root/src/lithium.cc

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DEFINITIONS

This source file includes following definitions.
  1. PrintTo
  2. LITHIUM_OPERAND_LIST
  3. TearDownCaches
  4. IsRedundant
  5. PrintDataTo
  6. PrintTo
  7. RecordPointer
  8. RemovePointer
  9. RecordUntagged
  10. PrintTo
  11. ElementsKindToShiftSize
  12. GetLabel
  13. LookupDestination
  14. GetAssemblyLabel
  15. MarkEmptyBlocks
  16. AddInstruction
  17. DefineConstantOperand
  18. GetParameterStackSlot
  19. ParameterAt
  20. GetGapAt
  21. IsGapAt
  22. NearestGapPos
  23. AddGapMove
  24. LookupConstant
  25. LookupLiteralRepresentation
  26. NewChunk
  27. Codegen

// Copyright 2012 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
//       copyright notice, this list of conditions and the following
//       disclaimer in the documentation and/or other materials provided
//       with the distribution.
//     * Neither the name of Google Inc. nor the names of its
//       contributors may be used to endorse or promote products derived
//       from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#include "v8.h"
#include "lithium.h"
#include "scopes.h"

#if V8_TARGET_ARCH_IA32
#include "ia32/lithium-ia32.h"
#include "ia32/lithium-codegen-ia32.h"
#elif V8_TARGET_ARCH_X64
#include "x64/lithium-x64.h"
#include "x64/lithium-codegen-x64.h"
#elif V8_TARGET_ARCH_ARM
#include "arm/lithium-arm.h"
#include "arm/lithium-codegen-arm.h"
#elif V8_TARGET_ARCH_MIPS
#include "mips/lithium-mips.h"
#include "mips/lithium-codegen-mips.h"
#else
#error "Unknown architecture."
#endif

namespace v8 {
namespace internal {


void LOperand::PrintTo(StringStream* stream) {
  LUnallocated* unalloc = NULL;
  switch (kind()) {
    case INVALID:
      stream->Add("(0)");
      break;
    case UNALLOCATED:
      unalloc = LUnallocated::cast(this);
      stream->Add("v%d", unalloc->virtual_register());
      switch (unalloc->policy()) {
        case LUnallocated::NONE:
          break;
        case LUnallocated::FIXED_REGISTER: {
          const char* register_name =
              Register::AllocationIndexToString(unalloc->fixed_index());
          stream->Add("(=%s)", register_name);
          break;
        }
        case LUnallocated::FIXED_DOUBLE_REGISTER: {
          const char* double_register_name =
              DoubleRegister::AllocationIndexToString(unalloc->fixed_index());
          stream->Add("(=%s)", double_register_name);
          break;
        }
        case LUnallocated::FIXED_SLOT:
          stream->Add("(=%dS)", unalloc->fixed_index());
          break;
        case LUnallocated::MUST_HAVE_REGISTER:
          stream->Add("(R)");
          break;
        case LUnallocated::WRITABLE_REGISTER:
          stream->Add("(WR)");
          break;
        case LUnallocated::SAME_AS_FIRST_INPUT:
          stream->Add("(1)");
          break;
        case LUnallocated::ANY:
          stream->Add("(-)");
          break;
      }
      break;
    case CONSTANT_OPERAND:
      stream->Add("[constant:%d]", index());
      break;
    case STACK_SLOT:
      stream->Add("[stack:%d]", index());
      break;
    case DOUBLE_STACK_SLOT:
      stream->Add("[double_stack:%d]", index());
      break;
    case REGISTER:
      stream->Add("[%s|R]", Register::AllocationIndexToString(index()));
      break;
    case DOUBLE_REGISTER:
      stream->Add("[%s|R]", DoubleRegister::AllocationIndexToString(index()));
      break;
    case ARGUMENT:
      stream->Add("[arg:%d]", index());
      break;
  }
}

#define DEFINE_OPERAND_CACHE(name, type)                      \
  L##name* L##name::cache = NULL;                             \
                                                              \
  void L##name::SetUpCache() {                                \
    if (cache) return;                                        \
    cache = new L##name[kNumCachedOperands];                  \
    for (int i = 0; i < kNumCachedOperands; i++) {            \
      cache[i].ConvertTo(type, i);                            \
    }                                                         \
  }                                                           \
                                                              \
  void L##name::TearDownCache() {                             \
    delete[] cache;                                           \
  }

LITHIUM_OPERAND_LIST(DEFINE_OPERAND_CACHE)
#undef DEFINE_OPERAND_CACHE

void LOperand::SetUpCaches() {
#define LITHIUM_OPERAND_SETUP(name, type) L##name::SetUpCache();
  LITHIUM_OPERAND_LIST(LITHIUM_OPERAND_SETUP)
#undef LITHIUM_OPERAND_SETUP
}


void LOperand::TearDownCaches() {
#define LITHIUM_OPERAND_TEARDOWN(name, type) L##name::TearDownCache();
  LITHIUM_OPERAND_LIST(LITHIUM_OPERAND_TEARDOWN)
#undef LITHIUM_OPERAND_TEARDOWN
}


bool LParallelMove::IsRedundant() const {
  for (int i = 0; i < move_operands_.length(); ++i) {
    if (!move_operands_[i].IsRedundant()) return false;
  }
  return true;
}


void LParallelMove::PrintDataTo(StringStream* stream) const {
  bool first = true;
  for (int i = 0; i < move_operands_.length(); ++i) {
    if (!move_operands_[i].IsEliminated()) {
      LOperand* source = move_operands_[i].source();
      LOperand* destination = move_operands_[i].destination();
      if (!first) stream->Add(" ");
      first = false;
      if (source->Equals(destination)) {
        destination->PrintTo(stream);
      } else {
        destination->PrintTo(stream);
        stream->Add(" = ");
        source->PrintTo(stream);
      }
      stream->Add(";");
    }
  }
}


void LEnvironment::PrintTo(StringStream* stream) {
  stream->Add("[id=%d|", ast_id());
  stream->Add("[parameters=%d|", parameter_count());
  stream->Add("[arguments_stack_height=%d|", arguments_stack_height());
  for (int i = 0; i < values_.length(); ++i) {
    if (i != 0) stream->Add(";");
    if (values_[i] == NULL) {
      stream->Add("[hole]");
    } else {
      values_[i]->PrintTo(stream);
    }
  }
  stream->Add("]");
}


void LPointerMap::RecordPointer(LOperand* op, Zone* zone) {
  // Do not record arguments as pointers.
  if (op->IsStackSlot() && op->index() < 0) return;
  ASSERT(!op->IsDoubleRegister() && !op->IsDoubleStackSlot());
  pointer_operands_.Add(op, zone);
}


void LPointerMap::RemovePointer(LOperand* op) {
  // Do not record arguments as pointers.
  if (op->IsStackSlot() && op->index() < 0) return;
  ASSERT(!op->IsDoubleRegister() && !op->IsDoubleStackSlot());
  for (int i = 0; i < pointer_operands_.length(); ++i) {
    if (pointer_operands_[i]->Equals(op)) {
      pointer_operands_.Remove(i);
      --i;
    }
  }
}


void LPointerMap::RecordUntagged(LOperand* op, Zone* zone) {
  // Do not record arguments as pointers.
  if (op->IsStackSlot() && op->index() < 0) return;
  ASSERT(!op->IsDoubleRegister() && !op->IsDoubleStackSlot());
  untagged_operands_.Add(op, zone);
}


void LPointerMap::PrintTo(StringStream* stream) {
  stream->Add("{");
  for (int i = 0; i < pointer_operands_.length(); ++i) {
    if (i != 0) stream->Add(";");
    pointer_operands_[i]->PrintTo(stream);
  }
  stream->Add("} @%d", position());
}


int ElementsKindToShiftSize(ElementsKind elements_kind) {
  switch (elements_kind) {
    case EXTERNAL_BYTE_ELEMENTS:
    case EXTERNAL_PIXEL_ELEMENTS:
    case EXTERNAL_UNSIGNED_BYTE_ELEMENTS:
      return 0;
    case EXTERNAL_SHORT_ELEMENTS:
    case EXTERNAL_UNSIGNED_SHORT_ELEMENTS:
      return 1;
    case EXTERNAL_INT_ELEMENTS:
    case EXTERNAL_UNSIGNED_INT_ELEMENTS:
    case EXTERNAL_FLOAT_ELEMENTS:
      return 2;
    case EXTERNAL_DOUBLE_ELEMENTS:
    case FAST_DOUBLE_ELEMENTS:
    case FAST_HOLEY_DOUBLE_ELEMENTS:
      return 3;
    case FAST_SMI_ELEMENTS:
    case FAST_ELEMENTS:
    case FAST_HOLEY_SMI_ELEMENTS:
    case FAST_HOLEY_ELEMENTS:
    case DICTIONARY_ELEMENTS:
    case NON_STRICT_ARGUMENTS_ELEMENTS:
      return kPointerSizeLog2;
  }
  UNREACHABLE();
  return 0;
}


LLabel* LChunk::GetLabel(int block_id) const {
  HBasicBlock* block = graph_->blocks()->at(block_id);
  int first_instruction = block->first_instruction_index();
  return LLabel::cast(instructions_[first_instruction]);
}


int LChunk::LookupDestination(int block_id) const {
  LLabel* cur = GetLabel(block_id);
  while (cur->replacement() != NULL) {
    cur = cur->replacement();
  }
  return cur->block_id();
}

Label* LChunk::GetAssemblyLabel(int block_id) const {
  LLabel* label = GetLabel(block_id);
  ASSERT(!label->HasReplacement());
  return label->label();
}

void LChunk::MarkEmptyBlocks() {
  HPhase phase("L_Mark empty blocks", this);
  for (int i = 0; i < graph()->blocks()->length(); ++i) {
    HBasicBlock* block = graph()->blocks()->at(i);
    int first = block->first_instruction_index();
    int last = block->last_instruction_index();
    LInstruction* first_instr = instructions()->at(first);
    LInstruction* last_instr = instructions()->at(last);

    LLabel* label = LLabel::cast(first_instr);
    if (last_instr->IsGoto()) {
      LGoto* goto_instr = LGoto::cast(last_instr);
      if (label->IsRedundant() &&
          !label->is_loop_header()) {
        bool can_eliminate = true;
        for (int i = first + 1; i < last && can_eliminate; ++i) {
          LInstruction* cur = instructions()->at(i);
          if (cur->IsGap()) {
            LGap* gap = LGap::cast(cur);
            if (!gap->IsRedundant()) {
              can_eliminate = false;
            }
          } else {
            can_eliminate = false;
          }
        }

        if (can_eliminate) {
          label->set_replacement(GetLabel(goto_instr->block_id()));
        }
      }
    }
  }
}


void LChunk::AddInstruction(LInstruction* instr, HBasicBlock* block) {
  LInstructionGap* gap = new(graph_->zone()) LInstructionGap(block);
  int index = -1;
  if (instr->IsControl()) {
    instructions_.Add(gap, zone());
    index = instructions_.length();
    instructions_.Add(instr, zone());
  } else {
    index = instructions_.length();
    instructions_.Add(instr, zone());
    instructions_.Add(gap, zone());
  }
  if (instr->HasPointerMap()) {
    pointer_maps_.Add(instr->pointer_map(), zone());
    instr->pointer_map()->set_lithium_position(index);
  }
}


LConstantOperand* LChunk::DefineConstantOperand(HConstant* constant) {
  return LConstantOperand::Create(constant->id(), zone());
}


int LChunk::GetParameterStackSlot(int index) const {
  // The receiver is at index 0, the first parameter at index 1, so we
  // shift all parameter indexes down by the number of parameters, and
  // make sure they end up negative so they are distinguishable from
  // spill slots.
  int result = index - info()->scope()->num_parameters() - 1;
  ASSERT(result < 0);
  return result;
}


// A parameter relative to ebp in the arguments stub.
int LChunk::ParameterAt(int index) {
  ASSERT(-1 <= index);  // -1 is the receiver.
  return (1 + info()->scope()->num_parameters() - index) *
      kPointerSize;
}


LGap* LChunk::GetGapAt(int index) const {
  return LGap::cast(instructions_[index]);
}


bool LChunk::IsGapAt(int index) const {
  return instructions_[index]->IsGap();
}


int LChunk::NearestGapPos(int index) const {
  while (!IsGapAt(index)) index--;
  return index;
}


void LChunk::AddGapMove(int index, LOperand* from, LOperand* to) {
  GetGapAt(index)->GetOrCreateParallelMove(
      LGap::START, zone())->AddMove(from, to, zone());
}


HConstant* LChunk::LookupConstant(LConstantOperand* operand) const {
  return HConstant::cast(graph_->LookupValue(operand->index()));
}


Representation LChunk::LookupLiteralRepresentation(
    LConstantOperand* operand) const {
  return graph_->LookupValue(operand->index())->representation();
}


LChunk* LChunk::NewChunk(HGraph* graph) {
  NoHandleAllocation no_handles;
  AssertNoAllocation no_gc;

  int values = graph->GetMaximumValueID();
  if (values > LUnallocated::kMaxVirtualRegisters) {
    if (FLAG_trace_bailout) {
      PrintF("Not enough virtual registers for (values).\n");
    }
    return NULL;
  }
  LAllocator allocator(values, graph);
  LChunkBuilder builder(graph->info(), graph, &allocator);
  LChunk* chunk = builder.Build();
  if (chunk == NULL) return NULL;

  if (!allocator.Allocate(chunk)) {
    if (FLAG_trace_bailout) {
      PrintF("Not enough virtual registers (regalloc).\n");
    }
    return NULL;
  }

  return chunk;
}


Handle<Code> LChunk::Codegen() {
  MacroAssembler assembler(info()->isolate(), NULL, 0);
  LCodeGen generator(this, &assembler, info());

  MarkEmptyBlocks();

  if (generator.GenerateCode()) {
    if (FLAG_trace_codegen) {
      PrintF("Crankshaft Compiler - ");
    }
    CodeGenerator::MakeCodePrologue(info());
    Code::Flags flags = Code::ComputeFlags(Code::OPTIMIZED_FUNCTION);
    Handle<Code> code =
        CodeGenerator::MakeCodeEpilogue(&assembler, flags, info());
    generator.FinishCode(code);
    CodeGenerator::PrintCode(code, info());
    return code;
  }
  return Handle<Code>::null();
}


} }  // namespace v8::internal

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