Introduce PushInt64AsTwoSmis and PopInt64AsTwoSmis macro instructions for X64

src/x64/macro-assembler-x64.cc

 // Copyright 2012 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 2204 matching lines @@
   return SmiIndex(dst, times_1);
 }
 
 
 void MacroAssembler::AddSmiField(Register dst, const Operand& src) {
   ASSERT_EQ(0, kSmiShift % kBitsPerByte);
   addl(dst, Operand(src, kSmiShift / kBitsPerByte));
 }
 
 
+void MacroAssembler::PushInt64AsTwoSmis(Register src, Register scratch) {
+  movq(scratch, src);
+  // High bits.
+  shr(src, Immediate(64 - kSmiShift));
+  shl(src, Immediate(kSmiShift));
+  push(src);
+  // Low bits.
+  shl(scratch, Immediate(kSmiShift));
+  push(scratch);
+}
+
+
+void MacroAssembler::PopInt64AsTwoSmis(Register dst, Register scratch) {
+  pop(scratch);
+  // Low bits.
+  shr(scratch, Immediate(kSmiShift));
+  pop(dst);
+  shr(dst, Immediate(kSmiShift));
+  // High bits.
+  shl(dst, Immediate(64 - kSmiShift));
+  or_(dst, scratch);
+}
+
+
 void MacroAssembler::JumpIfNotString(Register object,
                                      Register object_map,
                                      Label* not_string,
                                      Label::Distance near_jump) {
   Condition is_smi = CheckSmi(object);
   j(is_smi, not_string, near_jump);
   CmpObjectType(object, FIRST_NONSTRING_TYPE, object_map);
   j(above_equal, not_string, near_jump);
 }
 
@@ skipping 2459 matching lines @@
   j(greater, &no_memento_available);
   CompareRoot(MemOperand(scratch_reg, -AllocationMemento::kSize),
               Heap::kAllocationMementoMapRootIndex);
   bind(&no_memento_available);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64