Add custom typed ICs for pixel array loads.

src/ia32/ic-ia32.cc

Index: src/ia32/ic-ia32.cc
===================================================================
--- src/ia32/ic-ia32.cc	(revision 6456)
+++ src/ia32/ic-ia32.cc	(working copy)
@@ -760,6 +760,40 @@
 }
 
 
+void KeyedLoadIC::GeneratePixelArray(MacroAssembler* masm) {
+  // ----------- S t a t e -------------
+  //  -- eax    : key
+  //  -- edx    : receiver
+  //  -- esp[0] : return address
+  // -----------------------------------
+  Label slow;
+
+  // Verify that it's safe to access the receiver's elements.
+  GenerateKeyedLoadReceiverCheck(
+      masm, edx, ecx, Map::kHasNamedInterceptor, &slow);
+
+  // Verify that the receiver has pixel array elements
+  __ mov(ecx, FieldOperand(edx, JSObject::kElementsOffset));
+  __ CheckMap(ecx, Factory::pixel_array_map(), &slow, true);
+
+  // Verify that the key is a smi that's in range.
+  __ test(eax, Immediate(kSmiTagMask));
+  __ j(not_zero, &slow, not_taken);
+  __ SmiUntag(eax);
+  __ cmp(eax, FieldOperand(ecx, PixelArray::kLengthOffset));
+  __ j(above_equal, &slow);
+
+  // Load the element and tag it as an smi.
+  __ mov(ebx, FieldOperand(ecx, PixelArray::kExternalPointerOffset));
+  __ movzx_b(eax, Operand(ebx, eax, times_1, 0));
+  __ SmiTag(eax);
+  __ ret(0);
+
+  __ bind(&slow);
+  GenerateMiss(masm);
+}
+
+
 void KeyedStoreIC::GenerateGeneric(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- eax    : value