// Copyright 2021 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.

#ifndef V8_BASELINE_S390_BASELINE_ASSEMBLER_S390_INL_H_
#define V8_BASELINE_S390_BASELINE_ASSEMBLER_S390_INL_H_

#include "src/baseline/baseline-assembler.h"
#include "src/codegen/s390/assembler-s390-inl.h"
#include "src/codegen/interface-descriptors.h"

namespace v8 {
namespace internal {
namespace baseline {

namespace detail {

static constexpr Register kScratchRegisters[] = {r8, r9, ip, r1};
static constexpr int kNumScratchRegisters = arraysize(kScratchRegisters);

#ifdef DEBUG
inline bool Clobbers(Register target, MemOperand op) {
  return op.rb() == target || op.rx() == target;
}
#endif
}  // namespace detail

class BaselineAssembler::ScratchRegisterScope {
 public:
  explicit ScratchRegisterScope(BaselineAssembler* assembler)
      : assembler_(assembler),
        prev_scope_(assembler->scratch_register_scope_),
        registers_used_(prev_scope_ == nullptr ? 0
                                               : prev_scope_->registers_used_) {
    assembler_->scratch_register_scope_ = this;
  }
  ~ScratchRegisterScope() { assembler_->scratch_register_scope_ = prev_scope_; }

  Register AcquireScratch() {
    DCHECK_LT(registers_used_, detail::kNumScratchRegisters);
    return detail::kScratchRegisters[registers_used_++];
  }

 private:
  BaselineAssembler* assembler_;
  ScratchRegisterScope* prev_scope_;
  int registers_used_;
};

// TODO(v8:11429,leszeks): Unify condition names in the MacroAssembler.
enum class Condition : uint32_t {
  kEqual,
  kNotEqual,

  kLessThan,
  kGreaterThan,
  kLessThanEqual,
  kGreaterThanEqual,

  kUnsignedLessThan,
  kUnsignedGreaterThan,
  kUnsignedLessThanEqual,
  kUnsignedGreaterThanEqual,

  kOverflow,
  kNoOverflow,

  kZero,
  kNotZero
};

inline internal::Condition AsMasmCondition(Condition cond) {
  STATIC_ASSERT(sizeof(internal::Condition) == sizeof(Condition));
  switch (cond) {
    case Condition::kEqual:
      return eq;
    case Condition::kNotEqual:
      return ne;
    case Condition::kLessThan:
      return lt;
    case Condition::kGreaterThan:
      return gt;
    case Condition::kLessThanEqual:
      return le;
    case Condition::kGreaterThanEqual:
      return ge;

    case Condition::kUnsignedLessThan:
      return lt;
    case Condition::kUnsignedGreaterThan:
      return gt;
    case Condition::kUnsignedLessThanEqual:
      return le;
    case Condition::kUnsignedGreaterThanEqual:
      return ge;

    case Condition::kOverflow:
      return overflow;
    case Condition::kNoOverflow:
      return nooverflow;

    case Condition::kZero:
      return eq;
    case Condition::kNotZero:
      return ne;
    default:
      UNREACHABLE();
  }
}

inline bool IsSignedCondition(Condition cond) {
  switch (cond) {
    case Condition::kEqual:
    case Condition::kNotEqual:
    case Condition::kLessThan:
    case Condition::kGreaterThan:
    case Condition::kLessThanEqual:
    case Condition::kGreaterThanEqual:
    case Condition::kOverflow:
    case Condition::kNoOverflow:
    case Condition::kZero:
    case Condition::kNotZero:
      return true;

    case Condition::kUnsignedLessThan:
    case Condition::kUnsignedGreaterThan:
    case Condition::kUnsignedLessThanEqual:
    case Condition::kUnsignedGreaterThanEqual:
      return false;

    default:
      UNREACHABLE();
  }
}

#define __ assm->
// s390x helper
static void JumpIfHelper(MacroAssembler* assm, Condition cc, Register lhs,
                         Register rhs, Label* target) {
  if (IsSignedCondition(cc)) {
    __ CmpS64(lhs, rhs);
  } else {
    __ CmpU64(lhs, rhs);
  }
  __ b(AsMasmCondition(cc), target);
}

#undef __

#define __ masm_->

MemOperand BaselineAssembler::RegisterFrameOperand(
    interpreter::Register interpreter_register) {
  return MemOperand(fp, interpreter_register.ToOperand() * kSystemPointerSize);
}
void BaselineAssembler::RegisterFrameAddress(
    interpreter::Register interpreter_register, Register rscratch) {
  return __ AddS64(rscratch, fp,
                   interpreter_register.ToOperand() * kSystemPointerSize);
}
MemOperand BaselineAssembler::FeedbackVectorOperand() {
  return MemOperand(fp, BaselineFrameConstants::kFeedbackVectorFromFp);
}

void BaselineAssembler::Bind(Label* label) { __ bind(label); }
void BaselineAssembler::BindWithoutJumpTarget(Label* label) { __ bind(label); }

void BaselineAssembler::JumpTarget() {
  // NOP on arm.
}

void BaselineAssembler::Jump(Label* target, Label::Distance distance) {
  ASM_CODE_COMMENT(masm_);
  __ b(target);
}

void BaselineAssembler::JumpIfRoot(Register value, RootIndex index,
                                   Label* target, Label::Distance) {
  ASM_CODE_COMMENT(masm_);
  __ JumpIfRoot(value, index, target);
}

void BaselineAssembler::JumpIfNotRoot(Register value, RootIndex index,
                                      Label* target, Label::Distance) {
  ASM_CODE_COMMENT(masm_);
  __ JumpIfNotRoot(value, index, target);
}

void BaselineAssembler::JumpIfSmi(Register value, Label* target,
                                  Label::Distance) {
  ASM_CODE_COMMENT(masm_);
  __ JumpIfSmi(value, target);
}

void BaselineAssembler::JumpIfImmediate(Condition cc, Register left, int right,
                                        Label* target,
                                        Label::Distance distance) {
  ASM_CODE_COMMENT(masm_);
  JumpIf(cc, left, Operand(right), target, distance);
}

void BaselineAssembler::JumpIfNotSmi(Register value, Label* target,
                                     Label::Distance) {
  ASM_CODE_COMMENT(masm_);
  __ JumpIfNotSmi(value, target);
}

void BaselineAssembler::CallBuiltin(Builtin builtin) {
  ASM_CODE_COMMENT_STRING(masm_,
                          __ CommentForOffHeapTrampoline("call", builtin));
  if (masm()->options().short_builtin_calls) {
    // Generate pc-relative call.
    __ CallBuiltin(builtin);
  } else {
    ScratchRegisterScope temps(this);
    Register temp = temps.AcquireScratch();
    __ LoadEntryFromBuiltin(builtin, temp);
    __ Call(temp);
  }
}

void BaselineAssembler::TailCallBuiltin(Builtin builtin) {
  ASM_CODE_COMMENT_STRING(masm_,
                          __ CommentForOffHeapTrampoline("tail call", builtin));
  if (masm()->options().short_builtin_calls) {
    // Generate pc-relative call.
    __ TailCallBuiltin(builtin);
  } else {
    ScratchRegisterScope temps(this);
    Register temp = temps.AcquireScratch();
    __ LoadEntryFromBuiltin(builtin, temp);
    __ Jump(temp);
  }
}

void BaselineAssembler::TestAndBranch(Register value, int mask, Condition cc,
                                      Label* target, Label::Distance) {
  ASM_CODE_COMMENT(masm_);
  __ AndP(r0, value, Operand(mask));
  __ b(AsMasmCondition(cc), target);
}

void BaselineAssembler::JumpIf(Condition cc, Register lhs, const Operand& rhs,
                               Label* target, Label::Distance) {
  ASM_CODE_COMMENT(masm_);
  if (IsSignedCondition(cc)) {
    __ CmpS64(lhs, rhs);
  } else {
    __ CmpU64(lhs, rhs);
  }
  __ b(AsMasmCondition(cc), target);
}

void BaselineAssembler::JumpIfObjectType(Condition cc, Register object,
                                         InstanceType instance_type,
                                         Register map, Label* target,
                                         Label::Distance) {
  ASM_CODE_COMMENT(masm_);
  ScratchRegisterScope temps(this);
  Register type = temps.AcquireScratch();
  __ LoadMap(map, object);
  __ LoadU16(type, FieldMemOperand(map, Map::kInstanceTypeOffset));
  JumpIf(cc, type, Operand(instance_type), target);
}

void BaselineAssembler::JumpIfInstanceType(Condition cc, Register map,
                                           InstanceType instance_type,
                                           Label* target, Label::Distance) {
  ASM_CODE_COMMENT(masm_);
  ScratchRegisterScope temps(this);
  Register type = temps.AcquireScratch();
  if (FLAG_debug_code) {
    __ AssertNotSmi(map);
    __ CompareObjectType(map, type, type, MAP_TYPE);
    __ Assert(eq, AbortReason::kUnexpectedValue);
  }
  __ LoadU16(type, FieldMemOperand(map, Map::kInstanceTypeOffset));
  JumpIf(cc, type, Operand(instance_type), target);
}

void BaselineAssembler::JumpIfPointer(Condition cc, Register value,
                                      MemOperand operand, Label* target,
                                      Label::Distance) {
  ASM_CODE_COMMENT(masm_);
  ScratchRegisterScope temps(this);
  Register tmp = temps.AcquireScratch();
  __ LoadU64(tmp, operand);
  JumpIfHelper(masm_, cc, value, tmp, target);
}

void BaselineAssembler::JumpIfSmi(Condition cc, Register value, Smi smi,
                                  Label* target, Label::Distance) {
  ASM_CODE_COMMENT(masm_);
  __ AssertSmi(value);
  __ LoadSmiLiteral(r0, smi);
  JumpIfHelper(masm_, cc, value, r0, target);
}

void BaselineAssembler::JumpIfSmi(Condition cc, Register lhs, Register rhs,
                                  Label* target, Label::Distance) {
  ASM_CODE_COMMENT(masm_);
  __ AssertSmi(lhs);
  __ AssertSmi(rhs);
  JumpIfHelper(masm_, cc, lhs, rhs, target);
}

void BaselineAssembler::JumpIfTagged(Condition cc, Register value,
                                     MemOperand operand, Label* target,
                                     Label::Distance) {
  ASM_CODE_COMMENT(masm_);
  __ LoadU64(r0, operand);
  JumpIfHelper(masm_, cc, value, r0, target);
}

void BaselineAssembler::JumpIfTagged(Condition cc, MemOperand operand,
                                     Register value, Label* target,
                                     Label::Distance) {
  ASM_CODE_COMMENT(masm_);
  __ LoadU64(r0, operand);
  JumpIfHelper(masm_, cc, r0, value, target);
}
void BaselineAssembler::JumpIfByte(Condition cc, Register value, int32_t byte,
                                   Label* target, Label::Distance) {
  ASM_CODE_COMMENT(masm_);
  JumpIf(cc, value, Operand(byte), target);
}

void BaselineAssembler::Move(interpreter::Register output, Register source) {
  Move(RegisterFrameOperand(output), source);
}

void BaselineAssembler::Move(Register output, TaggedIndex value) {
  ASM_CODE_COMMENT(masm_);
  __ mov(output, Operand(value.ptr()));
}

void BaselineAssembler::Move(MemOperand output, Register source) {
  ASM_CODE_COMMENT(masm_);
  __ StoreU64(source, output);
}

void BaselineAssembler::Move(Register output, ExternalReference reference) {
  ASM_CODE_COMMENT(masm_);
  __ Move(output, reference);
}

void BaselineAssembler::Move(Register output, Handle<HeapObject> value) {
  ASM_CODE_COMMENT(masm_);
  __ Move(output, value);
}

void BaselineAssembler::Move(Register output, int32_t value) {
  ASM_CODE_COMMENT(masm_);
  __ mov(output, Operand(value));
}

void BaselineAssembler::MoveMaybeSmi(Register output, Register source) {
  ASM_CODE_COMMENT(masm_);
  __ mov(output, source);
}

void BaselineAssembler::MoveSmi(Register output, Register source) {
  ASM_CODE_COMMENT(masm_);
  __ mov(output, source);
}

namespace detail {

template <typename Arg>
inline Register ToRegister(BaselineAssembler* basm,
                           BaselineAssembler::ScratchRegisterScope* scope,
                           Arg arg) {
  Register reg = scope->AcquireScratch();
  basm->Move(reg, arg);
  return reg;
}
inline Register ToRegister(BaselineAssembler* basm,
                           BaselineAssembler::ScratchRegisterScope* scope,
                           Register reg) {
  return reg;
}

template <typename... Args>
struct PushAllHelper;
template <>
struct PushAllHelper<> {
  static int Push(BaselineAssembler* basm) { return 0; }
  static int PushReverse(BaselineAssembler* basm) { return 0; }
};
// TODO(ishell): try to pack sequence of pushes into one instruction by
// looking at regiser codes. For example, Push(r1, r2, r5, r0, r3, r4)
// could be generated as two pushes: Push(r1, r2, r5) and Push(r0, r3, r4).
template <typename Arg>
struct PushAllHelper<Arg> {
  static int Push(BaselineAssembler* basm, Arg arg) {
    BaselineAssembler::ScratchRegisterScope scope(basm);
    basm->masm()->Push(ToRegister(basm, &scope, arg));
    return 1;
  }
  static int PushReverse(BaselineAssembler* basm, Arg arg) {
    return Push(basm, arg);
  }
};
// TODO(ishell): try to pack sequence of pushes into one instruction by
// looking at regiser codes. For example, Push(r1, r2, r5, r0, r3, r4)
// could be generated as two pushes: Push(r1, r2, r5) and Push(r0, r3, r4).
template <typename Arg, typename... Args>
struct PushAllHelper<Arg, Args...> {
  static int Push(BaselineAssembler* basm, Arg arg, Args... args) {
    PushAllHelper<Arg>::Push(basm, arg);
    return 1 + PushAllHelper<Args...>::Push(basm, args...);
  }
  static int PushReverse(BaselineAssembler* basm, Arg arg, Args... args) {
    int nargs = PushAllHelper<Args...>::PushReverse(basm, args...);
    PushAllHelper<Arg>::Push(basm, arg);
    return nargs + 1;
  }
};
template <>
struct PushAllHelper<interpreter::RegisterList> {
  static int Push(BaselineAssembler* basm, interpreter::RegisterList list) {
    for (int reg_index = 0; reg_index < list.register_count(); ++reg_index) {
      PushAllHelper<interpreter::Register>::Push(basm, list[reg_index]);
    }
    return list.register_count();
  }
  static int PushReverse(BaselineAssembler* basm,
                         interpreter::RegisterList list) {
    for (int reg_index = list.register_count() - 1; reg_index >= 0;
         --reg_index) {
      PushAllHelper<interpreter::Register>::Push(basm, list[reg_index]);
    }
    return list.register_count();
  }
};

template <typename... T>
struct PopAllHelper;
template <>
struct PopAllHelper<> {
  static void Pop(BaselineAssembler* basm) {}
};
// TODO(ishell): try to pack sequence of pops into one instruction by
// looking at regiser codes. For example, Pop(r1, r2, r5, r0, r3, r4)
// could be generated as two pops: Pop(r1, r2, r5) and Pop(r0, r3, r4).
template <>
struct PopAllHelper<Register> {
  static void Pop(BaselineAssembler* basm, Register reg) {
    basm->masm()->Pop(reg);
  }
};
template <typename... T>
struct PopAllHelper<Register, T...> {
  static void Pop(BaselineAssembler* basm, Register reg, T... tail) {
    PopAllHelper<Register>::Pop(basm, reg);
    PopAllHelper<T...>::Pop(basm, tail...);
  }
};

}  // namespace detail

template <typename... T>
int BaselineAssembler::Push(T... vals) {
  return detail::PushAllHelper<T...>::Push(this, vals...);
}

template <typename... T>
void BaselineAssembler::PushReverse(T... vals) {
  detail::PushAllHelper<T...>::PushReverse(this, vals...);
}

template <typename... T>
void BaselineAssembler::Pop(T... registers) {
  detail::PopAllHelper<T...>::Pop(this, registers...);
}

void BaselineAssembler::LoadTaggedPointerField(Register output, Register source,
                                               int offset) {
  ASM_CODE_COMMENT(masm_);
  __ LoadTaggedPointerField(output, FieldMemOperand(source, offset), r0);
}

void BaselineAssembler::LoadTaggedSignedField(Register output, Register source,
                                              int offset) {
  ASM_CODE_COMMENT(masm_);
  __ LoadTaggedSignedField(output, FieldMemOperand(source, offset));
}

void BaselineAssembler::LoadTaggedAnyField(Register output, Register source,
                                           int offset) {
  ASM_CODE_COMMENT(masm_);
  __ LoadAnyTaggedField(output, FieldMemOperand(source, offset), r0);
}

void BaselineAssembler::LoadWord16FieldZeroExtend(Register output,
                                                  Register source, int offset) {
  ASM_CODE_COMMENT(masm_);
  __ LoadU16(output, FieldMemOperand(source, offset));
}

void BaselineAssembler::LoadWord8Field(Register output, Register source,
                                       int offset) {
  ASM_CODE_COMMENT(masm_);
  __ LoadU8(output, FieldMemOperand(source, offset));
}

void BaselineAssembler::StoreTaggedSignedField(Register target, int offset,
                                               Smi value) {
  ASM_CODE_COMMENT(masm_);
  ScratchRegisterScope temps(this);
  Register tmp = temps.AcquireScratch();
  __ LoadSmiLiteral(tmp, value);
  __ StoreTaggedField(tmp, FieldMemOperand(target, offset), r0);
}

void BaselineAssembler::StoreTaggedFieldWithWriteBarrier(Register target,
                                                         int offset,
                                                         Register value) {
  ASM_CODE_COMMENT(masm_);
  Register scratch = WriteBarrierDescriptor::SlotAddressRegister();
  DCHECK(!AreAliased(target, value, scratch));
  __ StoreTaggedField(value, FieldMemOperand(target, offset), r0);
  __ RecordWriteField(target, offset, value, scratch, kLRHasNotBeenSaved,
                      SaveFPRegsMode::kIgnore);
}

void BaselineAssembler::StoreTaggedFieldNoWriteBarrier(Register target,
                                                       int offset,
                                                       Register value) {
  __ StoreTaggedField(value, FieldMemOperand(target, offset), r0);
}

void BaselineAssembler::AddToInterruptBudgetAndJumpIfNotExceeded(
    int32_t weight, Label* skip_interrupt_label) {
  ASM_CODE_COMMENT(masm_);
  ScratchRegisterScope scratch_scope(this);
  Register feedback_cell = scratch_scope.AcquireScratch();
  LoadFunction(feedback_cell);
  LoadTaggedPointerField(feedback_cell, feedback_cell,
                         JSFunction::kFeedbackCellOffset);

  Register interrupt_budget = scratch_scope.AcquireScratch();
  __ LoadU32(
      interrupt_budget,
      FieldMemOperand(feedback_cell, FeedbackCell::kInterruptBudgetOffset));
  // Remember to set flags as part of the add!
  __ AddS32(interrupt_budget, Operand(weight));
  __ StoreU32(
      interrupt_budget,
      FieldMemOperand(feedback_cell, FeedbackCell::kInterruptBudgetOffset), r0);
  if (skip_interrupt_label) {
    // Use compare flags set by add
    DCHECK_LT(weight, 0);
    __ b(ge, skip_interrupt_label);
  }
}

void BaselineAssembler::AddToInterruptBudgetAndJumpIfNotExceeded(
    Register weight, Label* skip_interrupt_label) {
  ASM_CODE_COMMENT(masm_);
  ScratchRegisterScope scratch_scope(this);
  Register feedback_cell = scratch_scope.AcquireScratch();
  LoadFunction(feedback_cell);
  LoadTaggedPointerField(feedback_cell, feedback_cell,
                         JSFunction::kFeedbackCellOffset);

  Register interrupt_budget = scratch_scope.AcquireScratch();
  __ LoadU32(
      interrupt_budget,
      FieldMemOperand(feedback_cell, FeedbackCell::kInterruptBudgetOffset));
  // Remember to set flags as part of the add!
  __ AddS32(interrupt_budget, interrupt_budget, weight);
  __ StoreU32(
      interrupt_budget,
      FieldMemOperand(feedback_cell, FeedbackCell::kInterruptBudgetOffset));
  if (skip_interrupt_label) __ b(ge, skip_interrupt_label);
}

void BaselineAssembler::AddSmi(Register lhs, Smi rhs) {
  if (rhs.value() == 0) return;
  __ LoadSmiLiteral(r0, rhs);
  if (SmiValuesAre31Bits()) {
    __ AddS32(lhs, lhs, r0);
  } else {
    __ AddS64(lhs, lhs, r0);
  }
}

void BaselineAssembler::Word32And(Register output, Register lhs, int rhs) {
  __ AndP(output, lhs, Operand(rhs));
}

void BaselineAssembler::Switch(Register reg, int case_value_base,
                               Label** labels, int num_labels) {
  ASM_CODE_COMMENT(masm_);
  Label fallthrough, jump_table;
  if (case_value_base != 0) {
    __ AddS64(reg, Operand(-case_value_base));
  }

  // Mostly copied from code-generator-arm.cc
  ScratchRegisterScope scope(this);
  JumpIf(Condition::kUnsignedGreaterThanEqual, reg, Operand(num_labels),
         &fallthrough);
  // Ensure to emit the constant pool first if necessary.
  int entry_size_log2 = 3;
  __ ShiftLeftU32(reg, reg, Operand(entry_size_log2));
  __ larl(r1, &jump_table);
  __ lay(reg, MemOperand(reg, r1));
  __ b(reg);
  __ b(&fallthrough);
  __ bind(&jump_table);
  for (int i = 0; i < num_labels; ++i) {
    __ b(labels[i], Label::kFar);
    __ nop();
  }
  __ bind(&fallthrough);
}

#undef __

#define __ basm.

void BaselineAssembler::EmitReturn(MacroAssembler* masm) {
  ASM_CODE_COMMENT(masm);
  BaselineAssembler basm(masm);

  Register weight = BaselineLeaveFrameDescriptor::WeightRegister();
  Register params_size = BaselineLeaveFrameDescriptor::ParamsSizeRegister();

  {
    ASM_CODE_COMMENT_STRING(masm, "Update Interrupt Budget");

    Label skip_interrupt_label;
    __ AddToInterruptBudgetAndJumpIfNotExceeded(weight, &skip_interrupt_label);
    {
      __ masm()->SmiTag(params_size);
      __ Push(params_size, kInterpreterAccumulatorRegister);

      __ LoadContext(kContextRegister);
      __ LoadFunction(kJSFunctionRegister);
      __ Push(kJSFunctionRegister);
      __ CallRuntime(Runtime::kBytecodeBudgetInterrupt, 1);

      __ Pop(kInterpreterAccumulatorRegister, params_size);
      __ masm()->SmiUntag(params_size);
    }

    __ Bind(&skip_interrupt_label);
  }

  BaselineAssembler::ScratchRegisterScope temps(&basm);
  Register actual_params_size = temps.AcquireScratch();
  // Compute the size of the actual parameters + receiver (in bytes).
  __ Move(actual_params_size,
          MemOperand(fp, StandardFrameConstants::kArgCOffset));

  // If actual is bigger than formal, then we should use it to free up the stack
  // arguments.
  Label corrected_args_count;
  JumpIfHelper(__ masm(), Condition::kGreaterThanEqual, params_size,
               actual_params_size, &corrected_args_count);
  __ masm()->mov(params_size, actual_params_size);
  __ Bind(&corrected_args_count);

  // Leave the frame (also dropping the register file).
  __ masm()->LeaveFrame(StackFrame::BASELINE);

  // Drop receiver + arguments.
  __ masm()->DropArguments(params_size, TurboAssembler::kCountIsInteger,
                           TurboAssembler::kCountIncludesReceiver);
  __ masm()->Ret();
}

#undef __

inline void EnsureAccumulatorPreservedScope::AssertEqualToAccumulator(
    Register reg) {
  assembler_->masm()->CmpU64(reg, kInterpreterAccumulatorRegister);
  assembler_->masm()->Assert(eq, AbortReason::kUnexpectedValue);
}

}  // namespace baseline
}  // namespace internal
}  // namespace v8

#endif  // V8_BASELINE_S390_BASELINE_ASSEMBLER_S390_INL_H_