https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50740
Mark Warner <warnerme at ptd dot net> changed:
What |Removed |Added
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CC| |warnerme at ptd dot net
--- Comment #4 from Mark Warner <warnerme at ptd dot net> ---
In the file cpuid.h, there is a problem with the definition:
#define __cpuid(level, a, b, c, d) \
__asm__ ("cpuid\n\t" \
: "=a" (a), "=b" (b), "=c" (c), "=d" (d) \
: "0" (level))
With the ecx undefined, the leaf 7 (Extended Features %eax == 7) can not be
accessed. Leaf 7 (%eax) can only be accessed when sub-leaf (%ecx) is 0
I suggest instead:
#define __cpuid(level, a, b, c, d) \
__asm__ ("cpuid\n\t" \
: "=a" (a), "=b" (b), "=c" (c), "=d" (d) \
: "0" (level), "2" (0))
