[turbofan] Better and more sane support for tail calls

src/compiler/arm64/code-generator-arm64.cc

 // Copyright 2014 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.
 
 #include "src/compiler/code-generator.h"
 
 #include "src/arm64/frames-arm64.h"
 #include "src/arm64/macro-assembler-arm64.h"
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
@@ skipping 430 matching lines @@
                    i.InputRegister##width(1));                              \
     } else {                                                                \
       uint32_t imm =                                                        \
           static_cast<uint32_t>(i.InputOperand##width(1).ImmediateValue()); \
       __ asm_instr(i.OutputRegister##width(), i.InputRegister##width(0),    \
                    imm % (width));                                          \
     }                                                                       \
   } while (0)
 
 
-void CodeGenerator::AssembleDeconstructActivationRecord() {
+void CodeGenerator::AssembleDeconstructActivationRecord(int stack_param_delta) {
   CallDescriptor* descriptor = linkage()->GetIncomingDescriptor();
   int stack_slots = frame()->GetSpillSlotCount();
   if (descriptor->IsJSFunctionCall() || stack_slots > 0) {
     __ Mov(jssp, fp);
     __ Pop(fp, lr);
   }
+  if (stack_param_delta < 0) {
+    int offset = -stack_param_delta * kPointerSize;
+    __ Add(jssp, jssp, Operand(offset));
+  }
 }
 
 
 // Assembles an instruction after register allocation, producing machine code.
 void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
   Arm64OperandConverter i(this, instr);
   InstructionCode opcode = instr->opcode();
   switch (ArchOpcodeField::decode(opcode)) {
     case kArchCallCodeObject: {
       EnsureSpaceForLazyDeopt();
       if (instr->InputAt(0)->IsImmediate()) {
         __ Call(Handle<Code>::cast(i.InputHeapObject(0)),
                 RelocInfo::CODE_TARGET);
       } else {
         Register target = i.InputRegister(0);
         __ Add(target, target, Code::kHeaderSize - kHeapObjectTag);
         __ Call(target);
       }
       RecordCallPosition(instr);
       break;
     }
     case kArchTailCallCodeObject: {
-      AssembleDeconstructActivationRecord();
+      int stack_param_delta = i.InputInt32(instr->InputCount() - 1);
+      AssembleDeconstructActivationRecord(stack_param_delta);
       if (instr->InputAt(0)->IsImmediate()) {
         __ Jump(Handle<Code>::cast(i.InputHeapObject(0)),
                 RelocInfo::CODE_TARGET);
       } else {
         Register target = i.InputRegister(0);
         __ Add(target, target, Code::kHeaderSize - kHeapObjectTag);
         __ Jump(target);
       }
       break;
     }
@@ skipping 16 matching lines @@
     case kArchTailCallJSFunction: {
       Register func = i.InputRegister(0);
       if (FLAG_debug_code) {
         // Check the function's context matches the context argument.
         UseScratchRegisterScope scope(masm());
         Register temp = scope.AcquireX();
         __ Ldr(temp, FieldMemOperand(func, JSFunction::kContextOffset));
         __ cmp(cp, temp);
         __ Assert(eq, kWrongFunctionContext);
       }
-      AssembleDeconstructActivationRecord();
+      int stack_param_delta = i.InputInt32(instr->InputCount() - 1);
+      AssembleDeconstructActivationRecord(stack_param_delta);
       __ Ldr(x10, FieldMemOperand(func, JSFunction::kCodeEntryOffset));
       __ Jump(x10);
       break;
     }
     case kArchLazyBailout: {
       EnsureSpaceForLazyDeopt();
       RecordCallPosition(instr);
       break;
     }
     case kArchPrepareCallCFunction:
@@ skipping 977 matching lines @@
       padding_size -= kInstructionSize;
     }
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8