From: Richard Kenner <kenner@gcc.gnu.org>
Date: Sun, 23 Jan 1994 12:00:29 +0000 (-0500)
Subject: (simplify_comparison): Can remove NOT on both operands if we swap
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=ad25ba1779f5e1a0e2a640e12dda3f6c7a53a163;p=gcc.git

(simplify_comparison): Can remove NOT on both operands if we swap
comparison code.

From-SVN: r6410
---

diff --git a/gcc/combine.c b/gcc/combine.c
index d6993672925..1737e6ec465 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -8429,7 +8429,7 @@ simplify_comparison (code, pop0, pop1)
 	  && GET_CODE (XEXP (XEXP (op0, 0), 0)) == SUBREG
 	  && GET_CODE (XEXP (XEXP (op1, 0), 0)) == SUBREG
 	  && (GET_MODE (SUBREG_REG (XEXP (XEXP (op0, 0), 0)))
-	      == GET_MODE (SUBREG_REG (XEXP (XEXP (op0, 0), 0))))
+	      == GET_MODE (SUBREG_REG (XEXP (XEXP (op1, 0), 0))))
 	  && GET_CODE (XEXP (op0, 1)) == CONST_INT
 	  && GET_CODE (XEXP (op1, 1)) == CONST_INT
 	  && GET_CODE (XEXP (XEXP (op0, 0), 1)) == CONST_INT
@@ -8517,12 +8517,13 @@ simplify_comparison (code, pop0, pop1)
 	  code = unsigned_condition (code);
 	}
 
-      /* If both operands are NOT or both are NEG, we can strip off the
-	 outer operation if this is just an equality comparison.  */
-      else if ((code == EQ || code == NE)
-	       && ((GET_CODE (op0) == NOT && GET_CODE (op1) == NOT)
-		   || (GET_CODE (op0) == NEG && GET_CODE (op1) == NEG)))
-	op0 = XEXP (op0, 0), op1 = XEXP (op1, 0);
+      /* If both operands are NOT, we can strip off the outer operation
+	 and adjust the comparison code for swapped operands; similarly for
+	 NEG, except that this must be an equality comparison.  */
+      else if ((GET_CODE (op0) == NOT && GET_CODE (op1) == NOT)
+	       || (GET_CODE (op0) == NEG && GET_CODE (op1) == NEG
+		   && (code == EQ || code == NE)))
+	op0 = XEXP (op0, 0), op1 = XEXP (op1, 0), code = swap_condition (code);
 
       else
 	break;