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authorMarc Glisse <marc.glisse@inria.fr>2017-11-24 12:09:14 +0000
committerMarc Glisse <marc.glisse@inria.fr>2017-11-24 12:09:14 +0000
commit4162a3141359dcf8b1f2fda5ef62f288bae42817 (patch)
treeef3903e9980c30f58c98133ed57fa3cca8796713
parentd295eb524301bc8527dd83806574f25cb74282bc (diff)
Simplify 0 - ptr.
2017-11-24 Marc Glisse <marc.glisse@inria.fr> * match.pd (0-ptr): New transformation. git-svn-id: https://gcc.gnu.org/svn/gcc/trunk@255139 138bc75d-0d04-0410-961f-82ee72b054a4
-rw-r--r--gcc/ChangeLog4
-rw-r--r--gcc/match.pd4
2 files changed, 8 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 92b355a73df..b866e2512a1 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,7 @@
+2017-11-24 Marc Glisse <marc.glisse@inria.fr>
+
+ * match.pd (0-ptr): New transformation.
+
2017-11-24 Jan Hubicka <hubicka@ucw.cz>
PR bootstrap/83015
diff --git a/gcc/match.pd b/gcc/match.pd
index 84db1ee7360..9db48bda047 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -2456,9 +2456,13 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(if (INTEGRAL_TYPE_P (type))
(mult @0 { build_int_cst (type, 2); }))))
+/* 0 - X -> -X. */
(simplify
(minus integer_zerop @1)
(negate @1))
+(simplify
+ (pointer_diff integer_zerop @1)
+ (negate (convert @1)))
/* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
ARG0 is zero and X + ARG0 reduces to X, since that would mean