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Constexpr parse_number_string

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This commit is contained in:
Lenard Szolnoki 2023-03-04 16:49:34 +00:00
parent c487a69c1b
commit 82ee3b1b5f
1 changed files with 25 additions and 5 deletions
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30
include/fast_float/ascii_number.h
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@ -27,7 +27,16 @@ fastfloat_really_inline constexpr uint64_t byteswap(uint64_t val) {
| (val & 0x00000000000000FF) << 56; | (val & 0x00000000000000FF) << 56;
} }
fastfloat_really_inline uint64_t read_u64(const char *chars) { fastfloat_really_inline FASTFLOAT_CONSTEXPR20
uint64_t read_u64(const char *chars) {
if (cpp20_and_in_constexpr()) {
uint64_t val = 0;
for(int i = 0; i < 8; ++i) {
val |= uint64_t(*chars) << (i*8);
++chars;
}
return val;
}
uint64_t val; uint64_t val;
::memcpy(&val, chars, sizeof(uint64_t)); ::memcpy(&val, chars, sizeof(uint64_t));
#if FASTFLOAT_IS_BIG_ENDIAN == 1 #if FASTFLOAT_IS_BIG_ENDIAN == 1
@ -37,7 +46,16 @@ fastfloat_really_inline uint64_t read_u64(const char *chars) {
return val; return val;
} }
fastfloat_really_inline void write_u64(uint8_t *chars, uint64_t val) { fastfloat_really_inline FASTFLOAT_CONSTEXPR20
void write_u64(uint8_t *chars, uint64_t val) {
if (cpp20_and_in_constexpr()) {
for(int i = 0; i < 8; ++i) {
*chars = uint8_t(val);
val >>= 8;
++chars;
}
return;
}
#if FASTFLOAT_IS_BIG_ENDIAN == 1 #if FASTFLOAT_IS_BIG_ENDIAN == 1
// Need to read as-if the number was in little-endian order. // Need to read as-if the number was in little-endian order.
val = byteswap(val); val = byteswap(val);
@ -57,7 +75,8 @@ uint32_t parse_eight_digits_unrolled(uint64_t val) {
return uint32_t(val); return uint32_t(val);
} }
fastfloat_really_inline uint32_t parse_eight_digits_unrolled(const char *chars) noexcept { fastfloat_really_inline FASTFLOAT_CONSTEXPR20
uint32_t parse_eight_digits_unrolled(const char *chars) noexcept {
return parse_eight_digits_unrolled(read_u64(chars)); return parse_eight_digits_unrolled(read_u64(chars));
} }
@ -67,7 +86,8 @@ fastfloat_really_inline constexpr bool is_made_of_eight_digits_fast(uint64_t val
0x8080808080808080)); 0x8080808080808080));
} }
fastfloat_really_inline bool is_made_of_eight_digits_fast(const char *chars) noexcept { fastfloat_really_inline FASTFLOAT_CONSTEXPR20
bool is_made_of_eight_digits_fast(const char *chars) noexcept {
return is_made_of_eight_digits_fast(read_u64(chars)); return is_made_of_eight_digits_fast(read_u64(chars));
} }
@ -87,7 +107,7 @@ struct parsed_number_string {
// Assuming that you use no more than 19 digits, this will // Assuming that you use no more than 19 digits, this will
// parse an ASCII string. // parse an ASCII string.
fastfloat_really_inline fastfloat_really_inline FASTFLOAT_CONSTEXPR20
parsed_number_string parse_number_string(const char *p, const char *pend, parse_options options) noexcept { parsed_number_string parse_number_string(const char *p, const char *pend, parse_options options) noexcept {
const chars_format fmt = options.format; const chars_format fmt = options.format;
const char decimal_point = options.decimal_point; const char decimal_point = options.decimal_point;