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-rw-r--r--gcc/ChangeLog5
-rw-r--r--gcc/expr.c5
2 files changed, 9 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index af150ff0005..6595ef506de 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2006-04-17 Roger Sayle <roger@eyesopen.com>
+
+ * expr.c (expand_assignment): Optimize away no-op moves where the
+ source and destination are equal and have no side-effects.
+
2006-04-17 Richard Guenther <rguenther@suse.de>
PR target/26826
diff --git a/gcc/expr.c b/gcc/expr.c
index b0e958c23b6..f59cc426a17 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -3988,13 +3988,16 @@ expand_assignment (tree to, tree from)
rtx result;
/* Don't crash if the lhs of the assignment was erroneous. */
-
if (TREE_CODE (to) == ERROR_MARK)
{
result = expand_normal (from);
return;
}
+ /* Optimize away no-op moves without side-effects. */
+ if (operand_equal_p (to, from, 0))
+ return;
+
/* Assignment of a structure component needs special treatment
if the structure component's rtx is not simply a MEM.
Assignment of an array element at a constant index, and assignment of
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