fmtlib/fmt
1
0
Fork 1
mirror of https://github.com/fmtlib/fmt.git synced 2025-11-27 04:39:44 +01:00
Code Issues Packages Projects Releases Wiki Activity

Add countl_zero function

Browse Source 
Signed-off-by: Vladislav Shchapov <vladislav@shchapov.ru>
This commit is contained in:
Vladislav Shchapov
2022-11-30 22:32:32 +05:00
committed by Victor Zverovich
parent 8d50d814db
commit d24be2e95c
2 changed files with 21 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
include/fmt/format.h
View File

@@ -472,6 +472,16 @@ inline auto bit_cast(const From& from) -> To {
return result;
}
FMT_CONSTEXPR20 inline auto countl_zero(uint32_t n) -> int {
#ifdef FMT_BUILTIN_CLZ
if (!is_constant_evaluated()) return FMT_BUILTIN_CLZ(n);
#endif
int lz = 0;
constexpr uint32_t msb_mask = 1u << (num_bits<uint32_t>() - 1);
for (; (n & msb_mask) == 0; n <<= 1) lz++;
return lz;
}
FMT_INLINE void assume(bool condition) {
(void)condition;
#if FMT_HAS_BUILTIN(__builtin_assume) && !FMT_ICC_VERSION
@@ -3149,7 +3159,7 @@ FMT_CONSTEXPR20 void format_hexfloat(Float value, int precision,
const auto leading_mask = carrier_uint(0xF) << leading_shift;
const auto leading_xdigit =
static_cast<uint32_t>((f.f & leading_mask) >> leading_shift);
if (leading_xdigit > 1) f.e -= (32 - FMT_BUILTIN_CLZ(leading_xdigit) - 1);
if (leading_xdigit > 1) f.e -= (32 - countl_zero(leading_xdigit) - 1);
int print_xdigits = num_xdigits - 1;
if (precision >= 0 && print_xdigits > precision) {