simplify-rtx.c (simplify_plus_minus): Bump n_ops for NOT.

	* simplify-rtx.c (simplify_plus_minus): Bump n_ops for NOT.
	Don't allow -1 - x -> ~x simplifications in the first pass.

	* gcc.c-torture/execute/20020107-1.c: New test.

From-SVN: r48614

gcc/ChangeLog

+2002-01-07  Jakub Jelinek  <jakub@redhat.com>
+
+	* simplify-rtx.c (simplify_plus_minus): Bump n_ops for NOT.
+	Don't allow -1 - x -> ~x simplifications in the first pass.
+
 2002-01-07  Aldy Hernandez  <aldyh@redhat.com>
 
         * rs6000.c (altivec_expand_ternop_builtin): Don't die on invalid

gcc/simplify-rtx.c

@@ -1800,7 +1800,7 @@ simplify_plus_minus (code, mode, op0, op1)
 	      if (n_ops != 7)
 		{
 		  ops[n_ops].op = constm1_rtx;
-		  ops[n_ops].neg = this_neg;
+		  ops[n_ops++].neg = this_neg;
 		  ops[i].op = XEXP (this_op, 0);
 		  ops[i].neg = !this_neg;
 		  changed = 1;
@@ -1865,7 +1865,13 @@ simplify_plus_minus (code, mode, op0, op1)
 		    && ! (GET_CODE (tem) == CONST
 			  && GET_CODE (XEXP (tem, 0)) == ncode
 			  && XEXP (XEXP (tem, 0), 0) == lhs
-			  && XEXP (XEXP (tem, 0), 1) == rhs))
+			  && XEXP (XEXP (tem, 0), 1) == rhs)
+		    /* Don't allow -x + -1 -> ~x simplifications in the
+		       first pass.  This allows us the chance to combine
+		       the -1 with other constants.  */
+		    && ! (first
+			  && GET_CODE (tem) == NOT
+			  && XEXP (tem, 0) == rhs))
 		  {
 		    lneg &= rneg;
 		    if (GET_CODE (tem) == NEG)

gcc/testsuite/ChangeLog

+2002-01-07  Jakub Jelinek  <jakub@redhat.com>
+
+	* gcc.c-torture/execute/20020107-1.c: New test.
+
 2002-01-06  Craig Rodrigues  <rodrigc@gcc.gnu.org>
 
 	PR c/5279

gcc/testsuite/gcc.c-torture/execute/20020107-1.c

+/* This testcase failed because - 1 - buf was simplified into ~buf and when
+   later expanding it back into - buf + -1, -1 got lost.  */
+
+extern void abort (void);
+extern void exit (int);
+
+static void
+bar (int x)
+{
+  if (!x)
+    abort ();
+}
+
+char buf[10];
+
+inline char *
+foo (char *tmp)
+{
+  asm ("" : "=r" (tmp) : "0" (tmp));
+  return tmp + 2;
+}
+
+int
+main (void)
+{
+  bar ((foo (buf) - 1 - buf) == 1);
+  exit (0);
+}