MIPS: [turbofan] Add matching rule to use Nor instruction.

src/compiler/mips/instruction-selector-mips.cc

Index: src/compiler/mips/instruction-selector-mips.cc
diff --git a/src/compiler/mips/instruction-selector-mips.cc b/src/compiler/mips/instruction-selector-mips.cc
index 9df0af6cb989f264532ea4e228bc77c9ffcdecf4..9cc6f31dc35d21a6bd19cf432caa3e2f89fd1db7 100644
--- a/src/compiler/mips/instruction-selector-mips.cc
+++ b/src/compiler/mips/instruction-selector-mips.cc
@@ -294,6 +294,18 @@ void InstructionSelector::VisitWord32Or(Node* node) {
 
 
 void InstructionSelector::VisitWord32Xor(Node* node) {
+  Int32BinopMatcher m(node);
+  if (m.left().IsWord32Or() && CanCover(node, m.left().node()) &&
+      m.right().Is(-1)) {
+    Int32BinopMatcher mleft(m.left().node());
+    if (!mleft.right().HasValue()) {
+      MipsperandGenerator g(this);

[balazs.kilvady, 2015/11/19 12:28:31]

error: unknown type name 'MipsperandGenerator'; did you mean 
'MipsOperandGenerator'?

[dusan.milosavljevic, 2015/11/19 12:50:05]

Done.

+      Emit(kMipsNor, g.DefineAsRegister(node),
+           g.UseRegister(mleft.left().node()),
+           g.UseRegister(mleft.right().node()));
+      return;
+    }
+  }
   VisitBinop(this, node, kMipsXor);
 }