diff mbox series

x86: Fix shift-gf2p8affine-2.c failure on non-AVX512 CPU

Message ID CAMe9rOqgRLjt6imZzvEGoWLTyGJy2FyediBr96C9ZxAon6PC2w@mail.gmail.com
State New
Headers
Series x86: Fix shift-gf2p8affine-2.c failure on non-AVX512 CPU |

Commit Message

H.J. Lu May 4, 2026, 10:05 p.m. UTC 
  Enabling AVX512 via command line may cause the compiler to generate
AVX512 instructions even before the runtime CPU feature check, causing
the test to SIGILL if the CPU lacks AVX512.  Extract tests to do_test
and change main to call only if __builtin_cpu_supports ("gfni") returns
true to avoid any AVX512 instructions in main:

main:
        movq    __cpu_features2@GOTPCREL(%rip), %rax
        testb   $1, (%rax)
        jne     .L1577
        xorl    %eax, %eax
        ret
.L1577:
        pushq   %rax
        call    do_test
        xorl    %eax, %eax
        popq    %rdx
        ret

* gcc.target/i386/shift-gf2p8affine-2.c (do_test): New function.
Extracted from main.
(main): Drop __builtin_cpu_init.  Call do_test only if
__builtin_cpu_supports ("gfni") returns true.

Comments

Hongtao Liu May 5, 2026, 12:50 a.m. UTC | #1 
On Tue, May 5, 2026 at 6:06 AM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> Enabling AVX512 via command line may cause the compiler to generate
> AVX512 instructions even before the runtime CPU feature check, causing
> the test to SIGILL if the CPU lacks AVX512.  Extract tests to do_test
> and change main to call only if __builtin_cpu_supports ("gfni") returns
> true to avoid any AVX512 instructions in main:

Ok.
>
> main:
>         movq    __cpu_features2@GOTPCREL(%rip), %rax
>         testb   $1, (%rax)
>         jne     .L1577
>         xorl    %eax, %eax
>         ret
> .L1577:
>         pushq   %rax
>         call    do_test
>         xorl    %eax, %eax
>         popq    %rdx
>         ret
>
> * gcc.target/i386/shift-gf2p8affine-2.c (do_test): New function.
> Extracted from main.
> (main): Drop __builtin_cpu_init.  Call do_test only if
> __builtin_cpu_supports ("gfni") returns true.
>
>
> --
> H.J.
diff mbox series

Patch

From b277262e2d735bb70b4a7dd6dc0293ed9275887c Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Sun, 3 May 2026 04:39:19 +0800
Subject: [PATCH] x86: Fix shift-gf2p8affine-2.c failure on non-AVX512 CPU

Enabling AVX512 via command line may cause the compiler to generate
AVX512 instructions even before the runtime CPU feature check, causing
the test to SIGILL if the CPU lacks AVX512.  Extract tests to do_test
and change main to call only if __builtin_cpu_supports ("gfni") returns
true to avoid any AVX512 instructions in main:

main:
        movq    __cpu_features2@GOTPCREL(%rip), %rax
        testb   $1, (%rax)
        jne     .L1577
        xorl    %eax, %eax
        ret
.L1577:
        pushq   %rax
        call    do_test
        xorl    %eax, %eax
        popq    %rdx
        ret

	* gcc.target/i386/shift-gf2p8affine-2.c (do_test): New function.
	Extracted from main.
	(main): Drop __builtin_cpu_init.  Call do_test only if
	__builtin_cpu_supports ("gfni") returns true.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
---
 gcc/testsuite/gcc.target/i386/shift-gf2p8affine-2.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/gcc/testsuite/gcc.target/i386/shift-gf2p8affine-2.c b/gcc/testsuite/gcc.target/i386/shift-gf2p8affine-2.c
index ef088ab0b95..5b88ae098d7 100644
--- a/gcc/testsuite/gcc.target/i386/shift-gf2p8affine-2.c
+++ b/gcc/testsuite/gcc.target/i386/shift-gf2p8affine-2.c
@@ -151,12 +151,10 @@  FUNC (N5)
   func##N##ref (array2, len);				\
   if (memcmp (array, array2, len)) __builtin_abort ()
 
-int main ()
+__attribute__ ((noipa))
+void
+do_test (void)
 {
-  __builtin_cpu_init ();
-  if (!__builtin_cpu_supports ("gfni"))
-    return 0;
-
   const unsigned long len = 256;
   char array[len], array2[len];
   unsigned char filler = FILLER;
@@ -195,6 +193,11 @@  int main ()
   TEST (N5, sbyteshiftr);
   TEST (N5, ubyteror);
   TEST (N5, ubyterol);
+}
 
+int main ()
+{
+  if (__builtin_cpu_supports ("gfni"))
+    do_test ();
   return 0;
 }
-- 
2.54.0