Split IdenticalWithNumberCheck in two versions: once called from unoptimized code the other called…

runtime/vm/stub_code_x64.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/assembler.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
@@ skipping 2020 matching lines @@
                            RawBigint* left,
                            RawBigint* right);
 
 
 // Does identical check (object references are equal or not equal) with special
 // checks for boxed numbers.
 // Left and right are pushed on stack.
 // Return ZF set.
 // Note: A Mint cannot contain a value that would fit in Smi, a Bigint
 // cannot contain a value that fits in Mint or Smi.
-void StubCode::GenerateIdenticalWithNumberCheckStub(Assembler* assembler) {
-  const Register left = RAX;
-  const Register right = RDX;
-  // Preserve left, right and temp.
-  __ pushq(left);
-  __ pushq(right);
-  // TOS + 0: saved right
-  // TOS + 1: saved left
-  // TOS + 2: return address
-  // TOS + 3: right argument.
-  // TOS + 4: left argument.
-  __ movq(left, Address(RSP, 4 * kWordSize));
-  __ movq(right, Address(RSP, 3 * kWordSize));
+void StubCode::GenerateIdenticalWithNumberCheckStub(Assembler* assembler,
+                                                    const Register left,
+                                                    const Register right,
+                                                    const Register unused1,
+                                                    const Register unused2) {
   Label reference_compare, done, check_mint, check_bigint;
   // If any of the arguments is Smi do reference compare.
   __ testq(left, Immediate(kSmiTagMask));
   __ j(ZERO, &reference_compare);
   __ testq(right, Immediate(kSmiTagMask));
   __ j(ZERO, &reference_compare);
 
   // Value compare for two doubles.
   __ CompareClassId(left, kDoubleCid);
   __ j(NOT_EQUAL, &check_mint, Assembler::kNearJump);
@@ skipping 25 matching lines @@
   __ movq(RSI, right);
   __ CallRuntime(kBigintCompareRuntimeEntry);
   // Result in RAX, 0 means equal.
   __ LeaveFrame();
   __ cmpq(RAX, Immediate(0));
   __ jmp(&done);
 
   __ Bind(&reference_compare);
   __ cmpq(left, right);
   __ Bind(&done);
+}
+
+
+// Called only from unoptimized code. All relevant registers have been saved.
+// TOS + 0: return address
+// TOS + 1: right argument.
+// TOS + 2: left argument.
+// Returns ZF set.
+void StubCode::GenerateUnoptimizedIdenticalWithNumberCheckStub(
+    Assembler* assembler) {
+  const Register left = RAX;
+  const Register right = RDX;
+
+  __ movq(left, Address(RSP, 2 * kWordSize));
+  __ movq(right, Address(RSP, 1 * kWordSize));
+  GenerateIdenticalWithNumberCheckStub(assembler, left, right);
+  __ ret();
+}
+
+
+// Called from otpimzied code only. Must preserve any registers that are
+// destroyed.
+// TOS + 0: return address
+// TOS + 1: right argument.
+// TOS + 2: left argument.
+// Returns ZF set.
+void StubCode::GenerateOptimizedIdenticalWithNumberCheckStub(
+    Assembler* assembler) {
+  const Register left = RAX;
+  const Register right = RDX;
+  // Preserve left and right.
+  __ pushq(left);
+  __ pushq(right);
+  __ movq(left, Address(RSP, 4 * kWordSize));
+  __ movq(right, Address(RSP, 3 * kWordSize));
+  GenerateIdenticalWithNumberCheckStub(assembler, left, right);
   __ popq(right);
   __ popq(left);
   __ ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64