Add custom typed ICs for pixel array loads.

src/x64/ic-x64.cc

 // Copyright 2010 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 497 matching lines @@
   __ CompareRoot(scratch, Heap::kTheHoleValueRootIndex);
   // In case the loaded value is the_hole we have to consult GetProperty
   // to ensure the prototype chain is searched.
   __ j(equal, out_of_range);
   if (!result.is(scratch)) {
     __ movq(result, scratch);
   }
 }
 
 
+// Loads a indexed element from a pixel array.
+static void GenerateFastPixelArrayLoad(MacroAssembler* masm,
+                                       Register receiver,
+                                       Register key,
+                                       Register elements,
+                                       Register untagged_key,
+                                       Register result,
+                                       Label* not_pixel_array,
+                                       Label* key_not_smi,
+                                       Label* out_of_range) {
+  // Register use:
+  //   receiver - holds the receiver and is unchanged.
+  //   key - holds the key and is unchanged (must be a smi).
+  //   elements - is set to the the receiver's element if 
+  //       the receiver doesn't have a pixel array or the 
+  //       key is not a smi, otherwise it's the elements'
+  //       external pointer.
+  //   untagged_key - is set to the untagged key
+
+  // Check that the key is a smi.
+  if (key_not_smi != NULL)

[Mads Ager (chromium), 2011/01/28 10:39:16]

Braces or one-liner. 

+    __ JumpIfNotSmi(key, key_not_smi);
+  __ SmiToInteger32(untagged_key, key);
+
+  // Verify that the receiver has pixel array elements.
+  __ movq(elements, FieldOperand(receiver, JSObject::kElementsOffset));
+  __ CompareRoot(FieldOperand(elements, HeapObject::kMapOffset),
+                 Heap::kPixelArrayMapRootIndex);
+  __ j(not_equal, not_pixel_array);
+
+  // Check that the smi is in range.
+  __ cmpl(untagged_key, FieldOperand(elements, PixelArray::kLengthOffset));
+  __ j(above_equal, out_of_range);
+
+  // Load and tag the element as a smi.
+  __ movq(elements, FieldOperand(elements, PixelArray::kExternalPointerOffset));
+  __ movzxbq(result, Operand(elements, untagged_key, times_1, 0));
+  __ Integer32ToSmi(result, result);
+  __ ret(0);
+}
+
+
 // Checks whether a key is an array index string or a symbol string.
 // Falls through if the key is a symbol.
 static void GenerateKeyStringCheck(MacroAssembler* masm,
                                    Register key,
                                    Register map,
                                    Register hash,
                                    Label* index_string,
                                    Label* not_symbol) {
   // Register use:
   //   key - holds the key and is unchanged. Assumed to be non-smi.
@@ skipping 45 matching lines @@
                         rax,
                         rcx,
                         rbx,
                         rax,
                         NULL,
                         &slow);
   __ IncrementCounter(&Counters::keyed_load_generic_smi, 1);
   __ ret(0);
 
   __ bind(&check_pixel_array);
-  // Check whether the elements object is a pixel array.
-  // rdx: receiver
-  // rax: key
-  __ movq(rcx, FieldOperand(rdx, JSObject::kElementsOffset));
-  __ SmiToInteger32(rbx, rax);  // Used on both directions of next branch.
-  __ CompareRoot(FieldOperand(rcx, HeapObject::kMapOffset),
-                 Heap::kPixelArrayMapRootIndex);
-  __ j(not_equal, &check_number_dictionary);
-  __ cmpl(rbx, FieldOperand(rcx, PixelArray::kLengthOffset));
-  __ j(above_equal, &slow);
-  __ movq(rax, FieldOperand(rcx, PixelArray::kExternalPointerOffset));
-  __ movzxbq(rax, Operand(rax, rbx, times_1, 0));
-  __ Integer32ToSmi(rax, rax);
-  __ ret(0);
+  GenerateFastPixelArrayLoad(masm,
+                             rdx,
+                             rax,
+                             rcx,
+                             rbx,
+                             rax,
+                             &check_number_dictionary,
+                             NULL,
+                             &slow);
 
   __ bind(&check_number_dictionary);
   // Check whether the elements is a number dictionary.
   // rdx: receiver
   // rax: key
   // rbx: key as untagged int32
   // rcx: elements
   __ CompareRoot(FieldOperand(rcx, HeapObject::kMapOffset),
                  Heap::kHashTableMapRootIndex);
   __ j(not_equal, &slow);
@@ skipping 153 matching lines @@
   __ push(rcx);  // return address
 
   // Perform tail call to the entry.
   __ TailCallExternalReference(ExternalReference(
         IC_Utility(kKeyedLoadPropertyWithInterceptor)), 2, 1);
 
   __ bind(&slow);
   GenerateMiss(masm);
 }
 
+void KeyedLoadIC::GeneratePixelArray(MacroAssembler* masm) {
+  // ----------- S t a t e -------------
+  //  -- rax    : key
+  //  -- rdx    : receiver
+  //  -- rsp[0] : return address
+  // -----------------------------------
+  Label slow;
+
+  // Verify that it's safe to access the receiver's elements.
+  GenerateKeyedLoadReceiverCheck(
+      masm, rdx, rcx, Map::kHasNamedInterceptor, &slow);
+
+  // Generate the indexed load from the pixel array.
+  GenerateFastPixelArrayLoad(masm,
+                             rdx,
+                             rax,
+                             rcx,
+                             rbx,
+                             rax,
+                             &slow,
+                             &slow,
+                             &slow);
+
+  __ bind(&slow);
+  GenerateMiss(masm);
+}
+
 
 void KeyedStoreIC::GenerateGeneric(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- rax     : value
   //  -- rcx     : key
   //  -- rdx     : receiver
   //  -- rsp[0]  : return address
   // -----------------------------------
   Label slow, slow_with_tagged_index, fast, array, extra, check_pixel_array;
 
@@ skipping 923 matching lines @@
 }
 
 void PatchInlinedSmiCode(Address address) {
   UNIMPLEMENTED();
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64