[turbofan] Add more sanity checks to representation inference.

src/compiler/representation-change.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/representation-change.h"
 
 #include <sstream>
 
 #include "src/base/bits.h"
 #include "src/code-factory.h"
@@ skipping 124 matching lines @@
       return GetFloat32RepresentationFor(node, output_rep, output_type,
                                          truncation);
     case MachineRepresentation::kFloat64:
       return GetFloat64RepresentationFor(node, output_rep, output_type,
                                          truncation);
     case MachineRepresentation::kBit:
       return GetBitRepresentationFor(node, output_rep, output_type);
     case MachineRepresentation::kWord8:
     case MachineRepresentation::kWord16:
     case MachineRepresentation::kWord32:
-      return GetWord32RepresentationFor(node, output_rep, output_type);
+      return GetWord32RepresentationFor(node, output_rep, output_type,
+                                        truncation);
     case MachineRepresentation::kWord64:
       return GetWord64RepresentationFor(node, output_rep, output_type);
     case MachineRepresentation::kSimd128:  // Fall through.
       // TODO(bbudge) Handle conversions between tagged and untagged.
       break;
     case MachineRepresentation::kNone:
       return node;
   }
   UNREACHABLE();
   return nullptr;
@@ skipping 71 matching lines @@
       } else {
         int32_t value = OpParameter<int32_t>(node);
         return jsgraph()->Float32Constant(static_cast<float>(value));
       }
     case IrOpcode::kFloat32Constant:
       return node;  // No change necessary.
     default:
       break;
   }
   // Select the correct X -> Float32 operator.
-  const Operator* op;
-  if (output_rep == MachineRepresentation::kBit) {
-    return TypeError(node, output_rep, output_type,
-                     MachineRepresentation::kFloat32);
-  } else if (IsWord(output_rep)) {
+  const Operator* op = nullptr;
+  if (IsWord(output_rep)) {
     if (output_type->Is(Type::Signed32())) {
+      // int32 -> float64 -> float32
       op = machine()->ChangeInt32ToFloat64();
-    } else {
-      // Either the output is int32 or the uses only care about the
-      // low 32 bits (so we can pick int32 safely).
-      DCHECK(output_type->Is(Type::Unsigned32()) ||
-             truncation.TruncatesToWord32());
+      node = jsgraph()->graph()->NewNode(op, node);
+      op = machine()->TruncateFloat64ToFloat32();
+    } else if (output_type->Is(Type::Unsigned32()) ||
+               truncation.TruncatesToWord32()) {
+      // Either the output is uint32 or the uses only care about the
+      // low 32 bits (so we can pick uint32 safely).
+
+      // uint32 -> float64 -> float32
       op = machine()->ChangeUint32ToFloat64();
+      node = jsgraph()->graph()->NewNode(op, node);
+      op = machine()->TruncateFloat64ToFloat32();
     }
-    // int32 -> float64 -> float32
-    node = jsgraph()->graph()->NewNode(op, node);
-    op = machine()->TruncateFloat64ToFloat32();
   } else if (output_rep == MachineRepresentation::kTagged) {
-    op = simplified()->ChangeTaggedToFloat64();  // tagged -> float64 -> float32
-    node = jsgraph()->graph()->NewNode(op, node);
-    op = machine()->TruncateFloat64ToFloat32();
+    if (output_type->Is(Type::Number())) {
+      op = simplified()
+               ->ChangeTaggedToFloat64();  // tagged -> float64 -> float32
+      node = jsgraph()->graph()->NewNode(op, node);
+      op = machine()->TruncateFloat64ToFloat32();
+    }
   } else if (output_rep == MachineRepresentation::kFloat64) {
     op = machine()->TruncateFloat64ToFloat32();
-  } else {
+  }
+  if (op == nullptr) {
     return TypeError(node, output_rep, output_type,
                      MachineRepresentation::kFloat32);
   }
   return jsgraph()->graph()->NewNode(op, node);
 }
 
 
 Node* RepresentationChanger::GetFloat64RepresentationFor(
     Node* node, MachineRepresentation output_rep, Type* output_type,
     Truncation truncation) {
@@ skipping 11 matching lines @@
         return jsgraph()->Float64Constant(static_cast<double>(value));
       }
     case IrOpcode::kFloat64Constant:
       return node;  // No change necessary.
     case IrOpcode::kFloat32Constant:
       return jsgraph()->Float64Constant(OpParameter<float>(node));
     default:
       break;
   }
   // Select the correct X -> Float64 operator.
-  const Operator* op;
-  if (output_rep == MachineRepresentation::kBit) {
-    return TypeError(node, output_rep, output_type,
-                     MachineRepresentation::kFloat64);
-  } else if (IsWord(output_rep)) {
+  const Operator* op = nullptr;
+  if (IsWord(output_rep)) {
     if (output_type->Is(Type::Signed32())) {
       op = machine()->ChangeInt32ToFloat64();
-    } else {
-      // Either the output is int32 or the uses only care about the
-      // low 32 bits (so we can pick int32 safely).
-      DCHECK(output_type->Is(Type::Unsigned32()) ||
-             truncation.TruncatesToWord32());
+    } else if (output_type->Is(Type::Unsigned32()) ||
+               truncation.TruncatesToWord32()) {
+      // Either the output is uint32 or the uses only care about the
+      // low 32 bits (so we can pick uint32 safely).
       op = machine()->ChangeUint32ToFloat64();
     }
   } else if (output_rep == MachineRepresentation::kTagged) {
-    op = simplified()->ChangeTaggedToFloat64();
+    if (output_type->Is(Type::Number())) {
+      op = simplified()->ChangeTaggedToFloat64();
+    }
   } else if (output_rep == MachineRepresentation::kFloat32) {
     op = machine()->ChangeFloat32ToFloat64();
-  } else {
+  }
+  if (op == nullptr) {
     return TypeError(node, output_rep, output_type,
                      MachineRepresentation::kFloat64);
   }
   return jsgraph()->graph()->NewNode(op, node);
 }
 
 
 Node* RepresentationChanger::MakeTruncatedInt32Constant(double value) {
   return jsgraph()->Int32Constant(DoubleToInt32(value));
 }
 
-
 Node* RepresentationChanger::GetWord32RepresentationFor(
-    Node* node, MachineRepresentation output_rep, Type* output_type) {
+    Node* node, MachineRepresentation output_rep, Type* output_type,
+    Truncation truncation) {
   // Eagerly fold representation changes for constants.
   switch (node->opcode()) {
     case IrOpcode::kInt32Constant:
       return node;  // No change necessary.
     case IrOpcode::kFloat32Constant:
       return MakeTruncatedInt32Constant(OpParameter<float>(node));
     case IrOpcode::kNumberConstant:
     case IrOpcode::kFloat64Constant:
       return MakeTruncatedInt32Constant(OpParameter<double>(node));
     default:
       break;
   }
   // Select the correct X -> Word32 operator.
-  const Operator* op;
-  Type* type = NodeProperties::GetType(node);
-
+  const Operator* op = nullptr;
   if (output_rep == MachineRepresentation::kBit) {
     return node;  // Sloppy comparison -> word32
   } else if (output_rep == MachineRepresentation::kFloat64) {
-    // TODO(jarin) Use only output_type here, once we intersect it with the
-    // type inferred by the typer.
-    if (output_type->Is(Type::Unsigned32()) || type->Is(Type::Unsigned32())) {
+    if (output_type->Is(Type::Unsigned32())) {
       op = machine()->ChangeFloat64ToUint32();
-    } else if (output_type->Is(Type::Signed32()) ||
-               type->Is(Type::Signed32())) {
+    } else if (output_type->Is(Type::Signed32())) {
       op = machine()->ChangeFloat64ToInt32();
-    } else {
+    } else if (truncation.TruncatesToWord32()) {
       op = machine()->TruncateFloat64ToInt32(TruncationMode::kJavaScript);
     }
   } else if (output_rep == MachineRepresentation::kFloat32) {
     node = InsertChangeFloat32ToFloat64(node);  // float32 -> float64 -> int32
-    if (output_type->Is(Type::Unsigned32()) || type->Is(Type::Unsigned32())) {
+    if (output_type->Is(Type::Unsigned32())) {
       op = machine()->ChangeFloat64ToUint32();
-    } else if (output_type->Is(Type::Signed32()) ||
-               type->Is(Type::Signed32())) {
+    } else if (output_type->Is(Type::Signed32())) {
       op = machine()->ChangeFloat64ToInt32();
-    } else {
+    } else if (truncation.TruncatesToWord32()) {
       op = machine()->TruncateFloat64ToInt32(TruncationMode::kJavaScript);
     }
   } else if (output_rep == MachineRepresentation::kTagged) {
-    if (output_type->Is(Type::Unsigned32()) || type->Is(Type::Unsigned32())) {
+    if (output_type->Is(Type::Unsigned32())) {
       op = simplified()->ChangeTaggedToUint32();
-    } else if (output_type->Is(Type::Signed32()) ||
-               type->Is(Type::Signed32())) {
+    } else if (output_type->Is(Type::Signed32())) {
       op = simplified()->ChangeTaggedToInt32();
-    } else {
+    } else if (truncation.TruncatesToWord32()) {
       node = InsertChangeTaggedToFloat64(node);
       op = machine()->TruncateFloat64ToInt32(TruncationMode::kJavaScript);
     }
-  } else {
+  }
+  if (op == nullptr) {
     return TypeError(node, output_rep, output_type,
                      MachineRepresentation::kWord32);
   }
   return jsgraph()->graph()->NewNode(op, node);
 }
 
 
 Node* RepresentationChanger::GetBitRepresentationFor(
     Node* node, MachineRepresentation output_rep, Type* output_type) {
   // Eagerly fold representation changes for constants.
@@ skipping 145 matching lines @@
 
 
 Node* RepresentationChanger::InsertChangeTaggedToFloat64(Node* node) {
   return jsgraph()->graph()->NewNode(simplified()->ChangeTaggedToFloat64(),
                                      node);
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8