X87: Partial revert of rest parameter desugaring.

src/x87/code-stubs-x87.cc

 // 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.
 
 #if V8_TARGET_ARCH_X87
 
 #include "src/base/bits.h"
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
@@ skipping 835 matching lines @@
   __ bind(&runtime);
   __ pop(eax);   // Pop return address.
   __ push(edi);  // Push function.
   __ push(edx);  // Push parameters pointer.
   __ push(ecx);  // Push parameter count.
   __ push(eax);  // Push return address.
   __ TailCallRuntime(Runtime::kNewStrictArguments, 3, 1);
 }
 
 
+void RestParamAccessStub::GenerateNew(MacroAssembler* masm) {
+  // esp[0] : return address
+  // esp[4] : language mode
+  // esp[8] : index of rest parameter
+  // esp[12] : number of parameters
+  // esp[16] : receiver displacement
+
+  // Check if the calling frame is an arguments adaptor frame.
+  Label runtime;
+  __ mov(edx, Operand(ebp, StandardFrameConstants::kCallerFPOffset));
+  __ mov(ecx, Operand(edx, StandardFrameConstants::kContextOffset));
+  __ cmp(ecx, Immediate(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
+  __ j(not_equal, &runtime);
+
+  // Patch the arguments.length and the parameters pointer.
+  __ mov(ecx, Operand(edx, ArgumentsAdaptorFrameConstants::kLengthOffset));
+  __ mov(Operand(esp, 3 * kPointerSize), ecx);
+  __ lea(edx,
+         Operand(edx, ecx, times_2, StandardFrameConstants::kCallerSPOffset));
+  __ mov(Operand(esp, 4 * kPointerSize), edx);
+
+  __ bind(&runtime);
+  __ TailCallRuntime(Runtime::kNewRestParam, 4, 1);
+}
+
+
 void RegExpExecStub::Generate(MacroAssembler* masm) {
   // Just jump directly to runtime if native RegExp is not selected at compile
   // time or if regexp entry in generated code is turned off runtime switch or
   // at compilation.
 #ifdef V8_INTERPRETED_REGEXP
   __ TailCallRuntime(Runtime::kRegExpExec, 4, 1);
 #else  // V8_INTERPRETED_REGEXP
 
   // Stack frame on entry.
   //  esp[0]: return address
@@ skipping 4467 matching lines @@
                            Operand(ebp, 7 * kPointerSize), NULL);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X87