[turbofan] Better and more sane support for tail calls

src/compiler/arm/code-generator-arm.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/arm/macro-assembler-arm.h"
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
@@ skipping 336 matching lines @@
       __ cmp(offset, i.InputRegister(1));         \
     } else {                                      \
       __ cmp(offset, i.InputImmediate(1));        \
     }                                             \
     auto value = i.InputRegister(2);              \
     __ asm_instr(value, i.InputOffset(3), lo);    \
     DCHECK_EQ(LeaveCC, i.OutputSBit());           \
   } 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) {
     __ LeaveFrame(StackFrame::MANUAL);
   }
+  if (stack_param_delta < 0) {
+    int offset = -stack_param_delta * kPointerSize;
+    __ add(sp, sp, Operand(offset));
+  }
 }
 
 
 // Assembles an instruction after register allocation, producing machine code.
 void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
   ArmOperandConverter i(this, instr);
 
   masm()->MaybeCheckConstPool();
 
   switch (ArchOpcodeField::decode(instr->opcode())) {
     case kArchCallCodeObject: {
       EnsureSpaceForLazyDeopt();
       if (instr->InputAt(0)->IsImmediate()) {
         __ Call(Handle<Code>::cast(i.InputHeapObject(0)),
                 RelocInfo::CODE_TARGET);
       } else {
         __ add(ip, i.InputRegister(0),
                Operand(Code::kHeaderSize - kHeapObjectTag));
         __ Call(ip);
       }
       RecordCallPosition(instr);
       DCHECK_EQ(LeaveCC, i.OutputSBit());
       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 {
         __ add(ip, i.InputRegister(0),
                Operand(Code::kHeaderSize - kHeapObjectTag));
         __ Jump(ip);
       }
       DCHECK_EQ(LeaveCC, i.OutputSBit());
       break;
@@ skipping 14 matching lines @@
       break;
     }
     case kArchTailCallJSFunction: {
       Register func = i.InputRegister(0);
       if (FLAG_debug_code) {
         // Check the function's context matches the context argument.
         __ ldr(kScratchReg, FieldMemOperand(func, JSFunction::kContextOffset));
         __ cmp(cp, kScratchReg);
         __ Assert(eq, kWrongFunctionContext);
       }
-      AssembleDeconstructActivationRecord();
+      int stack_param_delta = i.InputInt32(instr->InputCount() - 1);
+      AssembleDeconstructActivationRecord(stack_param_delta);
       __ ldr(ip, FieldMemOperand(func, JSFunction::kCodeEntryOffset));
       __ Jump(ip);
       DCHECK_EQ(LeaveCC, i.OutputSBit());
       break;
     }
     case kArchLazyBailout: {
       EnsureSpaceForLazyDeopt();
       RecordCallPosition(instr);
       break;
     }
@@ skipping 893 matching lines @@
       padding_size -= v8::internal::Assembler::kInstrSize;
     }
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8