https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70680
Bug ID: 70680
Summary: [5/6 Regression] OpenMP SIMD linear variable
privatized too eagerly
Product: gcc
Version: 5.1.0
Status: UNCONFIRMED
Keywords: openmp
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: amonakov at gcc dot gnu.org
Target Milestone: ---
#include <stdio.h>
int main()
{
int i=0;
#pragma omp task default(shared) if(0)
{
#pragma omp simd
for (i=0; i<100; i++)
;
#ifdef USE
asm("" : : "r"(i));
#endif
}
printf("%d\n", i);
}
Per my understanding of the OpenMP spec, this program should always print
'100'; indeed, that is observed with gcc-4.9, but gcc-5 does not share 'i' with
the task region, unless a dummy use is injected after the openmp-simd loop:
$ gcc-4.9 -O2 -fopenmp t.c && ./a.out
100
$ gcc-5.1 -O2 -fopenmp t.c && ./a.out
0
$ gcc-5.1 -DUSE -O2 -fopenmp t.c && ./a.out
100
