Implement TypedArray.set function.

R=rossberg@chromium.org

Review URL: https://codereview.chromium.org/14581005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14576 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/messages.js

@@ -104,12 +104,15 @@ var kMessages = {
   parameterless_typed_array_constr:
                                  ["%0"," constructor should have at least one argument."],
   not_typed_array:               ["this is not a typed array."],
+  invalid_argument:              ["invalid_argument"],
   // RangeError
   invalid_array_length:          ["Invalid array length"],
   invalid_array_buffer_length:   ["Invalid array buffer length"],
   invalid_typed_array_offset:    ["Start offset is too large"],
   invalid_typed_array_length:    ["Length is too large"],
   invalid_typed_array_alignment: ["%0", "of", "%1", "should be a multiple of", "%3"],
+  typed_array_set_source_too_large:
+                                 ["Source is too large"],
   stack_overflow:                ["Maximum call stack size exceeded"],
   invalid_time_value:            ["Invalid time value"],
   // SyntaxError

src/objects.cc

@@ -13431,6 +13431,33 @@ ExternalArrayType JSTypedArray::type() {
 }
 
 
+size_t JSTypedArray::element_size() {
+  switch (elements()->map()->instance_type()) {
+    case EXTERNAL_BYTE_ARRAY_TYPE:
+      return 1;
+    case EXTERNAL_UNSIGNED_BYTE_ARRAY_TYPE:
+      return 1;
+    case EXTERNAL_SHORT_ARRAY_TYPE:
+      return 2;
+    case EXTERNAL_UNSIGNED_SHORT_ARRAY_TYPE:
+      return 2;
+    case EXTERNAL_INT_ARRAY_TYPE:
+      return 4;
+    case EXTERNAL_UNSIGNED_INT_ARRAY_TYPE:
+      return 4;
+    case EXTERNAL_FLOAT_ARRAY_TYPE:
+      return 4;
+    case EXTERNAL_DOUBLE_ARRAY_TYPE:
+      return 8;
+    case EXTERNAL_PIXEL_ARRAY_TYPE:
+      return 1;
+    default:
+      UNREACHABLE();
+      return 0;
+  }
+}
+
+
 Object* ExternalPixelArray::SetValue(uint32_t index, Object* value) {
   uint8_t clamped_value = 0;
   if (index < static_cast<uint32_t>(length())) {

src/objects.h

@@ -8733,6 +8733,7 @@ class JSTypedArray: public JSObject {
   static inline JSTypedArray* cast(Object* obj);
 
   ExternalArrayType type();
+  size_t element_size();
 
   // Dispatched behavior.
   DECLARE_PRINTER(JSTypedArray)

src/runtime.cc

@@ -891,6 +891,128 @@ TYPED_ARRAY_GETTER(Length, length)
 
 #undef TYPED_ARRAY_GETTER
 
+RUNTIME_FUNCTION(MaybeObject*, Runtime_TypedArraySetFastCases) {
+  HandleScope scope(isolate);
+  CONVERT_ARG_HANDLE_CHECKED(Object, target_obj, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Object, source_obj, 1);
+  CONVERT_ARG_HANDLE_CHECKED(Object, offset_obj, 2);
+
+  if (!target_obj->IsJSTypedArray())
+    return isolate->Throw(*isolate->factory()->NewTypeError(
+        "not_typed_array", HandleVector<Object>(NULL, 0)));
+
+  if (!source_obj->IsJSTypedArray())
+    return isolate->heap()->false_value();
+
+  Handle<JSTypedArray> target(JSTypedArray::cast(*target_obj));
+  Handle<JSTypedArray> source(JSTypedArray::cast(*source_obj));
+  size_t offset = NumberToSize(isolate, *offset_obj);
+  size_t target_length = NumberToSize(isolate, target->length());
+  size_t source_length = NumberToSize(isolate, source->length());
+  size_t target_byte_length = NumberToSize(isolate, target->byte_length());
+  size_t source_byte_length = NumberToSize(isolate, source->byte_length());
+  if (offset > target_length ||
+      offset + source_length > target_length ||
+      offset + source_length < offset)  // overflow
+    return isolate->Throw(*isolate->factory()->NewRangeError(
+          "typed_array_set_source_too_large", HandleVector<Object>(NULL, 0)));
+
+  Handle<JSArrayBuffer> target_buffer(JSArrayBuffer::cast(target->buffer()));
+  Handle<JSArrayBuffer> source_buffer(JSArrayBuffer::cast(source->buffer()));
+  size_t target_offset = NumberToSize(isolate, target->byte_offset());
+  size_t source_offset = NumberToSize(isolate, source->byte_offset());
+  uint8_t* target_base =
+      static_cast<uint8_t*>(target_buffer->backing_store()) + target_offset;
+  uint8_t* source_base =
+      static_cast<uint8_t*>(source_buffer->backing_store()) + source_offset;
+
+  // Typed arrays of the same type: use memmove.
+  if (target->type() == source->type()) {
+    memmove(target_base + offset * target->element_size(),
+        source_base, source_byte_length);
+    return isolate->heap()->true_value();
+  }
+
+  // Typed arrays of different types over the same backing store
+  if ((source_base <= target_base &&
+        source_base + source_byte_length > target_base) ||
+      (target_base <= source_base &&
+        target_base + target_byte_length > source_base)) {
+    size_t target_element_size = target->element_size();
+    size_t source_element_size = source->element_size();
+
+    size_t source_length = NumberToSize(isolate, source->length());
+
+    // Copy left part
+    size_t left_index;
+    {
+      // First un-mutated byte after the next write
+      uint8_t* target_ptr = target_base + (offset + 1) * target_element_size;
+      // Next read at source_ptr. We do not care for memory changing before
+      // source_ptr - we have already copied it.
+      uint8_t* source_ptr = source_base;
+      for (left_index = 0;
+           left_index < source_length && target_ptr <= source_ptr;
+           left_index++) {
+        Handle<Object> v = Object::GetElement(
+            source, static_cast<uint32_t>(left_index));
+        JSObject::SetElement(
+            target, static_cast<uint32_t>(offset + left_index), v,
+            NONE, kNonStrictMode);
+        target_ptr += target_element_size;
+        source_ptr += source_element_size;
+      }
+    }
+    // Copy right part
+    size_t right_index;
+    {
+      // First unmutated byte before the next write
+      uint8_t* target_ptr =
+        target_base + (offset + source_length - 1) * target_element_size;
+      // Next read before source_ptr. We do not care for memory changing after
+      // source_ptr - we have already copied it.
+      uint8_t* source_ptr =
+        source_base + source_length * source_element_size;
+      for (right_index = source_length - 1;
+           right_index >= left_index && target_ptr >= source_ptr;
+           right_index--) {
+        Handle<Object> v = Object::GetElement(
+            source, static_cast<uint32_t>(right_index));
+        JSObject::SetElement(
+            target, static_cast<uint32_t>(offset + right_index), v,
+            NONE, kNonStrictMode);
+        target_ptr -= target_element_size;
+        source_ptr -= source_element_size;
+      }
+    }
+    // There can be at most 8 entries left in the middle that need buffering
+    // (because the largest element_size is 8 times the smallest).
+    ASSERT((right_index + 1) - left_index <= 8);
+    Handle<Object> temp[8];
+    size_t idx;
+    for (idx = left_index; idx <= right_index; idx++) {
+      temp[idx - left_index] = Object::GetElement(
+          source, static_cast<uint32_t>(idx));
+    }
+    for (idx = left_index; idx <= right_index; idx++) {
+      JSObject::SetElement(
+          target, static_cast<uint32_t>(offset + idx), temp[idx-left_index],
+          NONE, kNonStrictMode);
+    }
+  } else {  // Non-overlapping typed arrays
+    for (size_t idx = 0; idx < source_length; idx++) {
+      Handle<Object> value = Object::GetElement(
+          source, static_cast<uint32_t>(idx));
+      JSObject::SetElement(
+          target, static_cast<uint32_t>(offset + idx), value,
+          NONE, kNonStrictMode);
+    }
+  }
+
+  return isolate->heap()->true_value();
+}
+
+
 RUNTIME_FUNCTION(MaybeObject*, Runtime_SetInitialize) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 1);

src/runtime.h

@@ -361,6 +361,7 @@ namespace internal {
   F(TypedArrayGetByteLength, 1, 1) \
   F(TypedArrayGetByteOffset, 1, 1) \
   F(TypedArrayGetLength, 1, 1) \
+  F(TypedArraySetFastCases, 3, 1) \
   \
   /* Statements */ \
   F(NewClosure, 3, 1) \

src/typedarray.js

@@ -145,6 +145,22 @@ function CreateSubArray(elementSize, constructor) {
   }
 }
 
+function TypedArraySet(obj, offset) {
+  var intOffset = IS_UNDEFINED(offset) ? 0 : TO_POSITIVE_INTEGER(offset);
+  if (%TypedArraySetFastCases(this, obj, intOffset))
+    return;
+
+  var l = obj.length;
+  if (IS_UNDEFINED(l)) {
+    throw MakeTypeError("invalid_argument");
+  }
+  if (intOffset + l > this.length) {
+    throw MakeRangeError("typed_array_set_source_too_large");
+  }
+  for (var i = 0; i < l; i++) {
+    this[intOffset + i] = obj[i];
+  }
+}
 
 // -------------------------------------------------------------------
 
@@ -166,7 +182,8 @@ function SetupTypedArray(arrayId, name, constructor, elementSize) {
   InstallGetter(constructor.prototype, "length", TypedArrayGetLength);
 
   InstallFunctions(constructor.prototype, DONT_ENUM, $Array(
-        "subarray", CreateSubArray(elementSize, constructor)
+        "subarray", CreateSubArray(elementSize, constructor),
+        "set", TypedArraySet
   ));
 }
 

test/mjsunit/harmony/typedarrays.js

@@ -371,6 +371,92 @@ for(i = 0; i < typedArrayConstructors.lenght; i++) {
 }
 
 
+function TestTypedArraySet() {
+  // Test array.set in different combinations.
+
+  function assertArrayPrefix(expected, array) {
+    for (var i = 0; i < expected.length; ++i) {
+      assertEquals(expected[i], array[i]);
+    }
+  }
+
+  var a11 = new Int16Array([1, 2, 3, 4, 0, -1])
+  var a12 = new Uint16Array(15)
+  a12.set(a11, 3)
+  assertArrayPrefix([0, 0, 0, 1, 2, 3, 4, 0, 0xffff, 0, 0], a12)
+  assertThrows(function(){ a11.set(a12) })
+
+  var a21 = [1, undefined, 10, NaN, 0, -1, {valueOf: function() {return 3}}]
+  var a22 = new Int32Array(12)
+  a22.set(a21, 2)
+  assertArrayPrefix([0, 0, 1, 0, 10, 0, 0, -1, 3, 0], a22)
+
+  var a31 = new Float32Array([2, 4, 6, 8, 11, NaN, 1/0, -3])
+  var a32 = a31.subarray(2, 6)
+  a31.set(a32, 4)
+  assertArrayPrefix([2, 4, 6, 8, 6, 8, 11, NaN], a31)
+  assertArrayPrefix([6, 8, 6, 8], a32)
+
+  var a4 = new Uint8ClampedArray([3,2,5,6])
+  a4.set(a4)
+  assertArrayPrefix([3, 2, 5, 6], a4)
+
+  // Cases with overlapping backing store but different element sizes.
+  var b = new ArrayBuffer(4)
+  var a5 = new Int16Array(b)
+  var a50 = new Int8Array(b)
+  var a51 = new Int8Array(b, 0, 2)
+  var a52 = new Int8Array(b, 1, 2)
+  var a53 = new Int8Array(b, 2, 2)
+
+  a5.set([0x5050, 0x0a0a])
+  assertArrayPrefix([0x50, 0x50, 0x0a, 0x0a], a50)
+  assertArrayPrefix([0x50, 0x50], a51)
+  assertArrayPrefix([0x50, 0x0a], a52)
+  assertArrayPrefix([0x0a, 0x0a], a53)
+
+  a50.set([0x50, 0x50, 0x0a, 0x0a])
+  a51.set(a5)
+  assertArrayPrefix([0x50, 0x0a, 0x0a, 0x0a], a50)
+
+  a50.set([0x50, 0x50, 0x0a, 0x0a])
+  a52.set(a5)
+  assertArrayPrefix([0x50, 0x50, 0x0a, 0x0a], a50)
+
+  a50.set([0x50, 0x50, 0x0a, 0x0a])
+  a53.set(a5)
+  assertArrayPrefix([0x50, 0x50, 0x50, 0x0a], a50)
+
+  a50.set([0x50, 0x51, 0x0a, 0x0b])
+  a5.set(a51)
+  assertArrayPrefix([0x0050, 0x0051], a5)
+
+  a50.set([0x50, 0x51, 0x0a, 0x0b])
+  a5.set(a52)
+  assertArrayPrefix([0x0051, 0x000a], a5)
+
+  a50.set([0x50, 0x51, 0x0a, 0x0b])
+  a5.set(a53)
+  assertArrayPrefix([0x000a, 0x000b], a5)
+
+  // Mixed types of same size.
+  var a61 = new Float32Array([1.2, 12.3])
+  var a62 = new Int32Array(2)
+  a62.set(a61)
+  assertArrayPrefix([1, 12], a62)
+  a61.set(a62)
+  assertArrayPrefix([1, 12], a61)
+
+  // Invalid source
+  var a = new Uint16Array(50);
+  assertThrows(function() { a.set(0) }, TypeError);
+  assertThrows(function() { a.set({}) }, TypeError);
+  assertThrows(function() { a.set.call({}) }, TypeError);
+  assertThrows(function() { a.set.call([]) }, TypeError);
+}
+
+TestTypedArraySet();
+
 // General tests for properties
 
 // Test property attribute [[Enumerable]]