[Bug c++/118166] New: simple bit operations for __int128 do not use vector operations/registers

[gero.peterhoff at gmx dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118166

            Bug ID: 118166
           Summary: simple bit operations for __int128 do not use vector
                    operations/registers
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gero.peterhoff at gmx dot net
  Target Milestone: ---

Example
__int128   bit_blend(const __int128 if_false, const __int128 if_true, const
__int128 mask)
{
    return ((if_false ^ if_true) & mask) ^ if_false;
}

generated (-std=gnu++23 -msse2 (or better) -O3)
bit_blend(__int128, __int128, __int128):
        xchg    rdi, rsi
        mov     rax, rdx
        mov     rdx, rcx
        xor     rax, rsi
        xor     rdx, rdi
        and     rax, r8
        and     rdx, r9
        xor     rax, rsi
        xor     rdx, rdi
        ret