Add empty loop exit block in transform_to_exit_first_loop_alt

2015-07-07  Tom de Vries  <tom@codesourcery.com>

	PR tree-optimization/66642
	* tree-parloops.c (transform_to_exit_first_loop_alt): Update function
	header comment.  Rename split_edge variable to edge_at_split.  Split
	exit edge to create new loop exit bb.  Insert loop exit phis in new loop
	exit bb.

	* testsuite/libgomp.c/parloops-exit-first-loop-alt-3.c (main): Test low
	iteration count case.
	* testsuite/libgomp.c/parloops-exit-first-loop-alt.c (init): New
	function, factor out of ...
	(main): ... here.  Test low iteration count case.

git-svn-id: https://gcc.gnu.org/svn/gcc/trunk@225521 138bc75d-0d04-0410-961f-82ee72b054a4

2 files changed, 31 insertions, 2 deletions

diff --git a/libgomp/testsuite/libgomp.c/parloops-exit-first-loop-alt-3.c b/libgomp/testsuite/libgomp.c/parloops-exit-first-loop-alt-3.c
index 7de1377cd56..958e554649c 100644
--- a/libgomp/testsuite/libgomp.c/parloops-exit-first-loop-alt-3.c
+++ b/libgomp/testsuite/libgomp.c/parloops-exit-first-loop-alt-3.c
@@ -36,5 +36,10 @@ main (void)
   if (res != 11995)
     abort ();
 
+  /* Test low iteration count case.  */
+  res = f (10);
+  if (res != 25)
+    abort ();
+
   return 0;
 }
diff --git a/libgomp/testsuite/libgomp.c/parloops-exit-first-loop-alt.c b/libgomp/testsuite/libgomp.c/parloops-exit-first-loop-alt.c
index d67a4f67ece..557764d3293 100644
--- a/libgomp/testsuite/libgomp.c/parloops-exit-first-loop-alt.c
+++ b/libgomp/testsuite/libgomp.c/parloops-exit-first-loop-alt.c
@@ -22,8 +22,8 @@ f (unsigned int n, unsigned int *__restrict__ a, unsigned int *__restrict__ b,
     c[i] = a[i] + b[i];
 }
 
-int
-main (void)
+static void __attribute__((noclone,noinline))
+init (void)
 {
   int i, j;
 
@@ -36,6 +36,14 @@ main (void)
 	b[k] = (k * 3) % 7;
 	c[k] = k * 2;
       }
+}
+
+int
+main (void)
+{
+  int i;
+
+  init ();
 
   f (N, a, b, c);
 
@@ -47,5 +55,21 @@ main (void)
 	abort ();
     }
 
+  /* Test low iteration count case.  */
+
+  init ();
+
+  f (10);
+
+  for (i = 0; i < N; i++)
+    {
+      unsigned int actual = c[i];
+      unsigned int expected = (i < 10
+			       ? i + ((i * 3) % 7)
+			       : i * 2);
+      if (actual != expected)
+	abort ();
+    }
+
   return 0;
 }