Implement specialized IC code stubs for pixel array stores.

src/x64/code-stubs-x64.h

Index: src/x64/code-stubs-x64.h
diff --git a/src/x64/code-stubs-x64.h b/src/x64/code-stubs-x64.h
index 8051d4bdbeb5aa898f485293f247c259741d1a7c..119b699304ac2ea4590f7080d75cf4fa421f7ded 100644
--- a/src/x64/code-stubs-x64.h
+++ b/src/x64/code-stubs-x64.h
@@ -452,14 +452,14 @@ class NumberToStringStub: public CodeStub {
 };
 
 
-// Generate code the to load an element from a pixel array. The receiver is
-// assumed to not be a smi and to have elements, the caller must guarantee this
-// precondition. If the receiver does not have elements that are pixel arrays,
-// the generated code jumps to not_pixel_array. If key is not a smi, then the
-// generated code branches to key_not_smi. Callers can specify NULL for
-// key_not_smi to signal that a smi check has already been performed on key so
-// that the smi check is not generated . If key is not a valid index within the
-// bounds of the pixel array, the generated code jumps to out_of_range.
+// Generate code to load an element from a pixel array. The receiver is assumed
+// to not be a smi and to have elements, the caller must guarantee this
+// precondition. If key is not a smi, then the generated code branches to
+// key_not_smi. Callers can specify NULL for key_not_smi to signal that a smi
+// check has already been performed on key so that the smi check is not
+// generated. If key is not a valid index within the bounds of the pixel array,
+// the generated code jumps to out_of_range. receiver, key and elements are
+// unchanged throughout the generated code sequence.
 void GenerateFastPixelArrayLoad(MacroAssembler* masm,
                                 Register receiver,
                                 Register key,
@@ -470,6 +470,30 @@ void GenerateFastPixelArrayLoad(MacroAssembler* masm,
                                 Label* key_not_smi,
                                 Label* out_of_range);
 
+// Generate code to store an element into a pixel array, clamping values between
+// [0..255]. The receiver is assumed to not be a smi and to have elements, the
+// caller must guarantee this precondition. If key is not a smi, then the
+// generated code branches to key_not_smi. Callers can specify NULL for
+// key_not_smi to signal that a smi check has already been performed on key so
+// that the smi check is not generated. If the value is not a smi, the
+// generated code will branch to value_not_smi.  If the receiver
+// doesn't have pixel array elements, the generated code will branch to
+// not_pixel_array, unless not_pixel_array is NULL, in which case the caller
+// must ensure that the receiver has pixel array elements.  If key is not a
+// valid index within the bounds of the pixel array, the generated code jumps to
+// out_of_range.
+void GenerateFastPixelArrayStore(MacroAssembler* masm,
+                                 Register receiver,
+                                 Register key,
+                                 Register value,
+                                 Register elements,
+                                 Register scratch1,
+                                 bool load_elements_from_receiver,
+                                 bool key_is_untagged,
+                                 Label* key_not_smi,
+                                 Label* value_not_smi,
+                                 Label* not_pixel_array,
+                                 Label* out_of_range);
 
 } }  // namespace v8::internal