From b8a914304da6ad15c03f90850858f97969809e95 Mon Sep 17 00:00:00 2001
From: Richard Kenner <kenner@gcc.gnu.org>
Date: Mon, 26 Apr 1993 19:12:11 -0400
Subject: [PATCH] (fold): Signedness matters for comparisons and right shifts.

From-SVN: r4243
---
 gcc/fold-const.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 43995c60a0b..5845489d256 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -3040,8 +3040,17 @@ fold (expr)
 	  if (op == 0)
 	    continue;		/* Valid for CALL_EXPR, at least.  */
 
-	  /* Strip any conversions that don't change the mode.  */
-	  STRIP_NOPS (op);
+	  if (kind == '<' || code == RSHIFT_EXPR)
+	    {
+	      /* Signedness matters here.  Perhaps we can refine this
+		 later.  */
+	      STRIP_TYPE_NOPS (op);
+	    }
+	  else
+	    {
+	      /* Strip any conversions that don't change the mode.  */
+	      STRIP_NOPS (op);
+	    }
 	  
 	  if (TREE_CODE (op) == COMPLEX_CST)
 	    subop = TREE_REALPART (op);
-- 
2.30.2