forked from illumos/gcc
/
calls.c
4510 lines (3843 loc) · 145 KB
/
calls.c
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/* Convert function calls to rtl insns, for GNU C compiler.
Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "rtl.h"
#include "tree.h"
#include "flags.h"
#include "expr.h"
#include "optabs.h"
#include "libfuncs.h"
#include "function.h"
#include "regs.h"
#include "toplev.h"
#include "output.h"
#include "tm_p.h"
#include "timevar.h"
#include "sbitmap.h"
#include "langhooks.h"
#include "target.h"
#include "cgraph.h"
#include "except.h"
#include "dbgcnt.h"
/* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
#define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
/* Data structure and subroutines used within expand_call. */
struct arg_data
{
/* Tree node for this argument. */
tree tree_value;
/* Mode for value; TYPE_MODE unless promoted. */
enum machine_mode mode;
/* Current RTL value for argument, or 0 if it isn't precomputed. */
rtx value;
/* Initially-compute RTL value for argument; only for const functions. */
rtx initial_value;
/* Register to pass this argument in, 0 if passed on stack, or an
PARALLEL if the arg is to be copied into multiple non-contiguous
registers. */
rtx reg;
/* Register to pass this argument in when generating tail call sequence.
This is not the same register as for normal calls on machines with
register windows. */
rtx tail_call_reg;
/* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
form for emit_group_move. */
rtx parallel_value;
/* If REG was promoted from the actual mode of the argument expression,
indicates whether the promotion is sign- or zero-extended. */
int unsignedp;
/* Number of bytes to put in registers. 0 means put the whole arg
in registers. Also 0 if not passed in registers. */
int partial;
/* Nonzero if argument must be passed on stack.
Note that some arguments may be passed on the stack
even though pass_on_stack is zero, just because FUNCTION_ARG says so.
pass_on_stack identifies arguments that *cannot* go in registers. */
int pass_on_stack;
/* Some fields packaged up for locate_and_pad_parm. */
struct locate_and_pad_arg_data locate;
/* Location on the stack at which parameter should be stored. The store
has already been done if STACK == VALUE. */
rtx stack;
/* Location on the stack of the start of this argument slot. This can
differ from STACK if this arg pads downward. This location is known
to be aligned to FUNCTION_ARG_BOUNDARY. */
rtx stack_slot;
/* Place that this stack area has been saved, if needed. */
rtx save_area;
/* If an argument's alignment does not permit direct copying into registers,
copy in smaller-sized pieces into pseudos. These are stored in a
block pointed to by this field. The next field says how many
word-sized pseudos we made. */
rtx *aligned_regs;
int n_aligned_regs;
};
/* A vector of one char per byte of stack space. A byte if nonzero if
the corresponding stack location has been used.
This vector is used to prevent a function call within an argument from
clobbering any stack already set up. */
static char *stack_usage_map;
/* Size of STACK_USAGE_MAP. */
static int highest_outgoing_arg_in_use;
/* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
stack location's tail call argument has been already stored into the stack.
This bitmap is used to prevent sibling call optimization if function tries
to use parent's incoming argument slots when they have been already
overwritten with tail call arguments. */
static sbitmap stored_args_map;
/* stack_arg_under_construction is nonzero when an argument may be
initialized with a constructor call (including a C function that
returns a BLKmode struct) and expand_call must take special action
to make sure the object being constructed does not overlap the
argument list for the constructor call. */
static int stack_arg_under_construction;
static void emit_call_1 (rtx, tree, tree, tree, HOST_WIDE_INT, HOST_WIDE_INT,
HOST_WIDE_INT, rtx, rtx, int, rtx, int,
CUMULATIVE_ARGS *);
static void precompute_register_parameters (int, struct arg_data *, int *);
static int store_one_arg (struct arg_data *, rtx, int, int, int);
static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
static int finalize_must_preallocate (int, int, struct arg_data *,
struct args_size *);
static void precompute_arguments (int, int, struct arg_data *);
static int compute_argument_block_size (int, struct args_size *, int);
static void initialize_argument_information (int, struct arg_data *,
struct args_size *, int,
tree, tree,
tree, CUMULATIVE_ARGS *, int,
rtx *, int *, int *, int *,
bool *, bool);
static void compute_argument_addresses (struct arg_data *, rtx, int);
static rtx rtx_for_function_call (tree, tree);
static void load_register_parameters (struct arg_data *, int, rtx *, int,
int, int *);
static rtx emit_library_call_value_1 (int, rtx, rtx, enum libcall_type,
enum machine_mode, int, va_list);
static int special_function_p (const_tree, int);
static int check_sibcall_argument_overlap_1 (rtx);
static int check_sibcall_argument_overlap (rtx, struct arg_data *, int);
static int combine_pending_stack_adjustment_and_call (int, struct args_size *,
unsigned int);
static tree split_complex_types (tree);
#ifdef REG_PARM_STACK_SPACE
static rtx save_fixed_argument_area (int, rtx, int *, int *);
static void restore_fixed_argument_area (rtx, rtx, int, int);
#endif
/* Force FUNEXP into a form suitable for the address of a CALL,
and return that as an rtx. Also load the static chain register
if FNDECL is a nested function.
CALL_FUSAGE points to a variable holding the prospective
CALL_INSN_FUNCTION_USAGE information. */
rtx
prepare_call_address (rtx funexp, rtx static_chain_value,
rtx *call_fusage, int reg_parm_seen, int sibcallp)
{
/* Make a valid memory address and copy constants through pseudo-regs,
but not for a constant address if -fno-function-cse. */
if (GET_CODE (funexp) != SYMBOL_REF)
/* If we are using registers for parameters, force the
function address into a register now. */
funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen)
? force_not_mem (memory_address (FUNCTION_MODE, funexp))
: memory_address (FUNCTION_MODE, funexp));
else if (! sibcallp)
{
#ifndef NO_FUNCTION_CSE
if (optimize && ! flag_no_function_cse)
funexp = force_reg (Pmode, funexp);
#endif
}
if (static_chain_value != 0)
{
static_chain_value = convert_memory_address (Pmode, static_chain_value);
emit_move_insn (static_chain_rtx, static_chain_value);
if (REG_P (static_chain_rtx))
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 (rtx funexp, tree fntree, 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
gcc_unreachable ();
/* Find the call we just emitted. */
call_insn = last_call_insn ();
/* 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 there. */
add_function_usage_to (call_insn, call_fusage);
/* If this is a const call, then set the insn's unchanging bit. */
if (ecf_flags & (ECF_CONST | 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
{
int rn = lookup_stmt_eh_region (fntree);
/* If rn < 0, then either (1) tree-ssa not used or (2) doesn't
throw, which we already took care of. */
if (rn > 0)
REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_EH_REGION, GEN_INT (rn),
REG_NOTES (call_insn));
note_current_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_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;
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 | ECF_NORETURN))
/* Just pretend we did the pop. */
stack_pointer_delta -= rounded_stack_size;
else if (flag_defer_pop && inhibit_defer_pop == 0
&& ! (ecf_flags & (ECF_CONST | ECF_PURE)))
pending_stack_adjust += rounded_stack_size;
else
adjust_stack (rounded_stack_size_rtx);
}
}
/* When we accumulate outgoing args, we must avoid any stack manipulations.
Restore the stack pointer to its original value now. Usually
ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
popping variants of functions exist as well.
??? We may optimize similar to defer_pop above, but it is
probably not worthwhile.
??? It will be worthwhile to enable combine_stack_adjustments even for
such machines. */
else if (n_popped)
anti_adjust_stack (GEN_INT (n_popped));
}
/* Determine if the function identified by NAME and FNDECL is one with
special properties we wish to know about.
For example, if the function might return more than one time (setjmp), then
set RETURNS_TWICE to a nonzero value.
Similarly set NORETURN if the function is in the longjmp family.
Set MAY_BE_ALLOCA for any memory allocation function that might allocate
space from the stack such as alloca. */
static int
special_function_p (const_tree fndecl, int flags)
{
if (fndecl && DECL_NAME (fndecl)
&& IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
/* Exclude functions not at the file scope, or not `extern',
since they are not the magic functions we would otherwise
think they are.
FIXME: this should be handled with attributes, not with this
hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
because you can declare fork() inside a function if you
wish. */
&& (DECL_CONTEXT (fndecl) == NULL_TREE
|| TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
&& TREE_PUBLIC (fndecl))
{
const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
const char *tname = name;
/* We assume that alloca will always be called by name. It
makes no sense to pass it as a pointer-to-function to
anything that does not understand its behavior. */
if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
&& name[0] == 'a'
&& ! strcmp (name, "alloca"))
|| (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
&& name[0] == '_'
&& ! strcmp (name, "__builtin_alloca"))))
flags |= ECF_MAY_BE_ALLOCA;
/* Disregard prefix _, __ 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_NORETURN;
}
else if ((tname[0] == 'q' && tname[1] == 's'
&& ! strcmp (tname, "qsetjmp"))
|| (tname[0] == 'v' && tname[1] == 'f'
&& ! strcmp (tname, "vfork"))
|| (tname[0] == 'g' && tname[1] == 'e'
&& !strcmp (tname, "getcontext")))
flags |= ECF_RETURNS_TWICE;
else if (tname[0] == 'l' && tname[1] == 'o'
&& ! strcmp (tname, "longjmp"))
flags |= ECF_NORETURN;
}
return flags;
}
/* Return nonzero when FNDECL represents a call to setjmp. */
int
setjmp_call_p (const_tree fndecl)
{
return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
}
/* Return true when exp contains alloca call. */
bool
alloca_call_p (const_tree exp)
{
if (TREE_CODE (exp) == CALL_EXPR
&& TREE_CODE (CALL_EXPR_FN (exp)) == ADDR_EXPR
&& (TREE_CODE (TREE_OPERAND (CALL_EXPR_FN (exp), 0)) == FUNCTION_DECL)
&& (special_function_p (TREE_OPERAND (CALL_EXPR_FN (exp), 0), 0)
& ECF_MAY_BE_ALLOCA))
return true;
return false;
}
/* Detect flags (function attributes) from the function decl or type node. */
int
flags_from_decl_or_type (const_tree exp)
{
int flags = 0;
const_tree type = exp;
if (DECL_P (exp))
{
type = TREE_TYPE (exp);
/* The function exp may have the `malloc' attribute. */
if (DECL_IS_MALLOC (exp))
flags |= ECF_MALLOC;
/* The function exp may have the `returns_twice' attribute. */
if (DECL_IS_RETURNS_TWICE (exp))
flags |= ECF_RETURNS_TWICE;
/* The function exp may have the `pure' attribute. */
if (DECL_IS_PURE (exp))
flags |= ECF_PURE;
if (DECL_IS_NOVOPS (exp))
flags |= ECF_NOVOPS;
if (TREE_NOTHROW (exp))
flags |= ECF_NOTHROW;
if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
flags |= ECF_CONST;
flags = special_function_p (exp, flags);
}
else if (TYPE_P (exp) && TYPE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
flags |= ECF_CONST;
if (TREE_THIS_VOLATILE (exp))
flags |= ECF_NORETURN;
/* 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);
}
return flags;
}
/* Detect flags from a CALL_EXPR. */
int
call_expr_flags (const_tree t)
{
int flags;
tree decl = get_callee_fndecl (t);
if (decl)
flags = flags_from_decl_or_type (decl);
else
{
t = TREE_TYPE (CALL_EXPR_FN (t));
if (t && TREE_CODE (t) == POINTER_TYPE)
flags = flags_from_decl_or_type (TREE_TYPE (t));
else
flags = 0;
}
return flags;
}
/* Precompute all register parameters as described by ARGS, storing values
into fields within the ARGS array.
NUM_ACTUALS indicates the total number elements in the ARGS array.
Set REG_PARM_SEEN if we encounter a register parameter. */
static void
precompute_register_parameters (int num_actuals, struct arg_data *args,
int *reg_parm_seen)
{
int i;
*reg_parm_seen = 0;
for (i = 0; i < num_actuals; i++)
if (args[i].reg != 0 && ! args[i].pass_on_stack)
{
*reg_parm_seen = 1;
if (args[i].value == 0)
{
push_temp_slots ();
args[i].value = expand_normal (args[i].tree_value);
preserve_temp_slots (args[i].value);
pop_temp_slots ();
}
/* If the value is a non-legitimate constant, force it into a
pseudo now. TLS symbols sometimes need a call to resolve. */
if (CONSTANT_P (args[i].value)
&& !LEGITIMATE_CONSTANT_P (args[i].value))
args[i].value = force_reg (args[i].mode, args[i].value);
/* If we are to promote the function arg to a wider mode,
do it now. */
if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
args[i].value
= convert_modes (args[i].mode,
TYPE_MODE (TREE_TYPE (args[i].tree_value)),
args[i].value, args[i].unsignedp);
/* If we're going to have to load the value by parts, pull the
parts into pseudos. The part extraction process can involve
non-trivial computation. */
if (GET_CODE (args[i].reg) == PARALLEL)
{
tree type = TREE_TYPE (args[i].tree_value);
args[i].parallel_value
= emit_group_load_into_temps (args[i].reg, args[i].value,
type, int_size_in_bytes (type));
}
/* If the value is expensive, and we are inside an appropriately
short loop, put the value into a pseudo and then put the pseudo
into the hard reg.
For small register classes, also do this if this call uses
register parameters. This is to avoid reload conflicts while
loading the parameters registers. */
else if ((! (REG_P (args[i].value)
|| (GET_CODE (args[i].value) == SUBREG
&& REG_P (SUBREG_REG (args[i].value)))))
&& args[i].mode != BLKmode
&& rtx_cost (args[i].value, SET) > COSTS_N_INSNS (1)
&& ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
|| optimize))
args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
}
}
#ifdef REG_PARM_STACK_SPACE
/* The argument list is the property of the called routine and it
may clobber it. If the fixed area has been used for previous
parameters, we must save and restore it. */
static rtx
save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
{
int low;
int high;
/* Compute the boundary of the area that needs to be saved, if any. */
high = reg_parm_stack_space;
#ifdef ARGS_GROW_DOWNWARD
high += 1;
#endif
if (high > highest_outgoing_arg_in_use)
high = highest_outgoing_arg_in_use;
for (low = 0; low < high; low++)
if (stack_usage_map[low] != 0)
{
int num_to_save;
enum machine_mode save_mode;
int delta;
rtx stack_area;
rtx save_area;
while (stack_usage_map[--high] == 0)
;
*low_to_save = low;
*high_to_save = high;
num_to_save = high - low + 1;
save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
/* If we don't have the required alignment, must do this
in BLKmode. */
if ((low & (MIN (GET_MODE_SIZE (save_mode),
BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
save_mode = BLKmode;
#ifdef ARGS_GROW_DOWNWARD
delta = -high;
#else
delta = low;
#endif
stack_area = gen_rtx_MEM (save_mode,
memory_address (save_mode,
plus_constant (argblock,
delta)));
set_mem_align (stack_area, PARM_BOUNDARY);
if (save_mode == BLKmode)
{
save_area = assign_stack_temp (BLKmode, num_to_save, 0);
emit_block_move (validize_mem (save_area), stack_area,
GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
}
else
{
save_area = gen_reg_rtx (save_mode);
emit_move_insn (save_area, stack_area);
}
return save_area;
}
return NULL_RTX;
}
static void
restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
{
enum machine_mode save_mode = GET_MODE (save_area);
int delta;
rtx stack_area;
#ifdef ARGS_GROW_DOWNWARD
delta = -high_to_save;
#else
delta = low_to_save;
#endif
stack_area = gen_rtx_MEM (save_mode,
memory_address (save_mode,
plus_constant (argblock, delta)));
set_mem_align (stack_area, PARM_BOUNDARY);
if (save_mode != BLKmode)
emit_move_insn (stack_area, save_area);
else
emit_block_move (stack_area, validize_mem (save_area),
GEN_INT (high_to_save - low_to_save + 1),
BLOCK_OP_CALL_PARM);
}
#endif /* REG_PARM_STACK_SPACE */
/* If any elements in ARGS refer to parameters that are to be passed in
registers, but not in memory, and whose alignment does not permit a
direct copy into registers. Copy the values into a group of pseudos
which we will later copy into the appropriate hard registers.
Pseudos for each unaligned argument will be stored into the array
args[argnum].aligned_regs. The caller is responsible for deallocating
the aligned_regs array if it is nonzero. */
static void
store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
{
int i, j;
for (i = 0; i < num_actuals; i++)
if (args[i].reg != 0 && ! args[i].pass_on_stack
&& args[i].mode == BLKmode
&& (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 endian_correction = 0;
if (args[i].partial)
{
gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
}
else
{
args[i].n_aligned_regs
= (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
}
args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs);
/* Structures smaller than a word are normally aligned to the
least significant byte. On a BYTES_BIG_ENDIAN machine,
this means we must skip the empty high order bytes when
calculating the bit offset. */
if (bytes < UNITS_PER_WORD
#ifdef BLOCK_REG_PADDING
&& (BLOCK_REG_PADDING (args[i].mode,
TREE_TYPE (args[i].tree_value), 1)
== downward)
#else
&& BYTES_BIG_ENDIAN
#endif
)
endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
for (j = 0; j < args[i].n_aligned_regs; j++)
{
rtx reg = gen_reg_rtx (word_mode);
rtx word = operand_subword_force (args[i].value, j, BLKmode);
int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
args[i].aligned_regs[j] = reg;
word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
word_mode, word_mode);
/* There is no need to restrict this code to loading items
in TYPE_ALIGN sized hunks. The bitfield instructions can
load up entire word sized registers efficiently.
??? This may not be needed anymore.
We use to emit a clobber here but that doesn't let later
passes optimize the instructions we emit. By storing 0 into
the register later passes know the first AND to zero out the
bitfield being set in the register is unnecessary. The store
of 0 will be deleted as will at least the first AND. */
emit_move_insn (reg, const0_rtx);
bytes -= bitsize / BITS_PER_UNIT;
store_bit_field (reg, bitsize, endian_correction, word_mode,
word);
}
}
}
/* Fill in ARGS_SIZE and ARGS array based on the parameters found in
CALL_EXPR EXP.
NUM_ACTUALS is the total number of parameters.
N_NAMED_ARGS is the total number of named arguments.
STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
value, or null.
FNDECL is the tree code for the target of this call (if known)
ARGS_SO_FAR holds state needed by the target to know where to place
the next argument.
REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
for arguments which are passed in registers.
OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
and may be modified by this routine.
OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
flags which may may be modified by this routine.
MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
that requires allocation of stack space.
CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
the thunked-to function. */
static void
initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
struct arg_data *args,
struct args_size *args_size,
int n_named_args ATTRIBUTE_UNUSED,
tree exp, tree struct_value_addr_value,
tree fndecl,
CUMULATIVE_ARGS *args_so_far,
int reg_parm_stack_space,
rtx *old_stack_level, int *old_pending_adj,
int *must_preallocate, int *ecf_flags,
bool *may_tailcall, bool call_from_thunk_p)
{
/* 1 if scanning parms front to back, -1 if scanning back to front. */
int inc;
/* Count arg position in order args appear. */
int argpos;
int i;
args_size->constant = 0;
args_size->var = 0;
/* In this loop, we consider args in the order they are written.
We fill up ARGS from the front or from the back if necessary
so that in any case the first arg to be pushed ends up at the front. */
if (PUSH_ARGS_REVERSED)
{
i = num_actuals - 1, inc = -1;
/* In this case, must reverse order of args
so that we compute and push the last arg first. */
}
else
{
i = 0, inc = 1;
}
/* First fill in the actual arguments in the ARGS array, splitting
complex arguments if necessary. */
{
int j = i;
call_expr_arg_iterator iter;
tree arg;
if (struct_value_addr_value)
{
args[j].tree_value = struct_value_addr_value;
j += inc;
}
FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
{
tree argtype = TREE_TYPE (arg);
if (targetm.calls.split_complex_arg
&& argtype
&& TREE_CODE (argtype) == COMPLEX_TYPE
&& targetm.calls.split_complex_arg (argtype))
{
tree subtype = TREE_TYPE (argtype);
args[j].tree_value = build1 (REALPART_EXPR, subtype, arg);
j += inc;
args[j].tree_value = build1 (IMAGPART_EXPR, subtype, arg);
}
else
args[j].tree_value = arg;
j += inc;
}
}
/* I counts args in order (to be) pushed; ARGPOS counts in order written. */
for (argpos = 0; argpos < num_actuals; i += inc, argpos++)
{
tree type = TREE_TYPE (args[i].tree_value);
int unsignedp;
enum machine_mode mode;
/* Replace erroneous argument with constant zero. */
if (type == error_mark_node || !COMPLETE_TYPE_P (type))
args[i].tree_value = integer_zero_node, type = integer_type_node;