// 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.

#if V8_TARGET_ARCH_PPC

#include "src/codegen.h"
#include "src/ic/ic.h"
#include "src/ic/stub-cache.h"

namespace v8 {
namespace internal {


Condition CompareIC::ComputeCondition(Token::Value op) {
  switch (op) {
    case Token::EQ_STRICT:
    case Token::EQ:
      return eq;
    case Token::LT:
      return lt;
    case Token::GT:
      return gt;
    case Token::LTE:
      return le;
    case Token::GTE:
      return ge;
    default:
      UNREACHABLE();
  }
}


bool CompareIC::HasInlinedSmiCode(Address address) {
  // The address of the instruction following the call.
  Address cmp_instruction_address =
      Assembler::return_address_from_call_start(address);

  // If the instruction following the call is not a cmp rx, #yyy, nothing
  // was inlined.
  Instr instr = Assembler::instr_at(cmp_instruction_address);
  return Assembler::IsCmpImmediate(instr);
}


//
// This code is paired with the JumpPatchSite class in full-codegen-ppc.cc
//
void PatchInlinedSmiCode(Isolate* isolate, Address address,
                         InlinedSmiCheck check) {
  Address cmp_instruction_address =
      Assembler::return_address_from_call_start(address);

  // If the instruction following the call is not a cmp rx, #yyy, nothing
  // was inlined.
  Instr instr = Assembler::instr_at(cmp_instruction_address);
  if (!Assembler::IsCmpImmediate(instr)) {
    return;
  }

  // The delta to the start of the map check instruction and the
  // condition code uses at the patched jump.
  int delta = Assembler::GetCmpImmediateRawImmediate(instr);
  delta += Assembler::GetCmpImmediateRegister(instr).code() * kOff16Mask;
  // If the delta is 0 the instruction is cmp r0, #0 which also signals that
  // nothing was inlined.
  if (delta == 0) {
    return;
  }

  if (FLAG_trace_ic) {
    LOG(isolate, PatchIC(address, cmp_instruction_address, delta));
  }

  Address patch_address =
      cmp_instruction_address - delta * Instruction::kInstrSize;
  Instr instr_at_patch = Assembler::instr_at(patch_address);
  Instr branch_instr =
      Assembler::instr_at(patch_address + Instruction::kInstrSize);
  // This is patching a conditional "jump if not smi/jump if smi" site.
  // Enabling by changing from
  //   cmp cr0, rx, rx
  // to
  //  rlwinm(r0, value, 0, 31, 31, SetRC);
  //  bc(label, BT/BF, 2)
  // and vice-versa to be disabled again.
  CodePatcher patcher(isolate, patch_address, 2);
  Register reg = Assembler::GetRA(instr_at_patch);
  if (check == ENABLE_INLINED_SMI_CHECK) {
    DCHECK(Assembler::IsCmpRegister(instr_at_patch));
    DCHECK_EQ(Assembler::GetRA(instr_at_patch).code(),
              Assembler::GetRB(instr_at_patch).code());
    patcher.masm()->TestIfSmi(reg, r0);
  } else {
    DCHECK(check == DISABLE_INLINED_SMI_CHECK);
    DCHECK(Assembler::IsAndi(instr_at_patch));
    patcher.masm()->cmp(reg, reg, cr0);
  }
  DCHECK(Assembler::IsBranch(branch_instr));

  // Invert the logic of the branch
  if (Assembler::GetCondition(branch_instr) == eq) {
    patcher.EmitCondition(ne);
  } else {
    DCHECK(Assembler::GetCondition(branch_instr) == ne);
    patcher.EmitCondition(eq);
  }
}
}  // namespace internal
}  // namespace v8

#endif  // V8_TARGET_ARCH_PPC
