Prevent deopt on double value assignment to typed arrays

src/hydrogen.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 3787 matching lines @@
   ASSERT(map->has_external_array_elements());
   AddInstruction(new(zone()) HCheckMap(object, map));
   HLoadElements* elements = new(zone()) HLoadElements(object);
   AddInstruction(elements);
   HInstruction* length = AddInstruction(
       new(zone()) HExternalArrayLength(elements));
   AddInstruction(new(zone()) HBoundsCheck(key, length));
   HLoadExternalArrayPointer* external_elements =
       new(zone()) HLoadExternalArrayPointer(elements);
   AddInstruction(external_elements);
-  if (expr->external_array_type() == kExternalPixelArray) {
-    HClampToUint8* clamp = new(zone()) HClampToUint8(val);
-    AddInstruction(clamp);
-    val = clamp;
+  ExternalArrayType array_type = expr->external_array_type();
+  switch (array_type) {
+    case kExternalPixelArray: {
+      HClampToUint8* clamp = new(zone()) HClampToUint8(val);
+      AddInstruction(clamp);
+      val = clamp;
+      break;
+    }
+    case kExternalByteArray:
+    case kExternalUnsignedByteArray:
+    case kExternalShortArray:
+    case kExternalUnsignedShortArray:
+    case kExternalIntArray:
+    case kExternalUnsignedIntArray: {
+      HToInt32* floor_val = new(zone()) HToInt32(val);
+      AddInstruction(floor_val);
+      val = floor_val;
+      break;
+    }
+    case kExternalFloatArray:
+    case kExternalDoubleArray:
+      break;
   }
   return new(zone()) HStoreKeyedSpecializedArrayElement(
       external_elements,
       key,
       val,
       expr->external_array_type());
 }
 
 
 HInstruction* HGraphBuilder::BuildStoreKeyed(HValue* object,
@@ skipping 2408 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify();
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal