[turbofan] Optimize certain chains of Branch into a Switch.

test/unittests/compiler/common-operator-unittest.cc

Index: test/unittests/compiler/common-operator-unittest.cc
diff --git a/test/unittests/compiler/common-operator-unittest.cc b/test/unittests/compiler/common-operator-unittest.cc
index 1f0c0fdaa4ab0b04900b701fd06e6e2d5dea7107..6e60cfd12ae228884390d8a388bc4b21c4a00155 100644
--- a/test/unittests/compiler/common-operator-unittest.cc
+++ b/test/unittests/compiler/common-operator-unittest.cc
@@ -133,7 +133,7 @@ class CommonOperatorTest : public TestWithZone {
 const int kArguments[] = {1, 5, 6, 42, 100, 10000, 65000};
 
 
-const size_t kCases[] = {2, 3, 4, 100, 255};
+const size_t kCases[] = {3, 4, 100, 255, 1024, 65000};
 
 
 const float kFloatValues[] = {-std::numeric_limits<float>::infinity(),
@@ -160,6 +160,20 @@ const double kDoubleValues[] = {-std::numeric_limits<double>::infinity(),
                                 std::numeric_limits<double>::signaling_NaN()};
 
 
+const int32_t kInt32Values[] = {
+    std::numeric_limits<int32_t>::min(), -1914954528, -1698749618, -1578693386,
+    -1577976073, -1573998034, -1529085059, -1499540537, -1299205097,
+    -1090814845, -938186388, -806828902, -750927650, -520676892, -513661538,
+    -453036354, -433622833, -282638793, -28375, -27788, -22770, -18806, -14173,
+    -11956, -11200, -10212, -8160, -3751, -2758, -1522, -121, -120, -118, -117,
+    -106, -84, -80, -74, -59, -52, -48, -39, -35, -17, -11, -10, -9, -7, -5, 0,
+    9, 12, 17, 23, 29, 31, 33, 35, 40, 47, 55, 56, 62, 64, 67, 68, 69, 74, 79,
+    84, 89, 90, 97, 104, 118, 124, 126, 127, 7278, 17787, 24136, 24202, 25570,
+    26680, 30242, 32399, 420886487, 642166225, 821912648, 822577803, 851385718,
+    1212241078, 1411419304, 1589626102, 1596437184, 1876245816, 1954730266,
+    2008792749, 2045320228, std::numeric_limits<int32_t>::max()};
+
+
 const BranchHint kHints[] = {BranchHint::kNone, BranchHint::kTrue,
                              BranchHint::kFalse};
 
@@ -199,12 +213,12 @@ TEST_F(CommonOperatorTest, Switch) {
 }
 
 
-TEST_F(CommonOperatorTest, Case) {
-  TRACED_FORRANGE(size_t, index, 0, 1024) {
-    const Operator* const op = common()->Case(index);
-    EXPECT_EQ(IrOpcode::kCase, op->opcode());
+TEST_F(CommonOperatorTest, IfValue) {
+  TRACED_FOREACH(int32_t, value, kInt32Values) {
+    const Operator* const op = common()->IfValue(value);
+    EXPECT_EQ(IrOpcode::kIfValue, op->opcode());
     EXPECT_EQ(Operator::kKontrol, op->properties());
-    EXPECT_EQ(index, CaseIndexOf(op));
+    EXPECT_EQ(value, OpParameter<int32_t>(op));
     EXPECT_EQ(0, op->ValueInputCount());
     EXPECT_EQ(0, op->EffectInputCount());
     EXPECT_EQ(1, op->ControlInputCount());