diff options
Diffstat (limited to 'absl/strings/numbers.cc')
-rw-r--r-- | absl/strings/numbers.cc | 17 |
1 files changed, 3 insertions, 14 deletions
diff --git a/absl/strings/numbers.cc b/absl/strings/numbers.cc index b4140b3605bc..68ef7999a981 100644 --- a/absl/strings/numbers.cc +++ b/absl/strings/numbers.cc @@ -32,6 +32,7 @@ #include "absl/base/internal/raw_logging.h" #include "absl/strings/ascii.h" +#include "absl/strings/internal/bits.h" #include "absl/strings/internal/memutil.h" #include "absl/strings/str_cat.h" @@ -302,18 +303,6 @@ char* numbers_internal::FastIntToBuffer(int64_t i, char* buffer) { return numbers_internal::FastIntToBuffer(u, buffer); } -// Returns the number of leading 0 bits in a 64-bit value. -// TODO(jorg): Replace with builtin_clzll if available. -// Are we shipping util/bits in absl? -static inline int CountLeadingZeros64(uint64_t n) { - int zeroes = 60; - if (n >> 32) zeroes -= 32, n >>= 32; - if (n >> 16) zeroes -= 16, n >>= 16; - if (n >> 8) zeroes -= 8, n >>= 8; - if (n >> 4) zeroes -= 4, n >>= 4; - return "\4\3\2\2\1\1\1\1\0\0\0\0\0\0\0\0"[n] + zeroes; -} - // Given a 128-bit number expressed as a pair of uint64_t, high half first, // return that number multiplied by the given 32-bit value. If the result is // too large to fit in a 128-bit number, divide it by 2 until it fits. @@ -351,7 +340,7 @@ static std::pair<uint64_t, uint64_t> Mul32(std::pair<uint64_t, uint64_t> num, uint64_t bits128_up = (bits96_127 >> 32) + (bits64_127 < bits64_95); if (bits128_up == 0) return {bits64_127, bits0_63}; - int shift = 64 - CountLeadingZeros64(bits128_up); + int shift = 64 - strings_internal::CountLeadingZeros64(bits128_up); uint64_t lo = (bits0_63 >> shift) + (bits64_127 << (64 - shift)); uint64_t hi = (bits64_127 >> shift) + (bits128_up << (64 - shift)); return {hi, lo}; @@ -382,7 +371,7 @@ static std::pair<uint64_t, uint64_t> PowFive(uint64_t num, int expfive) { 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5, 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5}; result = Mul32(result, powers_of_five[expfive & 15]); - int shift = CountLeadingZeros64(result.first); + int shift = strings_internal::CountLeadingZeros64(result.first); if (shift != 0) { result.first = (result.first << shift) + (result.second >> (64 - shift)); result.second = (result.second << shift); |