Implement in-heap backing store for typed arrays.

src/hydrogen-instructions.h

Index: src/hydrogen-instructions.h
diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index a19c3ee507908c45e891f6d2baab33e763ae3c2e..beb339b1d6de8061a1f1cb46460e3d5f23a144ab 100644
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -207,7 +207,8 @@ class LChunkBuilder;
   V(InobjectFields)                            \
   V(OsrEntries)                                \
   V(ExternalMemory)                            \
-  V(StringChars)
+  V(StringChars)                               \
+  V(TypedArrayElements)
 
 
 #define DECLARE_ABSTRACT_INSTRUCTION(type)                              \
@@ -6366,6 +6367,12 @@ class HLoadKeyed V8_FINAL
   bool is_external() const {
     return IsExternalArrayElementsKind(elements_kind());
   }
+  bool is_fixed_typed_array() const {
+    return IsFixedTypedArrayElementsKind(elements_kind());
+  }
+  bool is_typed_elements() const {
+    return is_external() || is_fixed_typed_array();
+  }
   HValue* elements() { return OperandAt(0); }
   HValue* key() { return OperandAt(1); }
   HValue* dependency() {
@@ -6394,9 +6401,10 @@ class HLoadKeyed V8_FINAL
   }
 
   virtual Representation RequiredInputRepresentation(int index) V8_OVERRIDE {
-    // kind_fast:       tagged[int32] (none)
-    // kind_double:     tagged[int32] (none)
-    // kind_external: external[int32] (none)
+    // kind_fast:                 tagged[int32] (none)
+    // kind_double:               tagged[int32] (none)
+    // kind_fixed_typed_array:    tagged[int32] (none)
+    // kind_external:             external[int32] (none)
     if (index == 0) {
       return is_external() ? Representation::External()
           : Representation::Tagged();
@@ -6446,7 +6454,7 @@ class HLoadKeyed V8_FINAL
     SetOperandAt(1, key);
     SetOperandAt(2, dependency != NULL ? dependency : obj);
 
-    if (!is_external()) {
+    if (!is_typed_elements()) {
       // I can detect the case between storing double (holey and fast) and
       // smi/object by looking at elements_kind_.
       ASSERT(IsFastSmiOrObjectElementsKind(elements_kind) ||
@@ -6473,13 +6481,21 @@ class HLoadKeyed V8_FINAL
       }
     } else {
       if (elements_kind == EXTERNAL_FLOAT_ELEMENTS ||
-          elements_kind == EXTERNAL_DOUBLE_ELEMENTS) {
+          elements_kind == EXTERNAL_DOUBLE_ELEMENTS ||
+          elements_kind == FLOAT32_ELEMENTS ||
+          elements_kind == FLOAT64_ELEMENTS) {
         set_representation(Representation::Double());
       } else {
         set_representation(Representation::Integer32());
       }
 
-      SetGVNFlag(kDependsOnExternalMemory);
+      if (is_external()) {
+        SetGVNFlag(kDependsOnExternalMemory);
+      } else if (is_fixed_typed_array()) {
+        SetGVNFlag(kDependsOnTypedArrayElements);
+      } else {
+        UNREACHABLE();
+      }
       // Native code could change the specialized array.
       SetGVNFlag(kDependsOnCalls);
     }
@@ -6738,10 +6754,11 @@ class HStoreKeyed V8_FINAL
                                  ElementsKind, StoreFieldOrKeyedMode);
 
   virtual Representation RequiredInputRepresentation(int index) V8_OVERRIDE {
-    // kind_fast:       tagged[int32] = tagged
-    // kind_double:     tagged[int32] = double
-    // kind_smi   :     tagged[int32] = smi
-    // kind_external: external[int32] = (double | int32)
+    // kind_fast:               tagged[int32] = tagged
+    // kind_double:             tagged[int32] = double
+    // kind_smi   :             tagged[int32] = smi
+    // kind_fixed_typed_array:  tagged[int32] = (double | int32)
+    // kind_external:           external[int32] = (double | int32)
     if (index == 0) {
       return is_external() ? Representation::External()
                            : Representation::Tagged();
@@ -6761,14 +6778,23 @@ class HStoreKeyed V8_FINAL
       return Representation::Smi();
     }
 
-    return is_external() ? Representation::Integer32()
-                         : Representation::Tagged();
+    return is_external() || is_fixed_typed_array()
+        ? Representation::Integer32()
+        : Representation::Tagged();
   }
 
   bool is_external() const {
     return IsExternalArrayElementsKind(elements_kind());
   }
 
+  bool is_fixed_typed_array() const {
+    return IsFixedTypedArrayElementsKind(elements_kind());
+  }
+
+  bool is_typed_elements() const {
+    return is_external() || is_fixed_typed_array();
+  }
+
   virtual Representation observed_input_representation(int index) V8_OVERRIDE {
     if (index < 2) return RequiredInputRepresentation(index);
     if (IsUninitialized()) {
@@ -6783,7 +6809,7 @@ class HStoreKeyed V8_FINAL
     if (IsFastSmiElementsKind(elements_kind())) {
       return Representation::Smi();
     }
-    if (is_external()) {
+    if (is_typed_elements()) {
       return Representation::Integer32();
     }
     // For fast object elements kinds, don't assume anything.
@@ -6868,13 +6894,18 @@ class HStoreKeyed V8_FINAL
       SetGVNFlag(kChangesDoubleArrayElements);
     } else if (IsFastSmiElementsKind(elements_kind)) {
       SetGVNFlag(kChangesArrayElements);
+    } else if (is_fixed_typed_array()) {
+      SetGVNFlag(kChangesTypedArrayElements);
+      SetFlag(kAllowUndefinedAsNaN);
     } else {
       SetGVNFlag(kChangesArrayElements);
     }
 
     // EXTERNAL_{UNSIGNED_,}{BYTE,SHORT,INT}_ELEMENTS are truncating.
-    if (elements_kind >= EXTERNAL_BYTE_ELEMENTS &&
-        elements_kind <= EXTERNAL_UNSIGNED_INT_ELEMENTS) {
+    if ((elements_kind >= EXTERNAL_BYTE_ELEMENTS &&
+        elements_kind <= EXTERNAL_UNSIGNED_INT_ELEMENTS) ||
+        (elements_kind >= UINT8_ELEMENTS &&
+        elements_kind <= INT32_ELEMENTS)) {
       SetFlag(kTruncatingToInt32);
     }
   }