https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98428
Bug ID: 98428
Summary: [11 regression] ICE with omp simd loop + optimization
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: e...@coeus-group.com
Target Milestone: ---
This is based on the gcc-11 currently in Debian experimental (gcc-11 (Debian
11-20201216-2) 11.0.0 20201216 (experimental) [master revision
4e42f6ebf48:da5e758223c:134afa38f0befc49f51747f3afe931fa4707c2f8]), but as
you'll see the build on Compiler Explorer also fails.
I'm getting an ICE when attempting to compile SIMDe on GCC 11 on x86_64 with
-O1. Here is a minimized test case (or, on Compiler Explorer if you prefer:
<https://godbolt.org/z/Kb7MWf>):
#include <emmintrin.h>
typedef struct {
float d[4];
} f;
typedef __m128 e;
f k;
float ak;
e j;
f fn1(e g) {
__builtin_memcpy(&k, &g, sizeof(k));
return k;
}
typedef struct {
float d[8];
} ag;
void l() {
ag ao;
f ap = fn1(j);
#pragma omp simd
for (size_t i = 0; i < sizeof(ao.d[0]); i += 2)
ao.d[i] = ao.d[i + 1] = ap.d[1];
ag g = ao;
__builtin_memcpy(&ak, &g, ak);
}
int main() {}
It generates an ICE with `-O1 -fopenmp-simd`. but removing either -O1 or
-fopenmp-simd makes compilation succeed. This only happens on gcc-11; gcc-10
works as expected.
The original code which I fed into C-Reduce is at
<https://github.com/simd-everywhere/simde/blob/76790a981bedab5dc1c8e393f8dccf0ea0e3917d/test/x86/avx512/broadcast.c#L772-L820>,
and the `simde_mm512_maskz_broadcast_f64x2` function it calls is at
<https://github.com/simd-everywhere/simde/blob/76790a981bedab5dc1c8e393f8dccf0ea0e3917d/simde/x86/avx512/broadcast.h#L255-L267>
