re PR tree-optimization/64728 (internal compiler error: SSA corruption)

2015-01-22  Richard Biener  <rguenther@suse.de>

	PR middle-end/64728
	* tree-ssa-coalesce.c (coalesce_partitions): Do not perform
	abnormal coalescing on undefined SSA names.

	* gcc.dg/torture/pr64728.c: New testcase.

From-SVN: r220003

gcc/ChangeLog

+2015-01-22  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/64728
+	* tree-ssa-coalesce.c (coalesce_partitions): Do not perform
+	abnormal coalescing on undefined SSA names.
+
 2015-22-01  Uros Bizjak  <ubizjak@gmail.com>
 
 	PR target/64688

gcc/testsuite/ChangeLog

+2015-01-22  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/64728
+	* gcc.dg/torture/pr64728.c: New testcase.
+
 2015-22-01  Uros Bizjak  <ubizjak@gmail.com>
 
 	PR target/64688

gcc/testsuite/gcc.dg/torture/pr64728.c

+/* { dg-do compile } */
+
+#include <setjmp.h>
+
+jmp_buf a;
+int b, d;
+void baz (long);
+
+static void
+bar (long *x)
+{
+  if (d)
+    *x = b;
+}
+
+void
+foo ()
+{
+  baz (0);
+  if (setjmp (a))
+    {
+      long c;
+      bar (&c);
+      baz (c);
+    }
+  baz (0);
+}

gcc/tree-ssa-coalesce.c

@@ -1213,8 +1213,13 @@ coalesce_partitions (var_map map, ssa_conflicts_p graph, coalesce_list_p cl,
 		 gsi_next (&gsi))
 	      {
 		gphi *phi = gsi.phi ();
+		tree arg = PHI_ARG_DEF (phi, e->dest_idx);
+		if (SSA_NAME_IS_DEFAULT_DEF (arg)
+		    && (!SSA_NAME_VAR (arg)
+			|| TREE_CODE (SSA_NAME_VAR (arg)) != PARM_DECL))
+		  continue;
+
 		tree res = PHI_RESULT (phi);
-	        tree arg = PHI_ARG_DEF (phi, e->dest_idx);
 		int v1 = SSA_NAME_VERSION (res);
 		int v2 = SSA_NAME_VERSION (arg);