[Bug target/95754] New: Failure to optimize __builtin_ia32_cmpb512_mask with anded first operand, 0 second operand and neq operation

[gabravier at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95754

            Bug ID: 95754
           Summary: Failure to optimize __builtin_ia32_cmpb512_mask with
                    anded first operand, 0 second operand and neq
                    operation
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gabravier at gmail dot com
  Target Milestone: ---

typedef char v64i8 __attribute__((vector_size(64)));

int64_t f(v64i8 a, v64i8 b)
{
    return __builtin_ia32_cmpb512_mask((a & b), (v64i8){0}, 4, -1);
}

This can be optimized to _mm512_test_epi8_mask(a, b). This transformation is
done by LLVM, but not by GCC.