https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114560
Bug ID: 114560
Summary: Compilation error when using
_mm512_maskz_expandloadu_epi16 with only -mavx512vbmi2
Product: gcc
Version: 11.4.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: meirav.grimberg at redis dot com
Target Milestone: ---
Hello,
I'm using gcc 11.4. The problem also exits in gcc13.
The following code fails to compile:
#include <immintrin.h>
int main(void) {
unsigned short vec[16];
for (size_t i =0; i < 16; i++) {
vec[i] = 2;
}
__mmask32 mask = 0xAAAAAAAA;
__m512i bf16_to_fp32 = _mm512_maskz_expandloadu_epi16(mask, vec);
return 0;
}
```
g++ test.cpp -o test -mavx512vbmi2;
In file included from /usr/lib/gcc/x86_64-linux-gnu/11/include/immintrin.h:81,
from test.cpp:1:
/usr/lib/gcc/x86_64-linux-gnu/11/include/avx512vbmi2intrin.h: In function ‘int
main()’:
/usr/lib/gcc/x86_64-linux-gnu/11/include/avx512vbmi2intrin.h:451:1: error:
inlining failed in call to ‘always_inline’ ‘__m512i
_mm512_maskz_expandloadu_epi16(__mmask32, const void*)’: target specific option
mismatch
451 | _mm512_maskz_expandloadu_epi16 (__mmask32 __A, const void * __B)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
test.cpp:9:58: note: called from here
9 | __m512i bf16_to_fp32 = _mm512_maskz_expandloadu_epi16(mask, vec);
According to Intel® Intrinsics Guide, only avx512vbmi2 flag is required to use
_mm512_maskz_expandloadu_epi16.
However, when I add -mavx512bw flag to the compilation command, it works as
expected with no errors.
i notice that indeed, in avx512vbmi2intrin.h this function is located within
the section that requires both flags:
#if !defined(__AVX512VBMI2__) || !defined(__AVX512BW__)
#pragma GCC push_options
#pragma GCC target("avx512vbmi2,avx512bw")
#define __DISABLE_AVX512VBMI2BW__
#endif /* __AVX512VBMI2BW__ */
...
extern __inline __m512i
__attribute__((__gnu_inline__, __always_inline__, __artificial__))
_mm512_maskz_expand_epi16 (__mmask32 __A, __m512i __B)
{
return (__m512i) __builtin_ia32_expandhi512_maskz ((__v32hi) __B,
(__v32hi) _mm512_setzero_si512 (), (__mmask32) __A);
}
...
#ifdef __DISABLE_AVX512VBMI2BW__
#undef __DISABLE_AVX512VBMI2BW__
#pragma GCC pop_options
#endif /* __DISABLE_AVX512VBMI2BW__ */
In addition, i tried to compile this code with clang14 and intel c++ compiler,
using only the -mavx512vbmi2 flag, and both succeeded.
Thank you.
