8b60459465
The attached testcase is miscompiled, because we optimize shared clauses to firstprivate when task body can't modify the variable even when the task has depend clause. That is wrong, because firstprivate means the variable will be copied immediately when the task is created, while with depend clause some other task might change it later before the dependencies are satisfied and the task should observe the value only after the change. 2020-12-18 Jakub Jelinek <jakub@redhat.com> * gimplify.c (struct gimplify_omp_ctx): Add has_depend member. (gimplify_scan_omp_clauses): Set it to true if OMP_CLAUSE_DEPEND appears on OMP_TASK. (gimplify_adjust_omp_clauses_1, gimplify_adjust_omp_clauses): Force GOVD_WRITTEN on shared variables if task construct has depend clause. * testsuite/libgomp.c/task-6.c: New test.
48 lines
704 B
C
48 lines
704 B
C
#include <stdlib.h>
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#include <unistd.h>
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int
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main ()
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{
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int x = 0, y = 0;
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#pragma omp parallel shared(x, y)
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#pragma omp master
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{
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#pragma omp task depend(out:y) shared(x, y)
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{
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sleep (1);
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x = 1;
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y = 1;
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}
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#pragma omp task depend(inout:y) shared(x, y)
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{
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if (x != 1 || y != 1)
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abort ();
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y++;
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}
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}
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if (x != 1 || y != 2)
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abort ();
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x = 0;
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y = 0;
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#pragma omp parallel
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#pragma omp master
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{
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#pragma omp task depend(out:y)
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{
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sleep (1);
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x = 1;
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y = 1;
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}
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#pragma omp task depend(inout:y)
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{
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if (x != 1 || y != 1)
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abort ();
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y++;
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}
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}
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if (x != 1 || y != 2)
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abort ();
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return 0;
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}
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