organicmaps/fast_double_parser
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Fixing legacy Win32 support

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Daniel Lemire 2022-05-19 12:25:13 -04:00
parent 182c61b1ce
commit 3b296fc600
1 changed files with 8 additions and 4 deletions
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12
include/fast_double_parser.h
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@ -202,10 +202,14 @@ inline int leading_zeroes(uint64_t input_num) {
else
return 64;
#else
unsigned long x1 = (unsigned long)(input_num >> 32), top, bottom;
_BitScanReverse(&top, x1);
_BitScanReverse(&bottom, (unsigned long)input_num);
return x1 ? top + 32 : bottom;
int last_bit = 0;
if(input_num & uint64_t(0xffffffff00000000)) input_num >>= 32, last_bit |= 32;
if(input_num & uint64_t( 0xffff0000)) input_num >>= 16, last_bit |= 16;
if(input_num & uint64_t( 0xff00)) input_num >>= 8, last_bit |= 8;
if(input_num & uint64_t( 0xf0)) input_num >>= 4, last_bit |= 4;
if(input_num & uint64_t( 0xc)) input_num >>= 2, last_bit |= 2;
if(input_num & uint64_t( 0x2)) input_num >>= 1, last_bit |= 1;
return 63 - last_bit;
#endif // defined(_M_X64) || defined(_M_ARM64) || defined (_M_IA64)
#else
return __builtin_clzll(input_num);