/* Convert function calls to rtl insns, for GNU C compiler. Copyright (C) 1989, 92-97, 1998, 1999 Free Software Foundation, Inc. This file is part of GNU CC. GNU CC 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 2, or (at your option) any later version. GNU CC 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 GNU CC; see the file COPYING. If not, write to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include "config.h" #include "system.h" #include "rtl.h" #include "tree.h" #include "flags.h" #include "expr.h" #include "regs.h" #include "insn-flags.h" #include "toplev.h" #include "output.h" #if !defined PREFERRED_STACK_BOUNDARY && defined STACK_BOUNDARY #define PREFERRED_STACK_BOUNDARY STACK_BOUNDARY #endif /* Decide whether a function's arguments should be processed from first to last or from last to first. They should if the stack and args grow in opposite directions, but only if we have push insns. */ #ifdef PUSH_ROUNDING #if defined (STACK_GROWS_DOWNWARD) != defined (ARGS_GROW_DOWNWARD) #define PUSH_ARGS_REVERSED /* If it's last to first */ #endif #endif /* 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; /* 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 registers to use. 0 means put the whole arg in registers. Also 0 if not passed in registers. */ int partial; /* Non-zero 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; /* Offset of this argument from beginning of stack-args. */ struct args_size offset; /* Similar, but offset to the start of the stack slot. Different from OFFSET if this arg pads downward. */ struct args_size slot_offset; /* Size of this argument on the stack, rounded up for any padding it gets, parts of the argument passed in registers do not count. If REG_PARM_STACK_SPACE is defined, then register parms are counted here as well. */ struct args_size size; /* 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; #ifdef ACCUMULATE_OUTGOING_ARGS /* Place that this stack area has been saved, if needed. */ rtx save_area; #endif /* 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; }; #ifdef ACCUMULATE_OUTGOING_ARGS /* A vector of one char per byte of stack space. A byte if non-zero 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; /* 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. */ int stack_arg_under_construction; #endif static int calls_function PROTO ((tree, int)); static int calls_function_1 PROTO ((tree, int)); static void emit_call_1 PROTO ((rtx, tree, tree, HOST_WIDE_INT, HOST_WIDE_INT, rtx, rtx, int, rtx, int)); static void special_function_p PROTO ((char *, tree, int *, int *, int *, int *)); static void precompute_register_parameters PROTO ((int, struct arg_data *, int *)); static void store_one_arg PROTO ((struct arg_data *, rtx, int, int, int)); static void store_unaligned_arguments_into_pseudos PROTO ((struct arg_data *, int)); #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE) static rtx save_fixed_argument_area PROTO ((int, rtx, int *, int *)); static void restore_fixed_argument_area PROTO ((rtx, rtx, int, int)); #endif /* If WHICH is 1, return 1 if EXP contains a call to the built-in function `alloca'. If WHICH is 0, return 1 if EXP contains a call to any function. Actually, we only need return 1 if evaluating EXP would require pushing arguments on the stack, but that is too difficult to compute, so we just assume any function call might require the stack. */ static tree calls_function_save_exprs; static int calls_function (exp, which) tree exp; int which; { int val; calls_function_save_exprs = 0; val = calls_function_1 (exp, which); calls_function_save_exprs = 0; return val; } static int calls_function_1 (exp, which) tree exp; int which; { register int i; enum tree_code code = TREE_CODE (exp); int type = TREE_CODE_CLASS (code); int length = tree_code_length[(int) code]; /* If this code is language-specific, we don't know what it will do. */ if ((int) code >= NUM_TREE_CODES) return 1; /* Only expressions and references can contain calls. */ if (type != 'e' && type != '<' && type != '1' && type != '2' && type != 'r' && type != 'b') return 0; switch (code) { case CALL_EXPR: if (which == 0) return 1; else if (TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0)) == FUNCTION_DECL)) { tree fndecl = TREE_OPERAND (TREE_OPERAND (exp, 0), 0); if ((DECL_BUILT_IN (fndecl) && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_ALLOCA) || (DECL_SAVED_INSNS (fndecl) && (FUNCTION_FLAGS (DECL_SAVED_INSNS (fndecl)) & FUNCTION_FLAGS_CALLS_ALLOCA))) return 1; } /* Third operand is RTL. */ length = 2; break; case SAVE_EXPR: if (SAVE_EXPR_RTL (exp) != 0) return 0; if (value_member (exp, calls_function_save_exprs)) return 0; calls_function_save_exprs = tree_cons (NULL_TREE, exp, calls_function_save_exprs); return (TREE_OPERAND (exp, 0) != 0 && calls_function_1 (TREE_OPERAND (exp, 0), which)); case BLOCK: { register tree local; for (local = BLOCK_VARS (exp); local; local = TREE_CHAIN (local)) if (DECL_INITIAL (local) != 0 && calls_function_1 (DECL_INITIAL (local), which)) return 1; } { register tree subblock; for (subblock = BLOCK_SUBBLOCKS (exp); subblock; subblock = TREE_CHAIN (subblock)) if (calls_function_1 (subblock, which)) return 1; } return 0; case METHOD_CALL_EXPR: length = 3; break; case WITH_CLEANUP_EXPR: length = 1; break; case RTL_EXPR: return 0; default: break; } for (i = 0; i < length; i++) if (TREE_OPERAND (exp, i) != 0 && calls_function_1 (TREE_OPERAND (exp, i), which)) return 1; return 0; } /* 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 (funexp, fndecl, call_fusage, reg_parm_seen) rtx funexp; tree fndecl; rtx *call_fusage; int reg_parm_seen; { rtx static_chain_value = 0; funexp = protect_from_queue (funexp, 0); if (fndecl != 0) /* Get possible static chain value for nested function in C. */ static_chain_value = lookup_static_chain (fndecl); /* Make a valid memory address and copy constants thru 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 { #ifndef NO_FUNCTION_CSE if (optimize && ! flag_no_function_cse) #ifdef NO_RECURSIVE_FUNCTION_CSE if (fndecl != current_function_decl) #endif funexp = force_reg (Pmode, funexp); #endif } if (static_chain_value != 0) { emit_move_insn (static_chain_rtx, static_chain_value); if (GET_CODE (static_chain_rtx) == REG) use_reg (call_fusage, static_chain_rtx); } 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 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. IS_CONST is true if this is a `const' call. */ static void emit_call_1 (funexp, fndecl, funtype, stack_size, struct_value_size, next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage, is_const) rtx funexp; tree fndecl ATTRIBUTE_UNUSED; tree funtype ATTRIBUTE_UNUSED; HOST_WIDE_INT stack_size; HOST_WIDE_INT struct_value_size; rtx next_arg_reg; rtx valreg; int old_inhibit_defer_pop; rtx call_fusage; int is_const; { rtx stack_size_rtx = GEN_INT (stack_size); rtx struct_value_size_rtx = GEN_INT (struct_value_size); rtx call_insn; #ifndef ACCUMULATE_OUTGOING_ARGS int already_popped = 0; #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); #ifndef ACCUMULATE_OUTGOING_ARGS #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop) if (HAVE_call_pop && HAVE_call_value_pop && (RETURN_POPS_ARGS (fndecl, funtype, stack_size) > 0 || stack_size == 0)) { rtx n_pop = GEN_INT (RETURN_POPS_ARGS (fndecl, funtype, stack_size)); 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), stack_size_rtx, next_arg_reg, n_pop); else pat = gen_call_pop (gen_rtx_MEM (FUNCTION_MODE, funexp), stack_size_rtx, next_arg_reg, n_pop); emit_call_insn (pat); already_popped = 1; } else #endif #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), stack_size_rtx, next_arg_reg, NULL_RTX)); else emit_call_insn (gen_call (gen_rtx_MEM (FUNCTION_MODE, funexp), stack_size_rtx, next_arg_reg, struct_value_size_rtx)); } else #endif abort (); /* Find the CALL insn we just emitted. */ for (call_insn = get_last_insn (); call_insn && GET_CODE (call_insn) != CALL_INSN; call_insn = PREV_INSN (call_insn)) ; if (! call_insn) abort (); /* Put the register usage information on the CALL. If there is already some usage information, put ours at the end. */ if (CALL_INSN_FUNCTION_USAGE (call_insn)) { rtx link; for (link = CALL_INSN_FUNCTION_USAGE (call_insn); XEXP (link, 1) != 0; link = XEXP (link, 1)) ; XEXP (link, 1) = call_fusage; } else CALL_INSN_FUNCTION_USAGE (call_insn) = call_fusage; /* If this is a const call, then set the insn's unchanging bit. */ if (is_const) CONST_CALL_P (call_insn) = 1; /* 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; #ifndef 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 (stack_size != 0 && RETURN_POPS_ARGS (fndecl, funtype, stack_size) > 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)); stack_size -= RETURN_POPS_ARGS (fndecl, funtype, stack_size); stack_size_rtx = GEN_INT (stack_size); } if (stack_size != 0) { if (flag_defer_pop && inhibit_defer_pop == 0 && !is_const) pending_stack_adjust += stack_size; else adjust_stack (stack_size_rtx); } #endif } /* 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 IS_LONGJMP for if the function is in the longjmp family. Set IS_MALLOC for any of the standard memory allocation functions which allocate from the heap. Set MAY_BE_ALLOCA for any memory allocation function that might allocate space from the stack such as alloca. */ static void special_function_p (name, fndecl, returns_twice, is_longjmp, is_malloc, may_be_alloca) char *name; tree fndecl; int *returns_twice; int *is_longjmp; int *is_malloc; int *may_be_alloca; { *returns_twice = 0; *is_longjmp = 0; *is_malloc = 0; *may_be_alloca = 0; if (name != 0 && 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. */ && DECL_CONTEXT (fndecl) == NULL_TREE && TREE_PUBLIC (fndecl)) { 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. */ *may_be_alloca = (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6 && name[0] == 'a' && ! strcmp (name, "alloca")) || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16 && name[0] == '_' && ! strcmp (name, "__builtin_alloca")))); /* Disregard prefix _, __ or __x. */ if (name[0] == '_') { if (name[1] == '_' && name[2] == 'x') tname += 3; else if (name[1] == '_') tname += 2; else tname += 1; } if (tname[0] == 's') { *returns_twice = ((tname[1] == 'e' && (! strcmp (tname, "setjmp") || ! strcmp (tname, "setjmp_syscall"))) || (tname[1] == 'i' && ! strcmp (tname, "sigsetjmp")) || (tname[1] == 'a' && ! strcmp (tname, "savectx"))); if (tname[1] == 'i' && ! strcmp (tname, "siglongjmp")) *is_longjmp = 1; } else if ((tname[0] == 'q' && tname[1] == 's' && ! strcmp (tname, "qsetjmp")) || (tname[0] == 'v' && tname[1] == 'f' && ! strcmp (tname, "vfork"))) *returns_twice = 1; else if (tname[0] == 'l' && tname[1] == 'o' && ! strcmp (tname, "longjmp")) *is_longjmp = 1; /* XXX should have "malloc" attribute on functions instead of recognizing them by name. */ else if (! strcmp (tname, "malloc") || ! strcmp (tname, "calloc") || ! strcmp (tname, "realloc") /* Note use of NAME rather than TNAME here. These functions are only reserved when preceded with __. */ || ! strcmp (name, "__vn") /* mangled __builtin_vec_new */ || ! strcmp (name, "__nw") /* mangled __builtin_new */ || ! strcmp (name, "__builtin_new") || ! strcmp (name, "__builtin_vec_new")) *is_malloc = 1; } } /* 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 (num_actuals, args, reg_parm_seen) 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_expr (args[i].tree_value, NULL_RTX, VOIDmode, 0); preserve_temp_slots (args[i].value); pop_temp_slots (); /* ANSI doesn't require a sequence point here, but PCC has one, so this will avoid some problems. */ emit_queue (); } /* 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 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. */ if ((! (GET_CODE (args[i].value) == REG || (GET_CODE (args[i].value) == SUBREG && GET_CODE (SUBREG_REG (args[i].value)) == REG))) && args[i].mode != BLKmode && rtx_cost (args[i].value, SET) > 2 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen) || preserve_subexpressions_p ())) args[i].value = copy_to_mode_reg (args[i].mode, args[i].value); } } #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(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 (reg_parm_stack_space, argblock, low_to_save, high_to_save) int reg_parm_stack_space; rtx argblock; int *low_to_save; int *high_to_save; { int i; rtx save_area = NULL_RTX; /* Compute the boundary of the that needs to be saved, if any. */ #ifdef ARGS_GROW_DOWNWARD for (i = 0; i < reg_parm_stack_space + 1; i++) #else for (i = 0; i < reg_parm_stack_space; i++) #endif { if (i >= highest_outgoing_arg_in_use || stack_usage_map[i] == 0) continue; if (*low_to_save == -1) *low_to_save = i; *high_to_save = i; } if (*low_to_save >= 0) { int num_to_save = *high_to_save - *low_to_save + 1; enum machine_mode save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1); rtx stack_area; /* If we don't have the required alignment, must do this in BLKmode. */ if ((*low_to_save & (MIN (GET_MODE_SIZE (save_mode), BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1))) save_mode = BLKmode; #ifdef ARGS_GROW_DOWNWARD stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, plus_constant (argblock, - *high_to_save))); #else stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, plus_constant (argblock, *low_to_save))); #endif 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), PARM_BOUNDARY / BITS_PER_UNIT); } else { save_area = gen_reg_rtx (save_mode); emit_move_insn (save_area, stack_area); } } return save_area; } static void restore_fixed_argument_area (save_area, argblock, high_to_save, low_to_save) rtx save_area; rtx argblock; int high_to_save; int low_to_save; { enum machine_mode save_mode = GET_MODE (save_area); #ifdef ARGS_GROW_DOWNWARD rtx stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, plus_constant (argblock, - high_to_save))); #else rtx stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, plus_constant (argblock, low_to_save))); #endif 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), PARM_BOUNDARY / BITS_PER_UNIT); } #endif /* 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 (args, num_actuals) 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 && (TYPE_ALIGN (TREE_TYPE (args[i].tree_value)) < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD))) { int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value)); int big_endian_correction = 0; args[i].n_aligned_regs = args[i].partial ? args[i].partial : (bytes + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD; args[i].aligned_regs = (rtx *) xmalloc (sizeof (rtx) * args[i].n_aligned_regs); /* Structures smaller than a word are aligned to the least significant byte (to the right). On a BYTES_BIG_ENDIAN machine, this means we must skip the empty high order bytes when calculating the bit offset. */ if (BYTES_BIG_ENDIAN && bytes < UNITS_PER_WORD) big_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); int bitalign = TYPE_ALIGN (TREE_TYPE (args[i].tree_value)); args[i].aligned_regs[j] = reg; /* 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, big_endian_correction, word_mode, extract_bit_field (word, bitsize, 0, 1, NULL_RTX, word_mode, word_mode, bitalign / BITS_PER_UNIT, BITS_PER_WORD), bitalign / BITS_PER_UNIT, BITS_PER_WORD); } } } /* Generate all the code for a function call 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 (exp, target, ignore) tree exp; rtx target; int ignore; { /* List of actual parameters. */ tree actparms = TREE_OPERAND (exp, 1); /* RTX for the function to be called. */ rtx funexp; /* Data type of the function. */ tree funtype; /* Declaration of the function being called, or 0 if the function is computed (not known by name). */ tree fndecl = 0; char *name = 0; /* 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; /* 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; /* 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; /* Count arg position in order args appear. */ int argpos; /* 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; /* Size of arguments before any adjustments (such as rounding). */ struct args_size original_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). */ #ifdef PUSH_ROUNDING int must_preallocate = 0; #else int must_preallocate = 1; #endif /* Size of the stack reserved for parameter registers. */ int reg_parm_stack_space = 0; /* 1 if scanning parms front to back, -1 if scanning back to front. */ int inc; /* Address of space preallocated for stack parms (on machines that lack push insns), or 0 if space not preallocated. */ rtx argblock = 0; /* Nonzero if it is plausible that this is a call to alloca. */ int may_be_alloca; /* Nonzero if this is a call to malloc or a related function. */ int is_malloc; /* Nonzero if this is a call to setjmp or a related function. */ int returns_twice; /* Nonzero if this is a call to `longjmp'. */ int is_longjmp; /* Nonzero if this is a call to an inline function. */ int is_integrable = 0; /* Nonzero if this is a call to a `const' function. Note that only explicitly named functions are handled as `const' here. */ int is_const = 0; /* Nonzero if this is a call to a `volatile' function. */ int is_volatile = 0; #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE) /* Define the boundary of the register parm stack space that needs to be save, if any. */ int low_to_save = -1, high_to_save; rtx save_area = 0; /* Place that it is saved */ #endif #ifdef ACCUMULATE_OUTGOING_ARGS int initial_highest_arg_in_use = highest_outgoing_arg_in_use; char *initial_stack_usage_map = stack_usage_map; int old_stack_arg_under_construction; #endif rtx old_stack_level = 0; int old_pending_adj = 0; int old_inhibit_defer_pop = inhibit_defer_pop; rtx call_fusage = 0; register tree p; register int i, j; /* The value of the function call can be put in a hard register. But if -fcheck-memory-usage, code which invokes functions (and thus damages some hard registers) can be inserted before using the value. So, target is always a pseudo-register in that case. */ if (current_function_check_memory_usage) target = 0; /* See if we can find a DECL-node for the actual function. As a result, decide whether this is a call to an integrable function. */ p = TREE_OPERAND (exp, 0); if (TREE_CODE (p) == ADDR_EXPR) { fndecl = TREE_OPERAND (p, 0); if (TREE_CODE (fndecl) != FUNCTION_DECL) fndecl = 0; else { if (!flag_no_inline && fndecl != current_function_decl && DECL_INLINE (fndecl) && DECL_SAVED_INSNS (fndecl) && RTX_INTEGRATED_P (DECL_SAVED_INSNS (fndecl))) is_integrable = 1; else if (! TREE_ADDRESSABLE (fndecl)) { /* In case this function later becomes inlinable, record that there was already a non-inline call to it. Use abstraction instead of setting TREE_ADDRESSABLE directly. */ if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline && optimize > 0) { warning_with_decl (fndecl, "can't inline call to `%s'"); warning ("called from here"); } mark_addressable (fndecl); } if (TREE_READONLY (fndecl) && ! TREE_THIS_VOLATILE (fndecl) && TYPE_MODE (TREE_TYPE (exp)) != VOIDmode) is_const = 1; if (TREE_THIS_VOLATILE (fndecl)) is_volatile = 1; } } /* If we don't have specific function to call, see if we have a constant or `noreturn' function from the type. */ if (fndecl == 0) { is_const = TREE_READONLY (TREE_TYPE (TREE_TYPE (p))); is_volatile = TREE_THIS_VOLATILE (TREE_TYPE (TREE_TYPE (p))); } #ifdef REG_PARM_STACK_SPACE #ifdef MAYBE_REG_PARM_STACK_SPACE reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE; #else reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl); #endif #endif #if defined(PUSH_ROUNDING) && ! defined(OUTGOING_REG_PARM_STACK_SPACE) if (reg_parm_stack_space > 0) must_preallocate = 1; #endif /* Warn if this value is an aggregate type, regardless of which calling convention we are using for it. */ if (warn_aggregate_return && AGGREGATE_TYPE_P (TREE_TYPE (exp))) warning ("function call has aggregate value"); /* Set up a place to return a structure. */ /* Cater to broken compilers. */ if (aggregate_value_p (exp)) { /* This call returns a big structure. */ is_const = 0; #ifdef PCC_STATIC_STRUCT_RETURN { pcc_struct_value = 1; /* Easier than making that case work right. */ if (is_integrable) { /* In case this is a static function, note that it has been used. */ if (! TREE_ADDRESSABLE (fndecl)) mark_addressable (fndecl); is_integrable = 0; } } #else /* not PCC_STATIC_STRUCT_RETURN */ { struct_value_size = int_size_in_bytes (TREE_TYPE (exp)); if (target && GET_CODE (target) == MEM) structure_value_addr = XEXP (target, 0); else { /* Assign a temporary to hold the value. */ tree d; /* 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. */ if (struct_value_size < 0) abort (); /* This DECL is just something to feed to mark_addressable; it doesn't get pushed. */ d = build_decl (VAR_DECL, NULL_TREE, TREE_TYPE (exp)); DECL_RTL (d) = assign_temp (TREE_TYPE (exp), 1, 0, 1); mark_addressable (d); structure_value_addr = XEXP (DECL_RTL (d), 0); TREE_USED (d) = 1; target = 0; } } #endif /* not PCC_STATIC_STRUCT_RETURN */ } /* If called function is inline, try to integrate it. */ if (is_integrable) { rtx temp; #ifdef ACCUMULATE_OUTGOING_ARGS rtx before_call = get_last_insn (); #endif temp = expand_inline_function (fndecl, actparms, target, ignore, TREE_TYPE (exp), structure_value_addr); /* If inlining succeeded, return. */ if (temp != (rtx) (HOST_WIDE_INT) -1) { #ifdef ACCUMULATE_OUTGOING_ARGS /* If the outgoing argument list must be preserved, push the stack before executing the inlined function if it makes any calls. */ for (i = reg_parm_stack_space - 1; i >= 0; i--) if (i < highest_outgoing_arg_in_use && stack_usage_map[i] != 0) break; if (stack_arg_under_construction || i >= 0) { rtx first_insn = before_call ? NEXT_INSN (before_call) : get_insns (); rtx insn, seq; /* Look for a call in the inline function code. If OUTGOING_ARGS_SIZE (DECL_SAVED_INSNS (fndecl)) is nonzero then there is a call and it is not necessary to scan the insns. */ if (OUTGOING_ARGS_SIZE (DECL_SAVED_INSNS (fndecl)) == 0) for (insn = first_insn; insn; insn = NEXT_INSN (insn)) if (GET_CODE (insn) == CALL_INSN) break; if (insn) { /* Reserve enough stack space so that the largest argument list of any function call in the inline function does not overlap the argument list being evaluated. This is usually an overestimate because allocate_dynamic_stack_space reserves space for an outgoing argument list in addition to the requested space, but there is no way to ask for stack space such that an argument list of a certain length can be safely constructed. Add the stack space reserved for register arguments, if any, in the inline function. What is really needed is the largest value of reg_parm_stack_space in the inline function, but that is not available. Using the current value of reg_parm_stack_space is wrong, but gives correct results on all supported machines. */ int adjust = (OUTGOING_ARGS_SIZE (DECL_SAVED_INSNS (fndecl)) + reg_parm_stack_space); start_sequence (); emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX); allocate_dynamic_stack_space (GEN_INT (adjust), NULL_RTX, BITS_PER_UNIT); seq = get_insns (); end_sequence (); emit_insns_before (seq, first_insn); emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX); } } #endif /* If the result is equivalent to TARGET, return TARGET to simplify checks in store_expr. They can be equivalent but not equal in the case of a function that returns BLKmode. */ if (temp != target && rtx_equal_p (temp, target)) return target; return temp; } /* If inlining failed, mark FNDECL as needing to be compiled separately after all. If function was declared inline, give a warning. */ if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline && optimize > 0 && ! TREE_ADDRESSABLE (fndecl)) { warning_with_decl (fndecl, "inlining failed in call to `%s'"); warning ("called from here"); } mark_addressable (fndecl); } /* When calling a const function, we must pop the stack args right away, so that the pop is deleted or moved with the call. */ if (is_const) NO_DEFER_POP; function_call_count++; if (fndecl && DECL_NAME (fndecl)) name = IDENTIFIER_POINTER (DECL_NAME (fndecl)); /* See if this is a call to a function that can return more than once or a call to longjmp or malloc. */ special_function_p (name, fndecl, &returns_twice, &is_longjmp, &is_malloc, &may_be_alloca); if (may_be_alloca) current_function_calls_alloca = 1; /* 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. */ if (pending_stack_adjust >= 32 || (pending_stack_adjust > 0 && may_be_alloca)) do_pending_stack_adjust (); /* Operand 0 is a pointer-to-function; get the type of the function. */ funtype = TREE_TYPE (TREE_OPERAND (exp, 0)); if (! POINTER_TYPE_P (funtype)) abort (); funtype = TREE_TYPE (funtype); /* Push the temporary stack slot level so that we can free any temporaries we make. */ push_temp_slots (); /* 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 last 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 == 0)); /* If struct_value_rtx is 0, it means pass the address as if it were an extra parameter. */ if (structure_value_addr && struct_value_rtx == 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 = (GET_CODE (structure_value_addr) != REG #ifdef ACCUMULATE_OUTGOING_ARGS || (stack_arg_under_construction && structure_value_addr == virtual_outgoing_args_rtx) #endif ? copy_addr_to_reg (structure_value_addr) : structure_value_addr); actparms = tree_cons (error_mark_node, make_tree (build_pointer_type (TREE_TYPE (funtype)), temp), actparms); structure_value_addr_parm = 1; } /* Count the arguments and set NUM_ACTUALS. */ for (p = actparms, i = 0; p; p = TREE_CHAIN (p)) i++; num_actuals = i; /* Compute number of named args. Normally, don't include the last named arg if anonymous args follow. We do include the last named arg if STRICT_ARGUMENT_NAMING is nonzero. (If no anonymous args follow, the result of list_length is actually one too large. This is harmless.) If SETUP_INCOMING_VARARGS is defined and STRICT_ARGUMENT_NAMING is 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 SETUP_INCOMING_VARARGS is not defined, we do not have any reliable way to pass unnamed args in registers, so we must force them into memory. */ if ((STRICT_ARGUMENT_NAMING #ifndef SETUP_INCOMING_VARARGS || 1 #endif ) && TYPE_ARG_TYPES (funtype) != 0) n_named_args = (list_length (TYPE_ARG_TYPES (funtype)) /* Don't include the last named arg. */ - (STRICT_ARGUMENT_NAMING ? 0 : 1) /* 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; /* Make a vector to hold all the information about each arg. */ args = (struct arg_data *) alloca (num_actuals * sizeof (struct arg_data)); bzero ((char *) args, num_actuals * sizeof (struct arg_data)); 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. */ #ifdef 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; #endif /* I counts args in order (to be) pushed; ARGPOS counts in order written. */ for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++) { tree type = TREE_TYPE (TREE_VALUE (p)); int unsignedp; enum machine_mode mode; args[i].tree_value = TREE_VALUE (p); /* Replace erroneous argument with constant zero. */ if (type == error_mark_node || TYPE_SIZE (type) == 0) args[i].tree_value = integer_zero_node, type = integer_type_node; /* If TYPE is a transparent union, pass things the way we would pass the first field of the union. We have already verified that the modes are the same. */ if (TYPE_TRANSPARENT_UNION (type)) type = TREE_TYPE (TYPE_FIELDS (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 words 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 ((TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST && contains_placeholder_p (TYPE_SIZE (type))) || TREE_ADDRESSABLE (type) #ifdef FUNCTION_ARG_PASS_BY_REFERENCE || FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, TYPE_MODE (type), type, argpos < n_named_args) #endif ) { /* If we're compiling a thunk, pass through invisible references instead of making a copy. */ if (current_function_is_thunk #ifdef FUNCTION_ARG_CALLEE_COPIES || (FUNCTION_ARG_CALLEE_COPIES (args_so_far, TYPE_MODE (type), type, argpos < n_named_args) /* If it's in a register, we must make a copy of it too. */ /* ??? Is this a sufficient test? Is there a better one? */ && !(TREE_CODE (args[i].tree_value) == VAR_DECL && REG_P (DECL_RTL (args[i].tree_value))) && ! TREE_ADDRESSABLE (type)) #endif ) { /* C++ uses a TARGET_EXPR to indicate that we want to make a new object from the argument. If we are passing by invisible reference, the callee will do that for us, so we can strip off the TARGET_EXPR. This is not always safe, but it is safe in the only case where this is a useful optimization; namely, when the argument is a plain object. In that case, the frontend is just asking the backend to make a bitwise copy of the argument. */ if (TREE_CODE (args[i].tree_value) == TARGET_EXPR && (TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (args[i].tree_value, 1))) == 'd') && ! REG_P (DECL_RTL (TREE_OPERAND (args[i].tree_value, 1)))) args[i].tree_value = TREE_OPERAND (args[i].tree_value, 1); args[i].tree_value = build1 (ADDR_EXPR, build_pointer_type (type), args[i].tree_value); type = build_pointer_type (type); } else { /* We make a copy of the object and pass the address to the function being called. */ rtx copy; if (TYPE_SIZE (type) == 0 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST || (flag_stack_check && ! STACK_CHECK_BUILTIN && (TREE_INT_CST_HIGH (TYPE_SIZE (type)) != 0 || (TREE_INT_CST_LOW (TYPE_SIZE (type)) > STACK_CHECK_MAX_VAR_SIZE * BITS_PER_UNIT)))) { /* This is a variable-sized object. Make space on the stack for it. */ rtx size_rtx = expr_size (TREE_VALUE (p)); 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))); } else { int size = int_size_in_bytes (type); copy = assign_stack_temp (TYPE_MODE (type), size, 0); } MEM_SET_IN_STRUCT_P (copy, AGGREGATE_TYPE_P (type)); store_expr (args[i].tree_value, copy, 0); is_const = 0; args[i].tree_value = build1 (ADDR_EXPR, build_pointer_type (type), make_tree (type, copy)); type = build_pointer_type (type); } } mode = TYPE_MODE (type); unsignedp = TREE_UNSIGNED (type); #ifdef PROMOTE_FUNCTION_ARGS mode = promote_mode (type, mode, &unsignedp, 1); #endif args[i].unsignedp = unsignedp; args[i].mode = mode; args[i].reg = FUNCTION_ARG (args_so_far, mode, type, argpos < n_named_args); #ifdef FUNCTION_ARG_PARTIAL_NREGS if (args[i].reg) args[i].partial = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, mode, type, argpos < n_named_args); #endif args[i].pass_on_stack = 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; /* If this is an addressable type, we cannot pre-evaluate it. Thus, we cannot consider this function call constant. */ if (TREE_ADDRESSABLE (type)) is_const = 0; /* 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 fndecl, &args_size, &args[i].offset, &args[i].size); #ifndef ARGS_GROW_DOWNWARD args[i].slot_offset = args_size; #endif /* If a part of the arg was put into registers, don't include that part in the amount pushed. */ if (reg_parm_stack_space == 0 && ! args[i].pass_on_stack) args[i].size.constant -= ((args[i].partial * UNITS_PER_WORD) / (PARM_BOUNDARY / BITS_PER_UNIT) * (PARM_BOUNDARY / BITS_PER_UNIT)); /* Update ARGS_SIZE, the total stack space for args so far. */ args_size.constant += args[i].size.constant; if (args[i].size.var) { ADD_PARM_SIZE (args_size, args[i].size.var); } /* Since the slot offset points to the bottom of the slot, we must record it after incrementing if the args grow down. */ #ifdef ARGS_GROW_DOWNWARD args[i].slot_offset = args_size; args[i].slot_offset.constant = -args_size.constant; if (args_size.var) { SUB_PARM_SIZE (args[i].slot_offset, args_size.var); } #endif /* 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); } #ifdef FINAL_REG_PARM_STACK_SPACE reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant, args_size.var); #endif /* 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. */ original_args_size = args_size; if (args_size.var) { /* If this function requires a variable-sized argument list, don't try to make a cse'able block for this call. We may be able to do this eventually, but it is too complicated to keep track of what insns go in the cse'able block and which don't. */ is_const = 0; must_preallocate = 1; args_size.var = ARGS_SIZE_TREE (args_size); args_size.constant = 0; #ifdef PREFERRED_STACK_BOUNDARY if (PREFERRED_STACK_BOUNDARY != BITS_PER_UNIT) args_size.var = round_up (args_size.var, STACK_BYTES); #endif if (reg_parm_stack_space > 0) { args_size.var = size_binop (MAX_EXPR, args_size.var, size_int (reg_parm_stack_space)); #ifndef OUTGOING_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. */ args_size.var = size_binop (MINUS_EXPR, args_size.var, size_int (reg_parm_stack_space)); #endif } } else { #ifdef PREFERRED_STACK_BOUNDARY args_size.constant = (((args_size.constant + (STACK_BYTES - 1)) / STACK_BYTES) * STACK_BYTES); #endif args_size.constant = MAX (args_size.constant, reg_parm_stack_space); #ifdef MAYBE_REG_PARM_STACK_SPACE if (reg_parm_stack_space == 0) args_size.constant = 0; #endif #ifndef OUTGOING_REG_PARM_STACK_SPACE args_size.constant -= reg_parm_stack_space; #endif } /* 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; 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; } /* 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 #ifndef ACCUMULATE_OUTGOING_ARGS || args_size.constant #endif )) structure_value_addr = copy_to_reg (structure_value_addr); /* If this function call is cse'able, precompute all the parameters. Note that if the parameter is constructed into a temporary, this will cause an additional copy because the parameter will be constructed into a temporary location and then copied into the outgoing arguments. If a parameter contains a call to alloca and this function uses the stack, precompute the parameter. */ /* 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. */ for (i = 0; i < num_actuals; i++) if (is_const || ((args_size.var != 0 || args_size.constant != 0) && calls_function (args[i].tree_value, 1)) || (must_preallocate && (args_size.var != 0 || args_size.constant != 0) && calls_function (args[i].tree_value, 0))) { /* If this is an addressable type, we cannot pre-evaluate it. */ if (TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))) abort (); push_temp_slots (); args[i].initial_value = args[i].value = expand_expr (args[i].tree_value, NULL_RTX, VOIDmode, 0); preserve_temp_slots (args[i].value); pop_temp_slots (); /* ANSI doesn't require a sequence point here, but PCC has one, so this will avoid some problems. */ emit_queue (); args[i].initial_value = args[i].value = protect_from_queue (args[i].initial_value, 0); if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) != args[i].mode) args[i].value = convert_modes (args[i].mode, TYPE_MODE (TREE_TYPE (args[i].tree_value)), args[i].value, args[i].unsignedp); } /* Now we are about to start emitting insns that can be deleted if a libcall is deleted. */ if (is_const || is_malloc) start_sequence (); /* If we have no actual push instructions, or shouldn't use them, make space for all args right now. */ if (args_size.var != 0) { 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; #ifdef ACCUMULATE_OUTGOING_ARGS /* 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; #endif } argblock = push_block (ARGS_SIZE_RTX (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 = 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 > current_function_outgoing_args_size) current_function_outgoing_args_size = needed; if (must_preallocate) { #ifdef 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. */ #ifndef OUTGOING_REG_PARM_STACK_SPACE /* 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. */ needed += reg_parm_stack_space; #endif #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 = (char *) alloca (highest_outgoing_arg_in_use); if (initial_highest_arg_in_use) bcopy (initial_stack_usage_map, stack_usage_map, initial_highest_arg_in_use); if (initial_highest_arg_in_use != highest_outgoing_arg_in_use) bzero (&stack_usage_map[initial_highest_arg_in_use], 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 /* not ACCUMULATE_OUTGOING_ARGS */ if (inhibit_defer_pop == 0) { /* Try to reuse some or all of the pending_stack_adjust to get this space. Maybe we can avoid any pushing. */ if (needed > pending_stack_adjust) { needed -= pending_stack_adjust; pending_stack_adjust = 0; } else { pending_stack_adjust -= needed; needed = 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); /* 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); #endif /* not ACCUMULATE_OUTGOING_ARGS */ } } #ifdef 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) { #ifndef OUTGOING_REG_PARM_STACK_SPACE rtx push_size = GEN_INT (reg_parm_stack_space + args_size.constant); #else rtx push_size = GEN_INT (args_size.constant); #endif 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; /* 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. */ stack_usage_map = (char *)alloca (highest_outgoing_arg_in_use); bzero (stack_usage_map, highest_outgoing_arg_in_use); 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; } #endif /* If we preallocated stack space, compute the address of each argument. We need not ensure it is a valid memory address here; it will be validized when it is used. */ if (argblock) { rtx arg_reg = argblock; int 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].offset); rtx slot_offset = ARGS_SIZE_RTX (args[i].slot_offset); rtx addr; /* Skip this parm if it will not be passed on the stack. */ if (! args[i].pass_on_stack && args[i].reg != 0) continue; if (GET_CODE (offset) == CONST_INT) addr = plus_constant (arg_reg, INTVAL (offset)); else addr = gen_rtx_PLUS (Pmode, arg_reg, offset); addr = plus_constant (addr, arg_offset); args[i].stack = gen_rtx_MEM (args[i].mode, addr); MEM_SET_IN_STRUCT_P (args[i].stack, AGGREGATE_TYPE_P (TREE_TYPE (args[i].tree_value))); if (GET_CODE (slot_offset) == CONST_INT) addr = plus_constant (arg_reg, INTVAL (slot_offset)); else addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset); addr = plus_constant (addr, arg_offset); args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr); } } #ifdef PUSH_ARGS_REVERSED #ifdef PREFERRED_STACK_BOUNDARY /* If we push args individually in reverse order, perform stack alignment before the first push (the last arg). */ if (argblock == 0) anti_adjust_stack (GEN_INT (args_size.constant - original_args_size.constant)); #endif #endif /* Don't try to defer pops if preallocating, not even from the first arg, since ARGBLOCK probably refers to the SP. */ if (argblock) NO_DEFER_POP; /* 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)) { 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_expr (TREE_OPERAND (exp, 0), NULL_RTX, VOIDmode, 0); pop_temp_slots (); /* FUNEXP can't be BLKmode */ /* Check the function is executable. */ if (current_function_check_memory_usage) emit_library_call (chkr_check_exec_libfunc, 1, VOIDmode, 1, funexp, ptr_mode); emit_queue (); } /* Figure out the register where the value, if any, will come back. */ valreg = 0; if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode && ! structure_value_addr) { if (pcc_struct_value) valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)), fndecl); else valreg = hard_function_value (TREE_TYPE (exp), fndecl); } /* 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 defined(ACCUMULATE_OUTGOING_ARGS) && defined(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. */ 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) store_one_arg (&args[i], argblock, may_be_alloca, args_size.var != 0, reg_parm_stack_space); /* 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) store_one_arg (&args[i], argblock, may_be_alloca, args_size.var != 0, reg_parm_stack_space); #ifndef PUSH_ARGS_REVERSED #ifdef PREFERRED_STACK_BOUNDARY /* If we pushed args in forward order, perform stack alignment after pushing the last arg. */ if (argblock == 0) anti_adjust_stack (GEN_INT (args_size.constant - original_args_size.constant)); #endif #endif /* If register arguments require space on the stack and stack space was not preallocated, allocate stack space here for arguments passed in registers. */ #if ! defined(ACCUMULATE_OUTGOING_ARGS) && defined(OUTGOING_REG_PARM_STACK_SPACE) if (must_preallocate == 0 && reg_parm_stack_space > 0) anti_adjust_stack (GEN_INT (reg_parm_stack_space)); #endif /* Pass the function the address in which to return a structure value. */ if (structure_value_addr && ! structure_value_addr_parm) { emit_move_insn (struct_value_rtx, force_reg (Pmode, force_operand (structure_value_addr, NULL_RTX))); /* Mark the memory for the aggregate as write-only. */ if (current_function_check_memory_usage) emit_library_call (chkr_set_right_libfunc, 1, VOIDmode, 3, structure_value_addr, ptr_mode, GEN_INT (struct_value_size), TYPE_MODE (sizetype), GEN_INT (MEMORY_USE_WO), TYPE_MODE (integer_type_node)); if (GET_CODE (struct_value_rtx) == REG) use_reg (&call_fusage, struct_value_rtx); } funexp = prepare_call_address (funexp, fndecl, &call_fusage, reg_parm_seen); /* Now 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. */ #ifdef LOAD_ARGS_REVERSED for (i = num_actuals - 1; i >= 0; i--) #else for (i = 0; i < num_actuals; i++) #endif { rtx reg = args[i].reg; int partial = args[i].partial; int nregs; if (reg) { /* Set to non-negative if must move a word at a time, even if just one word (e.g, partial == 1 && 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 with no fields. */ nregs = (partial ? partial : (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode ? ((int_size_in_bytes (TREE_TYPE (args[i].tree_value)) + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD) : -1)); /* 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_load (reg, args[i].value, int_size_in_bytes (TREE_TYPE (args[i].tree_value)), (TYPE_ALIGN (TREE_TYPE (args[i].tree_value)) / BITS_PER_UNIT)); } /* 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); /* 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) move_block_to_reg (REGNO (reg), validize_mem (args[i].value), nregs, 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) use_group_regs (&call_fusage, reg); else if (nregs == -1) use_reg (&call_fusage, reg); else use_regs (&call_fusage, REGNO (reg), nregs == 0 ? 1 : nregs); } } /* Perform postincrements before actually calling the function. */ emit_queue (); /* All arguments and registers used for the call must be set up by now! */ /* Generate the actual call instruction. */ emit_call_1 (funexp, fndecl, funtype, args_size.constant, struct_value_size, FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1), valreg, old_inhibit_defer_pop, call_fusage, is_const); /* If call is cse'able, make appropriate pair of reg-notes around it. Test valreg so we don't crash; may safely ignore `const' if return type is void. Disable for PARALLEL return values, because we have no way to move such values into a pseudo register. */ if (is_const && valreg != 0 && GET_CODE (valreg) != PARALLEL) { rtx note = 0; rtx temp = gen_reg_rtx (GET_MODE (valreg)); rtx insns; /* Mark the return value as a pointer if needed. */ if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE) { tree pointed_to = TREE_TYPE (TREE_TYPE (exp)); mark_reg_pointer (temp, TYPE_ALIGN (pointed_to) / BITS_PER_UNIT); } /* Construct an "equal form" for the value which mentions all the arguments in order as well as the function name. */ #ifdef PUSH_ARGS_REVERSED for (i = 0; i < num_actuals; i++) note = gen_rtx_EXPR_LIST (VOIDmode, args[i].initial_value, note); #else for (i = num_actuals - 1; i >= 0; i--) note = gen_rtx_EXPR_LIST (VOIDmode, args[i].initial_value, note); #endif note = gen_rtx_EXPR_LIST (VOIDmode, funexp, note); insns = get_insns (); end_sequence (); emit_libcall_block (insns, temp, valreg, note); valreg = temp; } else if (is_const) { /* Otherwise, just write out the sequence without a note. */ rtx insns = get_insns (); end_sequence (); emit_insns (insns); } else if (is_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 (TREE_TYPE (exp)) == POINTER_TYPE) mark_reg_pointer (temp, BIGGEST_ALIGNMENT / BITS_PER_UNIT); emit_move_insn (temp, valreg); /* The return value from a malloc-like function can not alias anything else. */ last = get_last_insn (); REG_NOTES (last) = gen_rtx_EXPR_LIST (REG_NOALIAS, temp, REG_NOTES (last)); /* Write out the sequence. */ insns = get_insns (); end_sequence (); emit_insns (insns); valreg = temp; } /* For calls to `setjmp', etc., inform flow.c it should complain if nonvolatile values are live. */ if (returns_twice) { emit_note (name, NOTE_INSN_SETJMP); current_function_calls_setjmp = 1; } if (is_longjmp) current_function_calls_longjmp = 1; /* Notice functions that cannot return. If optimizing, insns emitted below will be dead. If not optimizing, they will exist, which is useful if the user uses the `return' command in the debugger. */ if (is_volatile || is_longjmp) emit_barrier (); /* If value type not void, return an rtx for the value. */ /* If there are cleanups to be called, don't use a hard reg as target. We need to double check this and see if it matters anymore. */ if (any_pending_cleanups (1) && target && REG_P (target) && REGNO (target) < FIRST_PSEUDO_REGISTER) target = 0; if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode || ignore) { target = const0_rtx; } else if (structure_value_addr) { if (target == 0 || GET_CODE (target) != MEM) { target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), memory_address (TYPE_MODE (TREE_TYPE (exp)), structure_value_addr)); MEM_SET_IN_STRUCT_P (target, AGGREGATE_TYPE_P (TREE_TYPE (exp))); } } 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 (TREE_TYPE (exp)), copy_to_reg (valreg)); MEM_SET_IN_STRUCT_P (target, AGGREGATE_TYPE_P (TREE_TYPE (exp))); } /* Handle calls that return values in multiple non-contiguous locations. The Irix 6 ABI has examples of this. */ else if (GET_CODE (valreg) == PARALLEL) { int bytes = int_size_in_bytes (TREE_TYPE (exp)); if (target == 0) { target = assign_stack_temp (TYPE_MODE (TREE_TYPE (exp)), bytes, 0); MEM_SET_IN_STRUCT_P (target, AGGREGATE_TYPE_P (TREE_TYPE (exp))); preserve_temp_slots (target); } emit_group_store (target, valreg, bytes, TYPE_ALIGN (TREE_TYPE (exp)) / BITS_PER_UNIT); } else if (target && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp)) && GET_MODE (target) == GET_MODE (valreg)) /* 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); else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode) target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp)); else target = copy_to_reg (valreg); #ifdef PROMOTE_FUNCTION_RETURN /* If we promoted this return value, make the proper SUBREG. TARGET might be const0_rtx here, so be careful. */ if (GET_CODE (target) == REG && TYPE_MODE (TREE_TYPE (exp)) != BLKmode && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp))) { tree type = TREE_TYPE (exp); int unsignedp = TREE_UNSIGNED (type); /* If we don't promote as expected, something is wrong. */ if (GET_MODE (target) != promote_mode (type, TYPE_MODE (type), &unsignedp, 1)) abort (); target = gen_rtx_SUBREG (TYPE_MODE (type), target, 0); SUBREG_PROMOTED_VAR_P (target) = 1; SUBREG_PROMOTED_UNSIGNED_P (target) = unsignedp; } #endif /* 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); pending_stack_adjust = old_pending_adj; #ifdef ACCUMULATE_OUTGOING_ARGS 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; #endif } #ifdef ACCUMULATE_OUTGOING_ARGS else { #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, validize_mem (args[i].save_area), GEN_INT (args[i].size.constant), PARM_BOUNDARY / BITS_PER_UNIT); } highest_outgoing_arg_in_use = initial_highest_arg_in_use; stack_usage_map = initial_stack_usage_map; } #endif /* 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 (may_be_alloca && nonlocal_goto_handler_slots != 0) emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX); pop_temp_slots (); /* Free up storage we no longer need. */ for (i = 0; i < num_actuals; ++i) if (args[i].aligned_regs) free (args[i].aligned_regs); return target; } /* 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. The rtx values should have been passed through protect_from_queue already. NO_QUEUE will be true if and only if the library call is a `const' call which will be enclosed in REG_LIBCALL/REG_RETVAL notes; it is equivalent to the variable is_const in expand_call. NO_QUEUE must be true for const calls, because if it isn't, then any pending increment will be emitted between REG_LIBCALL/REG_RETVAL notes, and will be lost if the libcall sequence is optimized away. NO_QUEUE must be false for non-const calls, because if it isn't, the call insn will have its CONST_CALL_P bit set, and it will be incorrectly optimized. For instance, the instruction scheduler may incorrectly move memory references across the non-const call. */ void emit_library_call VPROTO((rtx orgfun, int no_queue, enum machine_mode outmode, int nargs, ...)) { #ifndef ANSI_PROTOTYPES rtx orgfun; int no_queue; enum machine_mode outmode; int nargs; #endif 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; register int argnum; rtx fun; 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 args_size offset; struct args_size size; rtx save_area; }; struct arg *argvec; int old_inhibit_defer_pop = inhibit_defer_pop; rtx call_fusage = 0; int reg_parm_stack_space = 0; #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE) /* Define the boundary of the register parm stack space that needs to be save, if any. */ int low_to_save = -1, high_to_save; rtx save_area = 0; /* Place that it is saved */ #endif #ifdef ACCUMULATE_OUTGOING_ARGS int initial_highest_arg_in_use = highest_outgoing_arg_in_use; char *initial_stack_usage_map = stack_usage_map; int needed; #endif #ifdef REG_PARM_STACK_SPACE /* Size of the stack reserved for parameter registers. */ #ifdef MAYBE_REG_PARM_STACK_SPACE reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE; #else reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0); #endif #endif VA_START (p, nargs); #ifndef ANSI_PROTOTYPES orgfun = va_arg (p, rtx); no_queue = va_arg (p, int); outmode = va_arg (p, enum machine_mode); nargs = va_arg (p, int); #endif fun = orgfun; /* 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 = (struct arg *) alloca (nargs * sizeof (struct arg)); bzero ((char *) argvec, nargs * sizeof (struct arg)); INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0); args_size.constant = 0; args_size.var = 0; push_temp_slots (); for (count = 0; count < nargs; count++) { rtx val = va_arg (p, rtx); enum machine_mode mode = va_arg (p, enum machine_mode); /* 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. */ if (mode == BLKmode || (GET_MODE (val) != mode && GET_MODE (val) != VOIDmode)) abort (); /* On some machines, there's no way to pass a float to a library fcn. Pass it as a double instead. */ #ifdef LIBGCC_NEEDS_DOUBLE if (LIBGCC_NEEDS_DOUBLE && mode == SFmode) val = convert_modes (DFmode, SFmode, val, 0), mode = DFmode; #endif /* There's no need to call protect_from_queue, because either emit_move_insn or emit_push_insn will do that. */ /* Make sure it is a reasonable operand for a move or push insn. */ if (GET_CODE (val) != REG && GET_CODE (val) != MEM && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val))) val = force_operand (val, NULL_RTX); #ifdef FUNCTION_ARG_PASS_BY_REFERENCE if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, mode, NULL_TREE, 1)) { /* We do not support FUNCTION_ARG_CALLEE_COPIES here since it can be viewed as just an efficiency improvement. */ rtx slot = assign_stack_temp (mode, GET_MODE_SIZE (mode), 0); emit_move_insn (slot, val); val = force_operand (XEXP (slot, 0), NULL_RTX); mode = Pmode; } #endif argvec[count].value = val; argvec[count].mode = mode; argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1); if (argvec[count].reg && GET_CODE (argvec[count].reg) == PARALLEL) abort (); #ifdef FUNCTION_ARG_PARTIAL_NREGS argvec[count].partial = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, mode, NULL_TREE, 1); #else argvec[count].partial = 0; #endif locate_and_pad_parm (mode, NULL_TREE, argvec[count].reg && argvec[count].partial == 0, NULL_TREE, &args_size, &argvec[count].offset, &argvec[count].size); if (argvec[count].size.var) abort (); if (reg_parm_stack_space == 0 && argvec[count].partial) argvec[count].size.constant -= argvec[count].partial * UNITS_PER_WORD; if (argvec[count].reg == 0 || argvec[count].partial != 0 || reg_parm_stack_space > 0) args_size.constant += argvec[count].size.constant; FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1); } va_end (p); #ifdef FINAL_REG_PARM_STACK_SPACE reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant, args_size.var); #endif /* If this machine requires an external definition for library functions, write one out. */ assemble_external_libcall (fun); original_args_size = args_size; #ifdef PREFERRED_STACK_BOUNDARY args_size.constant = (((args_size.constant + (STACK_BYTES - 1)) / STACK_BYTES) * STACK_BYTES); #endif args_size.constant = MAX (args_size.constant, reg_parm_stack_space); #ifndef OUTGOING_REG_PARM_STACK_SPACE args_size.constant -= reg_parm_stack_space; #endif if (args_size.constant > current_function_outgoing_args_size) current_function_outgoing_args_size = args_size.constant; #ifdef 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; #ifndef OUTGOING_REG_PARM_STACK_SPACE /* 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. */ needed += reg_parm_stack_space; #endif #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 = (char *) alloca (highest_outgoing_arg_in_use); if (initial_highest_arg_in_use) bcopy (initial_stack_usage_map, stack_usage_map, initial_highest_arg_in_use); if (initial_highest_arg_in_use != highest_outgoing_arg_in_use) bzero (&stack_usage_map[initial_highest_arg_in_use], 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 /* not ACCUMULATE_OUTGOING_ARGS */ #ifndef PUSH_ROUNDING argblock = push_block (GEN_INT (args_size.constant), 0, 0); #endif #endif #ifdef PUSH_ARGS_REVERSED #ifdef PREFERRED_STACK_BOUNDARY /* If we push args individually in reverse order, perform stack alignment before the first push (the last arg). */ if (argblock == 0) anti_adjust_stack (GEN_INT (args_size.constant - original_args_size.constant)); #endif #endif #ifdef PUSH_ARGS_REVERSED inc = -1; argnum = nargs - 1; #else inc = 1; argnum = 0; #endif #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(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. Here we compute the boundary of the that needs to be saved, if any. */ #ifdef ARGS_GROW_DOWNWARD for (count = 0; count < reg_parm_stack_space + 1; count++) #else for (count = 0; count < reg_parm_stack_space; count++) #endif { if (count >= highest_outgoing_arg_in_use || stack_usage_map[count] == 0) continue; if (low_to_save == -1) low_to_save = count; high_to_save = count; } if (low_to_save >= 0) { int num_to_save = high_to_save - low_to_save + 1; enum machine_mode save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1); rtx stack_area; /* If we don't have the required alignment, must do this in BLKmode. */ if ((low_to_save & (MIN (GET_MODE_SIZE (save_mode), BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1))) save_mode = BLKmode; #ifdef ARGS_GROW_DOWNWARD stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, plus_constant (argblock, - high_to_save))); #else stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, plus_constant (argblock, low_to_save))); #endif 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), PARM_BOUNDARY / BITS_PER_UNIT); } else { save_area = gen_reg_rtx (save_mode); emit_move_insn (save_area, stack_area); } } #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) { register enum machine_mode mode = argvec[argnum].mode; register rtx val = argvec[argnum].value; rtx reg = argvec[argnum].reg; int partial = argvec[argnum].partial; #ifdef ACCUMULATE_OUTGOING_ARGS int lower_bound, upper_bound, i; #endif if (! (reg != 0 && partial == 0)) { #ifdef 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].offset.constant + 1; lower_bound = upper_bound - argvec[argnum].size.constant; #else lower_bound = argvec[argnum].offset.constant; upper_bound = lower_bound + argvec[argnum].size.constant; #endif for (i = lower_bound; i < upper_bound; i++) if (stack_usage_map[i] /* Don't store things in the fixed argument area at this point; it has already been saved. */ && i > reg_parm_stack_space) break; if (i != upper_bound) { /* We need to make a save area. See what mode we can make it. */ enum machine_mode save_mode = mode_for_size (argvec[argnum].size.constant * BITS_PER_UNIT, MODE_INT, 1); rtx stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, plus_constant (argblock, argvec[argnum].offset.constant))); argvec[argnum].save_area = gen_reg_rtx (save_mode); emit_move_insn (argvec[argnum].save_area, stack_area); } #endif emit_push_insn (val, mode, NULL_TREE, NULL_RTX, 0, partial, reg, 0, argblock, GEN_INT (argvec[argnum].offset.constant), reg_parm_stack_space); #ifdef ACCUMULATE_OUTGOING_ARGS /* Now mark the segment we just used. */ for (i = lower_bound; i < upper_bound; i++) stack_usage_map[i] = 1; #endif NO_DEFER_POP; } } #ifndef PUSH_ARGS_REVERSED #ifdef PREFERRED_STACK_BOUNDARY /* If we pushed args in forward order, perform stack alignment after pushing the last arg. */ if (argblock == 0) anti_adjust_stack (GEN_INT (args_size.constant - original_args_size.constant)); #endif #endif #ifdef PUSH_ARGS_REVERSED argnum = nargs - 1; #else argnum = 0; #endif fun = prepare_call_address (fun, NULL_TREE, &call_fusage, 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) { register rtx val = argvec[argnum].value; rtx reg = argvec[argnum].reg; int partial = argvec[argnum].partial; if (reg != 0 && partial == 0) emit_move_insn (reg, val); NO_DEFER_POP; } /* For version 1.37, try deleting this entirely. */ if (! no_queue) emit_queue (); /* Any regs containing parms remain in use through the call. */ for (count = 0; count < nargs; count++) if (argvec[count].reg != 0) use_reg (&call_fusage, argvec[count].reg); /* 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; /* 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, get_identifier (XSTR (orgfun, 0)), build_function_type (outmode == VOIDmode ? void_type_node : type_for_mode (outmode, 0), NULL_TREE), args_size.constant, 0, FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1), outmode != VOIDmode ? hard_libcall_value (outmode) : NULL_RTX, old_inhibit_defer_pop + 1, call_fusage, no_queue); pop_temp_slots (); /* Now restore inhibit_defer_pop to its actual original value. */ OK_DEFER_POP; #ifdef ACCUMULATE_OUTGOING_ARGS #ifdef REG_PARM_STACK_SPACE if (save_area) { enum machine_mode save_mode = GET_MODE (save_area); #ifdef ARGS_GROW_DOWNWARD rtx stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, plus_constant (argblock, - high_to_save))); #else rtx stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, plus_constant (argblock, low_to_save))); #endif 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), PARM_BOUNDARY / BITS_PER_UNIT); } #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 stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, plus_constant (argblock, argvec[count].offset.constant))); 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; #endif } /* 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 VPROTO((rtx orgfun, rtx value, int no_queue, enum machine_mode outmode, int nargs, ...)) { #ifndef ANSI_PROTOTYPES rtx orgfun; rtx value; int no_queue; enum machine_mode outmode; int nargs; #endif 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; register int argnum; rtx fun; 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 args_size offset; struct args_size size; rtx save_area; }; struct arg *argvec; int old_inhibit_defer_pop = inhibit_defer_pop; rtx call_fusage = 0; rtx mem_value = 0; int pcc_struct_value = 0; int struct_value_size = 0; int is_const; int reg_parm_stack_space = 0; #ifdef ACCUMULATE_OUTGOING_ARGS int needed; #endif #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE) /* Define the boundary of the register parm stack space that needs to be save, if any. */ int low_to_save = -1, high_to_save; rtx save_area = 0; /* Place that it is saved */ #endif #ifdef ACCUMULATE_OUTGOING_ARGS /* 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; #endif #ifdef REG_PARM_STACK_SPACE #ifdef MAYBE_REG_PARM_STACK_SPACE reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE; #else reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0); #endif #endif VA_START (p, nargs); #ifndef ANSI_PROTOTYPES orgfun = va_arg (p, rtx); value = va_arg (p, rtx); no_queue = va_arg (p, int); outmode = va_arg (p, enum machine_mode); nargs = va_arg (p, int); #endif is_const = no_queue; fun = orgfun; /* If this kind of value comes back in memory, decide where in memory it should come back. */ if (aggregate_value_p (type_for_mode (outmode, 0))) { #ifdef PCC_STATIC_STRUCT_RETURN rtx pointer_reg = hard_function_value (build_pointer_type (type_for_mode (outmode, 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 && GET_CODE (value) == MEM) mem_value = value; else mem_value = assign_stack_temp (outmode, GET_MODE_SIZE (outmode), 0); #endif /* This call returns a big structure. */ is_const = 0; } /* ??? 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 = (struct arg *) alloca ((nargs + 1) * sizeof (struct arg)); bzero ((char *) argvec, (nargs + 1) * sizeof (struct arg)); INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0); 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_rtx == 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 (GET_CODE (addr) != REG && GET_CODE (addr) != MEM && ! (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); #ifdef FUNCTION_ARG_PARTIAL_NREGS if (FUNCTION_ARG_PARTIAL_NREGS (args_so_far, Pmode, NULL_TREE, 1)) abort (); #endif locate_and_pad_parm (Pmode, NULL_TREE, argvec[count].reg && argvec[count].partial == 0, NULL_TREE, &args_size, &argvec[count].offset, &argvec[count].size); if (argvec[count].reg == 0 || argvec[count].partial != 0 || reg_parm_stack_space > 0) args_size.constant += argvec[count].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 = va_arg (p, enum machine_mode); /* 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. */ if (mode == BLKmode || (GET_MODE (val) != mode && GET_MODE (val) != VOIDmode)) abort (); /* On some machines, there's no way to pass a float to a library fcn. Pass it as a double instead. */ #ifdef LIBGCC_NEEDS_DOUBLE if (LIBGCC_NEEDS_DOUBLE && mode == SFmode) val = convert_modes (DFmode, SFmode, val, 0), mode = DFmode; #endif /* There's no need to call protect_from_queue, because either emit_move_insn or emit_push_insn will do that. */ /* Make sure it is a reasonable operand for a move or push insn. */ if (GET_CODE (val) != REG && GET_CODE (val) != MEM && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val))) val = force_operand (val, NULL_RTX); #ifdef FUNCTION_ARG_PASS_BY_REFERENCE if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, mode, NULL_TREE, 1)) { /* We do not support FUNCTION_ARG_CALLEE_COPIES here since it can be viewed as just an efficiency improvement. */ rtx slot = assign_stack_temp (mode, GET_MODE_SIZE (mode), 0); emit_move_insn (slot, val); val = XEXP (slot, 0); mode = Pmode; } #endif argvec[count].value = val; argvec[count].mode = mode; argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1); if (argvec[count].reg && GET_CODE (argvec[count].reg) == PARALLEL) abort (); #ifdef FUNCTION_ARG_PARTIAL_NREGS argvec[count].partial = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, mode, NULL_TREE, 1); #else argvec[count].partial = 0; #endif locate_and_pad_parm (mode, NULL_TREE, argvec[count].reg && argvec[count].partial == 0, NULL_TREE, &args_size, &argvec[count].offset, &argvec[count].size); if (argvec[count].size.var) abort (); if (reg_parm_stack_space == 0 && argvec[count].partial) argvec[count].size.constant -= argvec[count].partial * UNITS_PER_WORD; if (argvec[count].reg == 0 || argvec[count].partial != 0 || reg_parm_stack_space > 0) args_size.constant += argvec[count].size.constant; FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1); } va_end (p); #ifdef FINAL_REG_PARM_STACK_SPACE reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant, args_size.var); #endif /* If this machine requires an external definition for library functions, write one out. */ assemble_external_libcall (fun); original_args_size = args_size; #ifdef PREFERRED_STACK_BOUNDARY args_size.constant = (((args_size.constant + (STACK_BYTES - 1)) / STACK_BYTES) * STACK_BYTES); #endif args_size.constant = MAX (args_size.constant, reg_parm_stack_space); #ifndef OUTGOING_REG_PARM_STACK_SPACE args_size.constant -= reg_parm_stack_space; #endif if (args_size.constant > current_function_outgoing_args_size) current_function_outgoing_args_size = args_size.constant; #ifdef 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; #ifndef OUTGOING_REG_PARM_STACK_SPACE /* 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. */ needed += reg_parm_stack_space; #endif #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 = (char *) alloca (highest_outgoing_arg_in_use); if (initial_highest_arg_in_use) bcopy (initial_stack_usage_map, stack_usage_map, initial_highest_arg_in_use); if (initial_highest_arg_in_use != highest_outgoing_arg_in_use) bzero (&stack_usage_map[initial_highest_arg_in_use], 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 /* not ACCUMULATE_OUTGOING_ARGS */ #ifndef PUSH_ROUNDING argblock = push_block (GEN_INT (args_size.constant), 0, 0); #endif #endif #ifdef PUSH_ARGS_REVERSED #ifdef PREFERRED_STACK_BOUNDARY /* If we push args individually in reverse order, perform stack alignment before the first push (the last arg). */ if (argblock == 0) anti_adjust_stack (GEN_INT (args_size.constant - original_args_size.constant)); #endif #endif #ifdef PUSH_ARGS_REVERSED inc = -1; argnum = nargs - 1; #else inc = 1; argnum = 0; #endif #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(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. Here we compute the boundary of the that needs to be saved, if any. */ #ifdef ARGS_GROW_DOWNWARD for (count = 0; count < reg_parm_stack_space + 1; count++) #else for (count = 0; count < reg_parm_stack_space; count++) #endif { if (count >= highest_outgoing_arg_in_use || stack_usage_map[count] == 0) continue; if (low_to_save == -1) low_to_save = count; high_to_save = count; } if (low_to_save >= 0) { int num_to_save = high_to_save - low_to_save + 1; enum machine_mode save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1); rtx stack_area; /* If we don't have the required alignment, must do this in BLKmode. */ if ((low_to_save & (MIN (GET_MODE_SIZE (save_mode), BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1))) save_mode = BLKmode; #ifdef ARGS_GROW_DOWNWARD stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, plus_constant (argblock, - high_to_save))); #else stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, plus_constant (argblock, low_to_save))); #endif 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), PARM_BOUNDARY / BITS_PER_UNIT); } else { save_area = gen_reg_rtx (save_mode); emit_move_insn (save_area, stack_area); } } #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) { register enum machine_mode mode = argvec[argnum].mode; register rtx val = argvec[argnum].value; rtx reg = argvec[argnum].reg; int partial = argvec[argnum].partial; #ifdef ACCUMULATE_OUTGOING_ARGS int lower_bound, upper_bound, i; #endif if (! (reg != 0 && partial == 0)) { #ifdef 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].offset.constant + 1; lower_bound = upper_bound - argvec[argnum].size.constant; #else lower_bound = argvec[argnum].offset.constant; upper_bound = lower_bound + argvec[argnum].size.constant; #endif for (i = lower_bound; i < upper_bound; i++) if (stack_usage_map[i] /* Don't store things in the fixed argument area at this point; it has already been saved. */ && i > reg_parm_stack_space) break; if (i != upper_bound) { /* We need to make a save area. See what mode we can make it. */ enum machine_mode save_mode = mode_for_size (argvec[argnum].size.constant * BITS_PER_UNIT, MODE_INT, 1); rtx stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, plus_constant (argblock, argvec[argnum].offset.constant))); argvec[argnum].save_area = gen_reg_rtx (save_mode); emit_move_insn (argvec[argnum].save_area, stack_area); } #endif emit_push_insn (val, mode, NULL_TREE, NULL_RTX, 0, partial, reg, 0, argblock, GEN_INT (argvec[argnum].offset.constant), reg_parm_stack_space); #ifdef ACCUMULATE_OUTGOING_ARGS /* Now mark the segment we just used. */ for (i = lower_bound; i < upper_bound; i++) stack_usage_map[i] = 1; #endif NO_DEFER_POP; } } #ifndef PUSH_ARGS_REVERSED #ifdef PREFERRED_STACK_BOUNDARY /* If we pushed args in forward order, perform stack alignment after pushing the last arg. */ if (argblock == 0) anti_adjust_stack (GEN_INT (args_size.constant - original_args_size.constant)); #endif #endif #ifdef PUSH_ARGS_REVERSED argnum = nargs - 1; #else argnum = 0; #endif fun = prepare_call_address (fun, NULL_TREE, &call_fusage, 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) { register rtx val = argvec[argnum].value; rtx reg = argvec[argnum].reg; int partial = argvec[argnum].partial; if (reg != 0 && partial == 0) emit_move_insn (reg, val); NO_DEFER_POP; } #if 0 /* For version 1.37, try deleting this entirely. */ if (! no_queue) emit_queue (); #endif /* Any regs containing parms remain in use through the call. */ for (count = 0; count < nargs; count++) if (argvec[count].reg != 0) use_reg (&call_fusage, argvec[count].reg); /* Pass the function the address in which to return a structure value. */ if (mem_value != 0 && struct_value_rtx != 0 && ! pcc_struct_value) { emit_move_insn (struct_value_rtx, force_reg (Pmode, force_operand (XEXP (mem_value, 0), NULL_RTX))); if (GET_CODE (struct_value_rtx) == REG) use_reg (&call_fusage, struct_value_rtx); } /* 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; /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which will set inhibit_defer_pop to that value. */ /* See the comment in emit_library_call about the function type we build and pass here. */ emit_call_1 (fun, get_identifier (XSTR (orgfun, 0)), build_function_type (type_for_mode (outmode, 0), NULL_TREE), args_size.constant, struct_value_size, FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1), mem_value == 0 ? hard_libcall_value (outmode) : NULL_RTX, old_inhibit_defer_pop + 1, call_fusage, is_const); /* 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) { if (mem_value) { if (value == 0) value = mem_value; if (value != mem_value) emit_move_insn (value, mem_value); } else if (value != 0) emit_move_insn (value, hard_libcall_value (outmode)); else value = hard_libcall_value (outmode); } #ifdef ACCUMULATE_OUTGOING_ARGS #ifdef REG_PARM_STACK_SPACE if (save_area) { enum machine_mode save_mode = GET_MODE (save_area); #ifdef ARGS_GROW_DOWNWARD rtx stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, plus_constant (argblock, - high_to_save))); #else rtx stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, plus_constant (argblock, low_to_save))); #endif 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), PARM_BOUNDARY / BITS_PER_UNIT); } #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 stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, plus_constant (argblock, argvec[count].offset.constant))); 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; #endif return value; } #if 0 /* Return an rtx which represents a suitable home on the stack given TYPE, the type of the argument looking for a home. This is called only for BLKmode arguments. SIZE is the size needed for this target. ARGS_ADDR is the address of the bottom of the argument block for this call. OFFSET describes this parameter's offset into ARGS_ADDR. It is meaningless if this machine uses push insns. */ static rtx target_for_arg (type, size, args_addr, offset) tree type; rtx size; rtx args_addr; struct args_size offset; { rtx target; rtx offset_rtx = ARGS_SIZE_RTX (offset); /* We do not call memory_address if possible, because we want to address as close to the stack as possible. For non-variable sized arguments, this will be stack-pointer relative addressing. */ if (GET_CODE (offset_rtx) == CONST_INT) target = plus_constant (args_addr, INTVAL (offset_rtx)); else { /* I have no idea how to guarantee that this will work in the presence of register parameters. */ target = gen_rtx_PLUS (Pmode, args_addr, offset_rtx); target = memory_address (QImode, target); } return gen_rtx_MEM (BLKmode, target); } #endif /* 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. */ static void store_one_arg (arg, argblock, may_be_alloca, variable_size, reg_parm_stack_space) struct arg_data *arg; rtx argblock; int may_be_alloca; int variable_size; int reg_parm_stack_space; { register tree pval = arg->tree_value; rtx reg = 0; int partial = 0; int used = 0; #ifdef ACCUMULATE_OUTGOING_ARGS int i, lower_bound, upper_bound; #endif if (TREE_CODE (pval) == ERROR_MARK) return; /* Push a new temporary level for any temporaries we make for this argument. */ push_temp_slots (); #ifdef ACCUMULATE_OUTGOING_ARGS /* 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->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->size.constant; #endif for (i = lower_bound; i < upper_bound; i++) if (stack_usage_map[i] /* Don't store things in the fixed argument area at this point; it has already been saved. */ && i > reg_parm_stack_space) break; if (i != upper_bound) { /* We need to make a save area. See what mode we can make it. */ enum machine_mode save_mode = mode_for_size (arg->size.constant * BITS_PER_UNIT, MODE_INT, 1); rtx stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, XEXP (arg->stack_slot, 0))); if (save_mode == BLKmode) { arg->save_area = assign_stack_temp (BLKmode, arg->size.constant, 0); MEM_SET_IN_STRUCT_P (arg->save_area, AGGREGATE_TYPE_P (TREE_TYPE (arg->tree_value))); preserve_temp_slots (arg->save_area); emit_block_move (validize_mem (arg->save_area), stack_area, GEN_INT (arg->size.constant), PARM_BOUNDARY / BITS_PER_UNIT); } else { arg->save_area = gen_reg_rtx (save_mode); emit_move_insn (arg->save_area, stack_area); } } } #endif /* 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) reg = arg->reg, partial = arg->partial; if (reg != 0 && partial == 0) /* Being passed entirely in a register. We shouldn't be called in this case. */ abort (); /* 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) { #ifdef ACCUMULATE_OUTGOING_ARGS /* 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++; #endif arg->value = expand_expr (pval, (partial || TYPE_MODE (TREE_TYPE (pval)) != arg->mode) ? NULL_RTX : arg->stack, VOIDmode, 0); /* 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); #ifdef ACCUMULATE_OUTGOING_ARGS if (arg->pass_on_stack) stack_arg_under_construction--; #endif } /* Don't allow anything left on stack from computation of argument to alloca. */ if (may_be_alloca) do_pending_stack_adjust (); if (arg->value == arg->stack) { /* If the value is already in the stack slot, we are done moving data. */ if (current_function_check_memory_usage && GET_CODE (arg->stack) == MEM) { emit_library_call (chkr_set_right_libfunc, 1, VOIDmode, 3, XEXP (arg->stack, 0), ptr_mode, ARGS_SIZE_RTX (arg->size), TYPE_MODE (sizetype), GEN_INT (MEMORY_USE_RW), TYPE_MODE (integer_type_node)); } } else if (arg->mode != BLKmode) { register int size; /* 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)); /* 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, 0, partial, reg, used - size, argblock, ARGS_SIZE_RTX (arg->offset), reg_parm_stack_space); } else { /* BLKmode, at least partly to be pushed. */ register 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->size.var != 0) { excess = 0; size_rtx = ARGS_SIZE_RTX (arg->size); } else { /* PUSH_ROUNDING has no effect on us, because emit_push_insn for BLKmode is careful to avoid it. */ excess = (arg->size.constant - int_size_in_bytes (TREE_TYPE (pval)) + partial * UNITS_PER_WORD); size_rtx = expr_size (pval); } emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx, TYPE_ALIGN (TREE_TYPE (pval)) / BITS_PER_UNIT, partial, reg, excess, argblock, ARGS_SIZE_RTX (arg->offset), reg_parm_stack_space); } /* Unless this is a partially-in-register argument, the argument is now in the stack. ??? Note that this can change arg->value from arg->stack to arg->stack_slot and it matters when they are not the same. It isn't totally clear that this is correct in all cases. */ if (partial == 0) arg->value = arg->stack_slot; /* Once we have pushed something, pops can't safely be deferred during the rest of the arguments. */ NO_DEFER_POP; /* ANSI doesn't require a sequence point here, but PCC has one, so this will avoid some problems. */ emit_queue (); /* 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 (); #ifdef ACCUMULATE_OUTGOING_ARGS /* Now mark the segment we just used. */ if (argblock && ! variable_size && arg->stack) for (i = lower_bound; i < upper_bound; i++) stack_usage_map[i] = 1; #endif }