Only allow single exit phi for reduction in try_create_reduction_list
2016-01-07 Tom de Vries <tom@codesourcery.com>
PR tree-optimization/69039
* tree-parloops.c (try_create_reduction_list): Only allow single exit
phi for reduction.
* gcc.dg/autopar/pr69039.c: New test.
---
gcc/testsuite/gcc.dg/autopar/pr69039.c | 15 +++++++++++++++
gcc/tree-parloops.c | 8 ++++++++
2 files changed, 23 insertions(+)
new file mode 100644
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -ftree-parallelize-loops=2" } */
+
+unsigned int b;
+
+unsigned int
+fn1 (unsigned int d)
+{
+ int i;
+
+ for (i = 0; i < 1000; i++)
+ b |= d;
+
+ return b;
+}
@@ -2595,6 +2595,14 @@ try_create_reduction_list (loop_p loop,
" FAILED: it is not a part of reduction.\n");
return false;
}
+ if (red->keep_res != NULL)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,
+ " FAILED: reduction has multiple exit phis.\n");
+ return false;
+ }
+ red->keep_res = phi;
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "reduction phi is ");