simplify-rtx.c (simplify_relational_operation): Don't simplify address ==…

simplify-rtx.c (simplify_relational_operation): Don't simplify address == constant into address + -constant == 0.

	* simplify-rtx.c (simplify_relational_operation): Don't
	simplify address == constant into address + -constant == 0.

	* gcc.dg/20040123-1.c: New test.

From-SVN: r76490

gcc/ChangeLog

+2004-01-24  Jakub Jelinek  <jakub@redhat.com>
+
+	* simplify-rtx.c (simplify_relational_operation): Don't
+	simplify address == constant into address + -constant == 0.
+
 2004-01-24  Kazu Hirata  <kazu@cs.umass.edu>
 
 	* gcc.c (process_command): Don't internationalize the

gcc/simplify-rtx.c

@@ -2530,6 +2530,8 @@ simplify_relational_operation (enum rtx_code code, enum machine_mode mode,
       && ! ((GET_CODE (op0) == REG || GET_CODE (trueop0) == CONST_INT)
 	    && (GET_CODE (op1) == REG || GET_CODE (trueop1) == CONST_INT))
       && 0 != (tem = simplify_binary_operation (MINUS, mode, op0, op1))
+      /* We cannot do this for == or != if tem is a nonzero address.  */
+      && ((code != EQ && code != NE) || ! nonzero_address_p (tem))
       && code != GTU && code != GEU && code != LTU && code != LEU)
     return simplify_relational_operation (signed_condition (code),
 					  mode, tem, const0_rtx);

gcc/testsuite/ChangeLog

+2004-01-24  Jakub Jelinek  <jakub@redhat.com>
+
+	* gcc.dg/20040123-1.c: New test.
+
 2004-01-23  Zack Weinberg  <zack@codesourcery.com>
 
 	* gcc.dg/builtins-30.c: Move dg-warning marks to the proper lines.

gcc/testsuite/gcc.dg/20040123-1.c

+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+/* { dg-final { scan-assembler "abort" } } */
+
+extern void abort (void);
+extern char a[];
+
+void foo (void)
+{
+  if ((void *) a == (void *) 0x4000UL)
+    abort ();
+}