Undocumented parameters for __builtin_cpu_supports()?

[Martin Reinecke]

Compiling and running the following code on a CPU with BMI2 support
prints "BMI2 detected" as one would expect:

#include <stdio.h>

int main(void)
{
if (__builtin_cpu_supports("bmi2"))
printf("BMI2 detected\n");
return 0;
}

However, "bmi2" is not documented in the list of arguments at
https://gcc.gnu.org/onlinedocs/gcc-8.2.0/gcc/x86-Built-in-Functions.html#x86-Built-in-Functions

Is this list supposed to be complete? If yes, I can open a PR. If not,
is there any other way to obtain the full list of allowed parameters?

Cheers,
Martin

[Martin Liška]

Post by Martin Reinecke
Compiling and running the following code on a CPU with BMI2 support
#include <stdio.h>
int main(void)
{
if (__builtin_cpu_supports("bmi2"))
printf("BMI2 detected\n");
return 0;
}
However, "bmi2" is not documented in the list of arguments at
https://gcc.gnu.org/onlinedocs/gcc-8.2.0/gcc/x86-Built-in-Functions.html#x86-Built-in-Functions

Hi.

Thanks for reporting that. Yes, it's missing.

Post by Martin Reinecke
Is this list supposed to be complete? If yes, I can open a PR. If not,
is there any other way to obtain the full list of allowed parameters?

If I see correctly, not.

I filed a PR for it:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87903

for which I'll prepare a patch.

Martin

Post by Martin Reinecke
Cheers,
Martin