From: Richard Kenner <kenner@vlsi1.ultra.nyu.edu>
Date: Fri, 18 Nov 2005 13:07:06 +0000 (+0000)
Subject: fold-const.c (build_range_check): Use proper type for subtraction when merging lower... 
X-Git-Tag: releases/gcc-4.1.0~717
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=438090c3723d1d050bbc31a891e86db520bbd9f1;p=thirdparty%2Fgcc.git

fold-const.c (build_range_check): Use proper type for subtraction when merging lower bound.

	* fold-const.c (build_range_check): Use proper type for subtraction
	when merging lower bound.

From-SVN: r107178
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 9a0a77cb00ef..ad2c25a44c95 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2005-11-18  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>
+
+	* fold-const.c (build_range_check): Use proper type for subtraction
+	when merging lower bound.
+
 2005-11-18  Zdenek Dvorak  <dvorakz@suse.cz>
 
 	PR rtl-optimization/24497
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 343cfae69037..abaac755e3b3 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -4062,10 +4062,22 @@ build_range_check (tree type, tree exp, int in_p, tree low, tree high)
     }
 
   if (value != 0 && ! TREE_OVERFLOW (value))
-    return build_range_check (type,
-			      fold_build2 (MINUS_EXPR, etype, exp, low),
-			      1, fold_convert (etype, integer_zero_node),
-			      value);
+    {
+      /* There is no requirement that LOW be within the range of ETYPE
+	 if the latter is a subtype.  It must, however, be within the base
+	 type of ETYPE.  So be sure we do the subtraction in that type.  */
+      if (INTEGRAL_TYPE_P (etype) && TREE_TYPE (etype))
+	{
+	  etype = TREE_TYPE (etype);
+	  exp = fold_convert (etype, exp);
+	  low = fold_convert (etype, low);
+	  value = fold_convert (etype, value);
+	}
+
+      return build_range_check (type,
+				fold_build2 (MINUS_EXPR, etype, exp, low),
+				1, build_int_cst (etype, 0), value);
+    }
 
   return 0;
 }