Add new Float32x4 type for SIMD.js.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 526f20dd1893d148c339fe53e86917914adfa0ab..74f6035cb04405933ad062cc6425985ab98743e9 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -121,6 +121,7 @@
 //             - ExternalTwoByteInternalizedString
 //       - Symbol
 //     - HeapNumber
+//     - Float32x4
 //     - Cell
 //     - PropertyCell
 //     - Code
@@ -394,6 +395,7 @@ const int kStubMinorKeyBits = kSmiValueSize - kStubMajorKeyBits - 1;
                                                                 \
   V(HEAP_NUMBER_TYPE)                                           \
   V(MUTABLE_HEAP_NUMBER_TYPE)                                   \
+  V(FLOAT32X4_TYPE)                                             \
   V(FOREIGN_TYPE)                                               \
   V(BYTE_ARRAY_TYPE)                                            \
   V(FREE_SPACE_TYPE)                                            \
@@ -689,6 +691,7 @@ enum InstanceType {
   // objects.
   HEAP_NUMBER_TYPE,
   MUTABLE_HEAP_NUMBER_TYPE,
+  FLOAT32X4_TYPE,  // FIRST_SIMD_TYPE, LAST_SIMD_TYPE
   FOREIGN_TYPE,
   BYTE_ARRAY_TYPE,
   FREE_SPACE_TYPE,
@@ -780,6 +783,9 @@ enum InstanceType {
   FIRST_UNIQUE_NAME_TYPE = INTERNALIZED_STRING_TYPE,
   LAST_UNIQUE_NAME_TYPE = SYMBOL_TYPE,
   FIRST_NONSTRING_TYPE = SYMBOL_TYPE,
+  // Boundaries for testing for a SIMD type.
+  FIRST_SIMD_TYPE = FLOAT32X4_TYPE,
+  LAST_SIMD_TYPE = FLOAT32X4_TYPE,
   // Boundaries for testing for an external array.
   FIRST_EXTERNAL_ARRAY_TYPE = EXTERNAL_INT8_ARRAY_TYPE,
   LAST_EXTERNAL_ARRAY_TYPE = EXTERNAL_UINT8_CLAMPED_ARRAY_TYPE,
@@ -946,6 +952,7 @@ template <class C> inline bool Is(Object* obj);
   V(FixedFloat32Array)             \
   V(FixedFloat64Array)             \
   V(FixedUint8ClampedArray)        \
+  V(Float32x4)                     \
   V(ByteArray)                     \
   V(FreeSpace)                     \
   V(JSReceiver)                    \
@@ -1607,6 +1614,44 @@ class HeapNumber: public HeapObject {
 };
 
 
+// The Float32x4 class describes heap allocated SIMD values holding 4 32-bit
+// IEEE floats.
+class Float32x4 : public HeapObject {
+ public:
+  inline double get_lane(int lane) const;

[titzer, 2015/06/03 13:27:15]

I think we should float here too.

[bbudge, 2015/06/03 20:31:48]

Done.

+  inline void set_lane(int lane, double value);
+
+  DECLARE_CAST(Float32x4)
+
+  // Dispatched behavior.
+  bool Float32x4BooleanValue();
+
+  void Float32x4Print(std::ostream& os);  // NOLINT
+  DECLARE_VERIFIER(Float32x4)
+
+  // Layout description.
+  static const int kValueOffset = HeapObject::kHeaderSize;
+#if defined(V8_TARGET_LITTLE_ENDIAN)

[titzer, 2015/06/03 13:27:15]

Can we leave these out of the header to force users to go through the get_lane()
and set_lane() methods?

[bbudge, 2015/06/03 20:31:48]

Done (I just deleted them, since they're not used anywhere and I'm not sure
they're needed.)

+  static const int kLane0Offset = kValueOffset;
+  static const int kLane1Offset = kValueOffset + 4;
+  static const int kLane2Offset = kValueOffset + 8;
+  static const int kLane3Offset = kValueOffset + 12;
+#elif defined(V8_TARGET_BIG_ENDIAN)
+  static const int kLane0Offset = kValueOffset + 12;
+  static const int kLane1Offset = kValueOffset + 8;
+  static const int kLane2Offset = kValueOffset + 4;
+  static const int kLane3Offset = kValueOffset;
+#else
+#error Unknown byte ordering
+#endif
+
+  static const int kSize = kValueOffset + kSimd128Size;
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(Float32x4);
+};
+
+
 enum EnsureElementsMode {
   DONT_ALLOW_DOUBLE_ELEMENTS,
   ALLOW_COPIED_DOUBLE_ELEMENTS,