X87: Implement ES6 rest parameters.

port 8bb2e397 (r26645).

original commit message:

BUG=

Review URL: https://codereview.chromium.org/929763002

Cr-Commit-Position: refs/heads/master@{#26649}

src/x87/code-stubs-x87.cc

@@ -840,6 +840,31 @@ void ArgumentsAccessStub::GenerateNewStrict(MacroAssembler* masm) {
 }
 
 
+void RestParamAccessStub::GenerateNew(MacroAssembler* masm) {
+  // esp[0] : return address
+  // esp[4] : index of rest parameter
+  // esp[8] : number of parameters
+  // esp[12] : 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, 2 * kPointerSize), ecx);
+  __ lea(edx, Operand(edx, ecx, times_2,
+                      StandardFrameConstants::kCallerSPOffset));
+  __ mov(Operand(esp, 3 * kPointerSize), edx);
+
+  __ bind(&runtime);
+  __ TailCallRuntime(Runtime::kNewRestParam, 3, 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

src/x87/full-codegen-x87.cc

@@ -233,6 +233,26 @@ void FullCodeGenerator::Generate() {
     }
   }
 
+  // Possibly allocate RestParameters
+  int rest_index;
+  Variable* rest_param = scope()->rest_parameter(&rest_index);
+  if (rest_param) {
+    Comment cmnt(masm_, "[ Allocate rest parameter array");
+
+    int num_parameters = info->scope()->num_parameters();
+    int offset = num_parameters * kPointerSize;
+    __ lea(edx,
+           Operand(ebp, StandardFrameConstants::kCallerSPOffset + offset));
+    __ push(edx);
+    __ push(Immediate(Smi::FromInt(num_parameters)));
+    __ push(Immediate(Smi::FromInt(rest_index)));
+
+    RestParamAccessStub stub(isolate());
+    __ CallStub(&stub);
+
+    SetVar(rest_param, eax, ebx, edx);
+  }
+
   Variable* arguments = scope()->arguments();
   if (arguments != NULL) {
     // Function uses arguments object.
@@ -254,7 +274,7 @@ void FullCodeGenerator::Generate() {
     // The stub will rewrite receiver and parameter count if the previous
     // stack frame was an arguments adapter frame.
     ArgumentsAccessStub::Type type;
-    if (is_strict(language_mode())) {
+    if (is_strict(language_mode()) || !is_simple_parameter_list()) {
       type = ArgumentsAccessStub::NEW_STRICT;
     } else if (function()->has_duplicate_parameters()) {
       type = ArgumentsAccessStub::NEW_SLOPPY_SLOW;