Initial revision
From-SVN: r445
This commit is contained in:
parent
c27db21538
commit
18ca7dab53
843
gcc/explow.c
Normal file
843
gcc/explow.c
Normal file
@ -0,0 +1,843 @@
|
||||
/* Subroutines for manipulating rtx's in semantically interesting ways.
|
||||
Copyright (C) 1987, 1991 Free Software Foundation, Inc.
|
||||
|
||||
This file is part of GNU CC.
|
||||
|
||||
GNU CC is free software; you can redistribute it and/or modify
|
||||
it under the terms of the GNU General Public License as published by
|
||||
the Free Software Foundation; either version 2, or (at your option)
|
||||
any later version.
|
||||
|
||||
GNU CC is distributed in the hope that it will be useful,
|
||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
GNU General Public License for more details.
|
||||
|
||||
You should have received a copy of the GNU General Public License
|
||||
along with GNU CC; see the file COPYING. If not, write to
|
||||
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
|
||||
|
||||
|
||||
#include "config.h"
|
||||
#include "rtl.h"
|
||||
#include "tree.h"
|
||||
#include "flags.h"
|
||||
#include "expr.h"
|
||||
#include "hard-reg-set.h"
|
||||
#include "insn-config.h"
|
||||
#include "recog.h"
|
||||
#include "insn-flags.h"
|
||||
#include "insn-codes.h"
|
||||
|
||||
/* Return an rtx for the sum of X and the integer C. */
|
||||
|
||||
rtx
|
||||
plus_constant (x, c)
|
||||
register rtx x;
|
||||
register int c;
|
||||
{
|
||||
register RTX_CODE code;
|
||||
register enum machine_mode mode;
|
||||
register rtx tem;
|
||||
int all_constant = 0;
|
||||
|
||||
if (c == 0)
|
||||
return x;
|
||||
|
||||
restart:
|
||||
|
||||
code = GET_CODE (x);
|
||||
mode = GET_MODE (x);
|
||||
switch (code)
|
||||
{
|
||||
case CONST_INT:
|
||||
return gen_rtx (CONST_INT, VOIDmode, (INTVAL (x) + c));
|
||||
|
||||
case CONST_DOUBLE:
|
||||
{
|
||||
int l1 = CONST_DOUBLE_LOW (x);
|
||||
int h1 = CONST_DOUBLE_HIGH (x);
|
||||
int l2 = c;
|
||||
int h2 = c < 0 ? ~0 : 0;
|
||||
int lv, hv;
|
||||
|
||||
add_double (l1, h1, l2, h2, &lv, &hv);
|
||||
|
||||
return immed_double_const (lv, hv, VOIDmode);
|
||||
}
|
||||
|
||||
case MEM:
|
||||
/* If this is a reference to the constant pool, try replacing it with
|
||||
a reference to a new constant. If the resulting address isn't
|
||||
valid, don't return it because we have no way to validize it. */
|
||||
if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF
|
||||
&& CONSTANT_POOL_ADDRESS_P (XEXP (x, 0)))
|
||||
{
|
||||
tem
|
||||
= force_const_mem (GET_MODE (x),
|
||||
plus_constant (get_pool_constant (XEXP (x, 0)),
|
||||
c));
|
||||
if (memory_address_p (GET_MODE (tem), XEXP (tem, 0)))
|
||||
return tem;
|
||||
}
|
||||
break;
|
||||
|
||||
case CONST:
|
||||
/* If adding to something entirely constant, set a flag
|
||||
so that we can add a CONST around the result. */
|
||||
x = XEXP (x, 0);
|
||||
all_constant = 1;
|
||||
goto restart;
|
||||
|
||||
case SYMBOL_REF:
|
||||
case LABEL_REF:
|
||||
all_constant = 1;
|
||||
break;
|
||||
|
||||
case PLUS:
|
||||
/* The interesting case is adding the integer to a sum.
|
||||
Look for constant term in the sum and combine
|
||||
with C. For an integer constant term, we make a combined
|
||||
integer. For a constant term that is not an explicit integer,
|
||||
we cannot really combine, but group them together anyway. */
|
||||
if (GET_CODE (XEXP (x, 0)) == CONST_INT)
|
||||
{
|
||||
c += INTVAL (XEXP (x, 0));
|
||||
x = XEXP (x, 1);
|
||||
}
|
||||
else if (GET_CODE (XEXP (x, 1)) == CONST_INT)
|
||||
{
|
||||
c += INTVAL (XEXP (x, 1));
|
||||
x = XEXP (x, 0);
|
||||
}
|
||||
else if (CONSTANT_P (XEXP (x, 0)))
|
||||
return gen_rtx (PLUS, mode,
|
||||
plus_constant (XEXP (x, 0), c),
|
||||
XEXP (x, 1));
|
||||
else if (CONSTANT_P (XEXP (x, 1)))
|
||||
return gen_rtx (PLUS, mode,
|
||||
XEXP (x, 0),
|
||||
plus_constant (XEXP (x, 1), c));
|
||||
}
|
||||
|
||||
if (c != 0)
|
||||
x = gen_rtx (PLUS, mode, x, gen_rtx (CONST_INT, VOIDmode, c));
|
||||
|
||||
if (GET_CODE (x) == SYMBOL_REF || GET_CODE (x) == LABEL_REF)
|
||||
return x;
|
||||
else if (all_constant)
|
||||
return gen_rtx (CONST, mode, x);
|
||||
else
|
||||
return x;
|
||||
}
|
||||
|
||||
/* This is the same a `plus_constant', except that it handles LO_SUM. */
|
||||
|
||||
rtx
|
||||
plus_constant_for_output (x, c)
|
||||
register rtx x;
|
||||
register int c;
|
||||
{
|
||||
register RTX_CODE code = GET_CODE (x);
|
||||
register enum machine_mode mode = GET_MODE (x);
|
||||
int all_constant = 0;
|
||||
|
||||
if (GET_CODE (x) == LO_SUM)
|
||||
return gen_rtx (LO_SUM, mode, XEXP (x, 0),
|
||||
plus_constant_for_output (XEXP (x, 1), c));
|
||||
|
||||
else
|
||||
return plus_constant (x, c);
|
||||
}
|
||||
|
||||
/* If X is a sum, return a new sum like X but lacking any constant terms.
|
||||
Add all the removed constant terms into *CONSTPTR.
|
||||
X itself is not altered. The result != X if and only if
|
||||
it is not isomorphic to X. */
|
||||
|
||||
rtx
|
||||
eliminate_constant_term (x, constptr)
|
||||
rtx x;
|
||||
rtx *constptr;
|
||||
{
|
||||
register rtx x0, x1;
|
||||
rtx tem;
|
||||
|
||||
if (GET_CODE (x) != PLUS)
|
||||
return x;
|
||||
|
||||
/* First handle constants appearing at this level explicitly. */
|
||||
if (GET_CODE (XEXP (x, 1)) == CONST_INT
|
||||
&& 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x), *constptr,
|
||||
XEXP (x, 1)))
|
||||
&& GET_CODE (tem) == CONST_INT)
|
||||
{
|
||||
*constptr = tem;
|
||||
return eliminate_constant_term (XEXP (x, 0), constptr);
|
||||
}
|
||||
|
||||
tem = const0_rtx;
|
||||
x0 = eliminate_constant_term (XEXP (x, 0), &tem);
|
||||
x1 = eliminate_constant_term (XEXP (x, 1), &tem);
|
||||
if ((x1 != XEXP (x, 1) || x0 != XEXP (x, 0))
|
||||
&& 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x),
|
||||
*constptr, tem))
|
||||
&& GET_CODE (tem) == CONST_INT)
|
||||
{
|
||||
*constptr = tem;
|
||||
return gen_rtx (PLUS, GET_MODE (x), x0, x1);
|
||||
}
|
||||
|
||||
return x;
|
||||
}
|
||||
|
||||
/* Returns the insn that next references REG after INSN, or 0
|
||||
if REG is clobbered before next referenced or we cannot find
|
||||
an insn that references REG in a straight-line piece of code. */
|
||||
|
||||
rtx
|
||||
find_next_ref (reg, insn)
|
||||
rtx reg;
|
||||
rtx insn;
|
||||
{
|
||||
rtx next;
|
||||
|
||||
for (insn = NEXT_INSN (insn); insn; insn = next)
|
||||
{
|
||||
next = NEXT_INSN (insn);
|
||||
if (GET_CODE (insn) == NOTE)
|
||||
continue;
|
||||
if (GET_CODE (insn) == CODE_LABEL
|
||||
|| GET_CODE (insn) == BARRIER)
|
||||
return 0;
|
||||
if (GET_CODE (insn) == INSN
|
||||
|| GET_CODE (insn) == JUMP_INSN
|
||||
|| GET_CODE (insn) == CALL_INSN)
|
||||
{
|
||||
if (reg_set_p (reg, insn))
|
||||
return 0;
|
||||
if (reg_mentioned_p (reg, PATTERN (insn)))
|
||||
return insn;
|
||||
if (GET_CODE (insn) == JUMP_INSN)
|
||||
{
|
||||
if (simplejump_p (insn))
|
||||
next = JUMP_LABEL (insn);
|
||||
else
|
||||
return 0;
|
||||
}
|
||||
if (GET_CODE (insn) == CALL_INSN
|
||||
&& REGNO (reg) < FIRST_PSEUDO_REGISTER
|
||||
&& call_used_regs[REGNO (reg)])
|
||||
return 0;
|
||||
}
|
||||
else
|
||||
abort ();
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* Return an rtx for the size in bytes of the value of EXP. */
|
||||
|
||||
rtx
|
||||
expr_size (exp)
|
||||
tree exp;
|
||||
{
|
||||
return expand_expr (size_in_bytes (TREE_TYPE (exp)),
|
||||
0, TYPE_MODE (sizetype), 0);
|
||||
}
|
||||
|
||||
/* Return a copy of X in which all memory references
|
||||
and all constants that involve symbol refs
|
||||
have been replaced with new temporary registers.
|
||||
Also emit code to load the memory locations and constants
|
||||
into those registers.
|
||||
|
||||
If X contains no such constants or memory references,
|
||||
X itself (not a copy) is returned.
|
||||
|
||||
If a constant is found in the address that is not a legitimate constant
|
||||
in an insn, it is left alone in the hope that it might be valid in the
|
||||
address.
|
||||
|
||||
X may contain no arithmetic except addition, subtraction and multiplication.
|
||||
Values returned by expand_expr with 1 for sum_ok fit this constraint. */
|
||||
|
||||
static rtx
|
||||
break_out_memory_refs (x)
|
||||
register rtx x;
|
||||
{
|
||||
if (GET_CODE (x) == MEM
|
||||
|| (CONSTANT_P (x) && LEGITIMATE_CONSTANT_P (x)
|
||||
&& GET_MODE (x) != VOIDmode))
|
||||
{
|
||||
register rtx temp = force_reg (GET_MODE (x), x);
|
||||
mark_reg_pointer (temp);
|
||||
x = temp;
|
||||
}
|
||||
else if (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS
|
||||
|| GET_CODE (x) == MULT)
|
||||
{
|
||||
register rtx op0 = break_out_memory_refs (XEXP (x, 0));
|
||||
register rtx op1 = break_out_memory_refs (XEXP (x, 1));
|
||||
if (op0 != XEXP (x, 0) || op1 != XEXP (x, 1))
|
||||
x = gen_rtx (GET_CODE (x), Pmode, op0, op1);
|
||||
}
|
||||
return x;
|
||||
}
|
||||
|
||||
/* Given a memory address or facsimile X, construct a new address,
|
||||
currently equivalent, that is stable: future stores won't change it.
|
||||
|
||||
X must be composed of constants, register and memory references
|
||||
combined with addition, subtraction and multiplication:
|
||||
in other words, just what you can get from expand_expr if sum_ok is 1.
|
||||
|
||||
Works by making copies of all regs and memory locations used
|
||||
by X and combining them the same way X does.
|
||||
You could also stabilize the reference to this address
|
||||
by copying the address to a register with copy_to_reg;
|
||||
but then you wouldn't get indexed addressing in the reference. */
|
||||
|
||||
rtx
|
||||
copy_all_regs (x)
|
||||
register rtx x;
|
||||
{
|
||||
if (GET_CODE (x) == REG)
|
||||
{
|
||||
if (REGNO (x) != FRAME_POINTER_REGNUM)
|
||||
x = copy_to_reg (x);
|
||||
}
|
||||
else if (GET_CODE (x) == MEM)
|
||||
x = copy_to_reg (x);
|
||||
else if (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS
|
||||
|| GET_CODE (x) == MULT)
|
||||
{
|
||||
register rtx op0 = copy_all_regs (XEXP (x, 0));
|
||||
register rtx op1 = copy_all_regs (XEXP (x, 1));
|
||||
if (op0 != XEXP (x, 0) || op1 != XEXP (x, 1))
|
||||
x = gen_rtx (GET_CODE (x), Pmode, op0, op1);
|
||||
}
|
||||
return x;
|
||||
}
|
||||
|
||||
/* Return something equivalent to X but valid as a memory address
|
||||
for something of mode MODE. When X is not itself valid, this
|
||||
works by copying X or subexpressions of it into registers. */
|
||||
|
||||
rtx
|
||||
memory_address (mode, x)
|
||||
enum machine_mode mode;
|
||||
register rtx x;
|
||||
{
|
||||
register rtx oldx;
|
||||
|
||||
/* By passing constant addresses thru registers
|
||||
we get a chance to cse them. */
|
||||
if (! cse_not_expected && CONSTANT_P (x) && LEGITIMATE_CONSTANT_P (x))
|
||||
return force_reg (Pmode, x);
|
||||
|
||||
/* Accept a QUEUED that refers to a REG
|
||||
even though that isn't a valid address.
|
||||
On attempting to put this in an insn we will call protect_from_queue
|
||||
which will turn it into a REG, which is valid. */
|
||||
if (GET_CODE (x) == QUEUED
|
||||
&& GET_CODE (QUEUED_VAR (x)) == REG)
|
||||
return x;
|
||||
|
||||
/* We get better cse by rejecting indirect addressing at this stage.
|
||||
Let the combiner create indirect addresses where appropriate.
|
||||
For now, generate the code so that the subexpressions useful to share
|
||||
are visible. But not if cse won't be done! */
|
||||
oldx = x;
|
||||
if (! cse_not_expected && GET_CODE (x) != REG)
|
||||
x = break_out_memory_refs (x);
|
||||
|
||||
/* At this point, any valid address is accepted. */
|
||||
GO_IF_LEGITIMATE_ADDRESS (mode, x, win);
|
||||
|
||||
/* If it was valid before but breaking out memory refs invalidated it,
|
||||
use it the old way. */
|
||||
if (memory_address_p (mode, oldx))
|
||||
goto win2;
|
||||
|
||||
/* Perform machine-dependent transformations on X
|
||||
in certain cases. This is not necessary since the code
|
||||
below can handle all possible cases, but machine-dependent
|
||||
transformations can make better code. */
|
||||
LEGITIMIZE_ADDRESS (x, oldx, mode, win);
|
||||
|
||||
/* PLUS and MULT can appear in special ways
|
||||
as the result of attempts to make an address usable for indexing.
|
||||
Usually they are dealt with by calling force_operand, below.
|
||||
But a sum containing constant terms is special
|
||||
if removing them makes the sum a valid address:
|
||||
then we generate that address in a register
|
||||
and index off of it. We do this because it often makes
|
||||
shorter code, and because the addresses thus generated
|
||||
in registers often become common subexpressions. */
|
||||
if (GET_CODE (x) == PLUS)
|
||||
{
|
||||
rtx constant_term = const0_rtx;
|
||||
rtx y = eliminate_constant_term (x, &constant_term);
|
||||
if (constant_term == const0_rtx
|
||||
|| ! memory_address_p (mode, y))
|
||||
return force_operand (x, 0);
|
||||
|
||||
y = gen_rtx (PLUS, GET_MODE (x), copy_to_reg (y), constant_term);
|
||||
if (! memory_address_p (mode, y))
|
||||
return force_operand (x, 0);
|
||||
return y;
|
||||
}
|
||||
if (GET_CODE (x) == MULT || GET_CODE (x) == MINUS)
|
||||
return force_operand (x, 0);
|
||||
|
||||
/* If we have a register that's an invalid address,
|
||||
it must be a hard reg of the wrong class. Copy it to a pseudo. */
|
||||
if (GET_CODE (x) == REG)
|
||||
return copy_to_reg (x);
|
||||
|
||||
/* Last resort: copy the value to a register, since
|
||||
the register is a valid address. */
|
||||
return force_reg (Pmode, x);
|
||||
|
||||
win2:
|
||||
x = oldx;
|
||||
win:
|
||||
if (flag_force_addr && ! cse_not_expected && GET_CODE (x) != REG
|
||||
/* Don't copy an addr via a reg if it is one of our stack slots. */
|
||||
&& ! (GET_CODE (x) == PLUS
|
||||
&& (XEXP (x, 0) == virtual_stack_vars_rtx
|
||||
|| XEXP (x, 0) == virtual_incoming_args_rtx)))
|
||||
{
|
||||
if (general_operand (x, Pmode))
|
||||
return force_reg (Pmode, x);
|
||||
else
|
||||
return force_operand (x, 0);
|
||||
}
|
||||
return x;
|
||||
}
|
||||
|
||||
/* Like `memory_address' but pretend `flag_force_addr' is 0. */
|
||||
|
||||
rtx
|
||||
memory_address_noforce (mode, x)
|
||||
enum machine_mode mode;
|
||||
rtx x;
|
||||
{
|
||||
int ambient_force_addr = flag_force_addr;
|
||||
rtx val;
|
||||
|
||||
flag_force_addr = 0;
|
||||
val = memory_address (mode, x);
|
||||
flag_force_addr = ambient_force_addr;
|
||||
return val;
|
||||
}
|
||||
|
||||
/* Convert a mem ref into one with a valid memory address.
|
||||
Pass through anything else unchanged. */
|
||||
|
||||
rtx
|
||||
validize_mem (ref)
|
||||
rtx ref;
|
||||
{
|
||||
if (GET_CODE (ref) != MEM)
|
||||
return ref;
|
||||
if (memory_address_p (GET_MODE (ref), XEXP (ref, 0)))
|
||||
return ref;
|
||||
/* Don't alter REF itself, since that is probably a stack slot. */
|
||||
return change_address (ref, GET_MODE (ref), XEXP (ref, 0));
|
||||
}
|
||||
|
||||
/* Return a modified copy of X with its memory address copied
|
||||
into a temporary register to protect it from side effects.
|
||||
If X is not a MEM, it is returned unchanged (and not copied).
|
||||
Perhaps even if it is a MEM, if there is no need to change it. */
|
||||
|
||||
rtx
|
||||
stabilize (x)
|
||||
rtx x;
|
||||
{
|
||||
register rtx addr;
|
||||
if (GET_CODE (x) != MEM)
|
||||
return x;
|
||||
addr = XEXP (x, 0);
|
||||
if (rtx_unstable_p (addr))
|
||||
{
|
||||
rtx temp = copy_all_regs (addr);
|
||||
rtx mem;
|
||||
if (GET_CODE (temp) != REG)
|
||||
temp = copy_to_reg (temp);
|
||||
mem = gen_rtx (MEM, GET_MODE (x), temp);
|
||||
|
||||
/* Mark returned memref with in_struct if it's in an array or
|
||||
structure. Copy const and volatile from original memref. */
|
||||
|
||||
MEM_IN_STRUCT_P (mem) = MEM_IN_STRUCT_P (x) || GET_CODE (addr) == PLUS;
|
||||
RTX_UNCHANGING_P (mem) = RTX_UNCHANGING_P (x);
|
||||
MEM_VOLATILE_P (mem) = MEM_VOLATILE_P (x);
|
||||
return mem;
|
||||
}
|
||||
return x;
|
||||
}
|
||||
|
||||
/* Copy the value or contents of X to a new temp reg and return that reg. */
|
||||
|
||||
rtx
|
||||
copy_to_reg (x)
|
||||
rtx x;
|
||||
{
|
||||
register rtx temp = gen_reg_rtx (GET_MODE (x));
|
||||
|
||||
/* If not an operand, must be an address with PLUS and MULT so
|
||||
do the computation. */
|
||||
if (! general_operand (x, VOIDmode))
|
||||
x = force_operand (x, temp);
|
||||
|
||||
if (x != temp)
|
||||
emit_move_insn (temp, x);
|
||||
|
||||
return temp;
|
||||
}
|
||||
|
||||
/* Like copy_to_reg but always give the new register mode Pmode
|
||||
in case X is a constant. */
|
||||
|
||||
rtx
|
||||
copy_addr_to_reg (x)
|
||||
rtx x;
|
||||
{
|
||||
return copy_to_mode_reg (Pmode, x);
|
||||
}
|
||||
|
||||
/* Like copy_to_reg but always give the new register mode MODE
|
||||
in case X is a constant. */
|
||||
|
||||
rtx
|
||||
copy_to_mode_reg (mode, x)
|
||||
enum machine_mode mode;
|
||||
rtx x;
|
||||
{
|
||||
register rtx temp = gen_reg_rtx (mode);
|
||||
|
||||
/* If not an operand, must be an address with PLUS and MULT so
|
||||
do the computation. */
|
||||
if (! general_operand (x, VOIDmode))
|
||||
x = force_operand (x, temp);
|
||||
|
||||
if (GET_MODE (x) != mode && GET_MODE (x) != VOIDmode)
|
||||
abort ();
|
||||
if (x != temp)
|
||||
emit_move_insn (temp, x);
|
||||
return temp;
|
||||
}
|
||||
|
||||
/* Load X into a register if it is not already one.
|
||||
Use mode MODE for the register.
|
||||
X should be valid for mode MODE, but it may be a constant which
|
||||
is valid for all integer modes; that's why caller must specify MODE.
|
||||
|
||||
The caller must not alter the value in the register we return,
|
||||
since we mark it as a "constant" register. */
|
||||
|
||||
rtx
|
||||
force_reg (mode, x)
|
||||
enum machine_mode mode;
|
||||
rtx x;
|
||||
{
|
||||
register rtx temp, insn;
|
||||
|
||||
if (GET_CODE (x) == REG)
|
||||
return x;
|
||||
temp = gen_reg_rtx (mode);
|
||||
insn = emit_move_insn (temp, x);
|
||||
/* Let optimizers know that TEMP's value never changes
|
||||
and that X can be substituted for it. */
|
||||
if (CONSTANT_P (x))
|
||||
{
|
||||
rtx note = find_reg_note (insn, REG_EQUAL, 0);
|
||||
|
||||
if (note)
|
||||
XEXP (note, 0) = x;
|
||||
else
|
||||
REG_NOTES (insn) = gen_rtx (EXPR_LIST, REG_EQUAL, x, REG_NOTES (insn));
|
||||
}
|
||||
return temp;
|
||||
}
|
||||
|
||||
/* If X is a memory ref, copy its contents to a new temp reg and return
|
||||
that reg. Otherwise, return X. */
|
||||
|
||||
rtx
|
||||
force_not_mem (x)
|
||||
rtx x;
|
||||
{
|
||||
register rtx temp;
|
||||
if (GET_CODE (x) != MEM || GET_MODE (x) == BLKmode)
|
||||
return x;
|
||||
temp = gen_reg_rtx (GET_MODE (x));
|
||||
emit_move_insn (temp, x);
|
||||
return temp;
|
||||
}
|
||||
|
||||
/* Copy X to TARGET (if it's nonzero and a reg)
|
||||
or to a new temp reg and return that reg.
|
||||
MODE is the mode to use for X in case it is a constant. */
|
||||
|
||||
rtx
|
||||
copy_to_suggested_reg (x, target, mode)
|
||||
rtx x, target;
|
||||
enum machine_mode mode;
|
||||
{
|
||||
register rtx temp;
|
||||
|
||||
if (target && GET_CODE (target) == REG)
|
||||
temp = target;
|
||||
else
|
||||
temp = gen_reg_rtx (mode);
|
||||
|
||||
emit_move_insn (temp, x);
|
||||
return temp;
|
||||
}
|
||||
|
||||
/* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
|
||||
This pops when ADJUST is positive. ADJUST need not be constant. */
|
||||
|
||||
void
|
||||
adjust_stack (adjust)
|
||||
rtx adjust;
|
||||
{
|
||||
rtx temp;
|
||||
adjust = protect_from_queue (adjust, 0);
|
||||
|
||||
if (adjust == const0_rtx)
|
||||
return;
|
||||
|
||||
temp = expand_binop (Pmode,
|
||||
#ifdef STACK_GROWS_DOWNWARD
|
||||
add_optab,
|
||||
#else
|
||||
sub_optab,
|
||||
#endif
|
||||
stack_pointer_rtx, adjust, stack_pointer_rtx, 0,
|
||||
OPTAB_LIB_WIDEN);
|
||||
|
||||
if (temp != stack_pointer_rtx)
|
||||
emit_move_insn (stack_pointer_rtx, temp);
|
||||
}
|
||||
|
||||
/* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
|
||||
This pushes when ADJUST is positive. ADJUST need not be constant. */
|
||||
|
||||
void
|
||||
anti_adjust_stack (adjust)
|
||||
rtx adjust;
|
||||
{
|
||||
rtx temp;
|
||||
adjust = protect_from_queue (adjust, 0);
|
||||
|
||||
if (adjust == const0_rtx)
|
||||
return;
|
||||
|
||||
temp = expand_binop (Pmode,
|
||||
#ifdef STACK_GROWS_DOWNWARD
|
||||
sub_optab,
|
||||
#else
|
||||
add_optab,
|
||||
#endif
|
||||
stack_pointer_rtx, adjust, stack_pointer_rtx, 0,
|
||||
OPTAB_LIB_WIDEN);
|
||||
|
||||
if (temp != stack_pointer_rtx)
|
||||
emit_move_insn (stack_pointer_rtx, temp);
|
||||
}
|
||||
|
||||
/* Round the size of a block to be pushed up to the boundary required
|
||||
by this machine. SIZE is the desired size, which need not be constant. */
|
||||
|
||||
rtx
|
||||
round_push (size)
|
||||
rtx size;
|
||||
{
|
||||
#ifdef STACK_BOUNDARY
|
||||
int align = STACK_BOUNDARY / BITS_PER_UNIT;
|
||||
if (align == 1)
|
||||
return size;
|
||||
if (GET_CODE (size) == CONST_INT)
|
||||
{
|
||||
int new = (INTVAL (size) + align - 1) / align * align;
|
||||
if (INTVAL (size) != new)
|
||||
size = gen_rtx (CONST_INT, VOIDmode, new);
|
||||
}
|
||||
else
|
||||
{
|
||||
size = expand_divmod (0, CEIL_DIV_EXPR, Pmode, size,
|
||||
gen_rtx (CONST_INT, VOIDmode, align),
|
||||
0, 1);
|
||||
size = expand_mult (Pmode, size,
|
||||
gen_rtx (CONST_INT, VOIDmode, align),
|
||||
0, 1);
|
||||
}
|
||||
#endif /* STACK_BOUNDARY */
|
||||
return size;
|
||||
}
|
||||
|
||||
/* Return an rtx representing the address of an area of memory dynamically
|
||||
pushed on the stack. This region of memory is always aligned to
|
||||
a multiple of BIGGEST_ALIGNMENT.
|
||||
|
||||
Any required stack pointer alignment is preserved.
|
||||
|
||||
SIZE is an rtx representing the size of the area.
|
||||
TARGET is a place in which the address can be placed. */
|
||||
|
||||
rtx
|
||||
allocate_dynamic_stack_space (size, target)
|
||||
rtx size;
|
||||
rtx target;
|
||||
{
|
||||
/* Ensure the size is in the proper mode. */
|
||||
if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode)
|
||||
size = convert_to_mode (Pmode, size, 1);
|
||||
|
||||
/* We will need to ensure that the address we return is aligned to
|
||||
BIGGEST_ALIGNMENT. If STACK_DYNAMIC_OFFSET is defined, we don't
|
||||
always know its final value at this point in the compilation (it
|
||||
might depend on the size of the outgoing parameter lists, for
|
||||
example), so we must align the value to be returned in that case.
|
||||
(Note that STACK_DYNAMIC_OFFSET will have a default non-zero value if
|
||||
STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
|
||||
We must also do an alignment operation on the returned value if
|
||||
the stack pointer alignment is less strict that BIGGEST_ALIGNMENT.
|
||||
|
||||
If we have to align, we must leave space in SIZE for the hole
|
||||
that might result from the alignment operation. */
|
||||
|
||||
#if defined (STACK_DYNAMIC_OFFSET) || defined(STACK_POINTER_OFFSET) || defined (ALLOCATE_OUTGOING_ARGS)
|
||||
#define MUST_ALIGN
|
||||
#endif
|
||||
|
||||
#if ! defined (MUST_ALIGN) && (!defined(STACK_BOUNDARY) || STACK_BOUNDARY < BIGGEST_ALIGNMENT)
|
||||
#define MUST_ALIGN
|
||||
#endif
|
||||
|
||||
#ifdef MUST_ALIGN
|
||||
|
||||
if (GET_CODE (size) == CONST_INT)
|
||||
size = gen_rtx (CONST_INT, VOIDmode,
|
||||
INTVAL (size) + (BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1));
|
||||
else
|
||||
size = expand_binop (Pmode, add_optab, size,
|
||||
gen_rtx (CONST_INT, VOIDmode,
|
||||
BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1),
|
||||
0, 1, OPTAB_LIB_WIDEN);
|
||||
#endif
|
||||
|
||||
#ifdef SETJMP_VIA_SAVE_AREA
|
||||
/* If setjmp restores regs from a save area in the stack frame,
|
||||
avoid clobbering the reg save area. Note that the offset of
|
||||
virtual_incoming_args_rtx includes the preallocated stack args space.
|
||||
It would be no problem to clobber that, but it's on the wrong side
|
||||
of the old save area. */
|
||||
{
|
||||
rtx dynamic_offset
|
||||
= expand_binop (Pmode, sub_optab, virtual_stack_dynamic_rtx,
|
||||
stack_pointer_rtx, 0, 1, OPTAB_LIB_WIDEN);
|
||||
size = expand_binop (Pmode, add_optab, size, dynamic_offset,
|
||||
0, 1, OPTAB_LIB_WIDEN);
|
||||
}
|
||||
#endif /* SETJMP_VIA_SAVE_AREA */
|
||||
|
||||
/* Round the size to a multiple of the required stack alignment.
|
||||
Since the stack if presumed to be rounded before this allocation,
|
||||
this will maintain the required alignment.
|
||||
|
||||
If the stack grows downward, we could save an insn by subtracting
|
||||
SIZE from the stack pointer and then aligning the stack pointer.
|
||||
The problem with this is that the stack pointer may be unaligned
|
||||
between the execution of the subtraction and alignment insns and
|
||||
some machines do not allow this. Even on those that do, some
|
||||
signal handlers malfunction if a signal should occur between those
|
||||
insns. Since this is an extremely rare event, we have no reliable
|
||||
way of knowing which systems have this problem. So we avoid even
|
||||
momentarily mis-aligning the stack. */
|
||||
|
||||
size = round_push (size);
|
||||
|
||||
do_pending_stack_adjust ();
|
||||
|
||||
if (target == 0)
|
||||
target = gen_reg_rtx (Pmode);
|
||||
|
||||
#ifndef STACK_GROWS_DOWNWARD
|
||||
emit_move_insn (target, virtual_stack_dynamic_rtx);
|
||||
#endif
|
||||
|
||||
/* Perform the required allocation from the stack. Some systems do
|
||||
this differently than simply incrementing/decrementing from the
|
||||
stack pointer. */
|
||||
#ifdef HAVE_allocate_stack
|
||||
if (HAVE_allocate_stack)
|
||||
{
|
||||
enum machine_mode mode
|
||||
= insn_operand_mode[(int) CODE_FOR_allocate_stack][0];
|
||||
|
||||
if (insn_operand_predicate[(int) CODE_FOR_allocate_stack][0]
|
||||
&& ! ((*insn_operand_predicate[(int) CODE_FOR_allocate_stack][0])
|
||||
(size, mode)))
|
||||
size = copy_to_mode_reg (mode, size);
|
||||
|
||||
emit_insn (gen_allocate_stack (size));
|
||||
}
|
||||
else
|
||||
#endif
|
||||
anti_adjust_stack (size);
|
||||
|
||||
#ifdef STACK_GROWS_DOWNWARD
|
||||
emit_move_insn (target, virtual_stack_dynamic_rtx);
|
||||
#endif
|
||||
|
||||
#ifdef MUST_ALIGN
|
||||
target = expand_divmod (0, CEIL_DIV_EXPR, Pmode, target,
|
||||
gen_rtx (CONST_INT, VOIDmode,
|
||||
BIGGEST_ALIGNMENT / BITS_PER_UNIT),
|
||||
0, 1);
|
||||
|
||||
target = expand_mult (Pmode, target,
|
||||
gen_rtx (CONST_INT, VOIDmode,
|
||||
BIGGEST_ALIGNMENT / BITS_PER_UNIT),
|
||||
0, 1);
|
||||
#endif
|
||||
|
||||
/* Some systems require a particular insn to refer to the stack
|
||||
to make the pages exist. */
|
||||
#ifdef HAVE_probe
|
||||
if (HAVE_probe)
|
||||
emit_insn (gen_probe ());
|
||||
#endif
|
||||
|
||||
return target;
|
||||
}
|
||||
|
||||
/* Return an rtx representing the register or memory location
|
||||
in which a scalar value of data type VALTYPE
|
||||
was returned by a function call to function FUNC.
|
||||
FUNC is a FUNCTION_DECL node if the precise function is known,
|
||||
otherwise 0. */
|
||||
|
||||
rtx
|
||||
hard_function_value (valtype, func)
|
||||
tree valtype;
|
||||
tree func;
|
||||
{
|
||||
return FUNCTION_VALUE (valtype, func);
|
||||
}
|
||||
|
||||
/* Return an rtx representing the register or memory location
|
||||
in which a scalar value of mode MODE was returned by a library call. */
|
||||
|
||||
rtx
|
||||
hard_libcall_value (mode)
|
||||
enum machine_mode mode;
|
||||
{
|
||||
return LIBCALL_VALUE (mode);
|
||||
}
|
Loading…
Reference in New Issue
Block a user