| // 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. |
| |
| #include "src/base/bits.h" |
| |
| #include <limits> |
| |
| #include "src/base/logging.h" |
| |
| namespace v8 { |
| namespace base { |
| namespace bits { |
| |
| uint32_t RoundUpToPowerOfTwo32(uint32_t value) { |
| DCHECK_LE(value, 0x80000000u); |
| value = value - 1; |
| value = value | (value >> 1); |
| value = value | (value >> 2); |
| value = value | (value >> 4); |
| value = value | (value >> 8); |
| value = value | (value >> 16); |
| return value + 1; |
| } |
| |
| |
| int32_t SignedMulHigh32(int32_t lhs, int32_t rhs) { |
| int64_t const value = static_cast<int64_t>(lhs) * static_cast<int64_t>(rhs); |
| return bit_cast<int32_t, uint32_t>(bit_cast<uint64_t>(value) >> 32u); |
| } |
| |
| |
| int32_t SignedMulHighAndAdd32(int32_t lhs, int32_t rhs, int32_t acc) { |
| return bit_cast<int32_t>(bit_cast<uint32_t>(acc) + |
| bit_cast<uint32_t>(SignedMulHigh32(lhs, rhs))); |
| } |
| |
| |
| int32_t SignedDiv32(int32_t lhs, int32_t rhs) { |
| if (rhs == 0) return 0; |
| if (rhs == -1) return -lhs; |
| return lhs / rhs; |
| } |
| |
| |
| int32_t SignedMod32(int32_t lhs, int32_t rhs) { |
| if (rhs == 0 || rhs == -1) return 0; |
| return lhs % rhs; |
| } |
| |
| } // namespace bits |
| } // namespace base |
| } // namespace v8 |