[PATCH 1/2] Add PRED_FORTRAN_LOOP_PREHEADER to DO loops with step bigger than +-1.

[marxin]

gcc/fortran/ChangeLog:

2016-07-01  Martin Liska  <mli...@suse.cz>

        * trans-stmt.c (gfc_trans_do): Add expect builtin for DO
        loops with step bigger than +-1.

gcc/testsuite/ChangeLog:

2016-07-01  Martin Liska  <mli...@suse.cz>

        * gfortran.dg/predict-1.f90: Ammend the test.
        * gfortran.dg/predict-2.f90: Likewise.
---
 gcc/fortran/trans-stmt.c                | 6 ++++--
 gcc/testsuite/gfortran.dg/predict-1.f90 | 9 +++++++--
 gcc/testsuite/gfortran.dg/predict-2.f90 | 6 +++---
 3 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/gcc/fortran/trans-stmt.c b/gcc/fortran/trans-stmt.c
index 84bf749..389fa5e 100644
--- a/gcc/fortran/trans-stmt.c
+++ b/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));
 
diff --git a/gcc/testsuite/gfortran.dg/predict-1.f90 
b/gcc/testsuite/gfortran.dg/predict-1.f90
index 81f0436..a3feea9 100644
--- a/gcc/testsuite/gfortran.dg/predict-1.f90
+++ b/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" } }
diff --git a/gcc/testsuite/gfortran.dg/predict-2.f90 
b/gcc/testsuite/gfortran.dg/predict-2.f90
index 4ae5c3a..11a9ec5 100644
--- a/gcc/testsuite/gfortran.dg/predict-2.f90
+++ b/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" } }
-- 
2.8.4