)); else emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE, funexp), rounded_stack_size_rtx, next_arg_reg, GEN_INT (struct_value_size))); } else #endif #if defined (HAVE_call) && defined (HAVE_call_value) if (HAVE_call && HAVE_call_value) { if (valreg) emit_call_insn (GEN_CALL_VALUE (valreg, gen_rtx_MEM (FUNCTION_MODE, funexp), rounded_stack_size_rtx, next_arg_reg, NULL_RTX)); else emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE, funexp), rounded_stack_size_rtx, next_arg_reg, GEN_INT (struct_value_size))); } else #endif gcc_unreachable (); /* Find the call we just emitted. */ call_insn = last_call_insn (); /* Put the register usage information there. */ add_function_usage_to (call_insn, call_fusage); /* If this is a const call, then set the insn's unchanging bit. */ if (ecf_flags & ECF_CONST) RTL_CONST_CALL_P (call_insn) = 1; /* If this is a pure call, then set the insn's unchanging bit. */ if (ecf_flags & ECF_PURE) RTL_PURE_CALL_P (call_insn) = 1; /* If this is a const call, then set the insn's unchanging bit. */ if (ecf_flags & ECF_LOOPING_CONST_OR_PURE) RTL_LOOPING_CONST_OR_PURE_CALL_P (call_insn) = 1; /* Create a nothrow REG_EH_REGION note, if needed. */ make_reg_eh_region_note (call_insn, ecf_flags, 0); if (ecf_flags & ECF_NORETURN) add_reg_note (call_insn, REG_NORETURN, const0_rtx); if (ecf_flags & ECF_RETURNS_TWICE) { add_reg_note (call_insn, REG_SETJMP, const0_rtx); cfun->calls_setjmp = 1; } SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0); /* Record debug information for virtual calls. */ if (flag_enable_icf_debug && fndecl == NULL) (*debug_hooks->virtual_call_token) (CALL_EXPR_FN (fntree), INSN_UID (call_insn)); /* Restore this now, so that we do defer pops for this call's args if the context of the call as a whole permits. */ inhibit_defer_pop = old_inhibit_defer_pop; if (n_popped > 0) { if (!already_popped) CALL_INSN_FUNCTION_USAGE (call_insn) = gen_rtx_EXPR_LIST (VOIDmode, gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx), CALL_INSN_FUNCTION_USAGE (call_insn)); rounded_stack_size -= n_popped; rounded_stack_size_rtx = GEN_INT (rounded_stack_size); stack_pointer_delta -= n_popped; /* If popup is needed, stack realign must use DRAP */ if (SUPPORTS_STACK_ALIGNMENT) crtl->need_drap = true; } if (!ACCUMULATE_OUTGOING_ARGS) { /* If returning from the subroutine does not automatically pop the args, we need an instruction to pop them sooner or later. Perhaps do it now; perhaps just record how much space to pop later. If returning from the subroutine does pop the args, indicate that the stack pointer will be changed. */ if (rounded_stack_size != 0) { if (ecf_flags & ECF_NORETURN) /* Just pretend we did the pop. */ stack_pointer_delta -= rounded_stack_size; else if (flag_defer_pop && inhibit_defer_pop == 0 && ! (ecf_flags & (ECF_CONST | ECF_PURE))) pending_stack_adjust += rounded_stack_size; else adjust_stack (rounded_stack_size_rtx); } } /* When we accumulate outgoing args, we must avoid any stack manipulations. Restore the stack pointer to its original value now. Usually ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions. On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and popping variants of functions exist as well. ??? We may optimize similar to defer_pop above, but it is probably not worthwhile. ??? It will be worthwhile to enable combine_stack_adjustments even for such machines. */ else if (n_popped) anti_adjust_stack (GEN_INT (n_popped)); } /* Determine if the function identified by NAME and FNDECL is one with special properties we wish to know about. For example, if the function might return more than one time (setjmp), then set RETURNS_TWICE to a nonzero value. Similarly set NORETURN if the function is in the longjmp family. Set MAY_BE_ALLOCA for any memory allocation function that might allocate space from the stack such as alloca. */ static int special_function_p (const_tree fndecl, int flags) { if (fndecl && DECL_NAME (fndecl) && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17 /* Exclude functions not at the file scope, or not `extern', since they are not the magic functions we would otherwise think they are. FIXME: this should be handled with attributes, not with this hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong because you can declare fork() inside a function if you wish. */ && (DECL_CONTEXT (fndecl) == NULL_TREE || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL) && TREE_PUBLIC (fndecl)) { const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl)); const char *tname = name; /* We assume that alloca will always be called by name. It makes no sense to pass it as a pointer-to-function to anything that does not understand its behavior. */ if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6 && name[0] == 'a' && ! strcmp (name, "alloca")) || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16 && name[0] == '_' && ! strcmp (name, "__builtin_alloca")))) flags |= ECF_MAY_BE_ALLOCA; /* Disregard prefix _, __, __x or __builtin_. */ if (name[0] == '_') { if (name[1] == '_' && name[2] == 'b' && !strncmp (name + 3, "uiltin_", 7)) tname += 10; else if (name[1] == '_' && name[2] == 'x') tname += 3; else if (name[1] == '_') tname += 2; else tname += 1; } if (tname[0] == 's') { if ((tname[1] == 'e' && (! strcmp (tname, "setjmp") || ! strcmp (tname, "setjmp_syscall"))) || (tname[1] == 'i' && ! strcmp (tname, "sigsetjmp")) || (tname[1] == 'a' && ! strcmp (tname, "savectx"))) flags |= ECF_RETURNS_TWICE; if (tname[1] == 'i' && ! strcmp (tname, "siglongjmp")) flags |= ECF_NORETURN; } else if ((tname[0] == 'q' && tname[1] == 's' && ! strcmp (tname, "qsetjmp")) || (tname[0] == 'v' && tname[1] == 'f' && ! strcmp (tname, "vfork")) || (tname[0] == 'g' && tname[1] == 'e' && !strcmp (tname, "getcontext"))) flags |= ECF_RETURNS_TWICE; else if (tname[0] == 'l' && tname[1] == 'o' && ! strcmp (tname, "longjmp")) flags |= ECF_NORETURN; } return flags; } /* Return nonzero when FNDECL represents a call to setjmp. */ int setjmp_call_p (const_tree fndecl) { return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE; } /* Return true if STMT is an alloca call. */ bool gimple_alloca_call_p (const_gimple stmt) { tree fndecl; if (!is_gimple_call (stmt)) return false; fndecl = gimple_call_fndecl (stmt); if (fndecl && (special_function_p (fndecl, 0) & ECF_MAY_BE_ALLOCA)) return true; return false; } /* Return true when exp contains alloca call. */ bool alloca_call_p (const_tree exp) { if (TREE_CODE (exp) == CALL_EXPR && TREE_CODE (CALL_EXPR_FN (exp)) == ADDR_EXPR && (TREE_CODE (TREE_OPERAND (CALL_EXPR_FN (exp), 0)) == FUNCTION_DECL) && (special_function_p (TREE_OPERAND (CALL_EXPR_FN (exp), 0), 0) & ECF_MAY_BE_ALLOCA)) return true; return false; } /* Detect flags (function attributes) from the function decl or type node. */ int flags_from_decl_or_type (const_tree exp) { int flags = 0; if (DECL_P (exp)) { /* The function exp may have the `malloc' attribute. */ if (DECL_IS_MALLOC (exp)) flags |= ECF_MALLOC; /* The function exp may have the `returns_twice' attribute. */ if (DECL_IS_RETURNS_TWICE (exp)) flags |= ECF_RETURNS_TWICE; /* Process the pure and const attributes. */ if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp)) flags |= ECF_CONST; if (DECL_PURE_P (exp)) flags |= ECF_PURE; if (DECL_LOOPING_CONST_OR_PURE_P (exp)) flags |= ECF_LOOPING_CONST_OR_PURE; if (DECL_IS_NOVOPS (exp)) flags |= ECF_NOVOPS; if (TREE_NOTHROW (exp)) flags |= ECF_NOTHROW; flags = special_function_p (exp, flags); } else if (TYPE_P (exp) && TYPE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp)) flags |= ECF_CONST; if (TREE_THIS_VOLATILE (exp)) flags |= ECF_NORETURN; return flags; } /* Detect flags from a CALL_EXPR. */ int call_expr_flags (const_tree t) { int flags; tree decl = get_callee_fndecl (t); if (decl) flags = flags_from_decl_or_type (decl); else { t = TREE_TYPE (CALL_EXPR_FN (t)); if (t && TREE_CODE (t) == POINTER_TYPE) flags = flags_from_decl_or_type (TREE_TYPE (t)); else flags = 0; } return flags; } /* Precompute all register parameters as described by ARGS, storing values into fields within the ARGS array. NUM_ACTUALS indicates the total number elements in the ARGS array. Set REG_PARM_SEEN if we encounter a register parameter. */ static void precompute_register_parameters (int num_actuals, struct arg_data *args, int *reg_parm_seen) { int i; *reg_parm_seen = 0; for (i = 0; i < num_actuals; i++) if (args[i].reg != 0 && ! args[i].pass_on_stack) { *reg_parm_seen = 1; if (args[i].value == 0) { push_temp_slots (); args[i].value = expand_normal (args[i].tree_value); preserve_temp_slots (args[i].value); pop_temp_slots (); } /* If the value is a non-legitimate constant, force it into a pseudo now. TLS symbols sometimes need a call to resolve. */ if (CONSTANT_P (args[i].value) && !LEGITIMATE_CONSTANT_P (args[i].value)) args[i].value = force_reg (args[i].mode, args[i].value); /* If we are to promote the function arg to a wider mode, do it now. */ if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value))) args[i].value = convert_modes (args[i].mode, TYPE_MODE (TREE_TYPE (args[i].tree_value)), args[i].value, args[i].unsignedp); /* If we're going to have to load the value by parts, pull the parts into pseudos. The part extraction process can involve non-trivial computation. */ if (GET_CODE (args[i].reg) == PARALLEL) { tree type = TREE_TYPE (args[i].tree_value); args[i].parallel_value = emit_group_load_into_temps (args[i].reg, args[i].value, type, int_size_in_bytes (type)); } /* If the value is expensive, and we are inside an appropriately short loop, put the value into a pseudo and then put the pseudo into the hard reg. For small register classes, also do this if this call uses register parameters. This is to avoid reload conflicts while loading the parameters registers. */ else if ((! (REG_P (args[i].value) || (GET_CODE (args[i].value) == SUBREG && REG_P (SUBREG_REG (args[i].value))))) && args[i].mode != BLKmode && rtx_cost (args[i].value, SET, optimize_insn_for_speed_p ()) > COSTS_N_INSNS (1) && ((SMALL_REGISTER_CLASSES && *reg_parm_seen) || optimize)) args[i].value = copy_to_mode_reg (args[i].mode, args[i].value); } } #ifdef REG_PARM_STACK_SPACE /* The argument list is the property of the called routine and it may clobber it. If the fixed area has been used for previous parameters, we must save and restore it. */ static rtx save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save) { int low; int high; /* Compute the boundary of the area that needs to be saved, if any. */ high = reg_parm_stack_space; #ifdef ARGS_GROW_DOWNWARD high += 1; #endif if (high > highest_outgoing_arg_in_use) high = highest_outgoing_arg_in_use; for (low = 0; low < high; low++) if (stack_usage_map[low] != 0) { int num_to_save; enum machine_mode save_mode; int delta; rtx stack_area; rtx save_area; while (stack_usage_map[--high] == 0) ; *low_to_save = low; *high_to_save = high; num_to_save = high - low + 1; save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1); /* If we don't have the required alignment, must do this in BLKmode. */ if ((low & (MIN (GET_MODE_SIZE (save_mode), BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1))) save_mode = BLKmode; #ifdef ARGS_GROW_DOWNWARD delta = -high; #else delta = low; #endif stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, plus_constant (argblock, delta))); set_mem_align (stack_area, PARM_BOUNDARY); if (save_mode == BLKmode) { save_area = assign_stack_temp (BLKmode, num_to_save, 0); emit_block_move (validize_mem (save_area), stack_area, GEN_INT (num_to_save), BLOCK_OP_CALL_PARM); } else { save_area = gen_reg_rtx (save_mode); emit_move_insn (save_area, stack_area); } return save_area; } return NULL_RTX; } static void restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save) { enum machine_mode save_mode = GET_MODE (save_area); int delta; rtx stack_area; #ifdef ARGS_GROW_DOWNWARD delta = -high_to_save; #else delta = low_to_save; #endif stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, plus_constant (argblock, delta))); set_mem_align (stack_area, PARM_BOUNDARY); if (save_mode != BLKmode) emit_move_insn (stack_area, save_area); else emit_block_move (stack_area, validize_mem (save_area), GEN_INT (high_to_save - low_to_save + 1), BLOCK_OP_CALL_PARM); } #endif /* REG_PARM_STACK_SPACE */ /* If any elements in ARGS refer to parameters that are to be passed in registers, but not in memory, and whose alignment does not permit a direct copy into registers. Copy the values into a group of pseudos which we will later copy into the appropriate hard registers. Pseudos for each unaligned argument will be stored into the array args[argnum].aligned_regs. The caller is responsible for deallocating the aligned_regs array if it is nonzero. */ static void store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals) { int i, j; for (i = 0; i < num_actuals; i++) if (args[i].reg != 0 && ! args[i].pass_on_stack && args[i].mode == BLKmode && MEM_P (args[i].value) && (MEM_ALIGN (args[i].value) < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD))) { int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value)); int endian_correction = 0; if (args[i].partial) { gcc_assert (args[i].partial % UNITS_PER_WORD == 0); args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD; } else { args[i].n_aligned_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD; } args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs); /* Structures smaller than a word are normally aligned to the least significant byte. On a BYTES_BIG_ENDIAN machine, this means we must skip the empty high order bytes when calculating the bit offset. */ if (bytes < UNITS_PER_WORD #ifdef BLOCK_REG_PADDING && (BLOCK_REG_PADDING (args[i].mode, TREE_TYPE (args[i].tree_value), 1) == downward) #else && BYTES_BIG_ENDIAN #endif ) endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT; for (j = 0; j < args[i].n_aligned_regs; j++) { rtx reg = gen_reg_rtx (word_mode); rtx word = operand_subword_force (args[i].value, j, BLKmode); int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD); args[i].aligned_regs[j] = reg; word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX, word_mode, word_mode); /* There is no need to restrict this code to loading items in TYPE_ALIGN sized hunks. The bitfield instructions can load up entire word sized registers efficiently. ??? This may not be needed anymore. We use to emit a clobber here but that doesn't let later passes optimize the instructions we emit. By storing 0 into the register later passes know the first AND to zero out the bitfield being set in the register is unnecessary. The store of 0 will be deleted as will at least the first AND. */ emit_move_insn (reg, const0_rtx); bytes -= bitsize / BITS_PER_UNIT; store_bit_field (reg, bitsize, endian_correction, word_mode, word); } } } /* Fill in ARGS_SIZE and ARGS array based on the parameters found in CALL_EXPR EXP. NUM_ACTUALS is the total number of parameters. N_NAMED_ARGS is the total number of named arguments. STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return value, or null. FNDECL is the tree code for the target of this call (if known) ARGS_SO_FAR holds state needed by the target to know where to place the next argument. REG_PARM_STACK_SPACE is the number of bytes of stack space reserved for arguments which are passed in registers. OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level and may be modified by this routine. OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer flags which may may be modified by this routine. MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference that requires allocation of stack space. CALL_FROM_THUNK_P is true if this call is the jump from a thunk to the thunked-to function. */ static void initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED, struct arg_data *args, struct args_size *args_size, int n_named_args ATTRIBUTE_UNUSED, tree exp, tree struct_value_addr_value, tree fndecl, tree fntype, CUMULATIVE_ARGS *args_so_far, int reg_parm_stack_space, rtx *old_stack_level, int *old_pending_adj, int *must_preallocate, int *ecf_flags, bool *may_tailcall, bool call_from_thunk_p) { location_t loc = EXPR_LOCATION (exp); /* 1 if scanning parms front to back, -1 if scanning back to front. */ int inc; /* Count arg position in order args appear. */ int argpos; int i; args_size->constant = 0; args_size->var = 0; /* In this loop, we consider args in the order they are written. We fill up ARGS from the front or from the back if necessary so that in any case the first arg to be pushed ends up at the front. */ if (PUSH_ARGS_REVERSED) { i = num_actuals - 1, inc = -1; /* In this case, must reverse order of args so that we compute and push the last arg first. */ } else { i = 0, inc = 1; } /* First fill in the actual arguments in the ARGS array, splitting complex arguments if necessary. */ { int j = i; call_expr_arg_iterator iter; tree arg; if (struct_value_addr_value) { args[j].tree_value = struct_value_addr_value; j += inc; } FOR_EACH_CALL_EXPR_ARG (arg, iter, exp) { tree argtype = TREE_TYPE (arg); if (targetm.calls.split_complex_arg && argtype && TREE_CODE (argtype) == COMPLEX_TYPE && targetm.calls.split_complex_arg (argtype)) { tree subtype = TREE_TYPE (argtype); args[j].tree_value = build1 (REALPART_EXPR, subtype, arg); j += inc; args[j].tree_value = build1 (IMAGPART_EXPR, subtype, arg); } else args[j].tree_value = arg; j += inc; } } /* I counts args in order (to be) pushed; ARGPOS counts in order written. */ for (argpos = 0; argpos < num_actuals; i += inc, argpos++) { tree type = TREE_TYPE (args[i].tree_value); int unsignedp; enum machine_mode mode; /* Replace erroneous argument with constant zero. */ if (type == error_mark_node || !COMPLETE_TYPE_P (type)) args[i].tree_value = integer_zero_node, type = integer_type_node; /* If TYPE is a transparent union or record, pass things the way we would pass the first field of the union or record. We have already verified that the modes are the same. */ if ((TREE_CODE (type) == UNION_TYPE || TREE_CODE (type) == RECORD_TYPE) && TYPE_TRANSPARENT_AGGR (type)) type = TREE_TYPE (first_field (type)); /* Decide where to pass this arg. args[i].reg is nonzero if all or part is passed in registers. args[i].partial is nonzero if part but not all is passed in registers, and the exact value says how many bytes are passed in registers. args[i].pass_on_stack is nonzero if the argument must at least be computed on the stack. It may then be loaded back into registers if args[i].reg is nonzero. These decisions are driven by the FUNCTION_... macros and must agree with those made by function.c. */ /* See if this argument should be passed by invisible reference. */ if (pass_by_reference (args_so_far, TYPE_MODE (type), type, argpos < n_named_args)) { bool callee_copies; tree base; callee_copies = reference_callee_copied (args_so_far, TYPE_MODE (type), type, argpos < n_named_args); /* If we're compiling a thunk, pass through invisible references instead of making a copy. */ if (call_from_thunk_p || (callee_copies && !TREE_ADDRESSABLE (type) && (base = get_base_address (args[i].tree_value)) && TREE_CODE (base) != SSA_NAME && (!DECL_P (base) || MEM_P (DECL_RTL (base))))) { /* We can't use sibcalls if a callee-copied argument is stored in the current function's frame. */ if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base)) *may_tailcall = false; args[i].tree_value = build_fold_addr_expr_loc (loc, args[i].tree_value); type = TREE_TYPE (args[i].tree_value); if (*ecf_flags & ECF_CONST) *ecf_flags &= ~(ECF_CONST | ECF_LOOPING_CONST_OR_PURE); } else { /* We make a copy of the object and pass the address to the function being called. */ rtx copy; if (!COMPLETE_TYPE_P (type) || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST || (flag_stack_check == GENERIC_STACK_CHECK && compare_tree_int (TYPE_SIZE_UNIT (type), STACK_CHECK_MAX_VAR_SIZE) > 0)) { /* This is a variable-sized object. Make space on the stack for it. */ rtx size_rtx = expr_size (args[i].tree_value); if (*old_stack_level == 0) { emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX); *old_pending_adj = pending_stack_adjust; pending_stack_adjust = 0; } copy = gen_rtx_MEM (BLKmode, allocate_dynamic_stack_space (size_rtx, NULL_RTX, TYPE_ALIGN (type))); set_mem_attributes (copy, type, 1); } else copy = assign_temp (type, 0, 1, 0); store_expr (args[i].tree_value, copy, 0, false); /* Just change the const function to pure and then let the next test clear the pure based on callee_copies. */ if (*ecf_flags & ECF_CONST) { *ecf_flags &= ~ECF_CONST; *ecf_flags |= ECF_PURE; } if (!callee_copies && *ecf_flags & ECF_PURE) *ecf_flags &= ~(ECF_PURE | ECF_LOOPING_CONST_OR_PURE); args[i].tree_value = build_fold_addr_expr_loc (loc, make_tree (type, copy)); type = TREE_TYPE (args[i].tree_value); *may_tailcall = false; } } unsignedp = TYPE_UNSIGNED (type); mode = promote_function_mode (type, TYPE_MODE (type), &unsignedp, fndecl ? TREE_TYPE (fndecl) : fntype, 0); args[i].unsignedp = unsignedp; args[i].mode = mode; args[i].reg = FUNCTION_ARG (*args_so_far, mode, type, argpos < n_named_args); #ifdef FUNCTION_INCOMING_ARG /* If this is a sibling call and the machine has register windows, the register window has to be unwinded before calling the routine, so arguments have to go into the incoming registers. */ args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type, argpos < n_named_args); #else args[i].tail_call_reg = args[i].reg; #endif if (args[i].reg) args[i].partial = targetm.calls.arg_partial_bytes (args_so_far, mode, type, argpos < n_named_args); args[i].pass_on_stack = targetm.calls.must_pass_in_stack (mode, type); /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]), it means that we are to pass this arg in the register(s) designated by the PARALLEL, but also to pass it in the stack. */ if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0) args[i].pass_on_stack = 1; /* If this is an addressable type, we must preallocate the stack since we must evaluate the object into its final location. If this is to be passed in both registers and the stack, it is simpler to preallocate. */ if (TREE_ADDRESSABLE (type) || (args[i].pass_on_stack && args[i].reg != 0)) *must_preallocate = 1; /* Compute the stack-size of this argument. */ if (args[i].reg == 0 || args[i].partial != 0 || reg_parm_stack_space > 0 || args[i].pass_on_stack) locate_and_pad_parm (mode, type, #ifdef STACK_PARMS_IN_REG_PARM_AREA 1, #else args[i].reg != 0, #endif args[i].pass_on_stack ? 0 : args[i].partial, fndecl, args_size, &args[i].locate); #ifdef BLOCK_REG_PADDING else /* The argument is passed entirely in registers. See at which end it should be padded. */ args[i].locate.where_pad = BLOCK_REG_PADDING (mode, type, int_size_in_bytes (type) <= UNITS_PER_WORD); #endif /* Update ARGS_SIZE, the total stack space for args so far. */ args_size->constant += args[i].locate.size.constant; if (args[i].locate.size.var) ADD_PARM_SIZE (*args_size, args[i].locate.size.var); /* Increment ARGS_SO_FAR, which has info about which arg-registers have been used, etc. */ FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type, argpos < n_named_args); } } /* Update ARGS_SIZE to contain the total size for the argument block. Return the original constant component of the argument block's size. REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved for arguments passed in registers. */ static int compute_argument_block_size (int reg_parm_stack_space, struct args_size *args_size, tree fndecl ATTRIBUTE_UNUSED, tree fntype ATTRIBUTE_UNUSED, int preferred_stack_boundary ATTRIBUTE_UNUSED) { int unadjusted_args_size = args_size->constant; /* For accumulate outgoing args mode we don't need to align, since the frame will be already aligned. Align to STACK_BOUNDARY in order to prevent backends from generating misaligned frame sizes. */ if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY) preferred_stack_boundary = STACK_BOUNDARY; /* Compute the actual size of the argument block required. The variable and constant sizes must be combined, the size may have to be rounded, and there may be a minimum required size. */ if (args_size->var) { args_size->var = ARGS_SIZE_TREE (*args_size); args_size->constant = 0; preferred_stack_boundary /= BITS_PER_UNIT; if (preferred_stack_boundary > 1) { /* We don't handle this case yet. To handle it correctly we have to add the delta, round and subtract the delta. Currently no machine description requires this support. */ gcc_assert (!(stack_pointer_delta & (preferred_stack_boundary - 1))); args_size->var = round_up (args_size->var, preferred_stack_boundary); } if (reg_parm_stack_space > 0) { args_size->var = size_binop (MAX_EXPR, args_size->var, ssize_int (reg_parm_stack_space)); /* The area corresponding to register parameters is not to count in the size of the block we need. So make the adjustment. */ if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))) args_size->var = size_binop (MINUS_EXPR, args_size->var, ssize_int (reg_parm_stack_space)); } } else { preferred_stack_boundary /= BITS_PER_UNIT; if (preferred_stack_boundary < 1) preferred_stack_boundary = 1; args_size->constant = (((args_size->constant + stack_pointer_delta + preferred_stack_boundary - 1) / preferred_stack_boundary * preferred_stack_boundary) - stack_pointer_delta); args_size->constant = MAX (args_size->constant, reg_parm_stack_space); if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))) args_size->constant -= reg_parm_stack_space; } return unadjusted_args_size; } /* Precompute parameters as needed for a function call. FLAGS is mask of ECF_* constants. NUM_ACTUALS is the number of arguments. ARGS is an array containing information for each argument; this routine fills in the INITIAL_VALUE and VALUE fields for each precomputed argument. */ static void precompute_arguments (int num_actuals, struct arg_data *args) { int i; /* If this is a libcall, then precompute all arguments so that we do not get extraneous instructions emitted as part of the libcall sequence. */ /* If we preallocated the stack space, and some arguments must be passed on the stack, then we must precompute any parameter which contains a function call which will store arguments on the stack. Otherwise, evaluating the parameter may clobber previous parameters which have already been stored into the stack. (we have code to avoid such case by saving the outgoing stack arguments, but it results in worse code) */ if (!ACCUMULATE_OUTGOING_ARGS) return; for (i = 0; i < num_actuals; i++) { tree type; enum machine_mode mode; if (TREE_CODE (args[i].tree_value) != CALL_EXPR) continue; /* If this is an addressable type, we cannot pre-evaluate it. */ type = TREE_TYPE (args[i].tree_value); gcc_assert (!TREE_ADDRESSABLE (type)); args[i].initial_value = args[i].value = expand_normal (args[i].tree_value); mode = TYPE_MODE (type); if (mode != args[i].mode) { int unsignedp = args[i].unsignedp; args[i].value = convert_modes (args[i].mode, mode, args[i].value, args[i].unsignedp); /* CSE will replace this only if it contains args[i].value pseudo, so convert it down to the declared mode using a SUBREG. */ if (REG_P (args[i].value) && GET_MODE_CLASS (args[i].mode) == MODE_INT && promote_mode (type, mode, &unsignedp) != args[i].mode) { args[i].initial_value = gen_lowpart_SUBREG (mode, args[i].value); SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1; SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value, args[i].unsignedp); } } } } /* Given the current state of MUST_PREALLOCATE and information about arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE, compute and return the final value for MUST_PREALLOCATE. */ static int finalize_must_preallocate (int must_preallocate, int num_actuals, struct arg_data *args, struct args_size *args_size) { /* See if we have or want to preallocate stack space. If we would have to push a partially-in-regs parm before other stack parms, preallocate stack space instead. If the size of some parm is not a multiple of the required stack alignment, we must preallocate. If the total size of arguments that would otherwise create a copy in a temporary (such as a CALL) is more than half the total argument list size, preallocation is faster. Another reason to preallocate is if we have a machine (like the m88k) where stack alignment is required to be maintained between every pair of insns, not just when the call is made. However, we assume here that such machines either do not have push insns (and hence preallocation would occur anyway) or the problem is taken care of with PUSH_ROUNDING. */ if (! must_preallocate) { int partial_seen = 0; int copy_to_evaluate_size = 0; int i; for (i = 0; i < num_actuals && ! must_preallocate; i++) { if (args[i].partial > 0 && ! args[i].pass_on_stack) partial_seen = 1; else if (partial_seen && args[i].reg == 0) must_preallocate = 1; if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode && (TREE_CODE (args[i].tree_value) == CALL_EXPR || TREE_CODE (args[i].tree_value) == TARGET_EXPR || TREE_CODE (args[i].tree_value) == COND_EXPR || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)))) copy_to_evaluate_size += int_size_in_bytes (TREE_TYPE (args[i].tree_value)); } if (copy_to_evaluate_size * 2 >= args_size->constant && args_size->constant > 0) must_preallocate = 1; } return must_preallocate; } /* If we preallocated stack space, compute the address of each argument and store it into the ARGS array. We need not ensure it is a valid memory address here; it will be validized when it is used. ARGBLOCK is an rtx for the address of the outgoing arguments. */ static void compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals) { if (argblock) { rtx arg_reg = argblock; int i, arg_offset = 0; if (GET_CODE (argblock) == PLUS) arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1)); for (i = 0; i < num_actuals; i++) { rtx offset = ARGS_SIZE_RTX (args[i].locate.offset); rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset); rtx addr; unsigned int align, boundary; unsigned int units_on_stack = 0; enum machine_mode partial_mode = VOIDmode; /* Skip this parm if it will not be passed on the stack. */ if (! args[i].pass_on_stack && args[i].reg != 0 && args[i].partial == 0) continue; if (CONST_INT_P (offset)) addr = plus_constant (arg_reg, INTVAL (offset)); else addr = gen_rtx_PLUS (Pmode, arg_reg, offset); addr = plus_constant (addr, arg_offset); if (args[i].partial != 0) { /* Only part of the parameter is being passed on the stack. Generate a simple memory reference of the correct size. */ units_on_stack = args[i].locate.size.constant; partial_mode = mode_for_size (units_on_stack * BITS_PER_UNIT, MODE_INT, 1); args[i].stack = gen_rtx_MEM (partial_mode, addr); set_mem_size (args[i].stack, GEN_INT (units_on_stack)); } else { args[i].stack = gen_rtx_MEM (args[i].mode, addr); set_mem_attributes (args[i].stack, TREE_TYPE (args[i].tree_value), 1); } align = BITS_PER_UNIT; boundary = args[i].locate.boundary; if (args[i].locate.where_pad != downward) align = boundary; else if (CONST_INT_P (offset)) { align = INTVAL (offset) * BITS_PER_UNIT | boundary; align = align & -align; } set_mem_align (args[i].stack, align); if (CONST_INT_P (slot_offset)) addr = plus_constant (arg_reg, INTVAL (slot_offset)); else addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset); addr = plus_constant (addr, arg_offset); if (args[i].partial != 0) { /* Only part of the parameter is being passed on the stack. Generate a simple memory reference of the correct size. */ args[i].stack_slot = gen_rtx_MEM (partial_mode, addr); set_mem_size (args[i].stack_slot, GEN_INT (units_on_stack)); } else { args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr); set_mem_attributes (args[i].stack_slot, TREE_TYPE (args[i].tree_value), 1); } set_mem_align (args[i].stack_slot, args[i].locate.boundary); /* Function incoming arguments may overlap with sibling call outgoing arguments and we cannot allow reordering of reads from function arguments with stores to outgoing arguments of sibling calls. */ set_mem_alias_set (args[i].stack, 0); set_mem_alias_set (args[i].stack_slot, 0); } } } /* Given a FNDECL and EXP, return an rtx suitable for use as a target address in a call instruction. FNDECL is the tree node for the target function. For an indirect call FNDECL will be NULL_TREE. ADDR is the operand 0 of CALL_EXPR for this call. */ static rtx rtx_for_function_call (tree fndecl, tree addr) { rtx funexp; /* Get the function to call, in the form of RTL. */ if (fndecl) { /* If this is the first use of the function, see if we need to make an external definition for it. */ if (!TREE_USED (fndecl) && fndecl != current_function_decl) { assemble_external (fndecl); TREE_USED (fndecl) = 1; } /* Get a SYMBOL_REF rtx for the function address. */ funexp = XEXP (DECL_RTL (fndecl), 0); } else /* Generate an rtx (probably a pseudo-register) for the address. */ { push_temp_slots (); funexp = expand_normal (addr); pop_temp_slots (); /* FUNEXP can't be BLKmode. */ } return funexp; } /* Return true if and only if SIZE storage units (usually bytes) starting from address ADDR overlap with already clobbered argument area. This function is used to determine if we should give up a sibcall. */ static bool mem_overlaps_already_clobbered_arg_p (rtx addr, unsigned HOST_WIDE_INT size) { HOST_WIDE_INT i; if (addr == crtl->args.internal_arg_pointer) i = 0; else if (GET_CODE (addr) == PLUS && XEXP (addr, 0) == crtl->args.internal_arg_pointer && CONST_INT_P (XEXP (addr, 1))) i = INTVAL (XEXP (addr, 1)); /* Return true for arg pointer based indexed addressing. */ else if (GET_CODE (addr) == PLUS && (XEXP (addr, 0) == crtl->args.internal_arg_pointer || XEXP (addr, 1) == crtl->args.internal_arg_pointer)) return true; else return false; #ifdef ARGS_GROW_DOWNWARD i = -i - size; #endif if (size > 0) { unsigned HOST_WIDE_INT k; for (k = 0; k < size; k++) if (i + k < stored_args_map->n_bits && TEST_BIT (stored_args_map, i + k)) return true; } return false; } /* Do the register loads required for any wholly-register parms or any parms which are passed both on the stack and in a register. Their expressions were already evaluated. Mark all register-parms as living through the call, putting these USE insns in the CALL_INSN_FUNCTION_USAGE field. When IS_SIBCALL, perform the check_sibcall_argument_overlap checking, setting *SIBCALL_FAILURE if appropriate. */ static void load_register_parameters (struct arg_data *args, int num_actuals, rtx *call_fusage, int flags, int is_sibcall, int *sibcall_failure) { int i, j; for (i = 0; i < num_actuals; i++) { rtx reg = ((flags & ECF_SIBCALL) ? args[i].tail_call_reg : args[i].reg); if (reg) { int partial = args[i].partial; int nregs; int size = 0; rtx before_arg = get_last_insn (); /* Set non-negative if we must move a word at a time, even if just one word (e.g, partial == 4 && mode == DFmode). Set to -1 if we just use a normal move insn. This value can be zero if the argument is a zero size structure. */ nregs = -1; if (GET_CODE (reg) == PARALLEL) ; else if (partial) { gcc_assert (partial % UNITS_PER_WORD == 0); nregs = partial / UNITS_PER_WORD; } else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode) { size = int_size_in_bytes (TREE_TYPE (args[i].tree_value)); nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD; } else size = GET_MODE_SIZE (args[i].mode); /* Handle calls that pass values in multiple non-contiguous locations. The Irix 6 ABI has examples of this. */ if (GET_CODE (reg) == PARALLEL) emit_group_move (reg, args[i].parallel_value); /* If simple case, just do move. If normal partial, store_one_arg has already loaded the register for us. In all other cases, load the register(s) from memory. */ else if (nregs == -1) { emit_move_insn (reg, args[i].value); #ifdef BLOCK_REG_PADDING /* Handle case where we have a value that needs shifting up to the msb. eg. a QImode value and we're padding upward on a BYTES_BIG_ENDIAN machine. */ if (size < UNITS_PER_WORD && (args[i].locate.where_pad == (BYTES_BIG_ENDIAN ? upward : downward))) { rtx x; int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT; /* Assigning REG here rather than a temp makes CALL_FUSAGE report the whole reg as used. Strictly speaking, the call only uses SIZE bytes at the msb end, but it doesn't seem worth generating rtl to say that. */ reg = gen_rtx_REG (word_mode, REGNO (reg)); x = expand_shift (LSHIFT_EXPR, word_mode, reg, build_int_cst (NULL_TREE, shift), reg, 1); if (x != reg) emit_move_insn (reg, x); } #endif } /* If we have pre-computed the values to put in the registers in the case of non-aligned structures, copy them in now. */ else if (args[i].n_aligned_regs != 0) for (j = 0; j < args[i].n_aligned_regs; j++) emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j), args[i].aligned_regs[j]); else if (partial == 0 || args[i].pass_on_stack) { rtx mem = validize_mem (args[i].value); /* Check for overlap with already clobbered argument area. */ if (is_sibcall && mem_overlaps_already_clobbered_arg_p (XEXP (args[i].value, 0), size)) *sibcall_failure = 1; /* Handle a BLKmode that needs shifting. */ if (nregs == 1 && size < UNITS_PER_WORD #ifdef BLOCK_REG_PADDING && args[i].locate.where_pad == downward #else && BYTES_BIG_ENDIAN #endif ) { rtx tem = operand_subword_force (mem, 0, args[i].mode); rtx ri = gen_rtx_REG (word_mode, REGNO (reg)); rtx x = gen_reg_rtx (word_mode); int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT; enum tree_code dir = BYTES_BIG_ENDIAN ? RSHIFT_EXPR : LSHIFT_EXPR; emit_move_insn (x, tem); x = expand_shift (dir, word_mode, x, build_int_cst (NULL_TREE, shift), ri, 1); if (x != ri) emit_move_insn (ri, x); } else move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode); } /* When a parameter is a block, and perhaps in other cases, it is possible that it did a load from an argument slot that was already clobbered. */ if (is_sibcall && check_sibcall_argument_overlap (before_arg, &args[i], 0)) *sibcall_failure = 1; /* Handle calls that pass values in multiple non-contiguous locations. The Irix 6 ABI has examples of this. */ if (GET_CODE (reg) == PARALLEL) use_group_regs (call_fusage, reg); else if (nregs == -1) use_reg (call_fusage, reg); else if (nregs > 0) use_regs (call_fusage, REGNO (reg), nregs); } } } /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY bytes, then we would need to push some additional bytes to pad the arguments. So, we compute an adjust to the stack pointer for an amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE bytes. Then, when the arguments are pushed the stack will be perfectly aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should be popped after the call. Returns the adjustment. */ static int combine_pending_stack_adjustment_and_call (int unadjusted_args_size, struct args_size *args_size, unsigned int preferred_unit_stack_boundary) { /* The number of bytes to pop so that the stack will be under-aligned by UNADJUSTED_ARGS_SIZE bytes. */ HOST_WIDE_INT adjustment; /* The alignment of the stack after the arguments are pushed, if we just pushed the arguments without adjust the stack here. */ unsigned HOST_WIDE_INT unadjusted_alignment; unadjusted_alignment = ((stack_pointer_delta + unadjusted_args_size) % preferred_unit_stack_boundary); /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes as possible -- leaving just enough left to cancel out the UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the PENDING_STACK_ADJUST is non-negative, and congruent to -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */ /* Begin by trying to pop all the bytes. */ unadjusted_alignment = (unadjusted_alignment - (pending_stack_adjust % preferred_unit_stack_boundary)); adjustment = pending_stack_adjust; /* Push enough additional bytes that the stack will be aligned after the arguments are pushed. */ if (preferred_unit_stack_boundary > 1) { if (unadjusted_alignment > 0) adjustment -= preferred_unit_stack_boundary - unadjusted_alignment; else adjustment += unadjusted_alignment; } /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of bytes after the call. The right number is the entire PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required by the arguments in the first place. */ args_size->constant = pending_stack_adjust - adjustment + unadjusted_args_size; return adjustment; } /* Scan X expression if it does not dereference any argument slots we already clobbered by tail call arguments (as noted in stored_args_map bitmap). Return nonzero if X expression dereferences such argument slots, zero otherwise. */ static int check_sibcall_argument_overlap_1 (rtx x) { RTX_CODE code; int i, j; const char *fmt; if (x == NULL_RTX) return 0; code = GET_CODE (x); if (code == MEM) return mem_overlaps_already_clobbered_arg_p (XEXP (x, 0), GET_MODE_SIZE (GET_MODE (x))); /* Scan all subexpressions. */ fmt = GET_RTX_FORMAT (code); for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++) { if (*fmt == 'e') { if (check_sibcall_argument_overlap_1 (XEXP (x, i))) return 1; } else if (*fmt == 'E') { for (j = 0; j < XVECLEN (x, i); j++) if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j))) return 1; } } return 0; } /* Scan sequence after INSN if it does not dereference any argument slots we already clobbered by tail call arguments (as noted in stored_args_map bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP should be 0). Return nonzero if sequence after INSN dereferences such argument slots, zero otherwise. */ static int check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map) { int low, high; if (insn == NULL_RTX) insn = get_insns (); else insn = NEXT_INSN (insn); for (; insn; insn = NEXT_INSN (insn)) if (INSN_P (insn) && check_sibcall_argument_overlap_1 (PATTERN (insn))) break; if (mark_stored_args_map) { #ifdef ARGS_GROW_DOWNWARD low = -arg->locate.slot_offset.constant - arg->locate.size.constant; #else low = arg->locate.slot_offset.constant; #endif for (high = low + arg->locate.size.constant; low < high; low++) SET_BIT (stored_args_map, low); } return insn != NULL_RTX; } /* Given that a function returns a value of mode MODE at the most significant end of hard register VALUE, shift VALUE left or right as specified by LEFT_P. Return true if some action was needed. */ bool shift_return_value (enum machine_mode mode, bool left_p, rtx value) { HOST_WIDE_INT shift; gcc_assert (REG_P (value) && HARD_REGISTER_P (value)); shift = GET_MODE_BITSIZE (GET_MODE (value)) - GET_MODE_BITSIZE (mode); if (shift == 0) return false; /* Use ashr rather than lshr for right shifts. This is for the benefit of the MIPS port, which requires SImode values to be sign-extended when stored in 64-bit registers. */ if (!force_expand_binop (GET_MODE (value), left_p ? ashl_optab : ashr_optab, value, GEN_INT (shift), value, 1, OPTAB_WIDEN)) gcc_unreachable (); return true; } /* If X is a likely-spilled register value, copy it to a pseudo register and return that register. Return X otherwise. */ static rtx avoid_likely_spilled_reg (rtx x) { rtx new_rtx; if (REG_P (x) && HARD_REGISTER_P (x) && CLASS_LIKELY_SPILLED_P (REGNO_REG_CLASS (REGNO (x)))) { /* Make sure that we generate a REG rather than a CONCAT. Moves into CONCATs can need nontrivial instructions, and the whole point of this function is to avoid using the hard register directly in such a situation. */ generating_concat_p = 0; new_rtx = gen_reg_rtx (GET_MODE (x)); generating_concat_p = 1; emit_move_insn (new_rtx, x); return new_rtx; } return x; } /* Generate all the code for a CALL_EXPR exp and return an rtx for its value. Store the value in TARGET (specified as an rtx) if convenient. If the value is stored in TARGET then TARGET is returned. If IGNORE is nonzero, then we ignore the value of the function call. */ rtx expand_call (tree exp, rtx target, int ignore) { /* Nonzero if we are currently expanding a call. */ static int currently_expanding_call = 0; /* RTX for the function to be called. */ rtx funexp; /* Sequence of insns to perform a normal "call". */ rtx normal_call_insns = NULL_RTX; /* Sequence of insns to perform a tail "call". */ rtx tail_call_insns = NULL_RTX; /* Data type of the function. */ tree funtype; tree type_arg_types; tree rettype; /* Declaration of the function being called, or 0 if the function is computed (not known by name). */ tree fndecl = 0; /* The type of the function being called. */ tree fntype; bool try_tail_call = CALL_EXPR_TAILCALL (exp); int pass; /* Register in which non-BLKmode value will be returned, or 0 if no value or if value is BLKmode. */ rtx valreg; /* Address where we should return a BLKmode value; 0 if value not BLKmode. */ rtx structure_value_addr = 0; /* Nonzero if that address is being passed by treating it as an extra, implicit first parameter. Otherwise, it is passed by being copied directly into struct_value_rtx. */ int structure_value_addr_parm = 0; /* Holds the value of implicit argument for the struct value. */ tree structure_value_addr_value = NULL_TREE; /* Size of aggregate value wanted, or zero if none wanted or if we are using the non-reentrant PCC calling convention or expecting the value in registers. */ HOST_WIDE_INT struct_value_size = 0; /* Nonzero if called function returns an aggregate in memory PCC style, by returning the address of where to find it. */ int pcc_struct_value = 0; rtx struct_value = 0; /* Number of actual parameters in this call, including struct value addr. */ int num_actuals; /* Number of named args. Args after this are anonymous ones and they must all go on the stack. */ int n_named_args; /* Number of complex actual arguments that need to be split. */ int num_complex_actuals = 0; /* Vector of information about each argument. Arguments are numbered in the order they will be pushed, not the order they are written. */ struct arg_data *args; /* Total size in bytes of all the stack-parms scanned so far. */ struct args_size args_size; struct args_size adjusted_args_size; /* Size of arguments before any adjustments (such as rounding). */ int unadjusted_args_size; /* Data on reg parms scanned so far. */ CUMULATIVE_ARGS args_so_far; /* Nonzero if a reg parm has been scanned. */ int reg_parm_seen; /* Nonzero if this is an indirect function call. */ /* Nonzero if we must avoid push-insns in the args for this call. If stack space is allocated for register parameters, but not by the caller, then it is preallocated in the fixed part of the stack frame. So the entire argument block must then be preallocated (i.e., we ignore PUSH_ROUNDING in that case). */ int must_preallocate = !PUSH_ARGS; /* Size of the stack reserved for parameter registers. */ int reg_parm_stack_space = 0; /* Address of space preallocated for stack parms (on machines that lack push insns), or 0 if space not preallocated. */ rtx argblock = 0; /* Mask of ECF_ flags. */ int flags = 0; #ifdef REG_PARM_STACK_SPACE /* Define the boundary of the register parm stack space that needs to be saved, if any. */ int low_to_save, high_to_save; rtx save_area = 0; /* Place that it is saved */ #endif int initial_highest_arg_in_use = highest_outgoing_arg_in_use; char *initial_stack_usage_map = stack_usage_map; char *stack_usage_map_buf = NULL; int old_stack_allocated; /* State variables to track stack modifications. */ rtx old_stack_level = 0; int old_stack_arg_under_construction = 0; int old_pending_adj = 0; int old_inhibit_defer_pop = inhibit_defer_pop; /* Some stack pointer alterations we make are performed via allocate_dynamic_stack_space. This modifies the stack_pointer_delta, which we then also need to save/restore along the way. */ int old_stack_pointer_delta = 0; rtx call_fusage; tree addr = CALL_EXPR_FN (exp); int i; /* The alignment of the stack, in bits. */ unsigned HOST_WIDE_INT preferred_stack_boundary; /* The alignment of the stack, in bytes. */ unsigned HOST_WIDE_INT preferred_unit_stack_boundary; /* The static chain value to use for this call. */ rtx static_chain_value; /* See if this is "nothrow" function call. */ if (TREE_NOTHROW (exp)) flags |= ECF_NOTHROW; /* See if we can find a DECL-node for the actual function, and get the function attributes (flags) from the function decl or type node. */ fndecl = get_callee_fndecl (exp); if (fndecl) { fntype = TREE_TYPE (fndecl); flags |= flags_from_decl_or_type (fndecl); } else { fntype = TREE_TYPE (TREE_TYPE (addr)); flags |= flags_from_decl_or_type (fntype); } rettype = TREE_TYPE (exp); struct_value = targetm.calls.struct_value_rtx (fntype, 0); /* Warn if this value is an aggregate type, regardless of which calling convention we are using for it. */ if (AGGREGATE_TYPE_P (rettype)) warning (OPT_Waggregate_return, "function call has aggregate value"); /* If the result of a non looping pure or const function call is ignored (or void), and none of its arguments are volatile, we can avoid expanding the call and just evaluate the arguments for side-effects. */ if ((flags & (ECF_CONST | ECF_PURE)) && (!(flags & ECF_LOOPING_CONST_OR_PURE)) && (ignore || target == const0_rtx || TYPE_MODE (rettype) == VOIDmode)) { bool volatilep = false; tree arg; call_expr_arg_iterator iter; FOR_EACH_CALL_EXPR_ARG (arg, iter, exp) if (TREE_THIS_VOLATILE (arg)) { volatilep = true; break; } if (! volatilep) { FOR_EACH_CALL_EXPR_ARG (arg, iter, exp) expand_expr (arg, const0_rtx, VOIDmode, EXPAND_NORMAL); return const0_rtx; } } #ifdef REG_PARM_STACK_SPACE reg_parm_stack_space = REG_PARM_STACK_SPACE (!fndecl ? fntype : fndecl); #endif if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))) && reg_parm_stack_space > 0 && PUSH_ARGS) must_preallocate = 1; /* Set up a place to return a structure. */ /* Cater to broken compilers. */ if (aggregate_value_p (exp, (!fndecl ? fntype : fndecl))) { /* This call returns a big structure. */ flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE); #ifdef PCC_STATIC_STRUCT_RETURN { pcc_struct_value = 1; } #else /* not PCC_STATIC_STRUCT_RETURN */ { struct_value_size = int_size_in_bytes (rettype); if (target && MEM_P (target) && CALL_EXPR_RETURN_SLOT_OPT (exp)) structure_value_addr = XEXP (target, 0); else { /* For variable-sized objects, we must be called with a target specified. If we were to allocate space on the stack here, we would have no way of knowing when to free it. */ rtx d = assign_temp (rettype, 0, 1, 1); mark_temp_addr_taken (d); structure_value_addr = XEXP (d, 0); target = 0; } } #endif /* not PCC_STATIC_STRUCT_RETURN */ } /* Figure out the amount to which the stack should be aligned. */ preferred_stack_boundary = PREFERRED_STACK_BOUNDARY; if (fndecl) { struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl); /* Without automatic stack alignment, we can't increase preferred stack boundary. With automatic stack alignment, it is unnecessary since unless we can guarantee that all callers will align the outgoing stack properly, callee has to align its stack anyway. */ if (i && i->preferred_incoming_stack_boundary && i->preferred_incoming_stack_boundary < preferred_stack_boundary) preferred_stack_boundary = i->preferred_incoming_stack_boundary; } /* Operand 0 is a pointer-to-function; get the type of the function. */ funtype = TREE_TYPE (addr); gcc_assert (POINTER_TYPE_P (funtype)); funtype = TREE_TYPE (funtype); /* Count whether there are actual complex arguments that need to be split into their real and imaginary parts. Munge the type_arg_types appropriately here as well. */ if (targetm.calls.split_complex_arg) { call_expr_arg_iterator iter; tree arg; FOR_EACH_CALL_EXPR_ARG (arg, iter, exp) { tree type = TREE_TYPE (arg); if (type && TREE_CODE (type) == COMPLEX_TYPE && targetm.calls.split_complex_arg (type)) num_complex_actuals++; } type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype)); } else type_arg_types = TYPE_ARG_TYPES (funtype); if (flags & ECF_MAY_BE_ALLOCA) cfun->calls_alloca = 1; /* If struct_value_rtx is 0, it means pass the address as if it were an extra parameter. Put the argument expression in structure_value_addr_value. */ if (structure_value_addr && struct_value == 0) { /* If structure_value_addr is a REG other than virtual_outgoing_args_rtx, we can use always use it. If it is not a REG, we must always copy it into a register. If it is virtual_outgoing_args_rtx, we must copy it to another register in some cases. */ rtx temp = (!REG_P (structure_value_addr) || (ACCUMULATE_OUTGOING_ARGS && stack_arg_under_construction && structure_value_addr == virtual_outgoing_args_rtx) ? copy_addr_to_reg (convert_memory_address (Pmode, structure_value_addr)) : structure_value_addr); structure_value_addr_value = make_tree (build_pointer_type (TREE_TYPE (funtype)), temp); structure_value_addr_parm = 1; } /* Count the arguments and set NUM_ACTUALS. */ num_actuals = call_expr_nargs (exp) + num_complex_actuals + structure_value_addr_parm; /* Compute number of named args. First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */ if (type_arg_types != 0) n_named_args = (list_length (type_arg_types) /* Count the struct value address, if it is passed as a parm. */ + structure_value_addr_parm); else /* If we know nothing, treat all args as named. */ n_named_args = num_actuals; /* Start updating where the next arg would go. On some machines (such as the PA) indirect calls have a different calling convention than normal calls. The fourth argument in INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call or not. */ INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl, n_named_args); /* Now possibly adjust the number of named args. Normally, don't include the last named arg if anonymous args follow. We do include the last named arg if targetm.calls.strict_argument_naming() returns nonzero. (If no anonymous args follow, the result of list_length is actually one too large. This is harmless.) If targetm.calls.pretend_outgoing_varargs_named() returns nonzero, and targetm.calls.strict_argument_naming() returns zero, this machine will be able to place unnamed args that were passed in registers into the stack. So treat all args as named. This allows the insns emitting for a specific argument list to be independent of the function declaration. If targetm.calls.pretend_outgoing_varargs_named() returns zero, we do not have any reliable way to pass unnamed args in registers, so we must force them into memory. */ if (type_arg_types != 0 && targetm.calls.strict_argument_naming (&args_so_far)) ; else if (type_arg_types != 0 && ! targetm.calls.pretend_outgoing_varargs_named (&args_so_far)) /* Don't include the last named arg. */ --n_named_args; else /* Treat all args as named. */ n_named_args = num_actuals; /* Make a vector to hold all the information about each arg. */ args = XALLOCAVEC (struct arg_data, num_actuals); memset (args, 0, num_actuals * sizeof (struct arg_data)); /* Build up entries in the ARGS array, compute the size of the arguments into ARGS_SIZE, etc. */ initialize_argument_information (num_actuals, args, &args_size, n_named_args, exp, structure_value_addr_value, fndecl, fntype, &args_so_far, reg_parm_stack_space, &old_stack_level, &old_pending_adj, &must_preallocate, &flags, &try_tail_call, CALL_FROM_THUNK_P (exp)); if (args_size.var) must_preallocate = 1; /* Now make final decision about preallocating stack space. */ must_preallocate = finalize_must_preallocate (must_preallocate, num_actuals, args, &args_size); /* If the structure value address will reference the stack pointer, we must stabilize it. We don't need to do this if we know that we are not going to adjust the stack pointer in processing this call. */ if (structure_value_addr && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr) || reg_mentioned_p (virtual_outgoing_args_rtx, structure_value_addr)) && (args_size.var || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant))) structure_value_addr = copy_to_reg (structure_value_addr); /* Tail calls can make things harder to debug, and we've traditionally pushed these optimizations into -O2. Don't try if we're already expanding a call, as that means we're an argument. Don't try if there's cleanups, as we know there's code to follow the call. */ if (currently_expanding_call++ != 0 || !flag_optimize_sibling_calls || args_size.var || dbg_cnt (tail_call) == false) try_tail_call = 0; /* Rest of purposes for tail call optimizations to fail. */ if ( #ifdef HAVE_sibcall_epilogue !HAVE_sibcall_epilogue #else 1 #endif || !try_tail_call /* Doing sibling call optimization needs some work, since structure_value_addr can be allocated on the stack. It does not seem worth the effort since few optimizable sibling calls will return a structure. */ || structure_value_addr != NULL_RTX #ifdef REG_PARM_STACK_SPACE /* If outgoing reg parm stack space changes, we can not do sibcall. */ || (OUTGOING_REG_PARM_STACK_SPACE (funtype) != OUTGOING_REG_PARM_STACK_SPACE (TREE_TYPE (current_function_decl))) || (reg_parm_stack_space != REG_PARM_STACK_SPACE (fndecl)) #endif /* Check whether the target is able to optimize the call into a sibcall. */ || !targetm.function_ok_for_sibcall (fndecl, exp) /* Functions that do not return exactly once may not be sibcall optimized. */ || (flags & (ECF_RETURNS_TWICE | ECF_NORETURN)) || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr))) /* If the called function is nested in the current one, it might access some of the caller's arguments, but could clobber them beforehand if the argument areas are shared. */ || (fndecl && decl_function_context (fndecl) == current_function_decl) /* If this function requires more stack slots than the current function, we cannot change it into a sibling call. crtl->args.pretend_args_size is not part of the stack allocated by our caller. */ || args_size.constant > (crtl->args.size - crtl->args.pretend_args_size) /* If the callee pops its own arguments, then it must pop exactly the same number of arguments as the current function. */ || (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant) != RETURN_POPS_ARGS (current_function_decl, TREE_TYPE (current_function_decl), crtl->args.size)) || !lang_hooks.decls.ok_for_sibcall (fndecl)) try_tail_call = 0; /* Check if caller and callee disagree in promotion of function return value. */ if (try_tail_call) { enum machine_mode caller_mode, caller_promoted_mode; enum machine_mode callee_mode, callee_promoted_mode; int caller_unsignedp, callee_unsignedp; tree caller_res = DECL_RESULT (current_function_decl); caller_unsignedp = TYPE_UNSIGNED (TREE_TYPE (caller_res)); caller_mode = DECL_MODE (caller_res); callee_unsignedp = TYPE_UNSIGNED (TREE_TYPE (funtype)); callee_mode = TYPE_MODE (TREE_TYPE (funtype)); caller_promoted_mode = promote_function_mode (TREE_TYPE (caller_res), caller_mode, &caller_unsignedp, TREE_TYPE (current_function_decl), 1); callee_promoted_mode = promote_function_mode (TREE_TYPE (funtype), callee_mode, &callee_unsignedp, funtype, 1); if (caller_mode != VOIDmode && (caller_promoted_mode != callee_promoted_mode || ((caller_mode != caller_promoted_mode || callee_mode != callee_promoted_mode) && (caller_unsignedp != callee_unsignedp || GET_MODE_BITSIZE (caller_mode) < GET_MODE_BITSIZE (callee_mode))))) try_tail_call = 0; } /* Ensure current function's preferred stack boundary is at least what we need. Stack alignment may also increase preferred stack boundary. */ if (crtl->preferred_stack_boundary < preferred_stack_boundary) crtl->preferred_stack_boundary = preferred_stack_boundary; else preferred_stack_boundary = crtl->preferred_stack_boundary; preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT; /* We want to make two insn chains; one for a sibling call, the other for a normal call. We will select one of the two chains after initial RTL generation is complete. */ for (pass = try_tail_call ? 0 : 1; pass < 2; pass++) { int sibcall_failure = 0; /* We want to emit any pending stack adjustments before the tail recursion "call". That way we know any adjustment after the tail recursion call can be ignored if we indeed use the tail call expansion. */ int save_pending_stack_adjust = 0; int save_stack_pointer_delta = 0; rtx insns; rtx before_call, next_arg_reg, after_args; if (pass == 0) { /* State variables we need to save and restore between iterations. */ save_pending_stack_adjust = pending_stack_adjust; save_stack_pointer_delta = stack_pointer_delta; } if (pass) flags &= ~ECF_SIBCALL; else flags |= ECF_SIBCALL; /* Other state variables that we must reinitialize each time through the loop (that are not initialized by the loop itself). */ argblock = 0; call_fusage = 0; /* Start a new sequence for the normal call case. From this point on, if the sibling call fails, we want to set sibcall_failure instead of continuing the loop. */ start_sequence (); /* Don't let pending stack adjusts add up to too much. Also, do all pending adjustments now if there is any chance this might be a call to alloca or if we are expanding a sibling call sequence. Also do the adjustments before a throwing call, otherwise exception handling can fail; PR 19225. */ if (pending_stack_adjust >= 32 || (pending_stack_adjust > 0 && (flags & ECF_MAY_BE_ALLOCA)) || (pending_stack_adjust > 0 && flag_exceptions && !(flags & ECF_NOTHROW)) || pass == 0) do_pending_stack_adjust (); /* Precompute any arguments as needed. */ if (pass) precompute_arguments (num_actuals, args); /* Now we are about to start emitting insns that can be deleted if a libcall is deleted. */ if (pass && (flags & ECF_MALLOC)) start_sequence (); if (pass == 0 && crtl->stack_protect_guard) stack_protect_epilogue (); adjusted_args_size = args_size; /* Compute the actual size of the argument block required. The variable and constant sizes must be combined, the size may have to be rounded, and there may be a minimum required size. When generating a sibcall pattern, do not round up, since we'll be re-using whatever space our caller provided. */ unadjusted_args_size = compute_argument_block_size (reg_parm_stack_space, &adjusted_args_size, fndecl, fntype, (pass == 0 ? 0 : preferred_stack_boundary)); old_stack_allocated = stack_pointer_delta - pending_stack_adjust; /* The argument block when performing a sibling call is the incoming argument block. */ if (pass == 0) { argblock = crtl->args.internal_arg_pointer; argblock #ifdef STACK_GROWS_DOWNWARD = plus_constant (argblock, crtl->args.pretend_args_size); #else = plus_constant (argblock, -crtl->args.pretend_args_size); #endif stored_args_map = sbitmap_alloc (args_size.constant); sbitmap_zero (stored_args_map); } /* If we have no actual push instructions, or shouldn't use them, make space for all args right now. */ else if (adjusted_args_size.var != 0) { if (old_stack_level == 0) { emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX); old_stack_pointer_delta = stack_pointer_delta; old_pending_adj = pending_stack_adjust; pending_stack_adjust = 0; /* stack_arg_under_construction says whether a stack arg is being constructed at the old stack level. Pushing the stack gets a clean outgoing argument block. */ old_stack_arg_under_construction = stack_arg_under_construction; stack_arg_under_construction = 0; } argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0); } else { /* Note that we must go through the motions of allocating an argument block even if the size is zero because we may be storing args in the area reserved for register arguments, which may be part of the stack frame. */ int needed = adjusted_args_size.constant; /* Store the maximum argument space used. It will be pushed by the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow checking). */ if (needed > crtl->outgoing_args_size) crtl->outgoing_args_size = needed; if (must_preallocate) { if (ACCUMULATE_OUTGOING_ARGS) { /* Since the stack pointer will never be pushed, it is possible for the evaluation of a parm to clobber something we have already written to the stack. Since most function calls on RISC machines do not use the stack, this is uncommon, but must work correctly. Therefore, we save any area of the stack that was already written and that we are using. Here we set up to do this by making a new stack usage map from the old one. The actual save will be done by store_one_arg. Another approach might be to try to reorder the argument evaluations to avoid this conflicting stack usage. */ /* Since we will be writing into the entire argument area, the map must be allocated for its entire size, not just the part that is the responsibility of the caller. */ if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))) needed += reg_parm_stack_space; #ifdef ARGS_GROW_DOWNWARD highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use, needed + 1); #else highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use, needed); #endif if (stack_usage_map_buf) free (stack_usage_map_buf); stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use); stack_usage_map = stack_usage_map_buf; if (initial_highest_arg_in_use) memcpy (stack_usage_map, initial_stack_usage_map, initial_highest_arg_in_use); if (initial_highest_arg_in_use != highest_outgoing_arg_in_use) memset (&stack_usage_map[initial_highest_arg_in_use], 0, (highest_outgoing_arg_in_use - initial_highest_arg_in_use)); needed = 0; /* The address of the outgoing argument list must not be copied to a register here, because argblock would be left pointing to the wrong place after the call to allocate_dynamic_stack_space below. */ argblock = virtual_outgoing_args_rtx; } else { if (inhibit_defer_pop == 0) { /* Try to reuse some or all of the pending_stack_adjust to get this space. */ needed = (combine_pending_stack_adjustment_and_call (unadjusted_args_size, &adjusted_args_size, preferred_unit_stack_boundary)); /* combine_pending_stack_adjustment_and_call computes an adjustment before the arguments are allocated. Account for them and see whether or not the stack needs to go up or down. */ needed = unadjusted_args_size - needed; if (needed < 0) { /* We're releasing stack space. */ /* ??? We can avoid any adjustment at all if we're already aligned. FIXME. */ pending_stack_adjust = -needed; do_pending_stack_adjust (); needed = 0; } else /* We need to allocate space. We'll do that in push_block below. */ pending_stack_adjust = 0; } /* Special case this because overhead of `push_block' in this case is non-trivial. */ if (needed == 0) argblock = virtual_outgoing_args_rtx; else { argblock = push_block (GEN_INT (needed), 0, 0); #ifdef ARGS_GROW_DOWNWARD argblock = plus_constant (argblock, needed); #endif } /* We only really need to call `copy_to_reg' in the case where push insns are going to be used to pass ARGBLOCK to a function call in ARGS. In that case, the stack pointer changes value from the allocation point to the call point, and hence the value of VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might as well always do it. */ argblock = copy_to_reg (argblock); } } } if (ACCUMULATE_OUTGOING_ARGS) { /* The save/restore code in store_one_arg handles all cases except one: a constructor call (including a C function returning a BLKmode struct) to initialize an argument. */ if (stack_arg_under_construction) { rtx push_size = GEN_INT (adjusted_args_size.constant + (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))) ? 0 : reg_parm_stack_space)); if (old_stack_level == 0) { emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX); old_stack_pointer_delta = stack_pointer_delta; old_pending_adj = pending_stack_adjust; pending_stack_adjust = 0; /* stack_arg_under_construction says whether a stack arg is being constructed at the old stack level. Pushing the stack gets a clean outgoing argument block. */ old_stack_arg_under_construction = stack_arg_under_construction; stack_arg_under_construction = 0; /* Make a new map for the new argument list. */ if (stack_usage_map_buf) free (stack_usage_map_buf); stack_usage_map_buf = XCNEWVEC (char, highest_outgoing_arg_in_use); stack_usage_map = stack_usage_map_buf; highest_outgoing_arg_in_use = 0; } allocate_dynamic_stack_space (push_size, NULL_RTX, BITS_PER_UNIT); } /* If argument evaluation might modify the stack pointer, copy the address of the argument list to a register. */ for (i = 0; i < num_actuals; i++) if (args[i].pass_on_stack) { argblock = copy_addr_to_reg (argblock); break; } } compute_argument_addresses (args, argblock, num_actuals); /* If we push args individually in reverse order, perform stack alignment before the first push (the last arg). */ if (PUSH_ARGS_REVERSED && argblock == 0 && adjusted_args_size.constant != unadjusted_args_size) { /* When the stack adjustment is pending, we get better code by combining the adjustments. */ if (pending_stack_adjust && ! inhibit_defer_pop) { pending_stack_adjust = (combine_pending_stack_adjustment_and_call (unadjusted_args_size, &adjusted_args_size, preferred_unit_stack_boundary)); do_pending_stack_adjust (); } else if (argblock == 0) anti_adjust_stack (GEN_INT (adjusted_args_size.constant - unadjusted_args_size)); } /* Now that the stack is properly aligned, pops can't safely be deferred during the evaluation of the arguments. */ NO_DEFER_POP; funexp = rtx_for_function_call (fndecl, addr); /* Figure out the register where the value, if any, will come back. */ valreg = 0; if (TYPE_MODE (rettype) != VOIDmode && ! structure_value_addr) { if (pcc_struct_value) valreg = hard_function_value (build_pointer_type (rettype), fndecl, NULL, (pass == 0)); else valreg = hard_function_value (rettype, fndecl, fntype, (pass == 0)); /* If VALREG is a PARALLEL whose first member has a zero offset, use that. This is for targets such as m68k that return the same value in multiple places. */ if (GET_CODE (valreg) == PARALLEL) { rtx elem = XVECEXP (valreg, 0, 0); rtx where = XEXP (elem, 0); rtx offset = XEXP (elem, 1); if (offset == const0_rtx && GET_MODE (where) == GET_MODE (valreg)) valreg = where; } } /* Precompute all register parameters. It isn't safe to compute anything once we have started filling any specific hard regs. */ precompute_register_parameters (num_actuals, args, ®_parm_seen); if (CALL_EXPR_STATIC_CHAIN (exp)) static_chain_value = expand_normal (CALL_EXPR_STATIC_CHAIN (exp)); else static_chain_value = 0; #ifdef REG_PARM_STACK_SPACE /* Save the fixed argument area if it's part of the caller's frame and is clobbered by argument setup for this call. */ if (ACCUMULATE_OUTGOING_ARGS && pass) save_area = save_fixed_argument_area (reg_parm_stack_space, argblock, &low_to_save, &high_to_save); #endif /* Now store (and compute if necessary) all non-register parms. These come before register parms, since they can require block-moves, which could clobber the registers used for register parms. Parms which have partial registers are not stored here, but we do preallocate space here if they want that. */ for (i = 0; i < num_actuals; i++) { if (args[i].reg == 0 || args[i].pass_on_stack) { rtx before_arg = get_last_insn (); if (store_one_arg (&args[i], argblock, flags, adjusted_args_size.var != 0, reg_parm_stack_space) || (pass == 0 && check_sibcall_argument_overlap (before_arg, &args[i], 1))) sibcall_failure = 1; } if (((flags & ECF_CONST) || ((flags & ECF_PURE) && ACCUMULATE_OUTGOING_ARGS)) && args[i].stack) call_fusage = gen_rtx_EXPR_LIST (VOIDmode, gen_rtx_USE (VOIDmode, args[i].stack), call_fusage); } /* If we have a parm that is passed in registers but not in memory and whose alignment does not permit a direct copy into registers, make a group of pseudos that correspond to each register that we will later fill. */ if (STRICT_ALIGNMENT) store_unaligned_arguments_into_pseudos (args, num_actuals); /* Now store any partially-in-registers parm. This is the last place a block-move can happen. */ if (reg_parm_seen) for (i = 0; i < num_actuals; i++) if (args[i].partial != 0 && ! args[i].pass_on_stack) { rtx before_arg = get_last_insn (); if (store_one_arg (&args[i], argblock, flags, adjusted_args_size.var != 0, reg_parm_stack_space) || (pass == 0 && check_sibcall_argument_overlap (before_arg, &args[i], 1))) sibcall_failure = 1; } /* If we pushed args in forward order, perform stack alignment after pushing the last arg. */ if (!PUSH_ARGS_REVERSED && argblock == 0) anti_adjust_stack (GEN_INT (adjusted_args_size.constant - unadjusted_args_size)); /* If register arguments require space on the stack and stack space was not preallocated, allocate stack space here for arguments passed in registers. */ if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))) && !ACCUMULATE_OUTGOING_ARGS && must_preallocate == 0 && reg_parm_stack_space > 0) anti_adjust_stack (GEN_INT (reg_parm_stack_space)); /* Pass the function the address in which to return a structure value. */ if (pass != 0 && structure_value_addr && ! structure_value_addr_parm) { structure_value_addr = convert_memory_address (Pmode, structure_value_addr); emit_move_insn (struct_value, force_reg (Pmode, force_operand (structure_value_addr, NULL_RTX))); if (REG_P (struct_value)) use_reg (&call_fusage, struct_value); } after_args = get_last_insn (); funexp = prepare_call_address (fndecl, funexp, static_chain_value, &call_fusage, reg_parm_seen, pass == 0); load_register_parameters (args, num_actuals, &call_fusage, flags, pass == 0, &sibcall_failure); /* Save a pointer to the last insn before the call, so that we can later safely search backwards to find the CALL_INSN. */ before_call = get_last_insn (); /* Set up next argument register. For sibling calls on machines with register windows this should be the incoming register. */ #ifdef FUNCTION_INCOMING_ARG if (pass == 0) next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode, void_type_node, 1); else #endif next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1); /* All arguments and registers used for the call must be set up by now! */ /* Stack must be properly aligned now. */ gcc_assert (!pass || !(stack_pointer_delta % preferred_unit_stack_boundary)); /* Generate the actual call instruction. */ emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size, adjusted_args_size.constant, struct_value_size, next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage, flags, & args_so_far); /* If the call setup or the call itself overlaps with anything of the argument setup we probably clobbered our call address. In that case we can't do sibcalls. */ if (pass == 0 && check_sibcall_argument_overlap (after_args, 0, 0)) sibcall_failure = 1; /* If a non-BLKmode value is returned at the most significant end of a register, shift the register right by the appropriate amount and update VALREG accordingly. BLKmode values are handled by the group load/store machinery below. */ if (!structure_value_addr && !pcc_struct_value && TYPE_MODE (rettype) != BLKmode && targetm.calls.return_in_msb (rettype)) { if (shift_return_value (TYPE_MODE (rettype), false, valreg)) sibcall_failure = 1; valreg = gen_rtx_REG (TYPE_MODE (rettype), REGNO (valreg)); } if (pass && (flags & ECF_MALLOC)) { rtx temp = gen_reg_rtx (GET_MODE (valreg)); rtx last, insns; /* The return value from a malloc-like function is a pointer. */ if (TREE_CODE (rettype) == POINTER_TYPE) mark_reg_pointer (temp, BIGGEST_ALIGNMENT); emit_move_insn (temp, valreg); /* The return value from a malloc-like function can not alias anything else. */ last = get_last_insn (); add_reg_note (last, REG_NOALIAS, temp); /* Write out the sequence. */ insns = get_insns (); end_sequence (); emit_insn (insns); valreg = temp; } /* For calls to `setjmp', etc., inform function.c:setjmp_warnings that it should complain if nonvolatile values are live. For functions that cannot return, inform flow that control does not fall through. */ if ((flags & ECF_NORETURN) || pass == 0) { /* The barrier must be emitted immediately after the CALL_INSN. Some ports emit more than just a CALL_INSN above, so we must search for it here. */ rtx last = get_last_insn (); while (!CALL_P (last)) { last = PREV_INSN (last); /* There was no CALL_INSN? */ gcc_assert (last != before_call); } emit_barrier_after (last); /* Stack adjustments after a noreturn call are dead code. However when NO_DEFER_POP is in effect, we must preserve stack_pointer_delta. */ if (inhibit_defer_pop == 0) { stack_pointer_delta = old_stack_allocated; pending_stack_adjust = 0; } } /* If value type not void, return an rtx for the value. */ if (TYPE_MODE (rettype) == VOIDmode || ignore) target = const0_rtx; else if (structure_value_addr) { if (target == 0 || !MEM_P (target)) { target = gen_rtx_MEM (TYPE_MODE (rettype), memory_address (TYPE_MODE (rettype), structure_value_addr)); set_mem_attributes (target, rettype, 1); } } else if (pcc_struct_value) { /* This is the special C++ case where we need to know what the true target was. We take care to never use this value more than once in one expression. */ target = gen_rtx_MEM (TYPE_MODE (rettype), copy_to_reg (valreg)); set_mem_attributes (target, rettype, 1); } /* Handle calls that return values in multiple non-contiguous locations. The Irix 6 ABI has examples of this. */ else if (GET_CODE (valreg) == PARALLEL) { if (target == 0) { /* This will only be assigned once, so it can be readonly. */ tree nt = build_qualified_type (rettype, (TYPE_QUALS (rettype) | TYPE_QUAL_CONST)); target = assign_temp (nt, 0, 1, 1); } if (! rtx_equal_p (target, valreg)) emit_group_store (target, valreg, rettype, int_size_in_bytes (rettype)); /* We can not support sibling calls for this case. */ sibcall_failure = 1; } else if (target && GET_MODE (target) == TYPE_MODE (rettype) && GET_MODE (target) == GET_MODE (valreg)) { bool may_overlap = false; /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard reg to a plain register. */ if (!REG_P (target) || HARD_REGISTER_P (target)) valreg = avoid_likely_spilled_reg (valreg); /* If TARGET is a MEM in the argument area, and we have saved part of the argument area, then we can't store directly into TARGET as it may get overwritten when we restore the argument save area below. Don't work too hard though and simply force TARGET to a register if it is a MEM; the optimizer is quite likely to sort it out. */ if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target)) for (i = 0; i < num_actuals; i++) if (args[i].save_area) { may_overlap = true; break; } if (may_overlap) target = copy_to_reg (valreg); else { /* TARGET and VALREG cannot be equal at this point because the latter would not have REG_FUNCTION_VALUE_P true, while the former would if it were referring to the same register. If they refer to the same register, this move will be a no-op, except when function inlining is being done. */ emit_move_insn (target, valreg); /* If we are setting a MEM, this code must be executed. Since it is emitted after the call insn, sibcall optimization cannot be performed in that case. */ if (MEM_P (target)) sibcall_failure = 1; } } else if (TYPE_MODE (rettype) == BLKmode) { rtx val = valreg; if (GET_MODE (val) != BLKmode) val = avoid_likely_spilled_reg (val); target = copy_blkmode_from_reg (target, val, rettype); /* We can not support sibling calls for this case. */ sibcall_failure = 1; } else target = copy_to_reg (avoid_likely_spilled_reg (valreg)); /* If we promoted this return value, make the proper SUBREG. TARGET might be const0_rtx here, so be careful. */ if (REG_P (target) && TYPE_MODE (rettype) != BLKmode && GET_MODE (target) != TYPE_MODE (rettype)) { tree type = rettype; int unsignedp = TYPE_UNSIGNED (type); int offset = 0; enum machine_mode pmode; /* Ensure we promote as expected, and get the new unsignedness. */ pmode = promote_function_mode (type, TYPE_MODE (type), &unsignedp, funtype, 1); gcc_assert (GET_MODE (target) == pmode); if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN) && (GET_MODE_SIZE (GET_MODE (target)) > GET_MODE_SIZE (TYPE_MODE (type)))) { offset = GET_MODE_SIZE (GET_MODE (target)) - GET_MODE_SIZE (TYPE_MODE (type)); if (! BYTES_BIG_ENDIAN) offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD; else if (! WORDS_BIG_ENDIAN) offset %= UNITS_PER_WORD; } target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset); SUBREG_PROMOTED_VAR_P (target) = 1; SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp); } /* If size of args is variable or this was a constructor call for a stack argument, restore saved stack-pointer value. */ if (old_stack_level) { emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX); stack_pointer_delta = old_stack_pointer_delta; pending_stack_adjust = old_pending_adj; old_stack_allocated = stack_pointer_delta - pending_stack_adjust; stack_arg_under_construction = old_stack_arg_under_construction; highest_outgoing_arg_in_use = initial_highest_arg_in_use; stack_usage_map = initial_stack_usage_map; sibcall_failure = 1; } else if (ACCUMULATE_OUTGOING_ARGS && pass) { #ifdef REG_PARM_STACK_SPACE if (save_area) restore_fixed_argument_area (save_area, argblock, high_to_save, low_to_save); #endif /* If we saved any argument areas, restore them. */ for (i = 0; i < num_actuals; i++) if (args[i].save_area) { enum machine_mode save_mode = GET_MODE (args[i].save_area); rtx stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, XEXP (args[i].stack_slot, 0))); if (save_mode != BLKmode) emit_move_insn (stack_area, args[i].save_area); else emit_block_move (stack_area, args[i].save_area, GEN_INT (args[i].locate.size.constant), BLOCK_OP_CALL_PARM); } highest_outgoing_arg_in_use = initial_highest_arg_in_use; stack_usage_map = initial_stack_usage_map; } /* If this was alloca, record the new stack level for nonlocal gotos. Check for the handler slots since we might not have a save area for non-local gotos. */ if ((flags & ECF_MAY_BE_ALLOCA) && cfun->nonlocal_goto_save_area != 0) update_nonlocal_goto_save_area (); /* Free up storage we no longer need. */ for (i = 0; i < num_actuals; ++i) if (args[i].aligned_regs) free (args[i].aligned_regs); insns = get_insns (); end_sequence (); if (pass == 0) { tail_call_insns = insns; /* Restore the pending stack adjustment now that we have finished generating the sibling call sequence. */ pending_stack_adjust = save_pending_stack_adjust; stack_pointer_delta = save_stack_pointer_delta; /* Prepare arg structure for next iteration. */ for (i = 0; i < num_actuals; i++) { args[i].value = 0; args[i].aligned_regs = 0; args[i].stack = 0; } sbitmap_free (stored_args_map); } else { normal_call_insns = insns; /* Verify that we've deallocated all the stack we used. */ gcc_assert ((flags & ECF_NORETURN) || (old_stack_allocated == stack_pointer_delta - pending_stack_adjust)); } /* If something prevents making this a sibling call, zero out the sequence. */ if (sibcall_failure) tail_call_insns = NULL_RTX; else break; } /* If tail call production succeeded, we need to remove REG_EQUIV notes on arguments too, as argument area is now clobbered by the call. */ if (tail_call_insns) { emit_insn (tail_call_insns); crtl->tail_call_emit = true; } else emit_insn (normal_call_insns); currently_expanding_call--; if (stack_usage_map_buf) free (stack_usage_map_buf); return target; } /* A sibling call sequence invalidates any REG_EQUIV notes made for this function's incoming arguments. At the start of RTL generation we know the only REG_EQUIV notes in the rtl chain are those for incoming arguments, so we can look for REG_EQUIV notes between the start of the function and the NOTE_INSN_FUNCTION_BEG. This is (slight) overkill. We could keep track of the highest argument we clobber and be more selective in removing notes, but it does not seem to be worth the effort. */ void fixup_tail_calls (void) { rtx insn; for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) { rtx note; /* There are never REG_EQUIV notes for the incoming arguments after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */ if (NOTE_P (insn) && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG) break; note = find_reg_note (insn, REG_EQUIV, 0); if (note) remove_note (insn, note); note = find_reg_note (insn, REG_EQUIV, 0); gcc_assert (!note); } } /* Traverse a list of TYPES and expand all complex types into their components. */ static tree split_complex_types (tree types) { tree p; /* Before allocating memory, check for the common case of no complex. */ for (p = types; p; p = TREE_CHAIN (p)) { tree type = TREE_VALUE (p); if (TREE_CODE (type) == COMPLEX_TYPE && targetm.calls.split_complex_arg (type)) goto found; } return types; found: types = copy_list (types); for (p = types; p; p = TREE_CHAIN (p)) { tree complex_type = TREE_VALUE (p); if (TREE_CODE (complex_type) == COMPLEX_TYPE && targetm.calls.split_complex_arg (complex_type)) { tree next, imag; /* Rewrite complex type with component type. */ TREE_VALUE (p) = TREE_TYPE (complex_type); next = TREE_CHAIN (p); /* Add another component type for the imaginary part. */ imag = build_tree_list (NULL_TREE, TREE_VALUE (p)); TREE_CHAIN (p) = imag; TREE_CHAIN (imag) = next; /* Skip the newly created node. */ p = TREE_CHAIN (p); } } return types; } /* Output a library call to function FUN (a SYMBOL_REF rtx). The RETVAL parameter specifies whether return value needs to be saved, other parameters are documented in the emit_library_call function below. */ static rtx emit_library_call_value_1 (int retval, rtx orgfun, rtx value, enum libcall_type fn_type, enum machine_mode outmode, int nargs, va_list p) { /* Total size in bytes of all the stack-parms scanned so far. */ struct args_size args_size; /* Size of arguments before any adjustments (such as rounding). */ struct args_size original_args_size; int argnum; rtx fun; /* Todo, choose the correct decl type of orgfun. Sadly this information isn't present here, so we default to native calling abi here. */ tree fndecl ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */ tree fntype ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */ int inc; int count; rtx argblock = 0; CUMULATIVE_ARGS args_so_far; struct arg { rtx value; enum machine_mode mode; rtx reg; int partial; struct locate_and_pad_arg_data locate; rtx save_area; }; struct arg *argvec; int old_inhibit_defer_pop = inhibit_defer_pop; rtx call_fusage = 0; rtx mem_value = 0; rtx valreg; int pcc_struct_value = 0; int struct_value_size = 0; int flags; int reg_parm_stack_space = 0; int needed; rtx before_call; tree tfom; /* type_for_mode (outmode, 0) */ #ifdef REG_PARM_STACK_SPACE /* Define the boundary of the register parm stack space that needs to be save, if any. */ int low_to_save = 0, high_to_save = 0; rtx save_area = 0; /* Place that it is saved. */ #endif /* Size of the stack reserved for parameter registers. */ int initial_highest_arg_in_use = highest_outgoing_arg_in_use; char *initial_stack_usage_map = stack_usage_map; char *stack_usage_map_buf = NULL; rtx struct_value = targetm.calls.struct_value_rtx (0, 0); #ifdef REG_PARM_STACK_SPACE reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0); #endif /* By default, library functions can not throw. */ flags = ECF_NOTHROW; switch (fn_type) { case LCT_NORMAL: break; case LCT_CONST: flags |= ECF_CONST; break; case LCT_PURE: flags |= ECF_PURE; break; case LCT_NORETURN: flags |= ECF_NORETURN; break; case LCT_THROW: flags = ECF_NORETURN; break; case LCT_RETURNS_TWICE: flags = ECF_RETURNS_TWICE; break; } fun = orgfun; /* Ensure current function's preferred stack boundary is at least what we need. */ if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY) crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY; /* If this kind of value comes back in memory, decide where in memory it should come back. */ if (outmode != VOIDmode) { tfom = lang_hooks.types.type_for_mode (outmode, 0); if (aggregate_value_p (tfom, 0)) { #ifdef PCC_STATIC_STRUCT_RETURN rtx pointer_reg = hard_function_value (build_pointer_type (tfom), 0, 0, 0); mem_value = gen_rtx_MEM (outmode, pointer_reg); pcc_struct_value = 1; if (value == 0) value = gen_reg_rtx (outmode); #else /* not PCC_STATIC_STRUCT_RETURN */ struct_value_size = GET_MODE_SIZE (outmode); if (value != 0 && MEM_P (value)) mem_value = value; else mem_value = assign_temp (tfom, 0, 1, 1); #endif /* This call returns a big structure. */ flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE); } } else tfom = void_type_node; /* ??? Unfinished: must pass the memory address as an argument. */ /* Copy all the libcall-arguments out of the varargs data and into a vector ARGVEC. Compute how to pass each argument. We only support a very small subset of the full argument passing conventions to limit complexity here since library functions shouldn't have many args. */ argvec = XALLOCAVEC (struct arg, nargs + 1); memset (argvec, 0, (nargs + 1) * sizeof (struct arg)); #ifdef INIT_CUMULATIVE_LIBCALL_ARGS INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun); #else INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0, nargs); #endif args_size.constant = 0; args_size.var = 0; count = 0; push_temp_slots (); /* If there's a structure value address to be passed, either pass it in the special place, or pass it as an extra argument. */ if (mem_value && struct_value == 0 && ! pcc_struct_value) { rtx addr = XEXP (mem_value, 0); nargs++; /* Make sure it is a reasonable operand for a move or push insn. */ if (!REG_P (addr) && !MEM_P (addr) && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr))) addr = force_operand (addr, NULL_RTX); argvec[count].value = addr; argvec[count].mode = Pmode; argvec[count].partial = 0; argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1); gcc_assert (targetm.calls.arg_partial_bytes (&args_so_far, Pmode, NULL_TREE, 1) == 0); locate_and_pad_parm (Pmode, NULL_TREE, #ifdef STACK_PARMS_IN_REG_PARM_AREA 1, #else argvec[count].reg != 0, #endif 0, NULL_TREE, &args_size, &argvec[count].locate); if (argvec[count].reg == 0 || argvec[count].partial != 0 || reg_parm_stack_space > 0) args_size.constant += argvec[count].locate.size.constant; FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1); count++; } for (; count < nargs; count++) { rtx val = va_arg (p, rtx); enum machine_mode mode = (enum machine_mode) va_arg (p, int); /* We cannot convert the arg value to the mode the library wants here; must do it earlier where we know the signedness of the arg. */ gcc_assert (mode != BLKmode && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode)); /* Make sure it is a reasonable operand for a move or push insn. */ if (!REG_P (val) && !MEM_P (val) && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val))) val = force_operand (val, NULL_RTX); if (pass_by_reference (&args_so_far, mode, NULL_TREE, 1)) { rtx slot; int must_copy = !reference_callee_copied (&args_so_far, mode, NULL_TREE, 1); /* If this was a CONST function, it is now PURE since it now reads memory. */ if (flags & ECF_CONST) { flags &= ~ECF_CONST; flags |= ECF_PURE; } if (MEM_P (val) && !must_copy) slot = val; else { slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0), 0, 1, 1); emit_move_insn (slot, val); } call_fusage = gen_rtx_EXPR_LIST (VOIDmode, gen_rtx_USE (VOIDmode, slot), call_fusage); if (must_copy) call_fusage = gen_rtx_EXPR_LIST (VOIDmode, gen_rtx_CLOBBER (VOIDmode, slot), call_fusage); mode = Pmode; val = force_operand (XEXP (slot, 0), NULL_RTX); } argvec[count].value = val; argvec[count].mode = mode; argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1); argvec[count].partial = targetm.calls.arg_partial_bytes (&args_so_far, mode, NULL_TREE, 1); locate_and_pad_parm (mode, NULL_TREE, #ifdef STACK_PARMS_IN_REG_PARM_AREA 1, #else argvec[count].reg != 0, #endif argvec[count].partial, NULL_TREE, &args_size, &argvec[count].locate); gcc_assert (!argvec[count].locate.size.var); if (argvec[count].reg == 0 || argvec[count].partial != 0 || reg_parm_stack_space > 0) args_size.constant += argvec[count].locate.size.constant; FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1); } /* If this machine requires an external definition for library functions, write one out. */ assemble_external_libcall (fun); original_args_size = args_size; args_size.constant = (((args_size.constant + stack_pointer_delta + STACK_BYTES - 1) / STACK_BYTES * STACK_BYTES) - stack_pointer_delta); args_size.constant = MAX (args_size.constant, reg_parm_stack_space); if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))) args_size.constant -= reg_parm_stack_space; if (args_size.constant > crtl->outgoing_args_size) crtl->outgoing_args_size = args_size.constant; if (ACCUMULATE_OUTGOING_ARGS) { /* Since the stack pointer will never be pushed, it is possible for the evaluation of a parm to clobber something we have already written to the stack. Since most function calls on RISC machines do not use the stack, this is uncommon, but must work correctly. Therefore, we save any area of the stack that was already written and that we are using. Here we set up to do this by making a new stack usage map from the old one. Another approach might be to try to reorder the argument evaluations to avoid this conflicting stack usage. */ needed = args_size.constant; /* Since we will be writing into the entire argument area, the map must be allocated for its entire size, not just the part that is the responsibility of the caller. */ if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))) needed += reg_parm_stack_space; #ifdef ARGS_GROW_DOWNWARD highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use, needed + 1); #else highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use, needed); #endif stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use); stack_usage_map = stack_usage_map_buf; if (initial_highest_arg_in_use) memcpy (stack_usage_map, initial_stack_usage_map, initial_highest_arg_in_use); if (initial_highest_arg_in_use != highest_outgoing_arg_in_use) memset (&stack_usage_map[initial_highest_arg_in_use], 0, highest_outgoing_arg_in_use - initial_highest_arg_in_use); needed = 0; /* We must be careful to use virtual regs before they're instantiated, and real regs afterwards. Loop optimization, for example, can create new libcalls after we've instantiated the virtual regs, and if we use virtuals anyway, they won't match the rtl patterns. */ if (virtuals_instantiated) argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET); else argblock = virtual_outgoing_args_rtx; } else { if (!PUSH_ARGS) argblock = push_block (GEN_INT (args_size.constant), 0, 0); } /* If we push args individually in reverse order, perform stack alignment before the first push (the last arg). */ if (argblock == 0 && PUSH_ARGS_REVERSED) anti_adjust_stack (GEN_INT (args_size.constant - original_args_size.constant)); if (PUSH_ARGS_REVERSED) { inc = -1; argnum = nargs - 1; } else { inc = 1; argnum = 0; } #ifdef REG_PARM_STACK_SPACE if (ACCUMULATE_OUTGOING_ARGS) { /* The argument list is the property of the called routine and it may clobber it. If the fixed area has been used for previous parameters, we must save and restore it. */ save_area = save_fixed_argument_area (reg_parm_stack_space, argblock, &low_to_save, &high_to_save); } #endif /* Push the args that need to be pushed. */ /* ARGNUM indexes the ARGVEC array in the order in which the arguments are to be pushed. */ for (count = 0; count < nargs; count++, argnum += inc) { enum machine_mode mode = argvec[argnum].mode; rtx val = argvec[argnum].value; rtx reg = argvec[argnum].reg; int partial = argvec[argnum].partial; unsigned int parm_align = argvec[argnum].locate.boundary; int lower_bound = 0, upper_bound = 0, i; if (! (reg != 0 && partial == 0)) { if (ACCUMULATE_OUTGOING_ARGS) { /* If this is being stored into a pre-allocated, fixed-size, stack area, save any previous data at that location. */ #ifdef ARGS_GROW_DOWNWARD /* stack_slot is negative, but we want to index stack_usage_map with positive values. */ upper_bound = -argvec[argnum].locate.slot_offset.constant + 1; lower_bound = upper_bound - argvec[argnum].locate.size.constant; #else lower_bound = argvec[argnum].locate.slot_offset.constant; upper_bound = lower_bound + argvec[argnum].locate.size.constant; #endif i = lower_bound; /* Don't worry about things in the fixed argument area; it has already been saved. */ if (i < reg_parm_stack_space) i = reg_parm_stack_space; while (i < upper_bound && stack_usage_map[i] == 0) i++; if (i < upper_bound) { /* We need to make a save area. */ unsigned int size = argvec[argnum].locate.size.constant * BITS_PER_UNIT; enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1); rtx adr = plus_constant (argblock, argvec[argnum].locate.offset.constant); rtx stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, adr)); if (save_mode == BLKmode) { argvec[argnum].save_area = assign_stack_temp (BLKmode, argvec[argnum].locate.size.constant, 0); emit_block_move (validize_mem (argvec[argnum].save_area), stack_area, GEN_INT (argvec[argnum].locate.size.constant), BLOCK_OP_CALL_PARM); } else { argvec[argnum].save_area = gen_reg_rtx (save_mode); emit_move_insn (argvec[argnum].save_area, stack_area); } } } emit_push_insn (val, mode, NULL_TREE, NULL_RTX, parm_align, partial, reg, 0, argblock, GEN_INT (argvec[argnum].locate.offset.constant), reg_parm_stack_space, ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad)); /* Now mark the segment we just used. */ if (ACCUMULATE_OUTGOING_ARGS) for (i = lower_bound; i < upper_bound; i++) stack_usage_map[i] = 1; NO_DEFER_POP; if ((flags & ECF_CONST) || ((flags & ECF_PURE) && ACCUMULATE_OUTGOING_ARGS)) { rtx use; /* Indicate argument access so that alias.c knows that these values are live. */ if (argblock) use = plus_constant (argblock, argvec[argnum].locate.offset.constant); else /* When arguments are pushed, trying to tell alias.c where exactly this argument is won't work, because the auto-increment causes confusion. So we merely indicate that we access something with a known mode somewhere on the stack. */ use = gen_rtx_PLUS (Pmode, virtual_outgoing_args_rtx, gen_rtx_SCRATCH (Pmode)); use = gen_rtx_MEM (argvec[argnum].mode, use); use = gen_rtx_USE (VOIDmode, use); call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage); } } } /* If we pushed args in forward order, perform stack alignment after pushing the last arg. */ if (argblock == 0 && !PUSH_ARGS_REVERSED) anti_adjust_stack (GEN_INT (args_size.constant - original_args_size.constant)); if (PUSH_ARGS_REVERSED) argnum = nargs - 1; else argnum = 0; fun = prepare_call_address (NULL, fun, NULL, &call_fusage, 0, 0); /* Now load any reg parms into their regs. */ /* ARGNUM indexes the ARGVEC array in the order in which the arguments are to be pushed. */ for (count = 0; count < nargs; count++, argnum += inc) { enum machine_mode mode = argvec[argnum].mode; rtx val = argvec[argnum].value; rtx reg = argvec[argnum].reg; int partial = argvec[argnum].partial; /* Handle calls that pass values in multiple non-contiguous locations. The PA64 has examples of this for library calls. */ if (reg != 0 && GET_CODE (reg) == PARALLEL) emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode)); else if (reg != 0 && partial == 0) emit_move_insn (reg, val); NO_DEFER_POP; } /* Any regs containing parms remain in use through the call. */ for (count = 0; count < nargs; count++) { rtx reg = argvec[count].reg; if (reg != 0 && GET_CODE (reg) == PARALLEL) use_group_regs (&call_fusage, reg); else if (reg != 0) { int partial = argvec[count].partial; if (partial) { int nregs; gcc_assert (partial % UNITS_PER_WORD == 0); nregs = partial / UNITS_PER_WORD; use_regs (&call_fusage, REGNO (reg), nregs); } else use_reg (&call_fusage, reg); } } /* Pass the function the address in which to return a structure value. */ if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value) { emit_move_insn (struct_value, force_reg (Pmode, force_operand (XEXP (mem_value, 0), NULL_RTX))); if (REG_P (struct_value)) use_reg (&call_fusage, struct_value); } /* Don't allow popping to be deferred, since then cse'ing of library calls could delete a call and leave the pop. */ NO_DEFER_POP; valreg = (mem_value == 0 && outmode != VOIDmode ? hard_libcall_value (outmode, orgfun) : NULL_RTX); /* Stack must be properly aligned now. */ gcc_assert (!(stack_pointer_delta & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1))); before_call = get_last_insn (); /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which will set inhibit_defer_pop to that value. */ /* The return type is needed to decide how many bytes the function pops. Signedness plays no role in that, so for simplicity, we pretend it's always signed. We also assume that the list of arguments passed has no impact, so we pretend it is unknown. */ emit_call_1 (fun, NULL, get_identifier (XSTR (orgfun, 0)), build_function_type (tfom, NULL_TREE), original_args_size.constant, args_size.constant, struct_value_size, FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1), valreg, old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far); /* For calls to `setjmp', etc., inform function.c:setjmp_warnings that it should complain if nonvolatile values are live. For functions that cannot return, inform flow that control does not fall through. */ if (flags & ECF_NORETURN) { /* The barrier note must be emitted immediately after the CALL_INSN. Some ports emit more than just a CALL_INSN above, so we must search for it here. */ rtx last = get_last_insn (); while (!CALL_P (last)) { last = PREV_INSN (last); /* There was no CALL_INSN? */ gcc_assert (last != before_call); } emit_barrier_after (last); } /* Now restore inhibit_defer_pop to its actual original value. */ OK_DEFER_POP; pop_temp_slots (); /* Copy the value to the right place. */ if (outmode != VOIDmode && retval) { if (mem_value) { if (value == 0) value = mem_value; if (value != mem_value) emit_move_insn (value, mem_value); } else if (GET_CODE (valreg) == PARALLEL) { if (value == 0) value = gen_reg_rtx (outmode); emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode)); } else { /* Convert to the proper mode if a promotion has been active. */ if (GET_MODE (valreg) != outmode) { int unsignedp = TYPE_UNSIGNED (tfom); gcc_assert (promote_function_mode (tfom, outmode, &unsignedp, fndecl ? TREE_TYPE (fndecl) : fntype, 1) == GET_MODE (valreg)); valreg = convert_modes (outmode, GET_MODE (valreg), valreg, 0); } if (value != 0) emit_move_insn (value, valreg); else value = valreg; } } if (ACCUMULATE_OUTGOING_ARGS) { #ifdef REG_PARM_STACK_SPACE if (save_area) restore_fixed_argument_area (save_area, argblock, high_to_save, low_to_save); #endif /* If we saved any argument areas, restore them. */ for (count = 0; count < nargs; count++) if (argvec[count].save_area) { enum machine_mode save_mode = GET_MODE (argvec[count].save_area); rtx adr = plus_constant (argblock, argvec[count].locate.offset.constant); rtx stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, adr)); if (save_mode == BLKmode) emit_block_move (stack_area, validize_mem (argvec[count].save_area), GEN_INT (argvec[count].locate.size.constant), BLOCK_OP_CALL_PARM); else emit_move_insn (stack_area, argvec[count].save_area); } highest_outgoing_arg_in_use = initial_highest_arg_in_use; stack_usage_map = initial_stack_usage_map; } if (stack_usage_map_buf) free (stack_usage_map_buf); return value; } /* Output a library call to function FUN (a SYMBOL_REF rtx) (emitting the queue unless NO_QUEUE is nonzero), for a value of mode OUTMODE, with NARGS different arguments, passed as alternating rtx values and machine_modes to convert them to. FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for `const' calls, LCT_PURE for `pure' calls, or other LCT_ value for other types of library calls. */ void emit_library_call (rtx orgfun, enum libcall_type fn_type, enum machine_mode outmode, int nargs, ...) { va_list p; va_start (p, nargs); emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p); va_end (p); } /* Like emit_library_call except that an extra argument, VALUE, comes second and says where to store the result. (If VALUE is zero, this function chooses a convenient way to return the value. This function returns an rtx for where the value is to be found. If VALUE is nonzero, VALUE is returned. */ rtx emit_library_call_value (rtx orgfun, rtx value, enum libcall_type fn_type, enum machine_mode outmode, int nargs, ...) { rtx result; va_list p; va_start (p, nargs); result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode, nargs, p); va_end (p); return result; } /* Store a single argument for a function call into the register or memory area where it must be passed. *ARG describes the argument value and where to pass it. ARGBLOCK is the address of the stack-block for all the arguments, or 0 on a machine where arguments are pushed individually. MAY_BE_ALLOCA nonzero says this could be a call to `alloca' so must be careful about how the stack is used. VARIABLE_SIZE nonzero says that this was a variable-sized outgoing argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate that we need not worry about saving and restoring the stack. FNDECL is the declaration of the function we are calling. Return nonzero if this arg should cause sibcall failure, zero otherwise. */ static int store_one_arg (struct arg_data *arg, rtx argblock, int flags, int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space) { tree pval = arg->tree_value; rtx reg = 0; int partial = 0; int used = 0; int i, lower_bound = 0, upper_bound = 0; int sibcall_failure = 0; if (TREE_CODE (pval) == ERROR_MARK) return 1; /* Push a new temporary level for any temporaries we make for this argument. */ push_temp_slots (); if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)) { /* If this is being stored into a pre-allocated, fixed-size, stack area, save any previous data at that location. */ if (argblock && ! variable_size && arg->stack) { #ifdef ARGS_GROW_DOWNWARD /* stack_slot is negative, but we want to index stack_usage_map with positive values. */ if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS) upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1; else upper_bound = 0; lower_bound = upper_bound - arg->locate.size.constant; #else if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS) lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)); else lower_bound = 0; upper_bound = lower_bound + arg->locate.size.constant; #endif i = lower_bound; /* Don't worry about things in the fixed argument area; it has already been saved. */ if (i < reg_parm_stack_space) i = reg_parm_stack_space; while (i < upper_bound && stack_usage_map[i] == 0) i++; if (i < upper_bound) { /* We need to make a save area. */ unsigned int size = arg->locate.size.constant * BITS_PER_UNIT; enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1); rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0)); rtx stack_area = gen_rtx_MEM (save_mode, adr); if (save_mode == BLKmode) { tree ot = TREE_TYPE (arg->tree_value); tree nt = build_qualified_type (ot, (TYPE_QUALS (ot) | TYPE_QUAL_CONST)); arg->save_area = assign_temp (nt, 0, 1, 1); preserve_temp_slots (arg->save_area); emit_block_move (validize_mem (arg->save_area), stack_area, GEN_INT (arg->locate.size.constant), BLOCK_OP_CALL_PARM); } else { arg->save_area = gen_reg_rtx (save_mode); emit_move_insn (arg->save_area, stack_area); } } } } /* If this isn't going to be placed on both the stack and in registers, set up the register and number of words. */ if (! arg->pass_on_stack) { if (flags & ECF_SIBCALL) reg = arg->tail_call_reg; else reg = arg->reg; partial = arg->partial; } /* Being passed entirely in a register. We shouldn't be called in this case. */ gcc_assert (reg == 0 || partial != 0); /* If this arg needs special alignment, don't load the registers here. */ if (arg->n_aligned_regs != 0) reg = 0; /* If this is being passed partially in a register, we can't evaluate it directly into its stack slot. Otherwise, we can. */ if (arg->value == 0) { /* stack_arg_under_construction is nonzero if a function argument is being evaluated directly into the outgoing argument list and expand_call must take special action to preserve the argument list if it is called recursively. For scalar function arguments stack_usage_map is sufficient to determine which stack slots must be saved and restored. Scalar arguments in general have pass_on_stack == 0. If this argument is initialized by a function which takes the address of the argument (a C++ constructor or a C function returning a BLKmode structure), then stack_usage_map is insufficient and expand_call must push the stack around the function call. Such arguments have pass_on_stack == 1. Note that it is always safe to set stack_arg_under_construction, but this generates suboptimal code if set when not needed. */ if (arg->pass_on_stack) stack_arg_under_construction++; arg->value = expand_expr (pval, (partial || TYPE_MODE (TREE_TYPE (pval)) != arg->mode) ? NULL_RTX : arg->stack, VOIDmode, EXPAND_STACK_PARM); /* If we are promoting object (or for any other reason) the mode doesn't agree, convert the mode. */ if (arg->mode != TYPE_MODE (TREE_TYPE (pval))) arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)), arg->value, arg->unsignedp); if (arg->pass_on_stack) stack_arg_under_construction--; } /* Check for overlap with already clobbered argument area. */ if ((flags & ECF_SIBCALL) && MEM_P (arg->value) && mem_overlaps_already_clobbered_arg_p (XEXP (arg->value, 0), arg->locate.size.constant)) sibcall_failure = 1; /* Don't allow anything left on stack from computation of argument to alloca. */ if (flags & ECF_MAY_BE_ALLOCA) do_pending_stack_adjust (); if (arg->value == arg->stack) /* If the value is already in the stack slot, we are done. */ ; else if (arg->mode != BLKmode) { int size; unsigned int parm_align; /* Argument is a scalar, not entirely passed in registers. (If part is passed in registers, arg->partial says how much and emit_push_insn will take care of putting it there.) Push it, and if its size is less than the amount of space allocated to it, also bump stack pointer by the additional space. Note that in C the default argument promotions will prevent such mismatches. */ size = GET_MODE_SIZE (arg->mode); /* Compute how much space the push instruction will push. On many machines, pushing a byte will advance the stack pointer by a halfword. */ #ifdef PUSH_ROUNDING size = PUSH_ROUNDING (size); #endif used = size; /* Compute how much space the argument should get: round up to a multiple of the alignment for arguments. */ if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval))) used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1) / (PARM_BOUNDARY / BITS_PER_UNIT)) * (PARM_BOUNDARY / BITS_PER_UNIT)); /* Compute the alignment of the pushed argument. */ parm_align = arg->locate.boundary; if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward) { int pad = used - size; if (pad) { unsigned int pad_align = (pad & -pad) * BITS_PER_UNIT; parm_align = MIN (parm_align, pad_align); } } /* This isn't already where we want it on the stack, so put it there. This can either be done with push or copy insns. */ emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX, parm_align, partial, reg, used - size, argblock, ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space, ARGS_SIZE_RTX (arg->locate.alignment_pad)); /* Unless this is a partially-in-register argument, the argument is now in the stack. */ if (partial == 0) arg->value = arg->stack; } else { /* BLKmode, at least partly to be pushed. */ unsigned int parm_align; int excess; rtx size_rtx; /* Pushing a nonscalar. If part is passed in registers, PARTIAL says how much and emit_push_insn will take care of putting it there. */ /* Round its size up to a multiple of the allocation unit for arguments. */ if (arg->locate.size.var != 0) { excess = 0; size_rtx = ARGS_SIZE_RTX (arg->locate.size); } else { /* PUSH_ROUNDING has no effect on us, because emit_push_insn for BLKmode is careful to avoid it. */ excess = (arg->locate.size.constant - int_size_in_bytes (TREE_TYPE (pval)) + partial); size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)), NULL_RTX, TYPE_MODE (sizetype), EXPAND_NORMAL); } parm_align = arg->locate.boundary; /* When an argument is padded down, the block is aligned to PARM_BOUNDARY, but the actual argument isn't. */ if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward) { if (arg->locate.size.var) parm_align = BITS_PER_UNIT; else if (excess) { unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT; parm_align = MIN (parm_align, excess_align); } } if ((flags & ECF_SIBCALL) && MEM_P (arg->value)) { /* emit_push_insn might not work properly if arg->value and argblock + arg->locate.offset areas overlap. */ rtx x = arg->value; int i = 0; if (XEXP (x, 0) == crtl->args.internal_arg_pointer || (GET_CODE (XEXP (x, 0)) == PLUS && XEXP (XEXP (x, 0), 0) == crtl->args.internal_arg_pointer && CONST_INT_P (XEXP (XEXP (x, 0), 1)))) { if (XEXP (x, 0) != crtl->args.internal_arg_pointer) i = INTVAL (XEXP (XEXP (x, 0), 1)); /* expand_call should ensure this. */ gcc_assert (!arg->locate.offset.var && arg->locate.size.var == 0 && CONST_INT_P (size_rtx)); if (arg->locate.offset.constant > i) { if (arg->locate.offset.constant < i + INTVAL (size_rtx)) sibcall_failure = 1; } else if (arg->locate.offset.constant < i) { /* Use arg->locate.size.constant instead of size_rtx because we only care about the part of the argument on the stack. */ if (i < (arg->locate.offset.constant + arg->locate.size.constant)) sibcall_failure = 1; } else { /* Even though they appear to be at the same location, if part of the outgoing argument is in registers, they aren't really at the same location. Check for this by making sure that the incoming size is the same as the outgoing size. */ if (arg->locate.size.constant != INTVAL (size_rtx)) sibcall_failure = 1; } } } emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx, parm_align, partial, reg, excess, argblock, ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space, ARGS_SIZE_RTX (arg->locate.alignment_pad)); /* Unless this is a partially-in-register argument, the argument is now in the stack. ??? Unlike the case above, in which we want the actual address of the data, so that we can load it directly into a register, here we want the address of the stack slot, so that it's properly aligned for word-by-word copying or something like that. It's not clear that this is always correct. */ if (partial == 0) arg->value = arg->stack_slot; } if (arg->reg && GET_CODE (arg->reg) == PARALLEL) { tree type = TREE_TYPE (arg->tree_value); arg->parallel_value = emit_group_load_into_temps (arg->reg, arg->value, type, int_size_in_bytes (type)); } /* Mark all slots this store used. */ if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL) && argblock && ! variable_size && arg->stack) for (i = lower_bound; i < upper_bound; i++) stack_usage_map[i] = 1; /* Once we have pushed something, pops can't safely be deferred during the rest of the arguments. */ NO_DEFER_POP; /* Free any temporary slots made in processing this argument. Show that we might have taken the address of something and pushed that as an operand. */ preserve_temp_slots (NULL_RTX); free_temp_slots (); pop_temp_slots (); return sibcall_failure; } /* Nonzero if we do not know how to pass TYPE solely in registers. */ bool must_pass_in_stack_var_size (enum machine_mode mode ATTRIBUTE_UNUSED, const_tree type) { if (!type) return false; /* If the type has variable size... */ if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST) return true; /* If the type is marked as addressable (it is required to be constructed into the stack)... */ if (TREE_ADDRESSABLE (type)) return true; return false; } /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one takes trailing padding of a structure into account. */ /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */ bool must_pass_in_stack_var_size_or_pad (enum machine_mode mode, const_tree type) { if (!type) return false; /* If the type has variable size... */ if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST) return true; /* If the type is marked as addressable (it is required to be constructed into the stack)... */ if (TREE_ADDRESSABLE (type)) return true; /* If the padding and mode of the type is such that a copy into a register would put it into the wrong part of the register. */ if (mode == BLKmode && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT) && (FUNCTION_ARG_PADDING (mode, type) == (BYTES_BIG_ENDIAN ? upward : downward))) return true; return false; }
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