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refector: pre-calculate digit separator presence and value

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재욱 2026-02-08 22:10:34 +09:00
parent ad90d9a01d
commit b9ffbe8dc6
1 changed files with 11 additions and 15 deletions
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26
include/fast_float/ascii_number.h
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@ -351,12 +351,14 @@ parse_number_string(UC const *p, UC const *pend,
} }
} }
UC const *const start_digits = p; UC const *const start_digits = p;
const UC separator = options.digit_separator;
const bool has_separator = (separator != UC('\0'));
uint64_t i = 0; // an unsigned int avoids signed overflows (which are bad) uint64_t i = 0; // an unsigned int avoids signed overflows (which are bad)
int64_t digit_count = 0; int64_t digit_count = 0;
while (p != pend) { while (p != pend) {
if (options.digit_separator != UC('\0') && *p == options.digit_separator) { if (has_separator && *p == separator) {
++p; ++p;
continue; continue;
} }
@ -380,9 +382,8 @@ parse_number_string(UC const *p, UC const *pend,
return report_parse_error<UC>(p, parse_error::no_digits_in_integer_part); return report_parse_error<UC>(p, parse_error::no_digits_in_integer_part);
} }
UC const *first_digit = start_digits; UC const *first_digit = start_digits;
while (first_digit != end_of_integer_part && while (first_digit != end_of_integer_part && has_separator &&
options.digit_separator != UC('\0') && *first_digit == separator) {
*first_digit == options.digit_separator) {
++first_digit; ++first_digit;
} }
if (first_digit != end_of_integer_part && *first_digit == UC('0') && if (first_digit != end_of_integer_part && *first_digit == UC('0') &&
@ -400,7 +401,7 @@ parse_number_string(UC const *p, UC const *pend,
UC const *before = p; UC const *before = p;
// can occur at most twice without overflowing, but let it occur more, since // can occur at most twice without overflowing, but let it occur more, since
// for integers with many digits, digit parsing is the primary bottleneck. // for integers with many digits, digit parsing is the primary bottleneck.
if (options.digit_separator == UC('\0')) { if (!has_separator) {
UC const *const before_simd = p; UC const *const before_simd = p;
loop_parse_if_eight_digits(p, pend, i); loop_parse_if_eight_digits(p, pend, i);
size_t const exploded = size_t(p - before_simd); size_t const exploded = size_t(p - before_simd);
@ -408,8 +409,7 @@ parse_number_string(UC const *p, UC const *pend,
} }
while (p != pend) { while (p != pend) {
if (options.digit_separator != UC('\0') && if (has_separator && *p == separator) {
*p == options.digit_separator) {
++p; ++p;
continue; continue;
} }
@ -499,8 +499,7 @@ parse_number_string(UC const *p, UC const *pend,
// E.g., 0.000000000...000. // E.g., 0.000000000...000.
UC const *start = start_digits; UC const *start = start_digits;
while ((start != pend) && (*start == UC('0') || *start == decimal_point || while ((start != pend) && (*start == UC('0') || *start == decimal_point ||
(options.digit_separator != UC('\0') && (has_separator && *start == separator))) {
*start == options.digit_separator))) {
if (*start == UC('0')) { if (*start == UC('0')) {
digit_count--; digit_count--;
} }
@ -517,8 +516,7 @@ parse_number_string(UC const *p, UC const *pend,
UC const *int_end = p + answer.integer.len(); UC const *int_end = p + answer.integer.len();
uint64_t const minimal_nineteen_digit_integer{1000000000000000000}; uint64_t const minimal_nineteen_digit_integer{1000000000000000000};
while ((i < minimal_nineteen_digit_integer) && (p != int_end)) { while ((i < minimal_nineteen_digit_integer) && (p != int_end)) {
if (options.digit_separator != UC('\0') && if (has_separator && *p == separator) {
*p == options.digit_separator) {
++p; ++p;
continue; continue;
} }
@ -528,8 +526,7 @@ parse_number_string(UC const *p, UC const *pend,
if (i >= minimal_nineteen_digit_integer) { // We have a big integer if (i >= minimal_nineteen_digit_integer) { // We have a big integer
int64_t remaining_integer_digits = 0; int64_t remaining_integer_digits = 0;
while (p != int_end) { while (p != int_end) {
if (options.digit_separator != UC('\0') && if (has_separator && *p == separator) {
*p == options.digit_separator) {
++p; ++p;
continue; continue;
} }
@ -542,8 +539,7 @@ parse_number_string(UC const *p, UC const *pend,
UC const *frac_end = p + answer.fraction.len(); UC const *frac_end = p + answer.fraction.len();
int64_t fraction_digits_consumed = 0; int64_t fraction_digits_consumed = 0;
while ((i < minimal_nineteen_digit_integer) && (p != frac_end)) { while ((i < minimal_nineteen_digit_integer) && (p != frac_end)) {
if (options.digit_separator != UC('\0') && if (has_separator && *p == separator) {
*p == options.digit_separator) {
++p; ++p;
continue; continue;
} }