On Wed, Feb 14, 2024 at 5:33 AM H.J. Lu <hjl.to...@gmail.com> wrote:
>
> Since push2/pop2 requires 16-byte stack alignment, don't generate them
> if the incoming stack isn't 16-byte aligned.
Ok.
>
> 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.
> ---
> gcc/config/i386/i386.cc | 24 ++++++++++++++-----
> .../gcc.target/i386/apx-push2pop2-2.c | 24 +++++++++++++++++++
> 2 files changed, 42 insertions(+), 6 deletions(-)
> create mode 100644 gcc/testsuite/gcc.target/i386/apx-push2pop2-2.c
>
> diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
> index a4e12602f70..46f238651a6 100644
> --- a/gcc/config/i386/i386.cc
> +++ b/gcc/config/i386/i386.cc
> @@ -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);
> diff --git a/gcc/testsuite/gcc.target/i386/apx-push2pop2-2.c
> b/gcc/testsuite/gcc.target/i386/apx-push2pop2-2.c
> new file mode 100644
> index 00000000000..975a6212b30
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/apx-push2pop2-2.c
> @@ -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" } } */
> --
> 2.43.0
>
--
BR,
Hongtao
