Add support for Float32 representation changes.

src/compiler/representation-change.h

 // Copyright 2014 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.
 
 #ifndef V8_COMPILER_REPRESENTATION_CHANGE_H_
 #define V8_COMPILER_REPRESENTATION_CHANGE_H_
 
 #include "src/base/bits.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/machine-operator.h"
@@ skipping 70 matching lines @@
           int32_t value = OpParameter<int32_t>(node);
           return jsgraph()->Constant(value);
         } else if (output_type & kRepBit) {
           return OpParameter<int32_t>(node) == 0 ? jsgraph()->FalseConstant()
                                                  : jsgraph()->TrueConstant();
         } else {
           return TypeError(node, output_type, kRepTagged);
         }
       case IrOpcode::kFloat64Constant:
         return jsgraph()->Constant(OpParameter<double>(node));
+      case IrOpcode::kFloat32Constant:
+        return jsgraph()->Constant(OpParameter<float>(node));
       default:
         break;
     }
     // Select the correct X -> Tagged operator.
     const Operator* op;
     if (output_type & kRepBit) {
       op = simplified()->ChangeBitToBool();
     } else if (output_type & rWord) {
       if (output_type & kTypeUint32) {
         op = simplified()->ChangeUint32ToTagged();
       } else if (output_type & kTypeInt32) {
         op = simplified()->ChangeInt32ToTagged();
       } else {
         return TypeError(node, output_type, kRepTagged);
       }
-    } else if (output_type & kRepFloat32) {
-      node = jsgraph()->graph()->NewNode(machine()->ChangeFloat32ToFloat64(),
-                                         node);
+    } else if (output_type & kRepFloat32) {  // float32 -> float64 -> tagged
+      node = InsertChangeFloat32ToFloat64(node);
       op = simplified()->ChangeFloat64ToTagged();
     } else if (output_type & kRepFloat64) {
       op = simplified()->ChangeFloat64ToTagged();
     } else {
       return TypeError(node, output_type, kRepTagged);
     }
     return jsgraph()->graph()->NewNode(op, node);
   }
 
   Node* GetFloat32RepresentationFor(Node* node, MachineTypeUnion output_type) {
     // Eagerly fold representation changes for constants.
     switch (node->opcode()) {
-      // TODO(turbofan): NumberConstant, Int32Constant, and Float64Constant?
+      case IrOpcode::kFloat64Constant:
+      case IrOpcode::kNumberConstant:
+        return jsgraph()->Float32Constant(OpParameter<float>(node));

[Benedikt Meurer, 2014/09/24 11:43:31]

DoubleToFloat32(OpParameter<double>(node))

[titzer, 2014/09/24 11:52:40]

Done.

+      case IrOpcode::kInt32Constant:
+        if (output_type & kTypeUint32) {
+          uint32_t value = OpParameter<uint32_t>(node);
+          return jsgraph()->Float32Constant(static_cast<float>(value));

[Benedikt Meurer, 2014/09/24 11:43:31]

is that static_cast<float> necessary?

[titzer, 2014/09/24 11:52:40]

Done.

+        } else {
+          int32_t value = OpParameter<int32_t>(node);
+          return jsgraph()->Float32Constant(value);
+        }
       case IrOpcode::kFloat32Constant:
         return node;  // No change necessary.
       default:
         break;
     }
-    // TODO(turbofan): Select the correct X -> Float32 operator.
-    return TypeError(node, output_type, kRepFloat32);
+    // Select the correct X -> Float32 operator.
+    const Operator* op;
+    if (output_type & kRepBit) {
+      return TypeError(node, output_type, kRepFloat32);
+    } else if (output_type & rWord) {
+      if (output_type & kTypeUint32) {
+        op = machine()->ChangeUint32ToFloat64();
+      } else {
+        op = machine()->ChangeInt32ToFloat64();
+      }
+      // int32 -> float64 -> float32
+      node = jsgraph()->graph()->NewNode(op, node);
+      op = machine()->TruncateFloat64ToFloat32();
+    } else if (output_type & kRepTagged) {
+      op = simplified()
+               ->ChangeTaggedToFloat64();  // tagged -> float64 -> float32
+      node = jsgraph()->graph()->NewNode(op, node);
+      op = machine()->TruncateFloat64ToFloat32();
+    } else if (output_type & kRepFloat64) {
+      op = machine()->ChangeFloat32ToFloat64();
+    } else {
+      return TypeError(node, output_type, kRepFloat32);
+    }
+    return jsgraph()->graph()->NewNode(op, node);
   }
 
   Node* GetFloat64RepresentationFor(Node* node, MachineTypeUnion output_type) {
     // Eagerly fold representation changes for constants.
     switch (node->opcode()) {
       case IrOpcode::kNumberConstant:
         return jsgraph()->Float64Constant(OpParameter<double>(node));
       case IrOpcode::kInt32Constant:
         if (output_type & kTypeUint32) {
           uint32_t value = OpParameter<uint32_t>(node);
           return jsgraph()->Float64Constant(static_cast<double>(value));
         } else {
           int32_t value = OpParameter<int32_t>(node);
           return jsgraph()->Float64Constant(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_type & kRepBit) {
       return TypeError(node, output_type, kRepFloat64);
     } else if (output_type & rWord) {
       if (output_type & kTypeUint32) {
         op = machine()->ChangeUint32ToFloat64();
       } else {
         op = machine()->ChangeInt32ToFloat64();
       }
     } else if (output_type & kRepTagged) {
       op = simplified()->ChangeTaggedToFloat64();
     } else if (output_type & kRepFloat32) {
       op = machine()->ChangeFloat32ToFloat64();
     } else {
       return TypeError(node, output_type, kRepFloat64);
     }
     return jsgraph()->graph()->NewNode(op, node);
   }
 
+  Node* MakeInt32Constant(double value) {
+    if (value < 0) {
+      DCHECK(IsInt32Double(value));
+      int32_t iv = static_cast<int32_t>(value);
+      return jsgraph()->Int32Constant(iv);
+    } else {
+      DCHECK(IsUint32Double(value));
+      int32_t iv = static_cast<int32_t>(static_cast<uint32_t>(value));
+      return jsgraph()->Int32Constant(iv);
+    }
+  }
+
   Node* GetWord32RepresentationFor(Node* node, MachineTypeUnion output_type,
                                    bool use_unsigned) {
     // Eagerly fold representation changes for constants.
     switch (node->opcode()) {
       case IrOpcode::kInt32Constant:
         return node;  // No change necessary.
       case IrOpcode::kNumberConstant:
-      case IrOpcode::kFloat64Constant: {
-        double value = OpParameter<double>(node);
-        if (value < 0) {
-          DCHECK(IsInt32Double(value));
-          int32_t iv = static_cast<int32_t>(value);
-          return jsgraph()->Int32Constant(iv);
-        } else {
-          DCHECK(IsUint32Double(value));
-          int32_t iv = static_cast<int32_t>(static_cast<uint32_t>(value));
-          return jsgraph()->Int32Constant(iv);
-        }
-      }
+      case IrOpcode::kFloat32Constant:
+        return MakeInt32Constant(OpParameter<float>(node));
+      case IrOpcode::kFloat64Constant:
+        return MakeInt32Constant(OpParameter<double>(node));
       default:
         break;
     }
     // Select the correct X -> Word32 operator.
     const Operator* op = NULL;
     if (output_type & kRepFloat64) {
       if (output_type & kTypeUint32 || use_unsigned) {
         op = machine()->ChangeFloat64ToUint32();
       } else {
         op = machine()->ChangeFloat64ToInt32();
       }
+    } else if (output_type & kRepFloat32) {
+      node = InsertChangeFloat32ToFloat64(node);  // float32 -> float64 -> int32
+      if (output_type & kTypeUint32 || use_unsigned) {
+        op = machine()->ChangeFloat64ToUint32();
+      } else {
+        op = machine()->ChangeFloat64ToInt32();
+      }
     } else if (output_type & kRepTagged) {
       if (output_type & kTypeUint32 || use_unsigned) {
         op = simplified()->ChangeTaggedToUint32();
       } else {
         op = simplified()->ChangeTaggedToInt32();
       }
     } else {
       return TypeError(node, output_type, kRepWord32);
     }
     return jsgraph()->graph()->NewNode(op, node);
@@ skipping 151 matching lines @@
 
       V8_Fatal(__FILE__, __LINE__,
                "RepresentationChangerError: node #%d:%s of "
                "%s cannot be changed to %s",
                node->id(), node->op()->mnemonic(), out_str.c_str(),
                use_str.c_str());
     }
     return node;
   }
 
+  Node* InsertChangeFloat32ToFloat64(Node* node) {
+    return jsgraph()->graph()->NewNode(machine()->ChangeFloat32ToFloat64(),
+                                       node);
+  }
+
   JSGraph* jsgraph() { return jsgraph_; }
   Isolate* isolate() { return isolate_; }
   SimplifiedOperatorBuilder* simplified() { return simplified_; }
   MachineOperatorBuilder* machine() { return jsgraph()->machine(); }
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_REPRESENTATION_CHANGE_H_