MIPS64: Implement optimization utilizing signaling NaN for holes in double arrays.

src/mips64/macro-assembler-mips64.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_MIPS_MACRO_ASSEMBLER_MIPS_H_
 #define V8_MIPS_MACRO_ASSEMBLER_MIPS_H_
 
 #include "src/assembler.h"
 #include "src/globals.h"
 #include "src/mips64/assembler-mips64.h"
@@ skipping 1051 matching lines @@
                             Label* fail);
 
   // Check to see if maybe_number can be stored as a double in
   // FastDoubleElements. If it can, store it at the index specified by key in
   // the FastDoubleElements array elements. Otherwise jump to fail.
   void StoreNumberToDoubleElements(Register value_reg,
                                    Register key_reg,
                                    Register elements_reg,
                                    Register scratch1,
                                    Register scratch2,
-                                   Register scratch3,
                                    Label* fail,
                                    int elements_offset = 0);
 
   // Compare an object's map with the specified map and its transitioned
   // elements maps if mode is ALLOW_ELEMENT_TRANSITION_MAPS. Jumps to
   // "branch_to" if the result of the comparison is "cond". If multiple map
   // compares are required, the compare sequences branches to early_success.
   void CompareMapAndBranch(Register obj,
                            Register scratch,
                            Handle<Map> map,
@@ skipping 26 matching lines @@
                 Label* fail,
                 SmiCheckType smi_check_type);
 
   // Check if the map of an object is equal to a specified weak map and branch
   // to a specified target if equal. Skip the smi check if not required
   // (object is known to be a heap object)
   void DispatchWeakMap(Register obj, Register scratch1, Register scratch2,
                        Handle<WeakCell> cell, Handle<Code> success,
                        SmiCheckType smi_check_type);
 
+  // If the value is a NaN, canonicalize the value else, do nothing.
+  void FPUCanonicalizeNaN(const DoubleRegister dst, const DoubleRegister src);
+
+
   // Get value of the weak cell.
   void GetWeakValue(Register value, Handle<WeakCell> cell);
 
   // Load the value of the weak cell in the value register. Branch to the
   // given miss label is the weak cell was cleared.
   void LoadWeakValue(Register value, Handle<WeakCell> cell, Label* miss);
 
   // Load and check the instance type of an object for being a string.
   // Loads the type into the second argument register.
   // Returns a condition that will be enabled if the object was a string.
@@ skipping 651 matching lines @@
 #define CODE_COVERAGE_TOSTRING(x) CODE_COVERAGE_STRINGIFY(x)
 #define __FILE_LINE__ __FILE__ ":" CODE_COVERAGE_TOSTRING(__LINE__)
 #define ACCESS_MASM(masm) masm->stop(__FILE_LINE__); masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 } }  // namespace v8::internal
 
 #endif  // V8_MIPS_MACRO_ASSEMBLER_MIPS_H_