re PR middle-end/59993 (ICE: SSA corruption)

2014-01-30  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/59993
	* tree-ssa-forwprop.c (associate_pointerplus): Check we
	can propagate form the earlier stmt and avoid the transform
	when the intermediate result is needed.

	* gcc.dg/torture/pr59993.c: New testcase.

From-SVN: r207316

gcc/ChangeLog

+2014-01-30  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/59993
+	* tree-ssa-forwprop.c (associate_pointerplus): Check we
+	can propagate form the earlier stmt and avoid the transform
+	when the intermediate result is needed.
+
 2014-01-30  Alangi Derick  <alangiderick@gmail.com>
 
 	* README.Portability: Fix typo.

gcc/testsuite/ChangeLog

+2014-01-30  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/59993
+	* gcc.dg/torture/pr59993.c: New testcase.
+
 2014-01-30  Richard Sandiford  <rdsandiford@googlemail.com>
 
 	* g++.dg/vect/pr33426-ivdep.cc, g++.dg/vect/pr33426-ivdep-2.cc,

gcc/testsuite/gcc.dg/torture/pr59993.c

+/* { dg-do compile } */
+
+#include <setjmp.h>
+
+extern int optind;
+jmp_buf jump_buf;
+int
+main (int argc, char **argv)
+{
+  foo (jump_buf, setjmp(jump_buf));
+  argv += optind;
+  bar(argv[1]);
+}

gcc/tree-ssa-forwprop.c

@@ -2926,11 +2926,13 @@ associate_pointerplus (gimple_stmt_iterator *gsi)
   /* Associate (p +p off1) +p off2 as (p +p (off1 + off2)).  */
   ptr = gimple_assign_rhs1 (stmt);
   off1 = gimple_assign_rhs2 (stmt);
-  if (TREE_CODE (ptr) != SSA_NAME)
+  if (TREE_CODE (ptr) != SSA_NAME
+      || !has_single_use (ptr))
     return false;
   def_stmt = SSA_NAME_DEF_STMT (ptr);
   if (!is_gimple_assign (def_stmt)
-      || gimple_assign_rhs_code (def_stmt) != POINTER_PLUS_EXPR)
+      || gimple_assign_rhs_code (def_stmt) != POINTER_PLUS_EXPR
+      || !can_propagate_from (def_stmt))
     return false;
   ptr = gimple_assign_rhs1 (def_stmt);
   off2 = gimple_assign_rhs2 (def_stmt);