re PR tree-optimization/46216 (ICE: SSA corruption)

2010-11-02  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/46216
	* tree-ssa-forwprop.c (tree_ssa_forward_propagate_single_use_vars):
	Check if we can propagate from a POINTER_PLUS_EXPR before doing so.

	* gcc.dg/torture/pr46216.c: New testcase.

From-SVN: r166203

gcc/ChangeLog

+2010-11-02  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/46216
+	* tree-ssa-forwprop.c (tree_ssa_forward_propagate_single_use_vars):
+	Check if we can propagate from a POINTER_PLUS_EXPR before doing so.
+
 2010-11-02  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 
 	* configure.ac (*-*-irix6*): Disable set_have_as_tls.

gcc/testsuite/ChangeLog

+2010-11-02  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/46216
+	* gcc.dg/torture/pr46216.c: New testcase.
+
 2010-11-02  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 
 	PR target/46131

gcc/testsuite/gcc.dg/torture/pr46216.c

+/* { dg-do compile } */
+
+typedef int Embryo_Cell;
+int
+embryo_program_run(Embryo_Cell *cip)
+{
+    unsigned char op;
+    Embryo_Cell offs;
+    static const void *switchtable[256] = {
+	&&SWITCHTABLE_EMBRYO_OP_NONE, &&SWITCHTABLE_EMBRYO_OP_LOAD_PRI
+    };
+    for (;;)
+      {
+	op = *cip++;
+	while (1) {
+	    goto *switchtable[op];
+SWITCHTABLE_EMBRYO_OP_LOAD_PRI:
+	    offs = *(Embryo_Cell *)cip++;
+SWITCHTABLE_EMBRYO_OP_NONE:
+	    break;
+	};
+      }
+    return offs;
+}

gcc/tree-ssa-forwprop.c

@@ -1983,7 +1983,8 @@ tree_ssa_forward_propagate_single_use_vars (void)
 		  else
 		    gsi_next (&gsi);
 		}
-	      else if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR)
+	      else if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR
+		       && can_propagate_from (stmt))
 		{
 		  if (TREE_CODE (gimple_assign_rhs2 (stmt)) == INTEGER_CST
 		      /* ???  Better adjust the interface to that function