Reviewers: dcarney,
Description:
[turbofan] Strength reduction of Word32And with Int32Mul.
- (x * (K << L)) & (-1 << L) => x * (K << L)
- ((K << L) * x) & (-1 << L) => x * (K << L)
[email protected]
Please review this at https://codereview.chromium.org/972653002/
Base URL: https://chromium.googlesource.com/v8/v8.git@master
Affected files (+33, -0 lines):
M src/compiler/machine-operator-reducer.cc
M test/unittests/compiler/machine-operator-reducer-unittest.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
a609a8095eb715d52fc7ceaa0a4624c492f5fb2d..5630bc8ef0ffae22a16159996867e751e3ab3884
100644
--- a/src/compiler/machine-operator-reducer.cc
+++ b/src/compiler/machine-operator-reducer.cc
@@ -906,6 +906,12 @@ Reduction
MachineOperatorReducer::ReduceWord32And(Node* node) {
return reduction.Changed() ? reduction : Changed(node);
}
}
+ } else if (m.left().IsInt32Mul()) {
+ Int32BinopMatcher mleft(m.left().node());
+ if (mleft.right().IsMultipleOf(-mask)) {
+ // (x * (K << L)) & (-1 << L) => x * (K << L)
+ return Replace(mleft.node());
+ }
}
}
return NoChange();
Index: test/unittests/compiler/machine-operator-reducer-unittest.cc
diff --git a/test/unittests/compiler/machine-operator-reducer-unittest.cc
b/test/unittests/compiler/machine-operator-reducer-unittest.cc
index
9656f57090524ad8bf3600ba57046bc3c6fce1c5..e41b01506117dced5c7bd1db8cbb11c9736ae961
100644
--- a/test/unittests/compiler/machine-operator-reducer-unittest.cc
+++ b/test/unittests/compiler/machine-operator-reducer-unittest.cc
@@ -616,6 +616,33 @@ TEST_F(MachineOperatorReducerTest,
Word32AndWithInt32AddAndConstant) {
}
+TEST_F(MachineOperatorReducerTest, Word32AndWithInt32MulAndConstant) {
+ Node* const p0 = Parameter(0);
+
+ TRACED_FORRANGE(int32_t, l, 1, 31) {
+ TRACED_FOREACH(int32_t, k, kInt32Values) {
+ if ((k << l) == 0) continue;
+
+ // (x * (K << L)) & (-1 << L) => x * (K << L)
+ Reduction const r1 = Reduce(graph()->NewNode(
+ machine()->Word32And(),
+ graph()->NewNode(machine()->Int32Mul(), p0, Int32Constant(k <<
l)),
+ Int32Constant(-1 << l)));
+ ASSERT_TRUE(r1.Changed());
+ EXPECT_THAT(r1.replacement(), IsInt32Mul(p0, IsInt32Constant(k <<
l)));
+
+ // ((K << L) * x) & (-1 << L) => x * (K << L)
+ Reduction const r2 = Reduce(graph()->NewNode(
+ machine()->Word32And(),
+ graph()->NewNode(machine()->Int32Mul(), Int32Constant(k << l),
p0),
+ Int32Constant(-1 << l)));
+ ASSERT_TRUE(r2.Changed());
+ EXPECT_THAT(r2.replacement(), IsInt32Mul(p0, IsInt32Constant(k <<
l)));
+ }
+ }
+}
+
+
TEST_F(MachineOperatorReducerTest,
Word32AndWithInt32AddAndInt32MulAndConstant) {
Node* const p0 = Parameter(0);
--
--
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