diff options
author | Paolo Bonzini <pbonzini@redhat.com> | 2024-05-09 12:38:10 +0200 |
---|---|---|
committer | Paolo Bonzini <pbonzini@redhat.com> | 2024-05-10 15:45:14 +0200 |
commit | 41c685dc59bb611096f3bb6a663cfa82e4cba97b (patch) | |
tree | f011fcbed8e10538ea3d14f2d576e0c281ada6e7 /chardev/char-fe.c | |
parent | 9f07e47a5e96c88c1d2892fbdcbc8ff0437b7ac3 (diff) |
target/i386: fix operand size for DATA16 REX.W POPCNT
According to the manual, 32-bit vs 64-bit is governed by REX.W
and REX ignores the 0x66 prefix. This can be confirmed with this
program:
#include <stdio.h>
int main()
{
int x = 0x12340000;
int y;
asm("popcntl %1, %0" : "=r" (y) : "r" (x)); printf("%x\n", y);
asm("mov $-1, %0; .byte 0x66; popcntl %1, %0" : "+r" (y) : "r" (x)); printf("%x\n", y);
asm("mov $-1, %0; .byte 0x66; popcntq %q1, %q0" : "+r" (y) : "r" (x)); printf("%x\n", y);
}
which prints 5/ffff0000/5 on real hardware and 5/ffff0000/ffff0000
on QEMU.
Cc: qemu-stable@nongnu.org
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'chardev/char-fe.c')
0 files changed, 0 insertions, 0 deletions