Add PRED_FORTRAN_LOOP_PREHEADER to DO loops with step

	* trans-stmt.c (gfc_trans_do): Add expect builtin for DO
	loops with step bigger than +-1.
	* gfortran.dg/predict-1.f90: Ammend the test.
	* gfortran.dg/predict-2.f90: Likewise.

From-SVN: r238112

gcc/fortran/ChangeLog

+2016-07-07  Martin Liska  <mliska@suse.cz>
+
+	* trans-stmt.c (gfc_trans_do): Add expect builtin for DO
+	loops with step bigger than +-1.
+
 2016-07-05  Alessandro Fanfarillo  <fanfarillo.gcc@gmail.com>
 
 	* array.c (gfc_match_array_ref): Add parsing support for

gcc/fortran/trans-stmt.c

@@ -2109,7 +2109,8 @@ gfc_trans_do (gfc_code * code, tree exit_cond)
       pos = build2 (COMPOUND_EXPR, void_type_node,
 		    fold_build2 (MODIFY_EXPR, void_type_node,
 				 countm1, tmp2),
-		    build3_loc (loc, COND_EXPR, void_type_node, tmp,
+		    build3_loc (loc, COND_EXPR, void_type_node,
+				gfc_unlikely (tmp, PRED_FORTRAN_LOOP_PREHEADER),
 				build1_loc (loc, GOTO_EXPR, void_type_node,
 					    exit_label), NULL_TREE));
 
@@ -2123,7 +2124,8 @@ gfc_trans_do (gfc_code * code, tree exit_cond)
       neg = build2 (COMPOUND_EXPR, void_type_node,
 		    fold_build2 (MODIFY_EXPR, void_type_node,
 				 countm1, tmp2),
-		    build3_loc (loc, COND_EXPR, void_type_node, tmp,
+		    build3_loc (loc, COND_EXPR, void_type_node,
+				gfc_unlikely (tmp, PRED_FORTRAN_LOOP_PREHEADER),
 				build1_loc (loc, GOTO_EXPR, void_type_node,
 					    exit_label), NULL_TREE));
 

gcc/testsuite/ChangeLog

+2016-07-07  Martin Liska  <mliska@suse.cz>
+
+	* gfortran.dg/predict-1.f90: Ammend the test.
+	* gfortran.dg/predict-2.f90: Likewise.
+
 2016-07-07  Ilya Enkovich  <ilya.enkovich@intel.com>
 
 	PR ipa/71624

gcc/testsuite/gfortran.dg/predict-1.f90

@@ -4,9 +4,14 @@
 subroutine test(block, array)
 integer :: i, block(9), array(2)
 
-do i = array(1), array(2)
+do i = array(1), array(2), 2
     block(i) = i
 end do
+
+do i = array(1), array(2), -2
+    block(i) = block(i) + i
+end do
+
 end subroutine test
 
-! { dg-final { scan-tree-dump-times "Fortran loop preheader heuristics of edge\[^:\]*: 99.0%" 1 "profile_estimate" } }
+! { dg-final { scan-tree-dump-times "Fortran loop preheader heuristics of edge\[^:\]*: 1.0%" 2 "profile_estimate" } }

gcc/testsuite/gfortran.dg/predict-2.f90

@@ -4,12 +4,12 @@
 subroutine test(block, array)
 integer :: i,j, block(9), array(2)
 
-do i = array(1), array(2)
-    do j = array(1), array(2)
+do i = array(1), array(2), 2
+    do j = array(1), array(2), 3
        block(i) = j
     end do
 end do
 end subroutine test
 
 ! { dg-final { scan-tree-dump-times "Fortran loop preheader heuristics of edge" 2 "profile_estimate" } }
-! { dg-final { scan-tree-dump-times "loop gueard" 0 "profile_estimate" } }
+! { dg-final { scan-tree-dump-times "loop guard" 0 "profile_estimate" } }