https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95144
Bug ID: 95144 Summary: Many AVX-512 functions take an int instead of unsigned int Product: gcc Version: 10.1.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: e...@coeus-group.com Target Milestone: --- There are a bunch of functions in AVX-512F which, according to Intel's documentation (https://software.intel.com/sites/landingpage/IntrinsicsGuide/), take an unsigned integer as an argument but GCC's header has the type as a signed integer. This causes problems with -Wsign-conversion. Here is an example which will generate a warning with -Wsign-conversion (or https://godbolt.org/z/kTBTAD if you prefer): #include <immintrin.h> static __m256i foo (__m256i a, unsigned int imm8) { return _mm256_srai_epi64(a, imm8); } __m256i bar(__m256i a) { return foo(a, 7); } AFAICT all the functions which take unsigned imm8 arguments have this problem in clang. Here is a quick list: * _mm256_mask_slli_epi16 * _mm256_mask_slli_epi32 * _mm256_mask_slli_epi64 * _mm256_mask_srai_epi16 * _mm256_mask_srai_epi32 * _mm256_mask_srai_epi64 * _mm256_mask_srli_epi32 * _mm256_mask_srli_epi64 * _mm256_maskz_slli_epi16 * _mm256_maskz_slli_epi32 * _mm256_maskz_slli_epi64 * _mm256_maskz_srai_epi16 * _mm256_maskz_srai_epi32 * _mm256_maskz_srai_epi64 * _mm256_maskz_srli_epi32 * _mm256_maskz_srli_epi64 * _mm256_srai_epi64 * _mm512_mask_slli_epi16 * _mm512_mask_slli_epi32 * _mm512_mask_slli_epi64 * _mm512_mask_srai_epi16 * _mm512_mask_srai_epi32 * _mm512_mask_srai_epi64 * _mm512_mask_srli_epi16 * _mm512_mask_srli_epi32 * _mm512_mask_srli_epi64 * _mm512_maskz_slli_epi16 * _mm512_maskz_slli_epi32 * _mm512_maskz_slli_epi64 * _mm512_maskz_srai_epi16 * _mm512_maskz_srai_epi32 * _mm512_maskz_srai_epi64 * _mm512_maskz_srli_epi32 * _mm512_maskz_srli_epi64 * _mm512_slli_epi16 * _mm512_slli_epi32 * _mm512_slli_epi64 * _mm512_srai_epi16 * _mm512_srai_epi32 * _mm512_srai_epi64 * _mm512_srli_epi16 * _mm512_srli_epi32 * _mm512_srli_epi64 * _mm_mask_slli_epi16 * _mm_mask_slli_epi32 * _mm_mask_slli_epi64 * _mm_mask_srai_epi16 * _mm_mask_srai_epi32 * _mm_mask_srai_epi64 * _mm_mask_srli_epi32 * _mm_mask_srli_epi64 * _mm_maskz_slli_epi16 * _mm_maskz_slli_epi32 * _mm_maskz_slli_epi64 * _mm_maskz_srai_epi16 * _mm_maskz_srai_epi32 * _mm_maskz_srai_epi64 * _mm_maskz_srli_epi32 * _mm_maskz_srli_epi64 It looks like clang has the same problem, though ICC and MSVC do not. Here is an almost identical bug report I filed against LLVM: https://bugs.llvm.org/show_bug.cgi?id=45931