From: Jim Wilson <wilson@gcc.gnu.org>
Date: Thu, 24 Oct 1996 19:08:23 +0000 (-0700)
Subject: (make_range, case PLUS_EXPR): Normalize an unsigned
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=5a9d82a6df29af137fb8677853eb9bd65ad147b3;p=gcc.git

(make_range, case PLUS_EXPR): Normalize an unsigned
range that wraps around 0.

From-SVN: r13030
---

diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index cb45cd28ee2..9b7fe455539 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -2809,7 +2809,15 @@ make_range (exp, pin_p, plow, phigh)
 	      || (n_high != 0 && TREE_OVERFLOW (n_high)))
 	    break;
 
-	  low = n_low, high = n_high;
+	  /* Check for an unsigned range which has wrapped around the maximum
+	     value thus making n_high < n_low, and normalize it.  */
+	  if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
+	    {
+	      low = n_high, high = n_low;
+	      in_p = ! in_p;
+	    }
+	  else
+	    low = n_low, high = n_high;
 	  exp = arg0;
 	  continue;