[turbofan] Combine Word32And with Int32Add and negative power of two.

src/compiler/machine-operator-reducer.cc

Index: src/compiler/machine-operator-reducer.cc
diff --git a/src/compiler/machine-operator-reducer.cc b/src/compiler/machine-operator-reducer.cc
index 6c4d5dcb953725ec4ba114c25c8add56ce7bceef..470e71d6738cf8a2a51d45f767d3ef3fc429144d 100644
--- a/src/compiler/machine-operator-reducer.cc
+++ b/src/compiler/machine-operator-reducer.cc
@@ -137,6 +137,19 @@ Reduction MachineOperatorReducer::Reduce(Node* node) {
           return Changed(node);
         }
       }
+      if (m.left().IsInt32Add() && m.right().IsNegativePowerOf2()) {
+        Int32BinopMatcher mleft(m.left().node());
+        if (mleft.right().HasValue() &&
+            (mleft.right().Value() & m.right().Value()) ==
+                mleft.right().Value()) {
+          // (x + K) & K => (x & K) + K

[Jarin, 2014/11/24 12:28:09]

How about (x + K1) & K2 => (x & K2) + K1?

[Benedikt Meurer, 2014/11/24 12:29:33]

This was the terminology that we always used here. Don't want to change that
now.

+          return Replace(graph()->NewNode(
+              machine()->Int32Add(),
+              graph()->NewNode(machine()->Word32And(), mleft.left().node(),
+                               m.right().node()),
+              mleft.right().node()));

[Jarin, 2014/11/24 12:28:09]

Funny indentation.

[Benedikt Meurer, 2014/11/24 12:29:33]

clang-format...

+        }
+      }
       break;
     }
     case IrOpcode::kWord32Or: {