BMI2 intrinsics in gcc

[AlvaroBegue]

Hi,

I am trying to use the BMI2 instructions with gcc built-ins. According to the documentation I can find, there should be a function _pdep_u64 if I am compiling with -mbmi2, but whatever I try, the compiler complains that it doesn't know that function.

I have gcc version 5.3.0.

Any ideas?

Thanks!
Álvaro.

[jwes]

Hi,

I am trying to use the BMI2 instructions with gcc built-ins. According to the documentation I can find, there should be a function _pdep_u64 if I am compiling with -mbmi2, but whatever I try, the compiler complains that it doesn't know that function.

I have gcc version 5.3.0.

Any ideas?

Thanks!
Álvaro.

I am no gcc expert, but I can use _pdep_u64 . I compile on gcc 5.3 with
g++ -O3 -m64 -D _WIN32_WINNT=0x0600 -march=native -Wno-write-strings -Wno-narrowing

Did you #include <immintrin.h> ?

[AlvaroBegue]

Did you #include <immintrin.h> ?

That was it. Thanks!

But why is that header file not mentioned in the documentation?

These would have been good places to put it:
https://gcc.gnu.org/onlinedocs/gcc-4.9. ... tions.html
https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html

[ZirconiumX]

Because that header is an Intel-provided system header that would probably be in the glibc documentation. The intrinsics GCC uses on x86 are described here.