Fix LoadOptimizer's handling of load/stores with constant indices for TypedData.

tests/language/vm/load_to_load_forwarding_vm_test.dart

Index: tests/language/vm/load_to_load_forwarding_vm_test.dart
diff --git a/tests/language/vm/load_to_load_forwarding_vm_test.dart b/tests/language/vm/load_to_load_forwarding_vm_test.dart
index 7da5fd26ae918ec822d47f4a7d0562a47181526b..d063eaf520011ecdb4670421124c114e176e6a5a 100644
--- a/tests/language/vm/load_to_load_forwarding_vm_test.dart
+++ b/tests/language/vm/load_to_load_forwarding_vm_test.dart
@@ -486,6 +486,40 @@ testAliasesRefinement() {
   return b.f;
 }
 
+testViewAliasing1() {
+  final f64 = new Float64List(1);
+  final f32 = new Float32List.view(f64.buffer);
+  f64[0] = 1.0;  // lower 32bits are all 0s

[Florian Schneider, 2015/01/26 13:30:39]

Comment: Should not be forwarded.

[Vyacheslav Egorov (Google), 2015/01/26 14:57:16]

Done.

+  f32[1] = 2.0;  // upper 32bits for 2.0f and 2.0 are the same
+  return f64[0];
+}
+
+testViewAliasing2() {
+  final f64 = new Float64List(2);
+  final f64v = new Float64List.view(f64.buffer, Float64List.BYTES_PER_ELEMENT);
+  f64[1] = 1.0;

[Florian Schneider, 2015/01/26 13:30:39]

Comment: Should be forwarded.

[Vyacheslav Egorov (Google), 2015/01/26 14:57:16]

Should *not* be forwarded.

+  f64v[0] = 2.0;
+  return f64[1];
+}
+
+testViewAliasing3() {
+  final u8 = new Uint8List(Float64List.BYTES_PER_ELEMENT * 2);
+  final f64 = new Float64List.view(u8.buffer, Float64List.BYTES_PER_ELEMENT);
+  f64[0] = 1.0;

[Florian Schneider, 2015/01/26 13:30:39]

Comment: Should be forwarded, [0,7] and [14], [15] don't overlap.

[Vyacheslav Egorov (Google), 2015/01/26 14:57:16]

note: view starts at 8 - means f64[0] is bytes 8-15. should not be forwarded.

+  u8[15] = 0x40;
+  u8[14] = 0x00;
+  return f64[0];
+}
+
+testViewAliasing4() {
+  final u8 = new Uint8List(Float64List.BYTES_PER_ELEMENT * 2);
+  final f64 = new Float64List.view(u8.buffer, Float64List.BYTES_PER_ELEMENT);
+  f64[0] = 2.0;  // Not aliased: should be forwarded.

[Florian Schneider, 2015/01/26 13:30:39]

This should not be forwarded, since f64[0] writes [0,7] and [0],[1] overlap.

[Vyacheslav Egorov (Google), 2015/01/26 14:57:16]

note: view starts at 8 like about. should *be* forwarded.

+  u8[0] = 0x40;
+  u8[1] = 0x00;
+  return f64[0];
+}
+
 main() {
   final fixed = new List(10);
   final growable = [];
@@ -552,4 +586,11 @@ main() {
   for (var i = 0; i < 20; i++) {
     Expect.equals(43, testAliasingStoreIndexed(global_array));
   }
+
+  for (var i = 0; i < 20; i++) {
+    Expect.equals(2.0, testViewAliasing1());
+    Expect.equals(2.0, testViewAliasing2());
+    Expect.equals(2.0, testViewAliasing3());
+    Expect.equals(2.0, testViewAliasing4());
+  }
 }