https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78102
Bug ID: 78102
Summary: [5/6/7 regression] GCC refuses to generate PCMPEQQ
instruction for SSE4.1
Product: gcc
Version: 7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: vegorov13 at mail dot ru
Target Milestone: ---
Test case: https://godbolt.org/g/kmycx1
#include <x86intrin.h>
__m128i pcmpeqq(const __m128i x, const __m128i y) {
return _mm_cmpeq_epi64(x, y);
}
Compiled with -msse4.1. Expected result: PCMPEQQ instruction emitted. However I
get non-vectorised code:
movaps XMMWORD PTR [rbp-32], xmm0
mov rdx, QWORD PTR [rbp-16]
mov rax, QWORD PTR [rbp-32]
cmp rdx, rax
setne al
movzx eax, al
sub rax, 1
mov QWORD PTR [rbp-72], rax
movq xmm0, QWORD PTR [rbp-72]
mov rdx, QWORD PTR [rbp-8]
mov rax, QWORD PTR [rbp-24]
cmp rdx, rax
setne al
movzx eax, al
sub rax, 1
mov QWORD PTR [rbp-72], rax
pinsrq xmm0, QWORD PTR [rbp-72], 1
If I use -msse4.2 instead, everything works fine. PCMPEQQ is a SSE4.1
instruction though.
