diff options
Diffstat (limited to 'runtime/base/bit_utils.h')
| -rw-r--r-- | runtime/base/bit_utils.h | 23 |
1 files changed, 8 insertions, 15 deletions
diff --git a/runtime/base/bit_utils.h b/runtime/base/bit_utils.h index 332012bda9..6f45dc8209 100644 --- a/runtime/base/bit_utils.h +++ b/runtime/base/bit_utils.h @@ -29,28 +29,21 @@ namespace art { template<typename T> static constexpr int CLZ(T x) { static_assert(std::is_integral<T>::value, "T must be integral"); - static_assert(std::is_unsigned<T>::value, "T must be unsigned"); + // TODO: assert unsigned. There is currently many uses with signed values. static_assert(sizeof(T) <= sizeof(long long), // NOLINT [runtime/int] [4] "T too large, must be smaller than long long"); - return - DCHECK_CONSTEXPR(x != 0, "x must not be zero", T(0)) - (sizeof(T) == sizeof(uint32_t)) - ? __builtin_clz(x) - : __builtin_clzll(x); + return (sizeof(T) == sizeof(uint32_t)) + ? __builtin_clz(x) // TODO: __builtin_clz[ll] has undefined behavior for x=0 + : __builtin_clzll(x); } template<typename T> static constexpr int CTZ(T x) { static_assert(std::is_integral<T>::value, "T must be integral"); - // A similar check to the above does not make sense. It isn't as non-intuitive to ask for - // trailing zeros in a negative number, and the quick backends do this for immediate encodings. - static_assert(sizeof(T) <= sizeof(long long), // NOLINT [runtime/int] [4] - "T too large, must be smaller than long long"); - return - DCHECK_CONSTEXPR(x != 0, "x must not be zero", T(0)) - (sizeof(T) == sizeof(uint32_t)) - ? __builtin_ctz(x) - : __builtin_ctzll(x); + // TODO: assert unsigned. There is currently many uses with signed values. + return (sizeof(T) == sizeof(uint32_t)) + ? __builtin_ctz(x) + : __builtin_ctzll(x); } template<typename T> |