From: Andrew MacLeod <amacleod@redhat.com>
Date: Fri, 16 Oct 2020 19:10:17 +0000 (-0400)
Subject: pointer_plus [0, 0] + const folding
X-Git-Tag: basepoints/gcc-12~4239
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=58492575a118fd14c8184823467c815347cde219;p=thirdparty%2Fgcc.git

pointer_plus [0, 0] + const folding

Return a constant range if POINTER_PLUS is [0,0] plus a const.

	* range-op.cc (pointer_plus_operator::wi_fold): Make pointer_plus
	[0, 0] + const return a [const, const] range.
---

diff --git a/gcc/range-op.cc b/gcc/range-op.cc
index de4cfe45a48d..0efa00186e82 100644
--- a/gcc/range-op.cc
+++ b/gcc/range-op.cc
@@ -3064,6 +3064,14 @@ pointer_plus_operator::wi_fold (irange &r, tree type,
 				const wide_int &rh_lb,
 				const wide_int &rh_ub) const
 {
+  // Check for [0,0] + const, and simply return the const.
+  if (lh_lb == 0 && lh_ub == 0 && rh_lb == rh_ub)
+    {
+      tree val = wide_int_to_tree (type, rh_lb);
+      r.set (val, val);
+      return;
+    }
+
   // For pointer types, we are really only interested in asserting
   // whether the expression evaluates to non-NULL.
   //