commit 198fc9a9eb7104d459bb5fea0aba5f2ff2c6f8d4
author Alexandru Moșoi <mosoi@google.com> Fri Aug 14 12:59:33 2015 +0200
committer Keith Randall <khr@golang.org> Fri Aug 14 23:14:36 2015 +0000
tree dfa0a22734b6d732124793ac35abcf5e11cb5998
parent 7a6de6d5f2e1e8e8908022789cf129581c90a4c3

[dev.ssa] cmd/compile/internal/ssa/gen: more simplifications and foldings.

Change-Id: I74d1267dbfced2663072b4f091732c0fb328690f
Reviewed-on: https://go-review.googlesource.com/13641
Reviewed-by: Keith Randall <khr@golang.org>

src/cmd/compile/internal/ssa/gen/generic.rules

diff --git a/src/cmd/compile/internal/ssa/gen/generic.rules b/src/cmd/compile/internal/ssa/gen/generic.rules
index 66bec77..74893ce 100644
--- a/src/cmd/compile/internal/ssa/gen/generic.rules
+++ b/src/cmd/compile/internal/ssa/gen/generic.rules
@@ -37,6 +37,23 @@
 (Neq16 x x) -> (ConstBool {false})
 (Neq8 x x) -> (ConstBool {false})
 
+// simplifications
+(Or64 x x) -> x
+(Or32 x x) -> x
+(Or16 x x) -> x
+(Or8 x x) -> x
+(And64 x x) -> x
+(And32 x x) -> x
+(And16 x x) -> x
+(And8 x x) -> x
+(Xor64 x x) -> (Const64 [0])
+(Xor32 x x) -> (Const32 [0])
+(Xor16 x x) -> (Const16 [0])
+(Xor8 x x) -> (Const8 [0])
+(Sub64 x x) -> (Const64 [0])
+(Sub32 x x) -> (Const32 [0])
+(Sub16 x x) -> (Const16 [0])
+(Sub8 x x) -> (Const8 [0])
 (Com8 (Com8 x)) -> x
 (Com16 (Com16 x)) -> x
 (Com32 (Com32 x)) -> x