[Bug target/96174] New: AVX-512 functions missing when compiled without optimization

[evan@coeus-group.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96174

            Bug ID: 96174
           Summary: AVX-512 functions missing when compiled without
                    optimization
           Product: gcc
           Version: 10.1.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: evan@coeus-group.com
  Target Milestone: ---

The avx512fintrin.h header sometimes uses different implementations depending
on whether __OPTIMIZE__ is defined, but many functions are missing if
__OPTIMIZE__ is not defined.

Here is a trivial test case:

  #include <immintrin.h>

  __mmask16 foo(__m512 a, __m512 b) {
    return _mm512_cmplt_ps_mask(a, b);
  }

On Compiler Explorer: https://godbolt.org/z/83jP63

I ran into this with _mm512_cmplt_ps_mask, but it looks like this all the
_mm512_cmp*_{pd,ps}_mask functions have the same problem.