Port SIMD types from dart:scalarlist to dart:typeddata.

sdk/lib/typeddata/typeddata_base.dart

Index: sdk/lib/typeddata/typeddata_base.dart
diff --git a/sdk/lib/typeddata/typeddata_base.dart b/sdk/lib/typeddata/typeddata_base.dart
index f40c403ec52a591108b4909553188515123172c5..ffe98ce875eb9bb24cd21efc8b8188341a53983f 100644
--- a/sdk/lib/typeddata/typeddata_base.dart
+++ b/sdk/lib/typeddata/typeddata_base.dart
@@ -309,6 +309,26 @@ abstract class ByteData implements TypedData {
    * `byteOffset + 8` is greater than the length of this object.
    */
   void setFloat64(int byteOffset, double value);
+
+  /**
+   * Returns the 4 floating point numbers represented by the sixteen bytes at
+   * the specified [byteOffset] in this object, in IEEE 754
+   * single-precision binary floating-point format (binary32).
+   *
+   * Throws [RangeError] if [byteOffset] is negative, or
+   * `byteOffset + 16` is greater than the length of this object.
+   */
+  Float32x4 getFloat32x4(int byteOffset);
+
+  /**
+   * Sets the sixteen bytes starting at the specified [byteOffset] in this
+   * object to the 4 IEEE 754 single-precision binary floating-point
+   * (binary32) numbers of the specified [value].
+   *
+   * Throws [RangeError] if [byteOffset] is negative, or
+   * `byteOffset + 16` is greater than the length of this object.
+   */
+  void setFloat32x4(int byteOffset, Float32x4 value);
 }
 
 
@@ -679,3 +699,36 @@ abstract class Float64List implements List<double>, TypedData {
 
   static const int BYTES_PER_ELEMENT = 8;
 }
+
+/**
+ * A fixed-length list of Float32x4 numbers that is viewable as a
+ * [TypedData]. For long lists, this implementation will be considerably more
+ * space- and time-efficient than the default [List] implementation.
+ */
+abstract class Float32x4List implements List<Float32x4>, TypedData {
+  /**
+   * Creates a [Float32x4List] of the specified length (in elements),
+   * all of whose elements are initially zero.
+   */
+  external factory Float32x4List(int length);
+
+  /**
+   * Creates a [Float32x4List] _view_ of the specified region in the specified
+   * byte buffer. Changes in the [Float32x4List] will be visible in the byte
+   * buffer and vice versa. If the [offsetInBytes] index of the region is not
+   * specified, it defaults to zero (the first byte in the byte buffer).
+   * If the length is not specified, it defaults to null, which indicates
+   * that the view extends to the end of the byte buffer.
+   *
+   * Throws [RangeError] if [offsetInBytes] or [length] are negative, or
+   * if [offsetInBytes] + ([length] * elementSizeInBytes) is greater than
+   * the length of [buffer].
+   *
+   * Throws [ArgumentError] if [offsetInBytes] is not a multiple of
+   * BYTES_PER_ELEMENT.
+   */
+  external factory Float32x4List.view(ByteBuffer buffer,
+                                      [int offsetInBytes = 0, int length]);
+
+  static const int BYTES_PER_ELEMENT = 16;
+}