Fix X - (X / Y) * Y in match.pd.

2015-10-29  Marc Glisse  <marc.glisse@inria.fr>

	* match.pd (X-(X/Y)*Y): Properly handle conversions and commutativity.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@229534 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ab1622c..3b72387 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,7 @@
+2015-10-29  Marc Glisse  <marc.glisse@inria.fr>
+
+       * match.pd (X-(X/Y)*Y): Properly handle conversions and commutativity.
+
 2015-10-29  Richard Sandiford  <richard.sandiford@arm.com>
 
        * tree-call-cdce.c (shrink_wrap_one_built_in_call): Remove

diff --git a/gcc/match.pd b/gcc/match.pd
index 1d6dde1..f6c5c07 100644 (file)
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -318,10 +318,12 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
 
 /* X - (X / Y) * Y is the same as X % Y.  */
 (simplify
- (minus (convert1? @0) (convert2? (mult (trunc_div @0 @1) @1)))
- (if ((INTEGRAL_TYPE_P (type) || VECTOR_INTEGER_TYPE_P (type))
-      && TYPE_UNSIGNED (TREE_TYPE (@0)) == TYPE_UNSIGNED (type))
-  (trunc_mod (convert @0) (convert @1))))
+ (minus (convert1? @2) (convert2? (mult:c (trunc_div @0 @1) @1)))
+ /* We cannot use matching captures here, since in the case of
+    constants we really want the type of @0, not @2.  */
+ (if (operand_equal_p (@0, @2, 0)
+      && (INTEGRAL_TYPE_P (type) || VECTOR_INTEGER_TYPE_P (type)))
+  (convert (trunc_mod @0 @1))))
 
 /* Optimize TRUNC_MOD_EXPR by a power of two into a BIT_AND_EXPR,
    i.e. "X % C" into "X & (C - 1)", if X and C are positive.