Insert new bound in try_transform_to_exit_first_loop_alt

2015-07-10  Tom de Vries  <tom@codesourcery.com>

	* tree-parloops.c (try_transform_to_exit_first_loop_alt): If not found,
	insert nit + 1 bound.

	* testsuite/libgomp.fortran/parloops-exit-first-loop-alt-2.f95: New test.
	* testsuite/libgomp.fortran/parloops-exit-first-loop-alt.f95: New test.

	* gfortran.dg/parloops-exit-first-loop-alt-2.f95: New test.
	* gfortran.dg/parloops-exit-first-loop-alt.f95: New test.

From-SVN: r225655

5 files changed, 70 insertions, 1 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 20a1301..91bf101 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2015-07-10  Tom de Vries  <tom@codesourcery.com>
+
+	* tree-parloops.c (try_transform_to_exit_first_loop_alt): If not found,
+	insert nit + 1 bound.
+
 2015-07-10  Richard Biener  <rguenther@suse.de>
 
 	* tree-if-conv.c (if_convertible_gimple_assign_stmt_p):
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 30717ce..59e446c 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2015-07-10  Tom de Vries  <tom@codesourcery.com>
+
+	* gfortran.dg/parloops-exit-first-loop-alt-2.f95: New test.
+	* gfortran.dg/parloops-exit-first-loop-alt.f95: New test.
+
 2015-07-10  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/66823
diff --git a/gcc/testsuite/gfortran.dg/parloops-exit-first-loop-alt-2.f95 b/gcc/testsuite/gfortran.dg/parloops-exit-first-loop-alt-2.f95
new file mode 100644
index 0000000..f26a6e3
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/parloops-exit-first-loop-alt-2.f95
@@ -0,0 +1,24 @@
+! { dg-additional-options "-O2" }
+! { dg-require-effective-target pthread }
+! { dg-additional-options "-ftree-parallelize-loops=2" }
+! { dg-additional-options "-fdump-tree-parloops" }
+
+! Constant bound, vector addition.
+
+subroutine foo ()
+  integer, parameter :: n = 1000
+  integer, dimension (0:n-1) :: a, b, c
+  common a, b, c
+  integer :: ii
+
+  do ii = 0, n - 1
+     c(ii) = a(ii) + b(ii) + 25
+  end do
+end subroutine foo
+
+! Three times plus 25:
+! - once in f._loopfn.0
+! - once in the parallel
+! - once in the low iteration count loop
+! Crucially, none for a peeled off last iteration following the parallel.
+! { dg-final { scan-tree-dump-times "(?n) \\+ 25;" 3 "parloops" } }
diff --git a/gcc/testsuite/gfortran.dg/parloops-exit-first-loop-alt.f95 b/gcc/testsuite/gfortran.dg/parloops-exit-first-loop-alt.f95
new file mode 100644
index 0000000..6dc8a38
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/parloops-exit-first-loop-alt.f95
@@ -0,0 +1,25 @@
+! { dg-additional-options "-O2" }
+! { dg-require-effective-target pthread }
+! { dg-additional-options "-ftree-parallelize-loops=2" }
+! { dg-additional-options "-fdump-tree-parloops" }
+
+! Variable bound, vector addition.
+
+subroutine foo (nr)
+  integer, intent(in) :: nr
+  integer, parameter :: n = 1000
+  integer, dimension (0:n-1) :: a, b, c
+  common a, b, c
+  integer :: ii
+
+  do ii = 0, nr - 1
+     c(ii) = a(ii) + b(ii) + 25
+  end do
+end subroutine foo
+
+! Three times plus 25:
+! - once in f._loopfn.0
+! - once in the parallel
+! - once in the low iteration count loop
+! Crucially, none for a peeled off last iteration following the parallel.
+! { dg-final { scan-tree-dump-times "(?n) \\+ 25;" 3 "parloops" } }
diff --git a/gcc/tree-parloops.c b/gcc/tree-parloops.c
index 846077a..bda5d05 100644
--- a/gcc/tree-parloops.c
+++ b/gcc/tree-parloops.c
@@ -1828,8 +1828,18 @@ try_transform_to_exit_first_loop_alt (struct loop *loop,
 	alt_bound = op1;
     }
 
+  /* If not found, insert nit + 1.  */
   if (alt_bound == NULL_TREE)
-    return false;
+    {
+      alt_bound = fold_build2 (PLUS_EXPR, nit_type, nit,
+			       build_int_cst_type (nit_type, 1));
+
+      gimple_stmt_iterator gsi = gsi_last_bb (loop_preheader_edge (loop)->src);
+
+      alt_bound
+	= force_gimple_operand_gsi (&gsi, alt_bound, true, NULL_TREE, false,
+				    GSI_CONTINUE_LINKING);
+    }
 
   transform_to_exit_first_loop_alt (loop, reduction_list, alt_bound);
   return true;