blob: 675674ec7f552987ee526c875d86d5eb69797da7 [file] [log] [blame]
/* Convert function calls to rtl insns, for GNU C compiler.
Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998
1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file 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 "libfuncs.h"
#include "function.h"
#include "regs.h"
#include "toplev.h"
#include "output.h"
#include "tm_p.h"
#include "timevar.h"
#include "sbitmap.h"
#include "langhooks.h"
#include "target.h"
#include "except.h"
#if !defined FUNCTION_OK_FOR_SIBCALL
#define FUNCTION_OK_FOR_SIBCALL(DECL) 1
#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
#ifndef PUSH_ARGS_REVERSED
#if defined (STACK_GROWS_DOWNWARD) != defined (ARGS_GROW_DOWNWARD)
#define PUSH_ARGS_REVERSED PUSH_ARGS
#endif
#endif
#endif
#ifndef PUSH_ARGS_REVERSED
#define PUSH_ARGS_REVERSED 0
#endif
#ifndef STACK_POINTER_OFFSET
#define STACK_POINTER_OFFSET 0
#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;
/* Register to pass this argument in when generating tail call sequence.
This is not the same register as for normal calls on machines with
register windows. */
rtx tail_call_reg;
/* If REG 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;
/* Nonzero if argument must be passed on stack.
Note that some arguments may be passed on the stack
even though pass_on_stack is zero, just because FUNCTION_ARG says so.
pass_on_stack identifies arguments that *cannot* go in registers. */
int pass_on_stack;
/* 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;
/* Place that this stack area has been saved, if needed. */
rtx save_area;
/* If an argument's alignment does not permit direct copying into registers,
copy in smaller-sized pieces into pseudos. These are stored in a
block pointed to by this field. The next field says how many
word-sized pseudos we made. */
rtx *aligned_regs;
int n_aligned_regs;
/* The amount that the stack pointer needs to be adjusted to
force alignment for the next argument. */
struct args_size alignment_pad;
};
/* A vector of one char per byte of stack space. A byte if nonzero if
the corresponding stack location has been used.
This vector is used to prevent a function call within an argument from
clobbering any stack already set up. */
static char *stack_usage_map;
/* Size of STACK_USAGE_MAP. */
static int highest_outgoing_arg_in_use;
/* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
stack location's tail call argument has been already stored into the stack.
This bitmap is used to prevent sibling call optimization if function tries
to use parent's incoming argument slots when they have been already
overwritten with tail call arguments. */
static sbitmap stored_args_map;
/* stack_arg_under_construction is nonzero when an argument may be
initialized with a constructor call (including a C function that
returns a BLKmode struct) and expand_call must take special action
to make sure the object being constructed does not overlap the
argument list for the constructor call. */
int stack_arg_under_construction;
static int calls_function PARAMS ((tree, int));
static int calls_function_1 PARAMS ((tree, int));
/* Nonzero if this is a call to a `const' function. */
#define ECF_CONST 1
/* Nonzero if this is a call to a `volatile' function. */
#define ECF_NORETURN 2
/* Nonzero if this is a call to malloc or a related function. */
#define ECF_MALLOC 4
/* Nonzero if it is plausible that this is a call to alloca. */
#define ECF_MAY_BE_ALLOCA 8
/* Nonzero if this is a call to a function that won't throw an exception. */
#define ECF_NOTHROW 16
/* Nonzero if this is a call to setjmp or a related function. */
#define ECF_RETURNS_TWICE 32
/* Nonzero if this is a call to `longjmp'. */
#define ECF_LONGJMP 64
/* Nonzero if this is a syscall that makes a new process in the image of
the current one. */
#define ECF_FORK_OR_EXEC 128
#define ECF_SIBCALL 256
/* Nonzero if this is a call to "pure" function (like const function,
but may read memory. */
#define ECF_PURE 512
/* Nonzero if this is a call to a function that returns with the stack
pointer depressed. */
#define ECF_SP_DEPRESSED 1024
/* Nonzero if this call is known to always return. */
#define ECF_ALWAYS_RETURN 2048
/* Create libcall block around the call. */
#define ECF_LIBCALL_BLOCK 4096
static void emit_call_1 PARAMS ((rtx, tree, tree, HOST_WIDE_INT,
HOST_WIDE_INT, HOST_WIDE_INT, rtx,
rtx, int, rtx, int,
CUMULATIVE_ARGS *));
static void precompute_register_parameters PARAMS ((int,
struct arg_data *,
int *));
static int store_one_arg PARAMS ((struct arg_data *, rtx, int, int,
int));
static void store_unaligned_arguments_into_pseudos PARAMS ((struct arg_data *,
int));
static int finalize_must_preallocate PARAMS ((int, int,
struct arg_data *,
struct args_size *));
static void precompute_arguments PARAMS ((int, int,
struct arg_data *));
static int compute_argument_block_size PARAMS ((int,
struct args_size *,
int));
static void initialize_argument_information PARAMS ((int,
struct arg_data *,
struct args_size *,
int, tree, tree,
CUMULATIVE_ARGS *,
int, rtx *, int *,
int *, int *));
static void compute_argument_addresses PARAMS ((struct arg_data *,
rtx, int));
static rtx rtx_for_function_call PARAMS ((tree, tree));
static void load_register_parameters PARAMS ((struct arg_data *,
int, rtx *, int));
static rtx emit_library_call_value_1 PARAMS ((int, rtx, rtx,
enum libcall_type,
enum machine_mode,
int, va_list));
static int special_function_p PARAMS ((tree, int));
static int flags_from_decl_or_type PARAMS ((tree));
static rtx try_to_integrate PARAMS ((tree, tree, rtx,
int, tree, rtx));
static int check_sibcall_argument_overlap_1 PARAMS ((rtx));
static int check_sibcall_argument_overlap PARAMS ((rtx, struct arg_data *));
static int combine_pending_stack_adjustment_and_call
PARAMS ((int, struct args_size *, int));
static tree fix_unsafe_tree PARAMS ((tree));
#ifdef REG_PARM_STACK_SPACE
static rtx save_fixed_argument_area PARAMS ((int, rtx, int *, int *));
static void restore_fixed_argument_area PARAMS ((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;
}
/* Recursive function to do the work of above function. */
static int
calls_function_1 (exp, which)
tree exp;
int which;
{
int i;
enum tree_code code = TREE_CODE (exp);
int class = TREE_CODE_CLASS (code);
int length = first_rtl_op (code);
/* If this code is language-specific, we don't know what it will do. */
if ((int) code >= NUM_TREE_CODES)
return 1;
switch (code)
{
case CALL_EXPR:
if (which == 0)
return 1;
else if ((TREE_CODE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))))
== FUNCTION_TYPE)
&& (TYPE_RETURNS_STACK_DEPRESSED
(TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))))))
return 1;
else if (TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
&& (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
== FUNCTION_DECL)
&& (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
0)
& ECF_MAY_BE_ALLOCA))
return 1;
break;
case CONSTRUCTOR:
{
tree tem;
for (tem = CONSTRUCTOR_ELTS (exp); tem != 0; tem = TREE_CHAIN (tem))
if (calls_function_1 (TREE_VALUE (tem), which))
return 1;
}
return 0;
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:
{
tree local;
tree subblock;
for (local = BLOCK_VARS (exp); local; local = TREE_CHAIN (local))
if (DECL_INITIAL (local) != 0
&& calls_function_1 (DECL_INITIAL (local), which))
return 1;
for (subblock = BLOCK_SUBBLOCKS (exp);
subblock;
subblock = TREE_CHAIN (subblock))
if (calls_function_1 (subblock, which))
return 1;
}
return 0;
case TREE_LIST:
for (; exp != 0; exp = TREE_CHAIN (exp))
if (calls_function_1 (TREE_VALUE (exp), which))
return 1;
return 0;
default:
break;
}
/* Only expressions, references, and blocks can contain calls. */
if (! IS_EXPR_CODE_CLASS (class) && class != 'r' && class != 'b')
return 0;
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, sibcallp)
rtx funexp;
tree fndecl;
rtx *call_fusage;
int reg_parm_seen;
int sibcallp;
{
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 if (! sibcallp)
{
#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_STACK_SIZE is that number rounded up to
PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
both to put into the call insn and to generate explicit popping
code if necessary.
STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
It is zero if this call doesn't want a structure value.
NEXT_ARG_REG is the rtx that results from executing
FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
just after all the args have had their registers assigned.
This could be whatever you like, but normally it is the first
arg-register beyond those used for args in this call,
or 0 if all the arg-registers are used in this call.
It is passed on to `gen_call' so you can put this info in the call insn.
VALREG is a hard register in which a value is returned,
or 0 if the call does not return a value.
OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
the args to this call were processed.
We restore `inhibit_defer_pop' to that value.
CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
denote registers used by the called function. */
static void
emit_call_1 (funexp, fndecl, funtype, stack_size, rounded_stack_size,
struct_value_size, next_arg_reg, valreg, old_inhibit_defer_pop,
call_fusage, ecf_flags, args_so_far)
rtx funexp;
tree fndecl ATTRIBUTE_UNUSED;
tree funtype ATTRIBUTE_UNUSED;
HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED;
HOST_WIDE_INT rounded_stack_size;
HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED;
rtx next_arg_reg ATTRIBUTE_UNUSED;
rtx valreg;
int old_inhibit_defer_pop;
rtx call_fusage;
int ecf_flags;
CUMULATIVE_ARGS *args_so_far ATTRIBUTE_UNUSED;
{
rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
rtx call_insn;
int already_popped = 0;
HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size);
#if defined (HAVE_call) && defined (HAVE_call_value)
rtx struct_value_size_rtx;
struct_value_size_rtx = GEN_INT (struct_value_size);
#endif
#ifdef CALL_POPS_ARGS
n_popped += CALL_POPS_ARGS (* args_so_far);
#endif
/* Ensure address is valid. SYMBOL_REF is already valid, so no need,
and we don't want to load it into a register as an optimization,
because prepare_call_address already did it if it should be done. */
if (GET_CODE (funexp) != SYMBOL_REF)
funexp = memory_address (FUNCTION_MODE, funexp);
#if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
if ((ecf_flags & ECF_SIBCALL)
&& HAVE_sibcall_pop && HAVE_sibcall_value_pop
&& (n_popped > 0 || stack_size == 0))
{
rtx n_pop = GEN_INT (n_popped);
rtx pat;
/* If this subroutine pops its own args, record that in the call insn
if possible, for the sake of frame pointer elimination. */
if (valreg)
pat = GEN_SIBCALL_VALUE_POP (valreg,
gen_rtx_MEM (FUNCTION_MODE, funexp),
rounded_stack_size_rtx, next_arg_reg,
n_pop);
else
pat = GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
rounded_stack_size_rtx, next_arg_reg, n_pop);
emit_call_insn (pat);
already_popped = 1;
}
else
#endif
#if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
/* If the target has "call" or "call_value" insns, then prefer them
if no arguments are actually popped. If the target does not have
"call" or "call_value" insns, then we must use the popping versions
even if the call has no arguments to pop. */
#if defined (HAVE_call) && defined (HAVE_call_value)
if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
&& n_popped > 0 && ! (ecf_flags & ECF_SP_DEPRESSED))
#else
if (HAVE_call_pop && HAVE_call_value_pop)
#endif
{
rtx n_pop = GEN_INT (n_popped);
rtx pat;
/* If this subroutine pops its own args, record that in the call insn
if possible, for the sake of frame pointer elimination. */
if (valreg)
pat = GEN_CALL_VALUE_POP (valreg,
gen_rtx_MEM (FUNCTION_MODE, funexp),
rounded_stack_size_rtx, next_arg_reg, n_pop);
else
pat = GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
rounded_stack_size_rtx, next_arg_reg, n_pop);
emit_call_insn (pat);
already_popped = 1;
}
else
#endif
#if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
if ((ecf_flags & ECF_SIBCALL)
&& HAVE_sibcall && HAVE_sibcall_value)
{
if (valreg)
emit_call_insn (GEN_SIBCALL_VALUE (valreg,
gen_rtx_MEM (FUNCTION_MODE, funexp),
rounded_stack_size_rtx,
next_arg_reg, NULL_RTX));
else
emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
rounded_stack_size_rtx, next_arg_reg,
struct_value_size_rtx));
}
else
#endif
#if defined (HAVE_call) && defined (HAVE_call_value)
if (HAVE_call && HAVE_call_value)
{
if (valreg)
emit_call_insn (GEN_CALL_VALUE (valreg,
gen_rtx_MEM (FUNCTION_MODE, funexp),
rounded_stack_size_rtx, next_arg_reg,
NULL_RTX));
else
emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
rounded_stack_size_rtx, next_arg_reg,
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 ();
/* Mark memory as used for "pure" function call. */
if (ecf_flags & ECF_PURE)
call_fusage
= gen_rtx_EXPR_LIST
(VOIDmode,
gen_rtx_USE (VOIDmode,
gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (VOIDmode))),
call_fusage);
/* 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 (ecf_flags & (ECF_CONST | ECF_PURE))
CONST_OR_PURE_CALL_P (call_insn) = 1;
/* If this call can't throw, attach a REG_EH_REGION reg note to that
effect. */
if (ecf_flags & ECF_NOTHROW)
REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_EH_REGION, const0_rtx,
REG_NOTES (call_insn));
else
note_eh_region_may_contain_throw ();
if (ecf_flags & ECF_NORETURN)
REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_NORETURN, const0_rtx,
REG_NOTES (call_insn));
if (ecf_flags & ECF_ALWAYS_RETURN)
REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_ALWAYS_RETURN, const0_rtx,
REG_NOTES (call_insn));
if (ecf_flags & ECF_RETURNS_TWICE)
{
REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_SETJMP, const0_rtx,
REG_NOTES (call_insn));
current_function_calls_setjmp = 1;
}
SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
/* 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;
/* Don't bother cleaning up after a noreturn function. */
if (ecf_flags & (ECF_NORETURN | ECF_LONGJMP))
return;
if (n_popped > 0)
{
if (!already_popped)
CALL_INSN_FUNCTION_USAGE (call_insn)
= gen_rtx_EXPR_LIST (VOIDmode,
gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
CALL_INSN_FUNCTION_USAGE (call_insn));
rounded_stack_size -= n_popped;
rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
stack_pointer_delta -= n_popped;
}
if (!ACCUMULATE_OUTGOING_ARGS)
{
/* If returning from the subroutine does not automatically pop the args,
we need an instruction to pop them sooner or later.
Perhaps do it now; perhaps just record how much space to pop later.
If returning from the subroutine does pop the args, indicate that the
stack pointer will be changed. */
if (rounded_stack_size != 0)
{
if (ecf_flags & ECF_SP_DEPRESSED)
/* Just pretend we did the pop. */
stack_pointer_delta -= rounded_stack_size;
else if (flag_defer_pop && inhibit_defer_pop == 0
&& ! (ecf_flags & (ECF_CONST | ECF_PURE)))
pending_stack_adjust += rounded_stack_size;
else
adjust_stack (rounded_stack_size_rtx);
}
}
/* When we accumulate outgoing args, we must avoid any stack manipulations.
Restore the stack pointer to its original value now. Usually
ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
popping variants of functions exist as well.
??? We may optimize similar to defer_pop above, but it is
probably not worthwhile.
??? It will be worthwhile to enable combine_stack_adjustments even for
such machines. */
else if (n_popped)
anti_adjust_stack (GEN_INT (n_popped));
}
/* Determine if the function identified by NAME and FNDECL is one with
special properties we wish to know about.
For example, if the function might return more than one time (setjmp), then
set RETURNS_TWICE to a nonzero value.
Similarly set LONGJMP for if the function is in the longjmp family.
Set 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 int
special_function_p (fndecl, flags)
tree fndecl;
int flags;
{
if (! (flags & ECF_MALLOC)
&& fndecl && DECL_NAME (fndecl)
&& IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
/* Exclude functions not at the file scope, or not `extern',
since they are not the magic functions we would otherwise
think they are. */
&& DECL_CONTEXT (fndecl) == NULL_TREE && TREE_PUBLIC (fndecl))
{
const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
const char *tname = name;
/* We assume that alloca will always be called by name. It
makes no sense to pass it as a pointer-to-function to
anything that does not understand its behavior. */
if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
&& name[0] == 'a'
&& ! strcmp (name, "alloca"))
|| (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
&& name[0] == '_'
&& ! strcmp (name, "__builtin_alloca"))))
flags |= ECF_MAY_BE_ALLOCA;
/* Disregard prefix _, __ 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')
{
if ((tname[1] == 'e'
&& (! strcmp (tname, "setjmp")
|| ! strcmp (tname, "setjmp_syscall")))
|| (tname[1] == 'i'
&& ! strcmp (tname, "sigsetjmp"))
|| (tname[1] == 'a'
&& ! strcmp (tname, "savectx")))
flags |= ECF_RETURNS_TWICE;
if (tname[1] == 'i'
&& ! strcmp (tname, "siglongjmp"))
flags |= ECF_LONGJMP;
}
else if ((tname[0] == 'q' && tname[1] == 's'
&& ! strcmp (tname, "qsetjmp"))
|| (tname[0] == 'v' && tname[1] == 'f'
&& ! strcmp (tname, "vfork")))
flags |= ECF_RETURNS_TWICE;
else if (tname[0] == 'l' && tname[1] == 'o'
&& ! strcmp (tname, "longjmp"))
flags |= ECF_LONGJMP;
else if ((tname[0] == 'f' && tname[1] == 'o'
&& ! strcmp (tname, "fork"))
/* Linux specific: __clone. check NAME to insist on the
leading underscores, to avoid polluting the ISO / POSIX
namespace. */
|| (name[0] == '_' && name[1] == '_'
&& ! strcmp (tname, "clone"))
|| (tname[0] == 'e' && tname[1] == 'x' && tname[2] == 'e'
&& tname[3] == 'c' && (tname[4] == 'l' || tname[4] == 'v')
&& (tname[5] == '\0'
|| ((tname[5] == 'p' || tname[5] == 'e')
&& tname[6] == '\0'))))
flags |= ECF_FORK_OR_EXEC;
/* Do not add any more malloc-like functions to this list,
instead mark them as malloc functions using the malloc attribute.
Note, realloc is not suitable for attribute malloc since
it may return the same address across multiple calls.
C++ operator new is not suitable because it is not required
to return a unique pointer; indeed, the standard placement new
just returns its argument. */
else if (TYPE_MODE (TREE_TYPE (TREE_TYPE (fndecl))) == Pmode
&& (! strcmp (tname, "malloc")
|| ! strcmp (tname, "calloc")
|| ! strcmp (tname, "strdup")))
flags |= ECF_MALLOC;
}
return flags;
}
/* Return nonzero when tree represent call to longjmp. */
int
setjmp_call_p (fndecl)
tree fndecl;
{
return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
}
/* Return true when exp contains alloca call. */
bool
alloca_call_p (exp)
tree exp;
{
if (TREE_CODE (exp) == CALL_EXPR
&& TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
&& (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
== FUNCTION_DECL)
&& (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
0) & ECF_MAY_BE_ALLOCA))
return true;
return false;
}
/* Detect flags (function attributes) from the function decl or type node. */
static int
flags_from_decl_or_type (exp)
tree exp;
{
int flags = 0;
tree type = exp;
/* ??? We can't set IS_MALLOC for function types? */
if (DECL_P (exp))
{
type = TREE_TYPE (exp);
/* The function exp may have the `malloc' attribute. */
if (DECL_P (exp) && DECL_IS_MALLOC (exp))
flags |= ECF_MALLOC;
/* The function exp may have the `pure' attribute. */
if (DECL_P (exp) && DECL_IS_PURE (exp))
flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
if (TREE_NOTHROW (exp))
flags |= ECF_NOTHROW;
if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
flags |= ECF_LIBCALL_BLOCK;
}
if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
flags |= ECF_CONST;
if (TREE_THIS_VOLATILE (exp))
flags |= ECF_NORETURN;
/* Mark if the function returns with the stack pointer depressed. We
cannot consider it pure or constant in that case. */
if (TREE_CODE (type) == FUNCTION_TYPE && TYPE_RETURNS_STACK_DEPRESSED (type))
{
flags |= ECF_SP_DEPRESSED;
flags &= ~(ECF_PURE | ECF_CONST | ECF_LIBCALL_BLOCK);
}
return flags;
}
/* Precompute all register parameters as described by ARGS, storing values
into fields within the ARGS array.
NUM_ACTUALS indicates the total number elements in the ARGS array.
Set REG_PARM_SEEN if we encounter a register parameter. */
static void
precompute_register_parameters (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 the value is a non-legitimate constant, force it into a
pseudo now. TLS symbols sometimes need a call to resolve. */
if (CONSTANT_P (args[i].value)
&& !LEGITIMATE_CONSTANT_P (args[i].value))
args[i].value = force_reg (args[i].mode, args[i].value);
/* If we are to promote the function arg to a wider mode,
do it now. */
if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
args[i].value
= convert_modes (args[i].mode,
TYPE_MODE (TREE_TYPE (args[i].tree_value)),
args[i].value, args[i].unsignedp);
/* If 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) > COSTS_N_INSNS (1)
&& ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
|| preserve_subexpressions_p ()))
args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
}
}
#ifdef REG_PARM_STACK_SPACE
/* The argument list is the property of the called routine and it
may clobber it. If the fixed area has been used for previous
parameters, we must save and restore it. */
static rtx
save_fixed_argument_area (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
set_mem_align (stack_area, PARM_BOUNDARY);
if (save_mode == BLKmode)
{
save_area = assign_stack_temp (BLKmode, num_to_save, 0);
emit_block_move (validize_mem (save_area), stack_area,
GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
}
else
{
save_area = gen_reg_rtx (save_mode);
emit_move_insn (save_area, stack_area);
}
}
return save_area;
}
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),
BLOCK_OP_CALL_PARM);
}
#endif /* REG_PARM_STACK_SPACE */
/* If any elements in ARGS refer to parameters that are to be passed in
registers, but not in memory, and whose alignment does not permit a
direct copy into registers. Copy the values into a group of pseudos
which we will later copy into the appropriate hard registers.
Pseudos for each unaligned argument will be stored into the array
args[argnum].aligned_regs. The caller is responsible for deallocating
the aligned_regs array if it is nonzero. */
static void
store_unaligned_arguments_into_pseudos (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);
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,
BITS_PER_WORD),
BITS_PER_WORD);
}
}
}
/* Fill in ARGS_SIZE and ARGS array based on the parameters found in
ACTPARMS.
NUM_ACTUALS is the total number of parameters.
N_NAMED_ARGS is the total number of named arguments.
FNDECL is the tree code for the target of this call (if known)
ARGS_SO_FAR holds state needed by the target to know where to place
the next argument.
REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
for arguments which are passed in registers.
OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
and may be modified by this routine.
OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
flags which may may be modified by this routine. */
static void
initialize_argument_information (num_actuals, args, args_size, n_named_args,
actparms, fndecl, args_so_far,
reg_parm_stack_space, old_stack_level,
old_pending_adj, must_preallocate,
ecf_flags)
int num_actuals ATTRIBUTE_UNUSED;
struct arg_data *args;
struct args_size *args_size;
int n_named_args ATTRIBUTE_UNUSED;
tree actparms;
tree fndecl;
CUMULATIVE_ARGS *args_so_far;
int reg_parm_stack_space;
rtx *old_stack_level;
int *old_pending_adj;
int *must_preallocate;
int *ecf_flags;
{
/* 1 if scanning parms front to back, -1 if scanning back to front. */
int inc;
/* Count arg position in order args appear. */
int argpos;
struct args_size alignment_pad;
int i;
tree p;
args_size->constant = 0;
args_size->var = 0;
/* In this loop, we consider args in the order they are written.
We fill up ARGS from the front or from the back if necessary
so that in any case the first arg to be pushed ends up at the front. */
if (PUSH_ARGS_REVERSED)
{
i = num_actuals - 1, inc = -1;
/* In this case, must reverse order of args
so that we compute and push the last arg first. */
}
else
{
i = 0, inc = 1;
}
/* 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 || !COMPLETE_TYPE_P (type))
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 (TREE_CODE (type) == UNION_TYPE && 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
&& (DECL_P (TREE_OPERAND (args[i].tree_value, 1)))
&& ! 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 if (TREE_CODE (args[i].tree_value) == TARGET_EXPR)
{
/* In the V3 C++ ABI, parameters are destroyed in the caller.
We implement this by passing the address of the temporary
rather than expanding it into another allocated slot. */
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 (!COMPLETE_TYPE_P (type)
|| TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
|| (flag_stack_check && ! STACK_CHECK_BUILTIN
&& (0 < compare_tree_int (TYPE_SIZE_UNIT (type),
STACK_CHECK_MAX_VAR_SIZE))))
{
/* 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)));
set_mem_attributes (copy, type, 1);
}
else
copy = assign_temp (type, 0, 1, 0);
store_expr (args[i].tree_value, copy, 0);
*ecf_flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
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_INCOMING_ARG
/* If this is a sibling call and the machine has register windows, the
register window has to be unwinded before calling the routine, so
arguments have to go into the incoming registers. */
args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
argpos < n_named_args);
#else
args[i].tail_call_reg = args[i].reg;
#endif
#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))
*ecf_flags &= ~ECF_LIBCALL_BLOCK;
/* 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, &alignment_pad);
#ifndef ARGS_GROW_DOWNWARD
args[i].slot_offset = *args_size;
#endif
args[i].alignment_pad = alignment_pad;
/* 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);
}
}
/* Update ARGS_SIZE to contain the total size for the argument block.
Return the original constant component of the argument block's size.
REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
for arguments passed in registers. */
static int
compute_argument_block_size (reg_parm_stack_space, args_size,
preferred_stack_boundary)
int reg_parm_stack_space;
struct args_size *args_size;
int preferred_stack_boundary ATTRIBUTE_UNUSED;
{
int unadjusted_args_size = args_size->constant;
/* For accumulate outgoing args mode we don't need to align, since the frame
will be already aligned. Align to STACK_BOUNDARY in order to prevent
backends from generating misaligned frame sizes. */
if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
preferred_stack_boundary = STACK_BOUNDARY;
/* Compute the actual size of the argument block required. The variable
and constant sizes must be combined, the size may have to be rounded,
and there may be a minimum required size. */
if (args_size->var)
{
args_size->var = ARGS_SIZE_TREE (*args_size);
args_size->constant = 0;
preferred_stack_boundary /= BITS_PER_UNIT;
if (preferred_stack_boundary > 1)
{
/* We don't handle this case yet. To handle it correctly we have
to add the delta, round and subtract the delta.
Currently no machine description requires this support. */
if (stack_pointer_delta & (preferred_stack_boundary - 1))
abort ();
args_size->var = round_up (args_size->var, preferred_stack_boundary);
}
if (reg_parm_stack_space > 0)
{
args_size->var
= size_binop (MAX_EXPR, args_size->var,
ssize_int (reg_parm_stack_space));
#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,
ssize_int (reg_parm_stack_space));
#endif
}
}
else
{
preferred_stack_boundary /= BITS_PER_UNIT;
if (preferred_stack_boundary < 1)
preferred_stack_boundary = 1;
args_size->constant = (((args_size->constant
+ stack_pointer_delta
+ preferred_stack_boundary - 1)
/ preferred_stack_boundary
* preferred_stack_boundary)
- stack_pointer_delta);
args_size->constant = MAX (args_size->constant,
reg_parm_stack_space);
#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
}
return unadjusted_args_size;
}
/* Precompute parameters as needed for a function call.
FLAGS is mask of ECF_* constants.
NUM_ACTUALS is the number of arguments.
ARGS is an array containing information for each argument; this
routine fills in the INITIAL_VALUE and VALUE fields for each
precomputed argument. */
static void
precompute_arguments (flags, num_actuals, args)
int flags;
int num_actuals;
struct arg_data *args;
{
int i;
/* 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. (we have code to avoid
such case by saving the outgoing stack arguments, but it results in
worse code) */
for (i = 0; i < num_actuals; i++)
if ((flags & ECF_LIBCALL_BLOCK)
|| calls_function (args[i].tree_value, !ACCUMULATE_OUTGOING_ARGS))
{
enum machine_mode mode;
/* If this is an addressable type, we cannot pre-evaluate it. */
if (TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)))
abort ();
args[i].value
= expand_expr (args[i].tree_value, NULL_RTX, VOIDmode, 0);
/* 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].value, 0);
mode = TYPE_MODE (TREE_TYPE (args[i].tree_value));
if (mode != args[i].mode)
{
args[i].value
= convert_modes (args[i].mode, mode,
args[i].value, args[i].unsignedp);
#ifdef PROMOTE_FOR_CALL_ONLY
/* CSE will replace this only if it contains args[i].value
pseudo, so convert it down to the declared mode using
a SUBREG. */
if (GET_CODE (args[i].value) == REG
&& GET_MODE_CLASS (args[i].mode) == MODE_INT)
{
args[i].initial_value
= gen_lowpart_SUBREG (mode, args[i].value);
SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
args[i].unsignedp);
}
#endif
}
}
}
/* Given the current state of MUST_PREALLOCATE and information about
arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
compute and return the final value for MUST_PREALLOCATE. */
static int
finalize_must_preallocate (must_preallocate, num_actuals, args, args_size)
int must_preallocate;
int num_actuals;
struct arg_data *args;
struct args_size *args_size;
{
/* See if we have or want to preallocate stack space.
If we would have to push a partially-in-regs parm
before other stack parms, preallocate stack space instead.
If the size of some parm is not a multiple of the required stack
alignment, we must preallocate.
If the total size of arguments that would otherwise create a copy in
a temporary (such as a CALL) is more than half the total argument list
size, preallocation is faster.
Another reason to preallocate is if we have a machine (like the m88k)
where stack alignment is required to be maintained between every
pair of insns, not just when the call is made. However, we assume here
that such machines either do not have push insns (and hence preallocation
would occur anyway) or the problem is taken care of with
PUSH_ROUNDING. */
if (! must_preallocate)
{
int partial_seen = 0;
int copy_to_evaluate_size = 0;
int i;
for (i = 0; i < num_actuals && ! must_preallocate; i++)
{
if (args[i].partial > 0 && ! args[i].pass_on_stack)
partial_seen = 1;
else if (partial_seen && args[i].reg == 0)
must_preallocate = 1;
if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
&& (TREE_CODE (args[i].tree_value) == CALL_EXPR
|| TREE_CODE (args[i].tree_value) == TARGET_EXPR
|| TREE_CODE (args[i].tree_value) == COND_EXPR
|| TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
copy_to_evaluate_size
+= int_size_in_bytes (TREE_TYPE (args[i].tree_value));
}
if (copy_to_evaluate_size * 2 >= args_size->constant
&& args_size->constant > 0)
must_preallocate = 1;
}
return must_preallocate;
}
/* If we preallocated stack space, compute the address of each argument
and store it into the ARGS array.
We need not ensure it is a valid memory address here; it will be
validized when it is used.
ARGBLOCK is an rtx for the address of the outgoing arguments. */
static void
compute_argument_addresses (args, argblock, num_actuals)
struct arg_data *args;
rtx argblock;
int num_actuals;
{
if (argblock)
{
rtx arg_reg = argblock;
int i, arg_offset = 0;
if (GET_CODE (argblock) == PLUS)
arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
for (i = 0; i < num_actuals; i++)
{
rtx offset = ARGS_SIZE_RTX (args[i].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);
set_mem_align (args[i].stack, PARM_BOUNDARY);
set_mem_attributes (args[i].stack,
TREE_TYPE (args[i].tree_value), 1);
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);
set_mem_align (args[i].stack_slot, PARM_BOUNDARY);
set_mem_attributes (args[i].stack_slot,
TREE_TYPE (args[i].tree_value), 1);
/* Function incoming arguments may overlap with sibling call
outgoing arguments and we cannot allow reordering of reads
from function arguments with stores to outgoing arguments
of sibling calls. */
set_mem_alias_set (args[i].stack, 0);
set_mem_alias_set (args[i].stack_slot, 0);
}
}
}
/* Given a FNDECL and EXP, return an rtx suitable for use as a target address
in a call instruction.
FNDECL is the tree node for the target function. For an indirect call
FNDECL will be NULL_TREE.
ADDR is the operand 0 of CALL_EXPR for this call. */
static rtx
rtx_for_function_call (fndecl, addr)
tree fndecl;
tree addr;
{
rtx funexp;
/* Get the function to call, in the form of RTL. */
if (fndecl)
{
/* If this is the first use of the function, see if we need to
make an external definition for it. */
if (! TREE_USED (fndecl))
{
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. */
{
rtx funaddr;
push_temp_slots ();
funaddr = funexp
= expand_expr (addr, NULL_RTX, VOIDmode, 0);
pop_temp_slots (); /* FUNEXP can't be BLKmode. */
emit_queue ();
}
return funexp;
}
/* 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. */
static void
load_register_parameters (args, num_actuals, call_fusage, flags)
struct arg_data *args;
int num_actuals;
rtx *call_fusage;
int flags;
{
int i, j;
#ifdef LOAD_ARGS_REVERSED
for (i = num_actuals - 1; i >= 0; i--)
#else
for (i = 0; i < num_actuals; i++)
#endif
{
rtx reg = ((flags & ECF_SIBCALL)
? args[i].tail_call_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)));
/* 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);
}
}
}
/* Try to integrate function. See expand_inline_function for documentation
about the parameters. */
static rtx
try_to_integrate (fndecl, actparms, target, ignore, type, structure_value_addr)
tree fndecl;
tree actparms;
rtx target;
int ignore;
tree type;
rtx structure_value_addr;
{
rtx temp;
rtx before_call;
int i;
rtx old_stack_level = 0;
int reg_parm_stack_space = 0;
#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
before_call = get_last_insn ();
timevar_push (TV_INTEGRATION);
temp = expand_inline_function (fndecl, actparms, target,
ignore, type,
structure_value_addr);
timevar_pop (TV_INTEGRATION);
/* If inlining succeeded, return. */
if (temp != (rtx) (size_t) - 1)
{
if (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 = NULL_RTX, seq;
/* Look for a call in the inline function code.
If DECL_SAVED_INSNS (fndecl)->outgoing_args_size is
nonzero then there is a call and it is not necessary
to scan the insns. */
if (DECL_SAVED_INSNS (fndecl)->outgoing_args_size == 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 = (DECL_SAVED_INSNS (fndecl)->outgoing_args_size
+ 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_insn_before (seq, first_insn);
emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
}
}
}
/* 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");
}
(*lang_hooks.mark_addressable) (fndecl);
return (rtx) (size_t) - 1;
}
/* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
bytes, then we would need to push some additional bytes to pad the
arguments. So, we compute an adjust to the stack pointer for an
amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
bytes. Then, when the arguments are pushed the stack will be perfectly
aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
be popped after the call. Returns the adjustment. */
static int
combine_pending_stack_adjustment_and_call (unadjusted_args_size,
args_size,
preferred_unit_stack_boundary)
int unadjusted_args_size;
struct args_size *args_size;
int preferred_unit_stack_boundary;
{
/* The number of bytes to pop so that the stack will be
under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
HOST_WIDE_INT adjustment;
/* The alignment of the stack after the arguments are pushed, if we
just pushed the arguments without adjust the stack here. */
HOST_WIDE_INT unadjusted_alignment;
unadjusted_alignment
= ((stack_pointer_delta + unadjusted_args_size)
% preferred_unit_stack_boundary);
/* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
as possible -- leaving just enough left to cancel out the
UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
PENDING_STACK_ADJUST is non-negative, and congruent to
-UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
/* Begin by trying to pop all the bytes. */
unadjusted_alignment
= (unadjusted_alignment
- (pending_stack_adjust % preferred_unit_stack_boundary));
adjustment = pending_stack_adjust;
/* Push enough additional bytes that the stack will be aligned
after the arguments are pushed. */
if (preferred_unit_stack_boundary > 1)
{
if (unadjusted_alignment > 0)
adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
else
adjustment += unadjusted_alignment;
}
/* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
bytes after the call. The right number is the entire
PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
by the arguments in the first place. */
args_size->constant
= pending_stack_adjust - adjustment + unadjusted_args_size;
return adjustment;
}
/* Scan X expression if it does not dereference any argument slots
we already clobbered by tail call arguments (as noted in stored_args_map
bitmap).
Return nonzero if X expression dereferences such argument slots,
zero otherwise. */
static int
check_sibcall_argument_overlap_1 (x)
rtx x;
{
RTX_CODE code;
int i, j;
unsigned int k;
const char *fmt;
if (x == NULL_RTX)
return 0;
code = GET_CODE (x);
if (code == MEM)
{
if (XEXP (x, 0) == current_function_internal_arg_pointer)
i = 0;
else if (GET_CODE (XEXP (x, 0)) == PLUS
&& XEXP (XEXP (x, 0), 0) ==
current_function_internal_arg_pointer
&& GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)
i = INTVAL (XEXP (XEXP (x, 0), 1));
else
return 0;
#ifdef ARGS_GROW_DOWNWARD
i = -i - GET_MODE_SIZE (GET_MODE (x));
#endif
for (k = 0; k < GET_MODE_SIZE (GET_MODE (x)); k++)
if (i + k < stored_args_map->n_bits
&& TEST_BIT (stored_args_map, i + k))
return 1;
return 0;
}
/* Scan all subexpressions. */
fmt = GET_RTX_FORMAT (code);
for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
{
if (*fmt == 'e')
{
if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
return 1;
}
else if (*fmt == 'E')
{
for (j = 0; j < XVECLEN (x, i); j++)
if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
return 1;
}
}
return 0;
}
/* Scan sequence after INSN if it does not dereference any argument slots
we already clobbered by tail call arguments (as noted in stored_args_map
bitmap). Add stack slots for ARG to stored_args_map bitmap afterwards.
Return nonzero if sequence after INSN dereferences such argument slots,
zero otherwise. */
static int
check_sibcall_argument_overlap (insn, arg)
rtx insn;
struct arg_data *arg;
{
int low, high;
if (insn == NULL_RTX)
insn = get_insns ();
else
insn = NEXT_INSN (insn);
for (; insn; insn = NEXT_INSN (insn))
if (INSN_P (insn)
&& check_sibcall_argument_overlap_1 (PATTERN (insn)))
break;
#ifdef ARGS_GROW_DOWNWARD
low = -arg->slot_offset.constant - arg->size.constant;
#else
low = arg->slot_offset.constant;
#endif
for (high = low + arg->size.constant; low < high; low++)
SET_BIT (stored_args_map, low);
return insn != NULL_RTX;
}
static tree
fix_unsafe_tree (t)
tree t;
{
switch (unsafe_for_reeval (t))
{
case 0: /* Safe. */
break;
case 1: /* Mildly unsafe. */
t = unsave_expr (t);
break;
case 2: /* Wildly unsafe. */
{
tree var = build_decl (VAR_DECL, NULL_TREE,
TREE_TYPE (t));
SET_DECL_RTL (var,
expand_expr (t, NULL_RTX, VOIDmode, EXPAND_NORMAL));
t = var;
}
break;
default:
abort ();
}
return t;
}
/* 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;
{
/* Nonzero if we are currently expanding a call. */
static int currently_expanding_call = 0;
/* List of actual parameters. */
tree actparms = TREE_OPERAND (exp, 1);
/* RTX for the function to be called. */
rtx funexp;
/* Sequence of insns to perform a tail recursive "call". */
rtx tail_recursion_insns = NULL_RTX;
/* Sequence of insns to perform a normal "call". */
rtx normal_call_insns = NULL_RTX;
/* Sequence of insns to perform a tail recursive "call". */
rtx tail_call_insns = NULL_RTX;
/* 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;
rtx insn;
int try_tail_call = 1;
int try_tail_recursion = 1;
int pass;
/* Register in which non-BLKmode value will be returned,
or 0 if no value or if value is BLKmode. */
rtx valreg;
/* Address where we should return a BLKmode value;
0 if value not BLKmode. */
rtx structure_value_addr = 0;
/* Nonzero if that address is being passed by treating it as
an extra, implicit first parameter. Otherwise,
it is passed by being copied directly into struct_value_rtx. */
int structure_value_addr_parm = 0;
/* 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;
/* Vector of information about each argument.
Arguments are numbered in the order they will be pushed,
not the order they are written. */
struct arg_data *args;
/* Total size in bytes of all the stack-parms scanned so far. */
struct args_size args_size;
struct args_size adjusted_args_size;
/* Size of arguments before any adjustments (such as rounding). */
int unadjusted_args_size;
/* Data on reg parms scanned so far. */
CUMULATIVE_ARGS args_so_far;
/* Nonzero if a reg parm has been scanned. */
int reg_parm_seen;
/* Nonzero if this is an indirect function call. */
/* Nonzero if we must avoid push-insns in the args for this call.
If stack space is allocated for register parameters, but not by the
caller, then it is preallocated in the fixed part of the stack frame.
So the entire argument block must then be preallocated (i.e., we
ignore PUSH_ROUNDING in that case). */
int must_preallocate = !PUSH_ARGS;
/* Size of the stack reserved for parameter registers. */
int reg_parm_stack_space = 0;
/* Address of space preallocated for stack parms
(on machines that lack push insns), or 0 if space not preallocated. */
rtx argblock = 0;
/* Mask of ECF_ flags. */
int flags = 0;
/* Nonzero if this is a call to an inline function. */
int is_integrable = 0;
#ifdef REG_PARM_STACK_SPACE
/* Define the boundary of the register parm stack space that needs to be
save, if any. */
int low_to_save = -1, high_to_save;
rtx save_area = 0; /* Place that it is saved */
#endif
int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
char *initial_stack_usage_map = stack_usage_map;
int old_stack_arg_under_construction = 0;
rtx old_stack_level = 0;
int old_pending_adj = 0;
int old_inhibit_defer_pop = inhibit_defer_pop;
int old_stack_allocated;
rtx call_fusage;
tree p = TREE_OPERAND (exp, 0);
tree addr = TREE_OPERAND (exp, 0);
int i;
/* The alignment of the stack, in bits. */
HOST_WIDE_INT preferred_stack_boundary;
/* The alignment of the stack, in bytes. */
HOST_WIDE_INT preferred_unit_stack_boundary;
/* See if this is "nothrow" function call. */
if (TREE_NOTHROW (exp))
flags |= ECF_NOTHROW;
/* See if we can find a DECL-node for the actual function.
As a result, decide whether this is a call to an integrable function. */
fndecl = get_callee_fndecl (exp);
if (fndecl)
{
if (!flag_no_inline
&& fndecl != current_function_decl
&& DECL_INLINE (fndecl)
&& DECL_SAVED_INSNS (fndecl)
&& DECL_SAVED_INSNS (fndecl)->inlinable)
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");
}
(*lang_hooks.mark_addressable) (fndecl);
}
flags |= flags_from_decl_or_type (fndecl);
}
/* If we don't have specific function to call, see if we have a
attributes set in the type. */
else
flags |= flags_from_decl_or_type (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
#ifndef OUTGOING_REG_PARM_STACK_SPACE
if (reg_parm_stack_space > 0 && PUSH_ARGS)
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. */
flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
#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))
(*lang_hooks.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
{
/* For variable-sized objects, we must be called with a target
specified. If we were to allocate space on the stack here,
we would have no way of knowing when to free it. */
rtx d = assign_temp (TREE_TYPE (exp), 1, 1, 1);
mark_temp_addr_taken (d);
structure_value_addr = XEXP (d, 0);
target = 0;
}
}
#endif /* not PCC_STATIC_STRUCT_RETURN */
}
/* If called function is inline, try to integrate it. */
if (is_integrable)
{
rtx temp = try_to_integrate (fndecl, actparms, target,
ignore, TREE_TYPE (exp),
structure_value_addr);
if (temp != (rtx) (size_t) - 1)
return temp;
}
/* Figure out the amount to which the stack should be aligned. */
preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
/* Operand 0 is a pointer-to-function; get the type of the function. */
funtype = TREE_TYPE (addr);
if (! POINTER_TYPE_P (funtype))
abort ();
funtype = TREE_TYPE (funtype);
/* See if this is a call to a function that can return more than once
or a call to longjmp or malloc. */
flags |= special_function_p (fndecl, flags);
if (flags & ECF_MAY_BE_ALLOCA)
current_function_calls_alloca = 1;
/* 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
|| (ACCUMULATE_OUTGOING_ARGS
&& stack_arg_under_construction
&& structure_value_addr == virtual_outgoing_args_rtx)
? 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, num_actuals = 0; p; p = TREE_CHAIN (p))
num_actuals++;
/* 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 PRETEND_OUTGOING_VARARGS_NAMED is set 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 PRETEND_OUTGOING_VARARGS_NAMED is not set, we do not have any
reliable way to pass unnamed args in registers, so we must force
them into memory. */
if ((STRICT_ARGUMENT_NAMING
|| ! PRETEND_OUTGOING_VARARGS_NAMED)
&& 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;
/* 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));
/* Make a vector to hold all the information about each arg. */
args = (struct arg_data *) alloca (num_actuals * sizeof (struct arg_data));
memset ((char *) args, 0, num_actuals * sizeof (struct arg_data));
/* Build up entries in the ARGS array, compute the size of the
arguments into ARGS_SIZE, etc. */
initialize_argument_information (num_actuals, args, &args_size,
n_named_args, actparms, fndecl,
&args_so_far, reg_parm_stack_space,
&old_stack_level, &old_pending_adj,
&must_preallocate, &flags);
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. */
flags &= ~ECF_LIBCALL_BLOCK;
must_preallocate = 1;
}
/* Now make final decision about preallocating stack space. */
must_preallocate = finalize_must_preallocate (must_preallocate,
num_actuals, args,
&args_size);
/* If the structure value address will reference the stack pointer, we
must stabilize it. We don't need to do this if we know that we are
not going to adjust the stack pointer in processing this call. */
if (structure_value_addr
&& (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
|| reg_mentioned_p (virtual_outgoing_args_rtx,
structure_value_addr))
&& (args_size.var
|| (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
structure_value_addr = copy_to_reg (structure_value_addr);
/* Tail calls can make things harder to debug, and we're traditionally
pushed these optimizations into -O2. Don't try if we're already
expanding a call, as that means we're an argument. Don't try if
there's cleanups, as we know there's code to follow the call.
If rtx_equal_function_value_matters is false, that means we've
finished with regular parsing. Which means that some of the
machinery we use to generate tail-calls is no longer in place.
This is most often true of sjlj-exceptions, which we couldn't
tail-call to anyway. */
if (currently_expanding_call++ != 0
|| !flag_optimize_sibling_calls
|| !rtx_equal_function_value_matters
|| any_pending_cleanups (1)
|| args_size.var)
try_tail_call = try_tail_recursion = 0;
/* Tail recursion fails, when we are not dealing with recursive calls. */
if (!try_tail_recursion
|| TREE_CODE (addr) != ADDR_EXPR
|| TREE_OPERAND (addr, 0) != current_function_decl)
try_tail_recursion = 0;
/* Rest of purposes for tail call optimizations to fail. */
if (
#ifdef HAVE_sibcall_epilogue
!HAVE_sibcall_epilogue
#else
1
#endif
|| !try_tail_call
/* Doing sibling call optimization needs some work, since
structure_value_addr can be allocated on the stack.
It does not seem worth the effort since few optimizable
sibling calls will return a structure. */
|| structure_value_addr != NULL_RTX
/* If the register holding the address is a callee saved
register, then we lose. We have no way to prevent that,
so we only allow calls to named functions. */
/* ??? This could be done by having the insn constraints
use a register class that is all call-clobbered. Any
reload insns generated to fix things up would appear
before the sibcall_epilogue. */
|| fndecl == NULL_TREE
|| (flags & (ECF_RETURNS_TWICE | ECF_LONGJMP | ECF_NORETURN))
|| !FUNCTION_OK_FOR_SIBCALL (fndecl)
/* If this function requires more stack slots than the current
function, we cannot change it into a sibling call. */
|| args_size.constant > current_function_args_size
/* If the callee pops its own arguments, then it must pop exactly
the same number of arguments as the current function. */
|| (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
!= RETURN_POPS_ARGS (current_function_decl,
TREE_TYPE (current_function_decl),
current_function_args_size))
|| !(*lang_hooks.decls.ok_for_sibcall) (fndecl))
try_tail_call = 0;
if (try_tail_call || try_tail_recursion)
{
int end, inc;
actparms = NULL_TREE;
/* Ok, we're going to give the tail call the old college try.
This means we're going to evaluate the function arguments
up to three times. There are two degrees of badness we can
encounter, those that can be unsaved and those that can't.
(See unsafe_for_reeval commentary for details.)
Generate a new argument list. Pass safe arguments through
unchanged. For the easy badness wrap them in UNSAVE_EXPRs.
For hard badness, evaluate them now and put their resulting
rtx in a temporary VAR_DECL.
initialize_argument_information has ordered the array for the
order to be pushed, and we must remember this when reconstructing
the original argument order. */
if (PUSH_ARGS_REVERSED)
{
inc = 1;
i = 0;
end = num_actuals;
}
else
{
inc = -1;
i = num_actuals - 1;
end = -1;
}
for (; i != end; i += inc)
{
args[i].tree_value = fix_unsafe_tree (args[i].tree_value);
/* We need to build actparms for optimize_tail_recursion. We can
safely trash away TREE_PURPOSE, since it is unused by this
function. */
if (try_tail_recursion)
actparms = tree_cons (NULL_TREE, args[i].tree_value, actparms);
}
/* Do the same for the function address if it is an expression. */
if (!fndecl)
addr = fix_unsafe_tree (addr);
/* Expanding one of those dangerous arguments could have added
cleanups, but otherwise give it a whirl. */
if (any_pending_cleanups (1))
try_tail_call = try_tail_recursion = 0;
}
/* Generate a tail recursion sequence when calling ourselves. */
if (try_tail_recursion)
{
/* We want to emit any pending stack adjustments before the tail
recursion "call". That way we know any adjustment after the tail
recursion call can be ignored if we indeed use the tail recursion
call expansion. */
int save_pending_stack_adjust = pending_stack_adjust;
int save_stack_pointer_delta = stack_pointer_delta;
/* Emit any queued insns now; otherwise they would end up in
only one of the alternates. */
emit_queue ();
/* Use a new sequence to hold any RTL we generate. We do not even
know if we will use this RTL yet. The final decision can not be
made until after RTL generation for the entire function is
complete. */
start_sequence ();
/* If expanding any of the arguments creates cleanups, we can't
do a tailcall. So, we'll need to pop the pending cleanups
list. If, however, all goes well, and there are no cleanups
then the call to expand_start_target_temps will have no
effect. */
expand_start_target_temps ();
if (optimize_tail_recursion (actparms, get_last_insn ()))
{
if (any_pending_cleanups (1))
try_tail_call = try_tail_recursion = 0;
else
tail_recursion_insns = get_insns ();
}
expand_end_target_temps ();
end_sequence ();
/* Restore the original pending stack adjustment for the sibling and
normal call cases below. */
pending_stack_adjust = save_pending_stack_adjust;
stack_pointer_delta = save_stack_pointer_delta;
}
if (profile_arc_flag && (flags & ECF_FORK_OR_EXEC))
{
/* A fork duplicates the profile information, and an exec discards
it. We can't rely on fork/exec to be paired. So write out the
profile information we have gathered so far, and clear it. */
/* ??? When Linux's __clone is called with CLONE_VM set, profiling
is subject to race conditions, just as with multithreaded
programs. */
emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__bb_fork_func"),
LCT_ALWAYS_RETURN,
VOIDmode, 0);
}
/* Ensure current function's preferred stack boundary is at least
what we need. We don't have to increase alignment for recursive
functions. */
if (cfun->preferred_stack_boundary < preferred_stack_boundary
&& fndecl != current_function_decl)
cfun->preferred_stack_boundary = preferred_stack_boundary;
preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
function_call_count++;
/* We want to make two insn chains; one for a sibling call, the other
for a normal call. We will select one of the two chains after
initial RTL generation is complete. */
for (pass = 0; pass < 2; pass++)
{
int sibcall_failure = 0;
/* We want to emit any pending stack adjustments before the tail
recursion "call". That way we know any adjustment after the tail
recursion call can be ignored if we indeed use the tail recursion
call expansion. */
int save_pending_stack_adjust = 0;
int save_stack_pointer_delta = 0;
rtx insns;
rtx before_call, next_arg_reg;
if (pass == 0)
{
if (! try_tail_call)
continue;
/* Emit any queued insns now; otherwise they would end up in
only one of the alternates. */
emit_queue ();
/* State variables we need to save and restore between
iterations. */
save_pending_stack_adjust = pending_stack_adjust;
save_stack_pointer_delta = stack_pointer_delta;
}
if (pass)
flags &= ~ECF_SIBCALL;
else
flags |= ECF_SIBCALL;
/* Other state variables that we must reinitialize each time
through the loop (that are not initialized by the loop itself). */
argblock = 0;
call_fusage = 0;
/* Start a new sequence for the normal call case.
From this point on, if the sibling call fails, we want to set
sibcall_failure instead of continuing the loop. */
start_sequence ();
if (pass == 0)
{
/* We know at this point that there are not currently any
pending cleanups. If, however, in the process of evaluating
the arguments we were to create some, we'll need to be
able to get rid of them. */
expand_start_target_temps ();
}
/* Don't let pending stack adjusts add up to too much.
Also, do all pending adjustments now if there is any chance
this might be a call to alloca or if we are expanding a sibling
call sequence or if we are calling a function that is to return
with stack pointer depressed. */
if (pending_stack_adjust >= 32
|| (pending_stack_adjust > 0
&& (flags & (ECF_MAY_BE_ALLOCA | ECF_SP_DEPRESSED)))
|| pass == 0)
do_pending_stack_adjust ();
/* 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 (pass && (flags & ECF_LIBCALL_BLOCK))
NO_DEFER_POP;
#ifdef FINAL_REG_PARM_STACK_SPACE
reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
args_size.var);
#endif
/* Precompute any arguments as needed. */
if (pass)
precompute_arguments (flags, num_actuals, args);
/* Now we are about to start emitting insns that can be deleted
if a libcall is deleted. */
if (pass && (flags & (ECF_LIBCALL_BLOCK | ECF_MALLOC)))
start_sequence ();
adjusted_args_size = args_size;
/* Compute the actual size of the argument block required. The variable
and constant sizes must be combined, the size may have to be rounded,
and there may be a minimum required size. When generating a sibcall
pattern, do not round up, since we'll be re-using whatever space our
caller provided. */
unadjusted_args_size
= compute_argument_block_size (reg_parm_stack_space,
&adjusted_args_size,
(pass == 0 ? 0
: preferred_stack_boundary));
old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
/* The argument block when performing a sibling call is the
incoming argument block. */
if (pass == 0)
{
argblock = virtual_incoming_args_rtx;
argblock
#ifdef STACK_GROWS_DOWNWARD
= plus_constant (argblock, current_function_pretend_args_size);
#else
= plus_constant (argblock, -current_function_pretend_args_size);
#endif
stored_args_map = sbitmap_alloc (args_size.constant);
sbitmap_zero (stored_args_map);
}
/* If we have no actual push instructions, or shouldn't use them,
make space for all args right now. */
else if (adjusted_args_size.var != 0)
{
if (old_stack_level == 0)
{
emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
old_pending_adj = pending_stack_adjust;
pending_stack_adjust = 0;
/* stack_arg_under_construction says whether a stack arg is
being constructed at the old stack level. Pushing the stack
gets a clean outgoing argument block. */
old_stack_arg_under_construction = stack_arg_under_construction;
stack_arg_under_construction = 0;
}
argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
}
else
{
/* Note that we must go through the motions of allocating an argument
block even if the size is zero because we may be storing args
in the area reserved for register arguments, which may be part of
the stack frame. */
int needed = adjusted_args_size.constant;
/* Store the maximum argument space used. It will be pushed by
the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
checking). */
if (needed > current_function_outgoing_args_size)
current_function_outgoing_args_size = needed;
if (must_preallocate)
{
if (ACCUMULATE_OUTGOING_ARGS)
{
/* Since the stack pointer will never be pushed, it is
possible for the evaluation of a parm to clobber
something we have already written to the stack.
Since most function calls on RISC machines do not use
the stack, this is uncommon, but must work correctly.
Therefore, we save any area of the stack that was already
written and that we are using. Here we set up to do this
by making a new stack usage map from the old one. The
actual save will be done by store_one_arg.
Another approach might be to try to reorder the argument
evaluations to avoid this conflicting stack usage. */
#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)
memcpy (stack_usage_map, initial_stack_usage_map,
initial_highest_arg_in_use);
if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
memset (&stack_usage_map[initial_highest_arg_in_use], 0,
(highest_outgoing_arg_in_use
- initial_highest_arg_in_use));
needed = 0;
/* The address of the outgoing argument list must not be
copied to a register here, because argblock would be left
pointing to the wrong place after the call to
allocate_dynamic_stack_space below. */
argblock = virtual_outgoing_args_rtx;
}
else
{
if (inhibit_defer_pop == 0)
{
/* Try to reuse some or all of the pending_stack_adjust
to get this space. */
needed
= (combine_pending_stack_adjustment_and_call
(unadjusted_args_size,
&adjusted_args_size,
preferred_unit_stack_boundary));
/* combine_pending_stack_adjustment_and_call computes
an adjustment before the arguments are allocated.
Account for them and see whether or not the stack
needs to go up or down. */
needed = unadjusted_args_size - needed;
if (needed < 0)
{
/* We're releasing stack space. */
/* ??? We can avoid any adjustment at all if we're
already aligned. FIXME. */
pending_stack_adjust = -needed;
do_pending_stack_adjust ();
needed = 0;
}
else
/* We need to allocate space. We'll do that in
push_block below. */
pending_stack_adjust = 0;
}
/* Special case this because overhead of `push_block' in
this case is non-trivial. */
if (needed == 0)
argblock = virtual_outgoing_args_rtx;
else
argblock = push_block (GEN_INT (needed), 0, 0);
/* 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);
/* 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
+ adjusted_args_size.constant);
#else
rtx push_size = GEN_INT (adjusted_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);
memset (stack_usage_map, 0, 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;
}
}
}
}
compute_argument_addresses (args, argblock, num_actuals);
/* If we push args individually in reverse order, perform stack alignment
before the first push (the last arg). */
if (PUSH_ARGS_REVERSED && argblock == 0
&& adjusted_args_size.constant != unadjusted_args_size)
{
/* When the stack adjustment is pending, we get better code
by combining the adjustments. */
if (pending_stack_adjust
&& ! (flags & ECF_LIBCALL_BLOCK)
&& ! inhibit_defer_pop)
{
pending_stack_adjust
= (combine_pending_stack_adjustment_and_call
(unadjusted_args_size,
&adjusted_args_size,
preferred_unit_stack_boundary));
do_pending_stack_adjust ();
}
else if (argblock == 0)
anti_adjust_stack (GEN_INT (adjusted_args_size.constant
- unadjusted_args_size));
}
/* Now that the stack is properly aligned, pops can't safely
be deferred during the evaluation of the arguments. */
NO_DEFER_POP;
funexp = rtx_for_function_call (fndecl, addr);
/* Figure out the register where the value, if any, will come back. */
valreg = 0;
if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
&& ! structure_value_addr)
{
if (pcc_struct_value)
valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
fndecl, (pass == 0));
else
valreg = hard_function_value (TREE_TYPE (exp), fndecl, (pass == 0));
}
/* 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, &reg_parm_seen);
#ifdef REG_PARM_STACK_SPACE
/* Save the fixed argument area if it's part of the caller's frame and
is clobbered by argument setup for this call. */
if (ACCUMULATE_OUTGOING_ARGS && pass)
save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
&low_to_save, &high_to_save);
#endif
/* Now store (and compute if necessary) all non-register parms.
These come before register parms, since they can require block-moves,
which could clobber the registers used for register parms.
Parms which have partial registers are not stored here,
but we do preallocate space here if they want that. */
for (i = 0; i < num_actuals; i++)
if (args[i].reg == 0 || args[i].pass_on_stack)
{
rtx before_arg = get_last_insn ();
if (store_one_arg (&args[i], argblock, flags,
adjusted_args_size.var != 0,
reg_parm_stack_space)
|| (pass == 0
&& check_sibcall_argument_overlap (before_arg,
&args[i])))
sibcall_failure = 1;
}
/* If we have a parm that is passed in registers but not in memory
and whose alignment does not permit a direct copy into registers,
make a group of pseudos that correspond to each register that we
will later fill. */
if (STRICT_ALIGNMENT)
store_unaligned_arguments_into_pseudos (args, num_actuals);
/* Now store any partially-in-registers parm.
This is the last place a block-move can happen. */
if (reg_parm_seen)
for (i = 0; i < num_actuals; i++)
if (args[i].partial != 0 && ! args[i].pass_on_stack)
{
rtx before_arg = get_last_insn ();
if (store_one_arg (&args[i], argblock, flags,
adjusted_args_size.var != 0,
reg_parm_stack_space)
|| (pass == 0
&& check_sibcall_argument_overlap (before_arg,
&args[i])))
sibcall_failure = 1;
}
/* If we pushed args in forward order, perform stack alignment
after pushing the last arg. */
if (!PUSH_ARGS_REVERSED && argblock == 0)
anti_adjust_stack (GEN_INT (adjusted_args_size.constant
- unadjusted_args_size));
/* If register arguments require space on the stack and stack space
was not preallocated, allocate stack space here for arguments
passed in registers. */
#ifdef OUTGOING_REG_PARM_STACK_SPACE
if (!ACCUMULATE_OUTGOING_ARGS
&& 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 (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
{
emit_move_insn (struct_value_rtx,
force_reg (Pmode,
force_operand (structure_value_addr,
NULL_RTX)));
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, pass == 0);
load_register_parameters (args, num_actuals, &call_fusage, flags);
/* Perform postincrements before actually calling the function. */
emit_queue ();
/* Save a pointer to the last insn before the call, so that we can
later safely search backwards to find the CALL_INSN. */
before_call = get_last_insn ();
/* Set up next argument register. For sibling calls on machines
with register windows this should be the incoming register. */
#ifdef FUNCTION_INCOMING_ARG
if (pass == 0)
next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
void_type_node, 1);
else
#endif
next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
void_type_node, 1);
/* All arguments and registers used for the call must be set up by
now! */
/* Stack must be properly aligned now. */
if (pass && stack_pointer_delta % preferred_unit_stack_boundary)
abort ();
/* Generate the actual call instruction. */
emit_call_1 (funexp, fndecl, funtype, unadjusted_args_size,
adjusted_args_size.constant, struct_value_size,
next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
flags, & args_so_far);
/* Verify that we've deallocated all the stack we used. */
if (pass
&& ! (flags & (ECF_NORETURN | ECF_LONGJMP))
&& old_stack_allocated != stack_pointer_delta - pending_stack_adjust)
abort ();
/* 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 (pass && (flags & ECF_LIBCALL_BLOCK))
{
rtx insns;
if (valreg == 0 || GET_CODE (valreg) == PARALLEL)
{
insns = get_insns ();
end_sequence ();
emit_insn (insns);
}
else
{
rtx note = 0;
rtx temp = gen_reg_rtx (GET_MODE (valreg));
/* Mark the return value as a pointer if needed. */
if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
mark_reg_pointer (temp,
TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp))));
/* Construct an "equal form" for the value which mentions all the
arguments in order as well as the function name. */
for (i = 0; i < num_actuals; i++)
note = gen_rtx_EXPR_LIST (VOIDmode,
args[i].initial_value, note);
note = gen_rtx_EXPR_LIST (VOIDmode, funexp, note);
insns = get_insns ();
end_sequence ();
if (flags & ECF_PURE)
note = gen_rtx_EXPR_LIST (VOIDmode,
gen_rtx_USE (VOIDmode,
gen_rtx_MEM (BLKmode,
gen_rtx_SCRATCH (VOIDmode))),
note);
emit_libcall_block (insns, temp, valreg, note);
valreg = temp;
}
}
else if (pass && (flags & ECF_MALLOC))
{
rtx temp = gen_reg_rtx (GET_MODE (valreg));
rtx last, insns;
/* The return value from a malloc-like function is a pointer. */
if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
emit_move_insn (temp, valreg);
/* The return value from a malloc-like function can not alias
anything else. */
last = get_last_insn ();
REG_NOTES (last) =
gen_rtx_EXPR_LIST (REG_NOALIAS, temp, REG_NOTES (last));
/* Write out the sequence. */
insns = get_insns ();
end_sequence ();
emit_insn (insns);
valreg = temp;
}
/* For calls to `setjmp', etc., inform flow.c it should complain
if nonvolatile values are live. For functions that cannot return,
inform flow that control does not fall through. */
if ((flags & (ECF_NORETURN | ECF_LONGJMP)) || pass == 0)
{
/* The barrier must be emitted
immediately after the CALL_INSN. Some ports emit more
than just a CALL_INSN above, so we must search for it here. */
rtx last = get_last_insn ();
while (GET_CODE (last) != CALL_INSN)
{
last = PREV_INSN (last);
/* There was no CALL_INSN? */
if (last == before_call)
abort ();
}
emit_barrier_after (last);
/* Stack adjustments after a noreturn call are dead code. */
stack_pointer_delta = old_stack_allocated;
pending_stack_adjust = 0;
}
if (flags & ECF_LONGJMP)
current_function_calls_longjmp = 1;
/* If this function is returning into a memory location marked as
readonly, it means it is initializing that location. But we normally
treat functions as not clobbering such locations, so we need to
specify that this one does. */
if (target != 0 && GET_CODE (target) == MEM
&& structure_value_addr != 0 && RTX_UNCHANGING_P (target))
emit_insn (gen_rtx_CLOBBER (VOIDmode, target));
/* 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))
{
if (target && REG_P (target)
&& REGNO (target) < FIRST_PSEUDO_REGISTER)
target = 0;
sibcall_failure = 1;
}
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));
set_mem_attributes (target, exp, 1);
}
}
else if (pcc_struct_value)
{
/* This is the special C++ case where we need to
know what the true target was. We take care to
never use this value more than once in one expression. */
target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
copy_to_reg (valreg));
set_mem_attributes (target, exp, 1);
}
/* Handle calls that return values in multiple non-contiguous locations.
The Irix 6 ABI has examples of this. */
else if (GET_CODE (valreg) == PARALLEL)
{
if (target == 0)
{
/* This will only be assigned once, so it can be readonly. */
tree nt = build_qualified_type (TREE_TYPE (exp),
(TYPE_QUALS (TREE_TYPE (exp))
| TYPE_QUAL_CONST));
target = assign_temp (nt, 0, 1, 1);
preserve_temp_slots (target);