From d43177addfb5f32bca4845af930bb67104f1845f Mon Sep 17 00:00:00 2001
From: Marc Glisse <marc.glisse@inria.fr>
Date: Thu, 23 Nov 2017 20:53:09 +0100
Subject: [PATCH] Simplify ptr - 0

2017-11-23  Marc Glisse  <marc.glisse@inria.fr>

	* match.pd (ptr-0): New transformation.

From-SVN: r255113
---
 gcc/ChangeLog | 4 ++++
 gcc/match.pd  | 5 +++++
 2 files changed, 9 insertions(+)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 704d4e22c93..be8dbe492d1 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,7 @@
+2017-11-23  Marc Glisse  <marc.glisse@inria.fr>
+
+	* match.pd (ptr-0): New transformation.
+
 2017-11-23  Charles Baylis  <charles.baylis@linaro.org>
 
 	* config/arm/arm-protos.h (enum arm_addr_mode_op): New.
diff --git a/gcc/match.pd b/gcc/match.pd
index 0949a9bcd2c..84db1ee7360 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -102,6 +102,11 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
  (pointer_plus integer_zerop @1)
  (non_lvalue (convert @1)))
 
+/* ptr - 0 -> (type)ptr */
+(simplify
+ (pointer_diff @0 integer_zerop)
+ (convert @0))
+
 /* See if ARG1 is zero and X + ARG1 reduces to X.
    Likewise if the operands are reversed.  */
 (simplify
-- 
2.11.4.GIT