runtime/lib/integers.cc

// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

#include "vm/bootstrap_natives.h"

#include "include/dart_api.h"
#include "vm/dart_entry.h"
#include "vm/dart_api_impl.h"
#include "vm/exceptions.h"
#include "vm/isolate.h"
#include "vm/native_entry.h"
#include "vm/object.h"
#include "vm/object_store.h"
#include "vm/symbols.h"

namespace dart {

DEFINE_FLAG(bool, trace_intrinsified_natives, false,
    "Report if any of the intrinsified natives are called");

// Smi natives.

// Returns false if integer is in wrong representation, e.g., as is a Bigint
// when it could have been a Smi.
static bool CheckInteger(const Integer& i) {
  if (i.IsBigint()) {
    const Bigint& bigint = Bigint::Cast(i);
    return !bigint.FitsIntoSmi() && !bigint.FitsIntoInt64();
  }
  if (i.IsMint()) {
    const Mint& mint = Mint::Cast(i);
    return !Smi::IsValid(mint.value());
  }
  return true;
}


DEFINE_NATIVE_ENTRY(Integer_bitAndFromInteger, 2) {
  const Integer& right = Integer::CheckedHandle(arguments->NativeArgAt(0));
  GET_NON_NULL_NATIVE_ARGUMENT(Integer, left, arguments->NativeArgAt(1));
  ASSERT(CheckInteger(right));
  ASSERT(CheckInteger(left));
  if (FLAG_trace_intrinsified_natives) {
    OS::Print("Integer_bitAndFromInteger %s & %s\n",
        right.ToCString(), left.ToCString());
  }
  const Integer& result = Integer::Handle(left.BitOp(Token::kBIT_AND, right));
  // A null result indicates that a bigint operation is required.
  return result.IsNull() ? result.raw() : result.AsValidInteger();
}


DEFINE_NATIVE_ENTRY(Integer_bitOrFromInteger, 2) {
  const Integer& right = Integer::CheckedHandle(arguments->NativeArgAt(0));
  GET_NON_NULL_NATIVE_ARGUMENT(Integer, left, arguments->NativeArgAt(1));
  ASSERT(CheckInteger(right));
  ASSERT(CheckInteger(left));
  if (FLAG_trace_intrinsified_natives) {
    OS::Print("Integer_bitOrFromInteger %s | %s\n",
        left.ToCString(), right.ToCString());
  }
  const Integer& result = Integer::Handle(left.BitOp(Token::kBIT_OR, right));
  // A null result indicates that a bigint operation is required.
  return result.IsNull() ? result.raw() : result.AsValidInteger();
}


DEFINE_NATIVE_ENTRY(Integer_bitXorFromInteger, 2) {
  const Integer& right = Integer::CheckedHandle(arguments->NativeArgAt(0));
  GET_NON_NULL_NATIVE_ARGUMENT(Integer, left, arguments->NativeArgAt(1));
  ASSERT(CheckInteger(right));
  ASSERT(CheckInteger(left));
  if (FLAG_trace_intrinsified_natives) {
    OS::Print("Integer_bitXorFromInteger %s ^ %s\n",
        left.ToCString(), right.ToCString());
  }
  const Integer& result = Integer::Handle(left.BitOp(Token::kBIT_XOR, right));
  // A null result indicates that a bigint operation is required.
  return result.IsNull() ? result.raw() : result.AsValidInteger();
}


DEFINE_NATIVE_ENTRY(Integer_addFromInteger, 2) {
  const Integer& right_int = Integer::CheckedHandle(arguments->NativeArgAt(0));
  GET_NON_NULL_NATIVE_ARGUMENT(Integer, left_int, arguments->NativeArgAt(1));
  ASSERT(CheckInteger(right_int));
  ASSERT(CheckInteger(left_int));
  if (FLAG_trace_intrinsified_natives) {
    OS::Print("Integer_addFromInteger %s + %s\n",
        left_int.ToCString(), right_int.ToCString());
  }
  const Integer& result =
      Integer::Handle(left_int.ArithmeticOp(Token::kADD, right_int));
  // A null result indicates that a bigint operation is required.
  return result.IsNull() ? result.raw() : result.AsValidInteger();
}


DEFINE_NATIVE_ENTRY(Integer_subFromInteger, 2) {
  const Integer& right_int = Integer::CheckedHandle(arguments->NativeArgAt(0));
  GET_NON_NULL_NATIVE_ARGUMENT(Integer, left_int, arguments->NativeArgAt(1));
  ASSERT(CheckInteger(right_int));
  ASSERT(CheckInteger(left_int));
  if (FLAG_trace_intrinsified_natives) {
    OS::Print("Integer_subFromInteger %s - %s\n",
        left_int.ToCString(), right_int.ToCString());
  }
  const Integer& result =
      Integer::Handle(left_int.ArithmeticOp(Token::kSUB, right_int));
  // A null result indicates that a bigint operation is required.
  return result.IsNull() ? result.raw() : result.AsValidInteger();
}


DEFINE_NATIVE_ENTRY(Integer_mulFromInteger, 2) {
  const Integer& right_int = Integer::CheckedHandle(arguments->NativeArgAt(0));
  GET_NON_NULL_NATIVE_ARGUMENT(Integer, left_int, arguments->NativeArgAt(1));
  ASSERT(CheckInteger(right_int));
  ASSERT(CheckInteger(left_int));
  if (FLAG_trace_intrinsified_natives) {
    OS::Print("Integer_mulFromInteger %s * %s\n",
        left_int.ToCString(), right_int.ToCString());
  }
  const Integer& result =
      Integer::Handle(left_int.ArithmeticOp(Token::kMUL, right_int));
  // A null result indicates that a bigint operation is required.
  return result.IsNull() ? result.raw() : result.AsValidInteger();
}


DEFINE_NATIVE_ENTRY(Integer_truncDivFromInteger, 2) {
  const Integer& right_int = Integer::CheckedHandle(arguments->NativeArgAt(0));
  GET_NON_NULL_NATIVE_ARGUMENT(Integer, left_int, arguments->NativeArgAt(1));
  ASSERT(CheckInteger(right_int));
  ASSERT(CheckInteger(left_int));
  ASSERT(!right_int.IsZero());
  const Integer& result =
      Integer::Handle(left_int.ArithmeticOp(Token::kTRUNCDIV, right_int));
  // A null result indicates that a bigint operation is required.
  return result.IsNull() ? result.raw() : result.AsValidInteger();
}


DEFINE_NATIVE_ENTRY(Integer_moduloFromInteger, 2) {
  const Integer& right_int = Integer::CheckedHandle(arguments->NativeArgAt(0));
  GET_NON_NULL_NATIVE_ARGUMENT(Integer, left_int, arguments->NativeArgAt(1));
  ASSERT(CheckInteger(right_int));
  ASSERT(CheckInteger(left_int));
  if (FLAG_trace_intrinsified_natives) {
    OS::Print("Integer_moduloFromInteger %s mod %s\n",
        left_int.ToCString(), right_int.ToCString());
  }
  if (right_int.IsZero()) {
    // Should have been caught before calling into runtime.
    UNIMPLEMENTED();
  }
  const Integer& result =
      Integer::Handle(left_int.ArithmeticOp(Token::kMOD, right_int));
  // A null result indicates that a bigint operation is required.
  return result.IsNull() ? result.raw() : result.AsValidInteger();
}


DEFINE_NATIVE_ENTRY(Integer_greaterThanFromInteger, 2) {
  const Integer& right = Integer::CheckedHandle(arguments->NativeArgAt(0));
  GET_NON_NULL_NATIVE_ARGUMENT(Integer, left, arguments->NativeArgAt(1));
  ASSERT(CheckInteger(right));
  ASSERT(CheckInteger(left));
  if (FLAG_trace_intrinsified_natives) {
    OS::Print("Integer_greaterThanFromInteger %s > %s\n",
        left.ToCString(), right.ToCString());
  }
  return Bool::Get(left.CompareWith(right) == 1).raw();
}


DEFINE_NATIVE_ENTRY(Integer_equalToInteger, 2) {
  const Integer& left = Integer::CheckedHandle(arguments->NativeArgAt(0));
  GET_NON_NULL_NATIVE_ARGUMENT(Integer, right, arguments->NativeArgAt(1));
  ASSERT(CheckInteger(left));
  ASSERT(CheckInteger(right));
  if (FLAG_trace_intrinsified_natives) {
    OS::Print("Integer_equalToInteger %s == %s\n",
        left.ToCString(), right.ToCString());
  }
  return Bool::Get(left.CompareWith(right) == 0).raw();
}


static RawInteger* ParseInteger(const String& value) {
  // Used by both Integer_parse and Integer_fromEnvironment.
  if (value.IsOneByteString()) {
    // Quick conversion for unpadded integers in strings.
    const intptr_t len = value.Length();
    if (len > 0) {
      const char* cstr = value.ToCString();
      ASSERT(cstr != NULL);
      char* p_end = NULL;
      const int64_t int_value = strtoll(cstr, &p_end, 10);
      if (p_end == (cstr + len)) {
        if ((int_value != LLONG_MIN) && (int_value != LLONG_MAX)) {
          return Integer::New(int_value);
        }
      }
    }
  }

  const String* int_string;
  bool is_positive;
  if (Scanner::IsValidInteger(value, &is_positive, &int_string)) {
    if (is_positive) {
      return Integer::New(*int_string);
    }
    String& temp = String::Handle();
    temp = String::Concat(Symbols::Dash(), *int_string);
    return Integer::New(temp);
  }

  return Integer::null();
}


DEFINE_NATIVE_ENTRY(Integer_parse, 1) {
  GET_NON_NULL_NATIVE_ARGUMENT(String, value, arguments->NativeArgAt(0));
  return ParseInteger(value);
}


DEFINE_NATIVE_ENTRY(Integer_fromEnvironment, 3) {
  GET_NON_NULL_NATIVE_ARGUMENT(String, name, arguments->NativeArgAt(1));
  GET_NATIVE_ARGUMENT(Integer, default_value, arguments->NativeArgAt(2));
  // Call the embedder to supply us with the environment.
  const String& env_value =
      String::Handle(Api::GetEnvironmentValue(thread, name));
  if (!env_value.IsNull()) {
    const Integer& result = Integer::Handle(ParseInteger(env_value));
    if (!result.IsNull()) {
      if (result.IsSmi()) {
        return result.raw();
      }
      return result.CheckAndCanonicalize(thread, NULL);
    }
  }
  return default_value.raw();
}


static RawInteger* ShiftOperationHelper(Token::Kind kind,
                                        const Integer& value,
                                        const Smi& amount) {
  if (amount.Value() < 0) {
    Exceptions::ThrowArgumentError(amount);
  }
  if (value.IsSmi()) {
    const Smi& smi_value = Smi::Cast(value);
    return smi_value.ShiftOp(kind, amount, Heap::kNew);
  }
  if (value.IsMint()) {
    const int64_t mint_value = value.AsInt64Value();
    const int count = Utils::HighestBit(mint_value);
    intptr_t shift_count = amount.Value();
    if (kind == Token::kSHR) {
      shift_count = -shift_count;
    }
    if ((count + shift_count) < Mint::kBits) {
      switch (kind) {
        case Token::kSHL:
          return Integer::New(mint_value << shift_count, Heap::kNew);
        case Token::kSHR:
          shift_count =
              (-shift_count > Mint::kBits) ? Mint::kBits : -shift_count;
          return Integer::New(mint_value >> shift_count, Heap::kNew);
        default:
          UNIMPLEMENTED();
      }
    } else {
      // Overflow in shift, use Bigints
      return Integer::null();
    }
  } else {
    ASSERT(value.IsBigint());
  }
  return Integer::null();
}


DEFINE_NATIVE_ENTRY(Smi_bitAndFromSmi, 2) {
  const Smi& left = Smi::CheckedHandle(arguments->NativeArgAt(0));
  GET_NON_NULL_NATIVE_ARGUMENT(Smi, right, arguments->NativeArgAt(1));
  if (FLAG_trace_intrinsified_natives) {
    OS::Print("Smi_bitAndFromSmi %s & %s\n",
        left.ToCString(), right.ToCString());
  }
  const Smi& left_value = Smi::Cast(left);
  const Smi& right_value = Smi::Cast(right);
  return Smi::New(left_value.Value() & right_value.Value());
}


DEFINE_NATIVE_ENTRY(Smi_shrFromInt, 2) {
  const Smi& amount = Smi::CheckedHandle(arguments->NativeArgAt(0));
  GET_NON_NULL_NATIVE_ARGUMENT(Integer, value, arguments->NativeArgAt(1));
  ASSERT(CheckInteger(amount));
  ASSERT(CheckInteger(value));
  const Integer& result = Integer::Handle(
      ShiftOperationHelper(Token::kSHR, value, amount));
  // A null result indicates that a bigint operation is required.
  return result.IsNull() ? result.raw() : result.AsValidInteger();
}



DEFINE_NATIVE_ENTRY(Smi_shlFromInt, 2) {
  const Smi& amount = Smi::CheckedHandle(arguments->NativeArgAt(0));
  GET_NON_NULL_NATIVE_ARGUMENT(Integer, value, arguments->NativeArgAt(1));
  ASSERT(CheckInteger(amount));
  ASSERT(CheckInteger(value));
  if (FLAG_trace_intrinsified_natives) {
    OS::Print("Smi_shlFromInt: %s << %s\n",
        value.ToCString(), amount.ToCString());
  }
  const Integer& result = Integer::Handle(
      ShiftOperationHelper(Token::kSHL, value, amount));
  // A null result indicates that a bigint operation is required.
  return result.IsNull() ? result.raw() : result.AsValidInteger();
}


DEFINE_NATIVE_ENTRY(Smi_bitNegate, 1) {
  const Smi& operand = Smi::CheckedHandle(arguments->NativeArgAt(0));
  if (FLAG_trace_intrinsified_natives) {
    OS::Print("Smi_bitNegate: %s\n", operand.ToCString());
  }
  intptr_t result = ~operand.Value();
  ASSERT(Smi::IsValid(result));
  return Smi::New(result);
}


DEFINE_NATIVE_ENTRY(Smi_bitLength, 1) {
  const Smi& operand = Smi::CheckedHandle(arguments->NativeArgAt(0));
  if (FLAG_trace_intrinsified_natives) {
    OS::Print("Smi_bitLength: %s\n", operand.ToCString());
  }
  int64_t value = operand.AsInt64Value();
  intptr_t result = Utils::BitLength(value);
  ASSERT(Smi::IsValid(result));
  return Smi::New(result);
}


// Mint natives.

DEFINE_NATIVE_ENTRY(Mint_bitNegate, 1) {
  const Mint& operand = Mint::CheckedHandle(arguments->NativeArgAt(0));
  ASSERT(CheckInteger(operand));
  if (FLAG_trace_intrinsified_natives) {
    OS::Print("Mint_bitNegate: %s\n", operand.ToCString());
  }
  int64_t result = ~operand.value();
  return Integer::New(result);
}


DEFINE_NATIVE_ENTRY(Mint_bitLength, 1) {
  const Mint& operand = Mint::CheckedHandle(arguments->NativeArgAt(0));
  ASSERT(CheckInteger(operand));
  if (FLAG_trace_intrinsified_natives) {
    OS::Print("Mint_bitLength: %s\n", operand.ToCString());
  }
  int64_t value = operand.AsInt64Value();
  intptr_t result = Utils::BitLength(value);
  ASSERT(Smi::IsValid(result));
  return Smi::New(result);
}


DEFINE_NATIVE_ENTRY(Mint_shlFromInt, 2) {
  // Use the preallocated out of memory exception to avoid calling
  // into dart code or allocating any code.
  const Instance& exception =
      Instance::Handle(isolate->object_store()->out_of_memory());
  Exceptions::Throw(thread, exception);
  UNREACHABLE();
  return 0;
}


// Bigint natives.

DEFINE_NATIVE_ENTRY(Bigint_getNeg, 1) {
  const Bigint& bigint = Bigint::CheckedHandle(arguments->NativeArgAt(0));
  return bigint.neg();
}


DEFINE_NATIVE_ENTRY(Bigint_getUsed, 1) {
  const Bigint& bigint = Bigint::CheckedHandle(arguments->NativeArgAt(0));
  return bigint.used();
}


DEFINE_NATIVE_ENTRY(Bigint_getDigits, 1) {
  const Bigint& bigint = Bigint::CheckedHandle(arguments->NativeArgAt(0));
  return bigint.digits();
}


DEFINE_NATIVE_ENTRY(Bigint_allocate, 4) {
  // First arg is null type arguments, since class Bigint is not parameterized.
  const Bool& neg = Bool::CheckedHandle(arguments->NativeArgAt(1));
  const Smi& used = Smi::CheckedHandle(arguments->NativeArgAt(2));
  const TypedData& digits = TypedData::CheckedHandle(arguments->NativeArgAt(3));
  ASSERT(!digits.IsNull());
  return Bigint::New(neg.value(), used.Value(), digits);
}

}  // namespace dart