[turbofan] IA: support better left operand for commutative binops

src/compiler/ia32/instruction-selector-ia32-unittest.cc

Index: src/compiler/ia32/instruction-selector-ia32-unittest.cc
diff --git a/src/compiler/ia32/instruction-selector-ia32-unittest.cc b/src/compiler/ia32/instruction-selector-ia32-unittest.cc
index 60708c1ebe64abff032339100eccd00d49d7e6ee..5c579a91bd2564e655767502177ae4536ec7030e 100644
--- a/src/compiler/ia32/instruction-selector-ia32-unittest.cc
+++ b/src/compiler/ia32/instruction-selector-ia32-unittest.cc
@@ -75,6 +75,39 @@ TEST_F(InstructionSelectorTest, Int32SubWithImmediate) {
 
 
 // -----------------------------------------------------------------------------
+// Better left operand for commutative binops
+
+TEST_F(InstructionSelectorTest, BetterLeftOperandTestAddBinop) {
+  StreamBuilder m(this, kMachInt32, kMachInt32, kMachInt32);
+  Node* param1 = m.Parameter(0);
+  Node* param2 = m.Parameter(1);
+  Node* add = m.Int32Add(param1, param2);
+  m.Return(m.Int32Add(add, param1));
+  Stream s = m.Build();
+  ASSERT_EQ(2U, s.size());
+  EXPECT_EQ(kIA32Add, s[0]->arch_opcode());
+  ASSERT_EQ(2U, s[0]->InputCount());
+  ASSERT_TRUE(s[0]->InputAt(0)->IsUnallocated());
+  EXPECT_EQ(param2->id(), s.ToVreg(s[0]->InputAt(0)));
+}
+
+
+TEST_F(InstructionSelectorTest, BetterLeftOperandTestMulBinop) {
+  StreamBuilder m(this, kMachInt32, kMachInt32, kMachInt32);
+  Node* param1 = m.Parameter(0);
+  Node* param2 = m.Parameter(1);
+  Node* mul = m.Int32Mul(param1, param2);
+  m.Return(m.Int32Mul(mul, param1));
+  Stream s = m.Build();
+  ASSERT_EQ(2U, s.size());
+  EXPECT_EQ(kIA32Imul, s[0]->arch_opcode());
+  ASSERT_EQ(2U, s[0]->InputCount());
+  ASSERT_TRUE(s[0]->InputAt(0)->IsUnallocated());
+  EXPECT_EQ(param2->id(), s.ToVreg(s[0]->InputAt(0)));
+}
+
+
+// -----------------------------------------------------------------------------
 // Loads and stores
 
 namespace {