Speeding up write_significand() (#2499)

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Roman-Koshelev 2021-10-09 15:27:38 +03:00 committed by GitHub
parent 26c1ca4c3e
commit 7e4bc94510
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@ -1713,14 +1713,20 @@ inline auto write_significand(Char* out, UInt significand, int significand_size,
int integral_size, Char decimal_point) -> Char* {
if (!decimal_point)
return format_decimal(out, significand, significand_size).end;
auto end = format_decimal(out + 1, significand, significand_size).end;
if (integral_size == 1) {
out[0] = out[1];
} else {
std::uninitialized_copy_n(out + 1, integral_size,
make_checked(out, to_unsigned(integral_size)));
out += significand_size + 1;
Char* end = out;
int floating_size = significand_size - integral_size;
for(int i = floating_size / 2; i > 0; --i) {
out -= 2;
copy2(out, digits2(significand % 100));
significand /= 100;
}
out[integral_size] = decimal_point;
if (floating_size % 2 != 0) {
*--out = static_cast<Char>('0' + significand % 10);
significand /= 10;
}
*--out = decimal_point;
format_decimal(out - integral_size, significand, integral_size);
return end;
}