[PATCH] Fix predcom ICE introduced by var clobber changes (PR tree-optimization/51246)
Jakub Jelinek
jakub@redhat.com
Thu Nov 24 16:28:00 GMT 2011
Hi!
When stmt is mem = {v} {CLOBBER};, then lhs is neither
SSA_NAME, but it doesn't satisfy gimple_assign_copy_p either.
With this patch it will set the new_tree also to the clobber,
making it clear that the next iteration uses unitialized variable.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2011-11-24 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/51246
* tree-predcom.c (replace_ref_with): Allow also clobber on the
rhs.
* gcc.c-torture/compile/pr51246.c: New test.
--- gcc/tree-predcom.c.jj 2011-09-26 14:07:06.000000000 +0200
+++ gcc/tree-predcom.c 2011-11-24 09:17:46.872962765 +0100
@@ -1306,8 +1306,10 @@ replace_ref_with (gimple stmt, tree new_
val = gimple_assign_lhs (stmt);
if (TREE_CODE (val) != SSA_NAME)
{
- gcc_assert (gimple_assign_copy_p (stmt));
val = gimple_assign_rhs1 (stmt);
+ gcc_assert (gimple_assign_single_p (stmt)
+ && (gimple_assign_copy_p (stmt)
+ || TREE_CLOBBER_P (val)));
}
}
else
--- gcc/testsuite/gcc.c-torture/compile/pr51246.c.jj 2011-11-24 09:15:10.322906812 +0100
+++ gcc/testsuite/gcc.c-torture/compile/pr51246.c 2011-11-24 09:14:52.000000000 +0100
@@ -0,0 +1,14 @@
+/* PR tree-optimization/51246 */
+
+int a, *b;
+
+void
+test (void)
+{
+ while (1)
+ {
+ int c;
+ a = c;
+ b = &c;
+ }
+}
Jakub
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