diff options
Diffstat (limited to 'absl/random/internal/fastmath.h')
-rw-r--r-- | absl/random/internal/fastmath.h | 23 |
1 files changed, 3 insertions, 20 deletions
diff --git a/absl/random/internal/fastmath.h b/absl/random/internal/fastmath.h index 6baeb5a7..963b7690 100644 --- a/absl/random/internal/fastmath.h +++ b/absl/random/internal/fastmath.h @@ -22,27 +22,22 @@ #include <cmath> #include <cstdint> -#include "absl/base/internal/bits.h" +#include "absl/numeric/bits.h" namespace absl { ABSL_NAMESPACE_BEGIN namespace random_internal { -// Returns the position of the first bit set. -inline int LeadingSetBit(uint64_t n) { - return 64 - base_internal::CountLeadingZeros64(n); -} - // Compute log2(n) using integer operations. // While std::log2 is more accurate than std::log(n) / std::log(2), for // very large numbers--those close to std::numeric_limits<uint64_t>::max() - 2, // for instance--std::log2 rounds up rather than down, which introduces // definite skew in the results. inline int IntLog2Floor(uint64_t n) { - return (n <= 1) ? 0 : (63 - base_internal::CountLeadingZeros64(n)); + return (n <= 1) ? 0 : (63 - countl_zero(n)); } inline int IntLog2Ceil(uint64_t n) { - return (n <= 1) ? 0 : (64 - base_internal::CountLeadingZeros64(n - 1)); + return (n <= 1) ? 0 : (64 - countl_zero(n - 1)); } inline double StirlingLogFactorial(double n) { @@ -55,18 +50,6 @@ inline double StirlingLogFactorial(double n) { (1.0 / 360.0) * ninv * ninv * ninv; } -// Rotate value right. -// -// We only implement the uint32_t / uint64_t versions because -// 1) those are the only ones we use, and -// 2) those are the only ones where clang detects the rotate idiom correctly. -inline constexpr uint32_t rotr(uint32_t value, uint8_t bits) { - return (value >> (bits & 31)) | (value << ((-bits) & 31)); -} -inline constexpr uint64_t rotr(uint64_t value, uint8_t bits) { - return (value >> (bits & 63)) | (value << ((-bits) & 63)); -} - } // namespace random_internal ABSL_NAMESPACE_END } // namespace absl |