[ABSU_EXPR] Add some of the missing patterns in match,pd

[Kugan Vivekanandarajah]

Hi,

This patch adds some of the missing patterns in match.pd for ABSU_EXPR.

Bootstrap and regression testing on x86_64-linux-gnu. Is this OK if no
regressions.

Thanks,
Kugan

gcc/ChangeLog:

2018-06-28  Kugan Vivekanandarajah  <kug...@linaro.org>

    * match.pd (absu(x)*absu(x) -> x*x): Handle.
        (absu(absu(X)) -> absu(X)): Likewise.
        (absu(-X) -> absu(X)): Likewise.
        (absu(X)  where X is nonnegative -> X): Likewise.

From 374ee7928039c16cb091bd02d5efd4c493aab86e Mon Sep 17 00:00:00 2001
From: Kugan Vivekanandarajah <kugan.vivekanandara...@linaro.org>
Date: Mon, 18 Jun 2018 10:51:06 +1000
Subject: [PATCH] add absu patterns

Change-Id: Ied504be83f00041a6c815d23e16a394b71445f27
---
 gcc/match.pd | 37 ++++++++++++++++++++++++-------------
 1 file changed, 24 insertions(+), 13 deletions(-)

diff --git a/gcc/match.pd b/gcc/match.pd
index c1e0963..a356a92 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -571,10 +571,12 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
    (copysigns (op @0) @1)
    (copysigns @0 @1))))
 
-/* abs(x)*abs(x) -> x*x.  Should be valid for all types.  */
-(simplify
- (mult (abs@1 @0) @1)
- (mult @0 @0))
+/* abs(x)*abs(x) -> x*x.  Should be valid for all types.
+   also for absu(x)*absu(x) -> x*x.  */
+(for op (abs absu)
+ (simplify
+  (mult (op@1 @0) @1)
+  (mult @0 @0)))
 
 /* cos(copysign(x, y)) -> cos(x).  Similarly for cosh.  */
 (for coss (COS COSH)
@@ -1013,15 +1015,24 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
       && tree_nop_conversion_p (type, TREE_TYPE (@2)))
   (bit_xor (convert @1) (convert @2))))
 
-(simplify
- (abs (abs@1 @0))
- @1)
-(simplify
- (abs (negate @0))
- (abs @0))
-(simplify
- (abs tree_expr_nonnegative_p@0)
- @0)
+/* Convert abs (abs (X)) into abs (X).
+   also absu (absu (X)) into absu (X).  */
+(for op (abs absu)
+ (simplify
+  (op (op@1 @0))
+  @1))
+
+/* Convert abs[u] (-X) -> abs[u] (X).  */
+(for op (abs absu)
+ (simplify
+  (op (negate @0))
+  (op @0)))
+
+/* Convert abs[u] (X)  where X is nonnegative -> (X).  */
+(for op (abs absu)
+ (simplify
+  (op tree_expr_nonnegative_p@0)
+  @0))
 
 /* A few cases of fold-const.c negate_expr_p predicate.  */
 (match negate_expr_p
-- 
2.7.4