[turbofan] Further simplify representation inference for NumberTo(U)int32.

Review URL: https://codereview.chromium.org/1471723002

Cr-Commit-Position: refs/heads/master@{#32174}

src/compiler/simplified-lowering.cc

@@ -130,7 +130,8 @@ class UseInfo {
 };
 
 
-UseInfo UseInfoFromRepresentation(MachineTypeUnion rep) {
+UseInfo UseInfoFromMachineType(MachineType type) {
+  MachineTypeUnion rep = RepresentationOf(type);
   DCHECK((rep & kTypeMask) == 0);
   if (rep & kRepTagged) return UseInfo::AnyTagged();
   if (rep & kRepFloat64) {
@@ -153,11 +154,6 @@ UseInfo UseInfoFromRepresentation(MachineTypeUnion rep) {
 }
 
 
-UseInfo UseInfoFromMachineType(MachineType type) {
-  return UseInfoFromRepresentation(RepresentationOf(type));
-}
-
-
 UseInfo UseInfoForBasePointer(const FieldAccess& access) {
   return access.tag() != 0 ? UseInfo::AnyTagged() : UseInfo::PointerInt();
 }
@@ -827,35 +823,15 @@ class RepresentationSelector {
         break;
       }
       case IrOpcode::kNumberToInt32: {
-        MachineTypeUnion use_rep = use & kRepMask;
-        Node* input = node->InputAt(0);
-        Type* in_upper = NodeProperties::GetType(input);
-        if (in_upper->Is(Type::Signed32())) {
-          // If the input has type int32, pass through representation.
-          VisitUnop(node, UseInfoFromRepresentation(use_rep),
-                    kTypeInt32 | use_rep);
-          if (lower()) DeferReplacement(node, node->InputAt(0));
-        } else {
-          // Just change representation if necessary.
-          VisitUnop(node, UseInfo::TruncatingWord32(), kMachInt32);
-          if (lower()) DeferReplacement(node, node->InputAt(0));
-        }
+        // Just change representation if necessary.
+        VisitUnop(node, UseInfo::TruncatingWord32(), kMachInt32);
+        if (lower()) DeferReplacement(node, node->InputAt(0));
         break;
       }
       case IrOpcode::kNumberToUint32: {
-        MachineTypeUnion use_rep = use & kRepMask;
-        Node* input = node->InputAt(0);
-        Type* in_upper = NodeProperties::GetType(input);
-        if (in_upper->Is(Type::Unsigned32())) {
-          // If the input has type uint32, pass through representation.
-          VisitUnop(node, UseInfoFromRepresentation(use_rep),
-                    kTypeUint32 | use_rep);
-          if (lower()) DeferReplacement(node, node->InputAt(0));
-        } else {
-          // Just change representation if necessary.
-          VisitUnop(node, UseInfo::TruncatingWord32(), kMachUint32);
-          if (lower()) DeferReplacement(node, node->InputAt(0));
-        }
+        // Just change representation if necessary.
+        VisitUnop(node, UseInfo::TruncatingWord32(), kMachUint32);
+        if (lower()) DeferReplacement(node, node->InputAt(0));
         break;
       }
       case IrOpcode::kNumberIsHoleNaN: {

test/cctest/compiler/test-simplified-lowering.cc

@@ -1045,28 +1045,6 @@ static void CheckChangeOf(IrOpcode::Value change, Node* of, Node* node) {
 }
 
 
-TEST(LowerNumberToInt32_to_nop) {
-  // NumberToInt32(x: kRepTagged | kTypeInt32) used as kRepTagged
-  TestingGraph t(Type::Signed32());
-  Node* trunc = t.graph()->NewNode(t.simplified()->NumberToInt32(), t.p0);
-  Node* use = t.Use(trunc, kRepTagged);
-  t.Return(use);
-  t.Lower();
-  CHECK_EQ(t.p0, use->InputAt(0));
-}
-
-
-TEST(LowerNumberToInt32_to_ChangeTaggedToFloat64) {
-  // NumberToInt32(x: kRepTagged | kTypeInt32) used as kRepFloat64
-  TestingGraph t(Type::Signed32());
-  Node* trunc = t.graph()->NewNode(t.simplified()->NumberToInt32(), t.p0);
-  Node* use = t.Use(trunc, kRepFloat64);
-  t.Return(use);
-  t.Lower();
-  CheckChangeOf(IrOpcode::kChangeTaggedToFloat64, t.p0, use->InputAt(0));
-}
-
-
 TEST(LowerNumberToInt32_to_ChangeTaggedToInt32) {
   // NumberToInt32(x: kRepTagged | kTypeInt32) used as kRepWord32
   TestingGraph t(Type::Signed32());
@@ -1105,28 +1083,6 @@ TEST(LowerNumberToInt32_to_TruncateFloat64ToInt32_with_change) {
 }
 
 
-TEST(LowerNumberToUint32_to_nop) {
-  // NumberToUint32(x: kRepTagged | kTypeUint32) used as kRepTagged
-  TestingGraph t(Type::Unsigned32());
-  Node* trunc = t.graph()->NewNode(t.simplified()->NumberToUint32(), t.p0);
-  Node* use = t.Use(trunc, kRepTagged);
-  t.Return(use);
-  t.Lower();
-  CHECK_EQ(t.p0, use->InputAt(0));
-}
-
-
-TEST(LowerNumberToUint32_to_ChangeTaggedToFloat64) {
-  // NumberToUint32(x: kRepTagged | kTypeUint32) used as kRepWord32
-  TestingGraph t(Type::Unsigned32());
-  Node* trunc = t.graph()->NewNode(t.simplified()->NumberToUint32(), t.p0);
-  Node* use = t.Use(trunc, kRepFloat64);
-  t.Return(use);
-  t.Lower();
-  CheckChangeOf(IrOpcode::kChangeTaggedToFloat64, t.p0, use->InputAt(0));
-}
-
-
 TEST(LowerNumberToUint32_to_ChangeTaggedToUint32) {
   // NumberToUint32(x: kRepTagged | kTypeUint32) used as kRepWord32
   TestingGraph t(Type::Unsigned32());