[committed] Fix task-reduction-8.c

Message ID 20181108194411.GV11625@tucnak
State New
Headers show
Series
  • [committed] Fix task-reduction-8.c
Related show

Commit Message

Jakub Jelinek Nov. 8, 2018, 7:44 p.m.
Hi!

I've noticed this test fails intermittently.
The problem is that it wasn't correct, without the in_reduction
clause this patch adds (or e.g. without #pragma omp atomic) there
is a data race, multiple tasks can update concurrently the same variable.

Tested on x86_64-linux, previously it would fail every 10-100 runs here,
now it doesn't fail in 10000 of them.

Committed to trunk.

2018-11-08  Jakub Jelinek  <jakub@redhat.com>

	* testsuite/libgomp.c-c++-common/task-reduction-8.c (bar): Add
	in_reduction clause for s[0].


	Jakub

Patch

--- libgomp/testsuite/libgomp.c-c++-common/task-reduction-8.c.jj	2018-11-08 18:08:04.178942068 +0100
+++ libgomp/testsuite/libgomp.c-c++-common/task-reduction-8.c	2018-11-08 20:31:32.824942285 +0100
@@ -45,7 +45,8 @@  unsigned long long int
 bar (int z, int *a, unsigned long long int *b, int *s)
 {
   unsigned long long int x = 1;
-  #pragma omp taskloop reduction (*:x) in_reduction (*:b[0])
+  #pragma omp taskloop reduction (*:x) in_reduction (*:b[0]) \
+		       in_reduction (+:s[0])
   for (int i = z; i < z + 8; i++)
     {
       #pragma omp task in_reduction (*:x)