X87: [turbofan] Further fixing ES6 tail call elimination in Turbofan.

src/compiler/x87/code-generator-x87.cc

Index: src/compiler/x87/code-generator-x87.cc
diff --git a/src/compiler/x87/code-generator-x87.cc b/src/compiler/x87/code-generator-x87.cc
index 98b6c88e1305dad90d065a22805663f2ecdcb6c9..82a2d14c51d281320dd16db048051e988c0b9fd1 100644
--- a/src/compiler/x87/code-generator-x87.cc
+++ b/src/compiler/x87/code-generator-x87.cc
@@ -362,12 +362,50 @@ void CodeGenerator::AssemblePrepareTailCall(int stack_param_delta) {
   frame_access_state()->SetFrameAccessToSP();
 }
 
+void CodeGenerator::AssemblePopArgumentsAdaptorFrame(Register args_reg,
+                                                     Register, Register,
+                                                     Register) {
+  // There are not enough temp registers left on ia32 for a call instruction
+  // so we pick some scratch registers and save/restore them manually here.
+  int scratch_count = 3;
+  Register scratch1 = ebx;
+  Register scratch2 = ecx;
+  Register scratch3 = edx;
+  DCHECK(!AreAliased(args_reg, scratch1, scratch2, scratch3));
+  Label done;
+
+  // Check if current frame is an arguments adaptor frame.
+  __ cmp(Operand(ebp, StandardFrameConstants::kContextOffset),
+         Immediate(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
+  __ j(not_equal, &done, Label::kNear);
+
+  __ push(scratch1);
+  __ push(scratch2);
+  __ push(scratch3);
+
+  // Load arguments count from current arguments adaptor frame (note, it
+  // does not include receiver).
+  Register caller_args_count_reg = scratch1;
+  __ mov(caller_args_count_reg,
+         Operand(ebp, ArgumentsAdaptorFrameConstants::kLengthOffset));
+  __ SmiUntag(caller_args_count_reg);
+
+  ParameterCount callee_args_count(args_reg);
+  __ PrepareForTailCall(callee_args_count, caller_args_count_reg, scratch2,
+                        scratch3, ReturnAddressState::kOnStack, scratch_count);
+  __ pop(scratch3);
+  __ pop(scratch2);
+  __ pop(scratch1);
+
+  __ bind(&done);
+}
 
 // Assembles an instruction after register allocation, producing machine code.
 void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
   X87OperandConverter i(this, instr);
-
-  switch (ArchOpcodeField::decode(instr->opcode())) {
+  InstructionCode opcode = instr->opcode();
+  ArchOpcode arch_opcode = ArchOpcodeField::decode(opcode);
+  switch (arch_opcode) {
     case kArchCallCodeObject: {
       if (FLAG_debug_code && FLAG_enable_slow_asserts) {
         __ VerifyX87StackDepth(1);
@@ -399,6 +437,7 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       frame_access_state()->ClearSPDelta();
       break;
     }
+    case kArchTailCallCodeObjectFromJSFunction:
     case kArchTailCallCodeObject: {
       if (FLAG_debug_code && FLAG_enable_slow_asserts) {
         __ VerifyX87StackDepth(1);
@@ -406,6 +445,10 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       __ fstp(0);
       int stack_param_delta = i.InputInt32(instr->InputCount() - 1);
       AssembleDeconstructActivationRecord(stack_param_delta);
+      if (arch_opcode == kArchTailCallCodeObjectFromJSFunction) {
+        AssemblePopArgumentsAdaptorFrame(kJavaScriptCallArgCountRegister,
+                                         no_reg, no_reg, no_reg);
+      }
       if (HasImmediateInput(instr, 0)) {
         Handle<Code> code = Handle<Code>::cast(i.InputHeapObject(0));
         __ jmp(code, RelocInfo::CODE_TARGET);
@@ -447,6 +490,7 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       frame_access_state()->ClearSPDelta();
       break;
     }
+    case kArchTailCallJSFunctionFromJSFunction:
     case kArchTailCallJSFunction: {
       Register func = i.InputRegister(0);
       if (FLAG_debug_code) {
@@ -460,6 +504,10 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       __ fstp(0);
       int stack_param_delta = i.InputInt32(instr->InputCount() - 1);
       AssembleDeconstructActivationRecord(stack_param_delta);
+      if (arch_opcode == kArchTailCallJSFunctionFromJSFunction) {
+        AssemblePopArgumentsAdaptorFrame(kJavaScriptCallArgCountRegister,
+                                         no_reg, no_reg, no_reg);
+      }
       __ jmp(FieldOperand(func, JSFunction::kCodeEntryOffset));
       frame_access_state()->ClearSPDelta();
       break;