https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101262
Bug ID: 101262
Summary: GCC11 OpenMP optimization causes sigsegv on aligned
constant array in darktable
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: johnnybit at gmail dot com
Target Milestone: ---
A loop with constant length arrays with openmp and simd optimization crashes
with sigsegv when compilled with GCC11. Same code works with previous versions
and with various Clang versions
the code in question looks like
#define PIXEL_CHAN 8
static const float centers_ops[PIXEL_CHAN] DT_ALIGNED_ARRAY = {-56.0f / 7.0f,
// = -8.0f
-48.0f / 7.0f,
-40.0f / 7.0f,
-32.0f / 7.0f,
-24.0f / 7.0f,
-16.0f / 7.0f,
-8.0f / 7.0f,
0.0f / 7.0f};
#pragma omp simd aligned(centers_ops, factors:64) safelen(PIXEL_CHAN)
reduction(+:result)
for(int i = 0; i < PIXEL_CHAN; ++i)
result += gaussian_func(expo - centers_ops[i], gauss_denom) * factors[i];
centers_ops is static const float [PIXEL_CHAN]
factors is const float *const restric factors (which is PIXEL_CHAN length)
the crash is on
result += gaussian_func(expo - centers_ops[i], gauss_denom) * factors[i];
line.
The reports in darktable are
https://github.com/darktable-org/darktable/issues/9340
https://github.com/darktable-org/darktable/issues/9002
