[Bug rtl-optimization/115021] New: [14/15 regression] unnecessary spill for vpternlog

[liuhongt at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115021

            Bug ID: 115021
           Summary: [14/15 regression] unnecessary spill for vpternlog
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: liuhongt at gcc dot gnu.org
  Target Milestone: ---

typedef signed char v16qi __attribute__ ((__vector_size__ (16)));
 v16qi foo (v16qi x) { return x >> 5; }

with -march=x86-64-v4 -O2,  GCC 13.2 generates

foo(signed char __vector(16)):
        mov     eax, 4
        vpsraw  xmm2, xmm0, 5
        vpbroadcastb    xmm1, eax
        mov     eax, 7
        vpbroadcastb    xmm3, eax
        vmovdqa xmm0, xmm1
        vpternlogd      xmm0, xmm2, xmm3, 120
        vpsubb  xmm0, xmm0, xmm1
        ret

GCC 14.1 generates

foo(signed char __vector(16)):
        mov     eax, 67372036
        vpsraw  xmm2, xmm0, 5
        vpbroadcastd    xmm1, eax
        mov     eax, 117901063
        vpbroadcastd    xmm3, eax
        vmovdqa xmm0, xmm1
        vmovdqa XMMWORD PTR [rsp-24], xmm3
        vpternlogd      xmm0, xmm2, XMMWORD PTR [rsp-24], 120
        vpsubb  xmm0, xmm0, xmm1
        ret

There's extra spill.