Introduce intrinsics for double values in Javascript.

src/a64/lithium-codegen-a64.cc

 // Copyright 2013 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 2213 matching lines @@
   __ Bind(&is_heap_number);
   DoubleRegister dbl_scratch = double_scratch();
   DoubleRegister dbl_scratch2 = ToDoubleRegister(instr->temp2());
   __ Ldr(dbl_scratch, FieldMemOperand(input, HeapNumber::kValueOffset));
   __ ClampDoubleToUint8(result, dbl_scratch, dbl_scratch2);
 
   __ Bind(&done);
 }
 
 
+void LCodeGen::DoDoubleBits(LDoubleBits* instr) {
+  DoubleRegister value_reg = ToDoubleRegister(instr->value());
+  Register result_reg = ToRegister(instr->result());
+  if (instr->hydrogen()->bits() == HDoubleBits::HIGH) {
+    __ Fmov(result_reg, value_reg);
+    __ Mov(result_reg, Operand(result_reg, LSR, 32));
+  } else {
+    __ Fmov(result_reg.W(), value_reg.S());
+  }
+}
+
+
+void LCodeGen::DoConstructDouble(LConstructDouble* instr) {
+  Register hi_reg = ToRegister(instr->hi());
+  Register lo_reg = ToRegister(instr->lo());
+  Register temp = ToRegister(instr->temp());
+  DoubleRegister result_reg = ToDoubleRegister(instr->result());
+
+  __ And(temp, lo_reg, Operand(0xffffffff));
+  __ Orr(temp, temp, Operand(hi_reg, LSL, 32));
+  __ Fmov(result_reg, temp);
+}
+
+
 void LCodeGen::DoClassOfTestAndBranch(LClassOfTestAndBranch* instr) {
   Handle<String> class_name = instr->hydrogen()->class_name();
   Label* true_label = instr->TrueLabel(chunk_);
   Label* false_label = instr->FalseLabel(chunk_);
   Register input = ToRegister(instr->value());
   Register scratch1 = ToRegister(instr->temp1());
   Register scratch2 = ToRegister(instr->temp2());
 
   __ JumpIfSmi(input, false_label);
 
@@ skipping 3429 matching lines @@
   __ Bind(&out_of_object);
   __ Ldr(result, FieldMemOperand(object, JSObject::kPropertiesOffset));
   // Index is equal to negated out of object property index plus 1.
   __ Sub(result, result, Operand::UntagSmiAndScale(index, kPointerSizeLog2));
   __ Ldr(result, FieldMemOperand(result,
                                  FixedArray::kHeaderSize - kPointerSize));
   __ Bind(&done);
 }
 
 } }  // namespace v8::internal