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x86CPUID(uint32_t eax, uint32_t ecx)
{
struct X86Regs regs;
# if defined(OF_AMD64) && defined(__GNUC__)
__asm__ (
"cpuid"
: "=a"(regs.eax), "=b"(regs.ebx), "=c"(regs.ecx), "=d"(regs.edx)
: "a"(eax), "c"(ecx)
);
# elif defined(OF_X86) && defined(__GNUC__)
/*
* This workaround is required by older GCC versions when using -fPIC,
* as ebx is a special register in PIC code. Yes, GCC is indeed not
* able to just push a register onto the stack before the __asm__ block
* and to pop it afterwards.
*/
__asm__ (
"xchgl %%ebx, %%edi\n\t"
"cpuid\n\t"
"xchgl %%edi, %%ebx"
: "=a"(regs.eax), "=D"(regs.ebx), "=c"(regs.ecx), "=d"(regs.edx)
: "a"(eax), "c"(ecx)
);
# else
memset(®s, 0, sizeof(regs));
# endif
return regs;
}
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x86CPUID(uint32_t eax, uint32_t ecx)
{
struct X86Regs regs;
# if defined(OF_AMD64) && defined(__GNUC__)
__asm__ (
"cpuid"
: "=a" (regs.eax),
"=b" (regs.ebx),
"=c" (regs.ecx),
"=d" (regs.edx)
: "a" (eax),
"c" (ecx)
);
# elif defined(OF_X86) && defined(__GNUC__)
/*
* This workaround is required by older GCC versions when using -fPIC,
* as ebx is a special register in PIC code. Yes, GCC is indeed not
* able to just push a register onto the stack before the __asm__ block
* and to pop it afterwards.
*/
__asm__ (
"xchgl %%ebx, %%edi\n\t"
"cpuid\n\t"
"xchgl %%edi, %%ebx"
: "=a" (regs.eax),
"=D" (regs.ebx),
"=c" (regs.ecx),
"=d" (regs.edx)
: "a" (eax),
"c" (ecx)
);
# else
memset(®s, 0, sizeof(regs));
# endif
return regs;
}
|