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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/100758] __builtin_cpu_supports does not (always) detect "sse2"
Date: Thu, 09 Feb 2023 16:37:27 +0000 [thread overview]
Message-ID: <bug-100758-4-fB8ukSn9PH@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-100758-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100758
--- Comment #18 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to Erich Eckner from comment #17)
> With that, I get a segfault in cpuid():
>
> (gdb) run
> Starting program: /tmp/a.out
> [Thread debugging using libthread_db enabled]
> Using host libthread_db library "/lib/libthread_db.so.1".
>
> Program received signal SIGSEGV, Segmentation fault.
> 0x0000555555555191 in cpuid ()
> (gdb) bt
> #0 0x0000555555555191 in cpuid ()
> #1 0x00005555555551ef in main ()
> (gdb)
>
> ... same on x86_64 - maybe, there's a typo, somewhere?
Sorry, wrote it without actually trying to compile it, I've swapped the last 2
arguments of cpuid.
Use
static void cpuid( unsigned int ax, unsigned int cx, unsigned int *p )
{
unsigned int flags;
__asm __volatile
("movl %%ebx, %%esi\n\t"
"cpuid\n\t"
"xchgl %%ebx, %%esi"
: "=a" (p[0]), "=S" (p[1]),
"=c" (p[2]), "=d" (p[3])
: "0" (ax), "2" (cx));
}
int main() {
unsigned int regs[4];
for (int j=0; j<=18; j++) {
int k = j > 10 ? -__INT_MAX__ - 1 + (j - 11) : j;
cpuid( k, 0, regs );
__builtin_printf("%d %d ", k, 0);
for (int i=0; i<4; i++) {
__builtin_printf("%08x ", regs[i]);
}
__builtin_printf("\n");
cpuid( k, 1, regs );
__builtin_printf("%d %d ", k, 1);
for (int i=0; i<4; i++) {
__builtin_printf("%08x ", regs[i]);
}
__builtin_printf("\n");
}
return 0;
}
next prev parent reply other threads:[~2023-02-09 16:37 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-25 18:37 [Bug c/100758] New: " gcc at eckner dot net
2021-05-26 7:57 ` [Bug target/100758] " marxin at gcc dot gnu.org
2021-05-26 9:12 ` gcc at eckner dot net
2021-05-26 9:23 ` marxin at gcc dot gnu.org
2021-05-26 9:46 ` gcc at eckner dot net
2021-05-26 9:54 ` rguenth at gcc dot gnu.org
2021-05-26 10:09 ` marxin at gcc dot gnu.org
2021-05-26 10:13 ` gcc at eckner dot net
2021-06-01 13:26 ` marxin at gcc dot gnu.org
2023-01-27 20:48 ` iam at valdikss dot org.ru
2023-02-01 14:03 ` marxin at gcc dot gnu.org
2023-02-01 14:23 ` iam at valdikss dot org.ru
2023-02-01 14:32 ` marxin at gcc dot gnu.org
2023-02-09 10:50 ` cvs-commit at gcc dot gnu.org
2023-02-09 11:40 ` jakub at gcc dot gnu.org
2023-02-09 11:47 ` marxin at gcc dot gnu.org
2023-02-09 12:22 ` jakub at gcc dot gnu.org
2023-02-09 16:22 ` gcc at eckner dot net
2023-02-09 16:37 ` jakub at gcc dot gnu.org [this message]
2023-02-09 16:45 ` cvs-commit at gcc dot gnu.org
2023-02-09 20:37 ` gcc at eckner dot net
2023-02-09 21:35 ` iam at valdikss dot org.ru
2023-02-10 8:27 ` marxin at gcc dot gnu.org
2023-02-10 9:45 ` jakub at gcc dot gnu.org
2023-02-20 9:50 ` Mayshao-oc at zhaoxin dot com
2023-03-19 5:29 ` cvs-commit at gcc dot gnu.org
2023-05-02 20:14 ` cvs-commit at gcc dot gnu.org
2023-05-03 15:21 ` cvs-commit at gcc dot gnu.org
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