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x86-64: Generate push2/pop2 only if the incoming stack is 16-byte aligned

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Since push2/pop2 requires 16-byte stack alignment, don't generate them
if the incoming stack isn't 16-byte aligned.

gcc/

	PR target/113912
	* config/i386/i386.cc (ix86_can_use_push2pop2): New.
	(ix86_pro_and_epilogue_can_use_push2pop2): Use it.
	(ix86_emit_save_regs): Don't generate push2 if
	ix86_can_use_push2pop2 return false.
	(ix86_expand_epilogue): Don't generate pop2 if
	ix86_can_use_push2pop2 return false.

gcc/testsuite/

	PR target/113912
	* gcc.target/i386/apx-push2pop2-2.c: New test.
This commit is contained in:
H.J. Lu 2024-02-13 13:32:44 -08:00 • committed by H.J. Lu
parent e63ae9085a
commit 853eb57759
2 changed files with 42 additions and 6 deletions
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24
gcc/config/i386/i386.cc
View file

@ -6802,16 +6802,24 @@ get_probe_interval (void)
#define SPLIT_STACK_AVAILABLE 256
/* Helper function to determine whether push2/pop2 can be used in prologue or
epilogue for register save/restore. */
/* Return true if push2/pop2 can be generated. */
static bool
ix86_pro_and_epilogue_can_use_push2pop2 (int nregs)
ix86_can_use_push2pop2 (void)
{
/* Use push2/pop2 only if the incoming stack is 16-byte aligned. */
unsigned int incoming_stack_boundary
= (crtl->parm_stack_boundary > ix86_incoming_stack_boundary
? crtl->parm_stack_boundary : ix86_incoming_stack_boundary);
if (incoming_stack_boundary % 128 != 0)
return incoming_stack_boundary % 128 == 0;
}
/* Helper function to determine whether push2/pop2 can be used in prologue or
epilogue for register save/restore. */
static bool
ix86_pro_and_epilogue_can_use_push2pop2 (int nregs)
{
if (!ix86_can_use_push2pop2 ())
return false;
int aligned = cfun->machine->fs.sp_offset % 16 == 0;
return TARGET_APX_PUSH2POP2
@ -7401,7 +7409,9 @@ ix86_emit_save_regs (void)
int regno;
rtx_insn *insn;
if (!TARGET_APX_PUSH2POP2 || cfun->machine->func_type != TYPE_NORMAL)
if (!TARGET_APX_PUSH2POP2
|| !ix86_can_use_push2pop2 ()
|| cfun->machine->func_type != TYPE_NORMAL)
{
for (regno = FIRST_PSEUDO_REGISTER - 1; regno >= 0; regno--)
if (GENERAL_REGNO_P (regno) && ix86_save_reg (regno, true, true))
@ -10039,7 +10049,9 @@ ix86_expand_epilogue (int style)
m->fs.cfa_reg == stack_pointer_rtx);
}
if (TARGET_APX_PUSH2POP2 && m->func_type == TYPE_NORMAL)
if (TARGET_APX_PUSH2POP2
&& ix86_can_use_push2pop2 ()
&& m->func_type == TYPE_NORMAL)
ix86_emit_restore_regs_using_pop2 ();
else
ix86_emit_restore_regs_using_pop (TARGET_APX_PPX);

24
gcc/testsuite/gcc.target/i386/apx-push2pop2-2.c Normal file
View file

@ -0,0 +1,24 @@
/* { dg-do compile { target { ! ia32 } } } */
/* { dg-options "-O2 -mpreferred-stack-boundary=3 -mapx-features=push2pop2 -fomit-frame-pointer" } */
extern int bar (int);
void foo ()
{
int a,b,c,d,e,f,i;
a = bar (5);
b = bar (a);
c = bar (b);
d = bar (c);
e = bar (d);
f = bar (e);
for (i = 1; i < 10; i++)
{
a += bar (a + i) + bar (b + i) +
bar (c + i) + bar (d + i) +
bar (e + i) + bar (f + i);
}
}
/* { dg-final { scan-assembler-not "push2(|p)\[\\t \]*%r" } } */
/* { dg-final { scan-assembler-not "pop2(|p)\[\\t \]*%r" } } */