From 25505bab6714096eabdfc5cff0aae9c20f40141f Mon Sep 17 00:00:00 2001
From: canqun <canqun@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Sun, 14 Aug 2005 02:06:06 +0000
Subject: [PATCH] * trans-stmt.c (gfc_trans_arithmetic_if): Optimized in
case of equal labels.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@103074 138bc75d-0d04-0410-961f-82ee72b054a4
---
gcc/fortran/ChangeLog | 5 +++++
gcc/fortran/trans-stmt.c | 41 ++++++++++++++++++++++++++++++----------
2 files changed, 36 insertions(+), 10 deletions(-)
diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index d8b46198ea75..158123a2143e 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,8 @@
+2005-08-14 Canqun Yang <canqun@nudt.edu.cn>
+
+ * trans-stmt.c (gfc_trans_arithmetic_if): Optimized in case of equal
+ labels.
+
2005-09-11 Francois-Xavier Coudert <coudert@clipper.ens.fr>
Steven Bosscher <stevenb@suse.de>
diff --git a/gcc/fortran/trans-stmt.c b/gcc/fortran/trans-stmt.c
index 72407ae44254..040214ed27f4 100644
--- a/gcc/fortran/trans-stmt.c
+++ b/gcc/fortran/trans-stmt.c
@@ -461,6 +461,14 @@ gfc_trans_if (gfc_code * code)
}
else // cond > 0
goto label3;
+
+ An optimized version can be generated in case of equal labels.
+ E.g., if label1 is equal to label2, we can translate it to
+
+ if (cond <= 0)
+ goto label1;
+ else
+ goto label3;
*/
tree
@@ -482,18 +490,31 @@ gfc_trans_arithmetic_if (gfc_code * code)
/* Build something to compare with. */
zero = gfc_build_const (TREE_TYPE (se.expr), integer_zero_node);
- /* If (cond < 0) take branch1 else take branch2.
- First build jumps to the COND .LT. 0 and the COND .EQ. 0 cases. */
- branch1 = build1_v (GOTO_EXPR, gfc_get_label_decl (code->label));
- branch2 = build1_v (GOTO_EXPR, gfc_get_label_decl (code->label2));
+ if (code->label->value != code->label2->value)
+ {
+ /* If (cond < 0) take branch1 else take branch2.
+ First build jumps to the COND .LT. 0 and the COND .EQ. 0 cases. */
+ branch1 = build1_v (GOTO_EXPR, gfc_get_label_decl (code->label));
+ branch2 = build1_v (GOTO_EXPR, gfc_get_label_decl (code->label2));
- tmp = build2 (LT_EXPR, boolean_type_node, se.expr, zero);
- branch1 = build3_v (COND_EXPR, tmp, branch1, branch2);
+ if (code->label->value != code->label3->value)
+ tmp = build2 (LT_EXPR, boolean_type_node, se.expr, zero);
+ else
+ tmp = build2 (NE_EXPR, boolean_type_node, se.expr, zero);
- /* if (cond <= 0) take branch1 else take branch2. */
- branch2 = build1_v (GOTO_EXPR, gfc_get_label_decl (code->label3));
- tmp = build2 (LE_EXPR, boolean_type_node, se.expr, zero);
- branch1 = build3_v (COND_EXPR, tmp, branch1, branch2);
+ branch1 = build3_v (COND_EXPR, tmp, branch1, branch2);
+ }
+ else
+ branch1 = build1_v (GOTO_EXPR, gfc_get_label_decl (code->label));
+
+ if (code->label->value != code->label3->value
+ && code->label2->value != code->label3->value)
+ {
+ /* if (cond <= 0) take branch1 else take branch2. */
+ branch2 = build1_v (GOTO_EXPR, gfc_get_label_decl (code->label3));
+ tmp = build2 (LE_EXPR, boolean_type_node, se.expr, zero);
+ branch1 = build3_v (COND_EXPR, tmp, branch1, branch2);
+ }
/* Append the COND_EXPR to the evaluation of COND, and return. */
gfc_add_expr_to_block (&se.pre, branch1);
--
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