V8Binding/v8/src/x64/cfg-x64.cc

// Copyright 2009 the V8 project authors. All rights reserved.
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// 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.
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//       contributors may be used to endorse or promote products derived
//       from this software without specific prior written permission.
//
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// 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,
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#include "v8.h"

#include "cfg.h"
#include "codegen-inl.h"
#include "codegen-x64.h"
#include "debug.h"
#include "macro-assembler-x64.h"

namespace v8 {
namespace internal {

#define __ ACCESS_MASM(masm)

void InstructionBlock::Compile(MacroAssembler* masm) {
  ASSERT(!is_marked());
  is_marked_ = true;
  {
    Comment cmt(masm, "[ InstructionBlock");
    for (int i = 0, len = instructions_.length(); i < len; i++) {
      // If the location of the current instruction is a temp, then the
      // instruction cannot be in tail position in the block.  Allocate the
      // temp based on peeking ahead to the next instruction.
      Instruction* instr = instructions_[i];
      Location* loc = instr->location();
      if (loc->is_temporary()) {
        instructions_[i+1]->FastAllocate(TempLocation::cast(loc));
      }
      instructions_[i]->Compile(masm);
    }
  }
  successor_->Compile(masm);
}


void EntryNode::Compile(MacroAssembler* masm) {
  ASSERT(!is_marked());
  is_marked_ = true;
  Label deferred_enter, deferred_exit;
  {
    Comment cmnt(masm, "[ EntryNode");
    __ push(rbp);
    __ movq(rbp, rsp);
    __ push(rsi);
    __ push(rdi);
    int count = CfgGlobals::current()->fun()->scope()->num_stack_slots();
    if (count > 0) {
      __ movq(kScratchRegister, Factory::undefined_value(),
              RelocInfo::EMBEDDED_OBJECT);
      for (int i = 0; i < count; i++) {
        __ push(kScratchRegister);
      }
    }
    if (FLAG_trace) {
      __ CallRuntime(Runtime::kTraceEnter, 0);
    }
    if (FLAG_check_stack) {
      ExternalReference stack_limit =
          ExternalReference::address_of_stack_guard_limit();
      __ movq(kScratchRegister, stack_limit);
      __ cmpq(rsp, Operand(kScratchRegister, 0));
      __ j(below, &deferred_enter);
      __ bind(&deferred_exit);
    }
  }
  successor_->Compile(masm);
  if (FLAG_check_stack) {
    Comment cmnt(masm, "[ Deferred Stack Check");
    __ bind(&deferred_enter);
    StackCheckStub stub;
    __ CallStub(&stub);
    __ jmp(&deferred_exit);
  }
}


void ExitNode::Compile(MacroAssembler* masm) {
  ASSERT(!is_marked());
  is_marked_ = true;
  Comment cmnt(masm, "[ ExitNode");
  if (FLAG_trace) {
    __ push(rax);
    __ CallRuntime(Runtime::kTraceExit, 1);
  }
  __ RecordJSReturn();
  __ movq(rsp, rbp);
  __ pop(rbp);
  int count = CfgGlobals::current()->fun()->scope()->num_parameters();
  __ ret((count + 1) * kPointerSize);
  // Add padding that will be overwritten by a debugger breakpoint.
  // "movq rsp, rbp; pop rbp" has length 4.  "ret k" has length 3.
  const int kPadding = Debug::kX64JSReturnSequenceLength - 4 - 3;
  for (int i = 0; i < kPadding; ++i) {
    __ int3();
  }
}


void PropLoadInstr::Compile(MacroAssembler* masm) {
  // The key should not be on the stack---if it is a compiler-generated
  // temporary it is in the accumulator.
  ASSERT(!key()->is_on_stack());

  Comment cmnt(masm, "[ Load from Property");
  // If the key is known at compile-time we may be able to use a load IC.
  bool is_keyed_load = true;
  if (key()->is_constant()) {
    // Still use the keyed load IC if the key can be parsed as an integer so
    // we will get into the case that handles [] on string objects.
    Handle<Object> key_val = Constant::cast(key())->handle();
    uint32_t ignored;
    if (key_val->IsSymbol() &&
        !String::cast(*key_val)->AsArrayIndex(&ignored)) {
      is_keyed_load = false;
    }
  }

  if (!object()->is_on_stack()) object()->Push(masm);
  // A test rax instruction after the call indicates to the IC code that it
  // was inlined.  Ensure there is not one after the call below.
  if (is_keyed_load) {
    key()->Push(masm);
    Handle<Code> ic(Builtins::builtin(Builtins::KeyedLoadIC_Initialize));
    __ Call(ic, RelocInfo::CODE_TARGET);
    __ pop(rbx);  // Discard key.
  } else {
    key()->Get(masm, rcx);
    Handle<Code> ic(Builtins::builtin(Builtins::LoadIC_Initialize));
    __ Call(ic, RelocInfo::CODE_TARGET);
  }
  __ pop(rbx);  // Discard receiver.
  location()->Set(masm, rax);
}


void BinaryOpInstr::Compile(MacroAssembler* masm) {
  // The right-hand value should not be on the stack---if it is a
  // compiler-generated temporary it is in the accumulator.
  ASSERT(!right()->is_on_stack());

  Comment cmnt(masm, "[ BinaryOpInstr");
  // We can overwrite one of the operands if it is a temporary.
  OverwriteMode mode = NO_OVERWRITE;
  if (left()->is_temporary()) {
    mode = OVERWRITE_LEFT;
  } else if (right()->is_temporary()) {
    mode = OVERWRITE_RIGHT;
  }

  // Push both operands and call the specialized stub.
  if (!left()->is_on_stack()) left()->Push(masm);
  right()->Push(masm);
  GenericBinaryOpStub stub(op(), mode, SMI_CODE_IN_STUB);
  __ CallStub(&stub);
  location()->Set(masm, rax);
}


void ReturnInstr::Compile(MacroAssembler* masm) {
  // The location should be 'Effect'.  As a side effect, move the value to
  // the accumulator.
  Comment cmnt(masm, "[ ReturnInstr");
  value()->Get(masm, rax);
}


void Constant::Get(MacroAssembler* masm, Register reg) {
  __ Move(reg, handle_);
}


void Constant::Push(MacroAssembler* masm) {
  __ Push(handle_);
}


static Operand ToOperand(SlotLocation* loc) {
  switch (loc->type()) {
    case Slot::PARAMETER: {
      int count = CfgGlobals::current()->fun()->scope()->num_parameters();
      return Operand(rbp, (1 + count - loc->index()) * kPointerSize);
    }
    case Slot::LOCAL: {
      const int kOffset = JavaScriptFrameConstants::kLocal0Offset;
      return Operand(rbp, kOffset - loc->index() * kPointerSize);
    }
    default:
      UNREACHABLE();
      return Operand(rax, 0);
  }
}


void Constant::MoveToSlot(MacroAssembler* masm, SlotLocation* loc) {
  __ Move(ToOperand(loc), handle_);
}


void SlotLocation::Get(MacroAssembler* masm, Register reg) {
  __ movq(reg, ToOperand(this));
}


void SlotLocation::Set(MacroAssembler* masm, Register reg) {
  __ movq(ToOperand(this), reg);
}


void SlotLocation::Push(MacroAssembler* masm) {
  __ push(ToOperand(this));
}


void SlotLocation::Move(MacroAssembler* masm, Value* value) {
  // We dispatch to the value because in some cases (temp or constant) we
  // can use special instruction sequences.
  value->MoveToSlot(masm, this);
}


void SlotLocation::MoveToSlot(MacroAssembler* masm, SlotLocation* loc) {
  __ movq(kScratchRegister, ToOperand(this));
  __ movq(ToOperand(loc), kScratchRegister);
}


void TempLocation::Get(MacroAssembler* masm, Register reg) {
  switch (where_) {
    case ACCUMULATOR:
      if (!reg.is(rax)) __ movq(reg, rax);
      break;
    case STACK:
      __ pop(reg);
      break;
    case NOT_ALLOCATED:
      UNREACHABLE();
  }
}


void TempLocation::Set(MacroAssembler* masm, Register reg) {
  switch (where_) {
    case ACCUMULATOR:
      if (!reg.is(rax)) __ movq(rax, reg);
      break;
    case STACK:
      __ push(reg);
      break;
    case NOT_ALLOCATED:
      UNREACHABLE();
  }
}


void TempLocation::Push(MacroAssembler* masm) {
  switch (where_) {
    case ACCUMULATOR:
      __ push(rax);
      break;
    case STACK:
    case NOT_ALLOCATED:
      UNREACHABLE();
  }
}


void TempLocation::Move(MacroAssembler* masm, Value* value) {
  switch (where_) {
    case ACCUMULATOR:
      value->Get(masm, rax);
      break;
    case STACK:
      value->Push(masm);
      break;
    case NOT_ALLOCATED:
      UNREACHABLE();
  }
}


void TempLocation::MoveToSlot(MacroAssembler* masm, SlotLocation* loc) {
  switch (where_) {
    case ACCUMULATOR:
      __ movq(ToOperand(loc), rax);
      break;
    case STACK:
      __ pop(ToOperand(loc));
      break;
    case NOT_ALLOCATED:
      UNREACHABLE();
  }
}


#undef __

} }  // namespace v8::internal