Add transform_to_exit_first_loop_alt

2015-06-05  Tom de Vries  <tom@codesourcery.com>

	merge from gomp4 branch:
	2015-05-28  Tom de Vries  <tom@codesourcery.com>

	PR tree-optimization/65443
	* tree-parloops.c (replace_imm_uses, replace_uses_in_bb_by)
	(replace_uses_in_bbs_by, transform_to_exit_first_loop_alt)
	(try_transform_to_exit_first_loop_alt): New function.
	(transform_to_exit_first_loop): Use
	try_transform_to_exit_first_loop_alt.

	* gcc.dg/parloops-exit-first-loop-alt-2.c: New test.
	* gcc.dg/parloops-exit-first-loop-alt-3.c: New test.
	* gcc.dg/parloops-exit-first-loop-alt.c: New test.

	* testsuite/libgomp.c/parloops-exit-first-loop-alt-2.c: New test.
	* testsuite/libgomp.c/parloops-exit-first-loop-alt-3.c: New test.
	* testsuite/libgomp.c/parloops-exit-first-loop-alt.c: New test.

From-SVN: r224154

gcc/ChangeLog

+2015-06-05  Tom de Vries  <tom@codesourcery.com>
+
+	merge from gomp4 branch:
+	2015-05-28  Tom de Vries  <tom@codesourcery.com>
+
+	PR tree-optimization/65443
+	* tree-parloops.c (replace_imm_uses, replace_uses_in_bb_by)
+	(replace_uses_in_bbs_by, transform_to_exit_first_loop_alt)
+	(try_transform_to_exit_first_loop_alt): New function.
+	(transform_to_exit_first_loop): Use
+	try_transform_to_exit_first_loop_alt.
+
 2015-06-05  James Greenhalgh  <james.greenhalgh@arm.com>
 
 	* builtins.c (expand_builtin_atomic_compare_exchange): Call

gcc/testsuite/ChangeLog

+2015-06-05  Tom de Vries  <tom@codesourcery.com>
+
+	merge from gomp4 branch:
+	2015-05-28  Tom de Vries  <tom@codesourcery.com>
+
+	PR tree-optimization/65443
+	* gcc.dg/parloops-exit-first-loop-alt-2.c: New test.
+	* gcc.dg/parloops-exit-first-loop-alt-3.c: New test.
+	* gcc.dg/parloops-exit-first-loop-alt.c: New test.
+
 2015-06-05  Nathan Sidwell  <nathan@acm.org>
 
 	PR c++/52595

gcc/testsuite/gcc.dg/parloops-exit-first-loop-alt-2.c

+/* { dg-do compile } */
+/* { dg-require-effective-target pthread } */
+/* { dg-options "-O2 -ftree-parallelize-loops=2 -fdump-tree-parloops" } */
+
+#define N 1000
+
+unsigned int a[N];
+unsigned int b[N];
+unsigned int c[N];
+
+void __attribute__((noclone,noinline))
+f (unsigned int n)
+{
+  int i;
+
+    for (i = 0; i < N; ++i)
+      c[i] = a[i] + b[i];
+}
+
+/* Three times three array accesses:
+   - three in f._loopfn.0
+   - three in the parallel
+   - three in the low iteration count loop
+   Crucially, none for a peeled off last iteration following the parallel.  */
+/* { dg-final { scan-tree-dump-times "(?n)\\\[i" 9 "parloops" } } */

gcc/testsuite/gcc.dg/parloops-exit-first-loop-alt-3.c

+/* { dg-do compile } */
+/* { dg-require-effective-target pthread } */
+/* { dg-options "-O2 -ftree-parallelize-loops=2 -fdump-tree-parloops" } */
+
+unsigned int *a;
+
+unsigned int __attribute__((noclone,noinline))
+f (unsigned int n)
+{
+  int i;
+  unsigned int sum = 1;
+
+  for (i = 0; i < n; ++i)
+    sum += a[i];
+
+  return sum;
+}
+
+/* Three array accesses:
+   - one in f._loopfn.0
+   - one in the parallel
+   - one in the low iteration count loop
+   Crucially, none for a peeled off last iteration following the parallel.  */
+/* { dg-final { scan-tree-dump-times "(?n)\\\* 4" 3 "parloops" } } */

gcc/testsuite/gcc.dg/parloops-exit-first-loop-alt.c

+/* { dg-do compile } */
+/* { dg-require-effective-target pthread } */
+/* { dg-options "-O2 -ftree-parallelize-loops=2 -fdump-tree-parloops" } */
+
+#define N 1000
+
+unsigned int a[N];
+unsigned int b[N];
+unsigned int c[N];
+
+void __attribute__((noclone,noinline))
+f (unsigned int n)
+{
+  int i;
+
+  for (i = 0; i < n; ++i)
+    c[i] = a[i] + b[i];
+}
+
+/* Three times three array accesses:
+   - three in f._loopfn.0
+   - three in the parallel
+   - three in the low iteration count loop
+   Crucially, none for a peeled off last iteration following the parallel.  */
+/* { dg-final { scan-tree-dump-times "(?n)\\\[i" 9 "parloops" } } */

libgomp/ChangeLog

+2015-06-05  Tom de Vries  <tom@codesourcery.com>
+
+	merge from gomp4 branch:
+	2015-05-28  Tom de Vries  <tom@codesourcery.com>
+
+	PR tree-optimization/65443
+	* testsuite/libgomp.c/parloops-exit-first-loop-alt-2.c: New test.
+	* testsuite/libgomp.c/parloops-exit-first-loop-alt-3.c: New test.
+	* testsuite/libgomp.c/parloops-exit-first-loop-alt.c: New test.
+
 2015-05-29  Bernhard Reutner-Fischer  <aldot@gcc.gnu.org>
 
 	* testsuite/libgomp.graphite/bounds.c: Adjust for

libgomp/testsuite/libgomp.c/parloops-exit-first-loop-alt-2.c

+/* { dg-do run } */
+/* { dg-options "-O2 -ftree-parallelize-loops=2" } */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#define N 1000
+
+unsigned int a[N];
+unsigned int b[N];
+unsigned int c[N];
+
+void __attribute__((noclone,noinline))
+f (void)
+{
+  int i;
+
+  for (i = 0; i < N; ++i)
+    c[i] = a[i] + b[i];
+}
+
+int
+main (void)
+{
+  int i, j;
+
+  /* Complexify loop to inhibit parloops.  */
+  for (j = 0; j < 100; ++j)
+    for (i = 0; i < 10; i++)
+      {
+	int k = i + (10 * j);
+	a[k] = k;
+	b[k] = (k * 3) % 7;
+	c[k] = k * 2;
+      }
+
+  f ();
+
+  for (i = 0; i < N; i++)
+    {
+      unsigned int actual = c[i];
+      unsigned int expected = i + ((i * 3) % 7);
+      if (actual != expected)
+	abort ();
+    }
+
+  return 0;
+}

libgomp/testsuite/libgomp.c/parloops-exit-first-loop-alt-3.c

+/* { dg-do run } */
+/* { dg-options "-O2 -ftree-parallelize-loops=2" } */
+
+unsigned int *a;
+
+unsigned int __attribute__((noclone,noinline))
+f (unsigned int n)
+{
+  int i;
+  unsigned int sum = 1;
+
+  for (i = 0; i < n; ++i)
+    sum += a[i];
+
+  return sum;
+}
+
+int
+main (void)
+{
+  unsigned int res;
+  unsigned int array[4000];
+  int i;
+  for (i = 0; i < 4000; ++i)
+    array[i] = i % 7;
+  a = &array[0];
+  res = f (4000);
+  return !(res == 11995);
+}

libgomp/testsuite/libgomp.c/parloops-exit-first-loop-alt.c

+/* { dg-do run } */
+/* { dg-options "-O2 -ftree-parallelize-loops=2" } */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#define N 1000
+
+unsigned int a[N];
+unsigned int b[N];
+unsigned int c[N];
+
+void __attribute__((noclone,noinline))
+f (unsigned int n)
+{
+  int i;
+
+  for (i = 0; i < n; ++i)
+    c[i] = a[i] + b[i];
+}
+
+int
+main (void)
+{
+  int i, j;
+
+  /* Complexify loop to inhibit parloops.  */
+  for (j = 0; j < 100; ++j)
+    for (i = 0; i < 10; i++)
+      {
+	int k = i + (10 * j);
+	a[k] = k;
+	b[k] = (k * 3) % 7;
+	c[k] = k * 2;
+      }
+
+  f (N);
+
+  for (i = 0; i < N; i++)
+    {
+      unsigned int actual = c[i];
+      unsigned int expected = i + ((i * 3) % 7);
+      if (actual != expected)
+	abort ();
+    }
+
+  return 0;
+}