coffee/fast_float
1
0
Fork 0
mirror of https://github.com/fastfloat/fast_float.git synced 2026-02-09 11:16:45 +08:00
Code Issues Packages Projects Releases Wiki Activity

review of the fastfloat_strncasecmp3 fastfloat_strncasecmp5 fastfloat_strncasecmp and parse_infnan

Browse Source
This commit is contained in:
IRainman 2026-01-21 02:25:53 +03:00
parent 3b7dc1e0d7
commit f9e222083a
2 changed files with 13 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
include/fast_float/float_common.h
View File

@ -334,7 +334,7 @@ fastfloat_strncasecmp3(UC const *actual_mixedcase,
} }
} }
} else { } else {
uint64_t val1, val2; uint64_t val1{0}, val2{0};
uint64_t mask; uint64_t mask;
FASTFLOAT_IF_CONSTEXPR17(sizeof(UC) == 1) { mask = 0x2020202020202020; } FASTFLOAT_IF_CONSTEXPR17(sizeof(UC) == 1) { mask = 0x2020202020202020; }
else FASTFLOAT_IF_CONSTEXPR17(sizeof(UC) == 2) { else FASTFLOAT_IF_CONSTEXPR17(sizeof(UC) == 2) {
@ -344,15 +344,15 @@ fastfloat_strncasecmp3(UC const *actual_mixedcase,
mask = 0x0000002000000020; mask = 0x0000002000000020;
} }
FASTFLOAT_IF_CONSTEXPR17(sizeof(UC) == 1 || sizeof(UC) == 2) { FASTFLOAT_IF_CONSTEXPR17(sizeof(UC) == 1 || sizeof(UC) == 2) {
std::memcpy(&val1, actual_mixedcase, 3 * sizeof(UC)); ::memcpy(&val1, actual_mixedcase, 3 * sizeof(UC));
std::memcpy(&val2, expected_lowercase, 3 * sizeof(UC)); ::memcpy(&val2, expected_lowercase, 3 * sizeof(UC));
val1 |= mask; val1 |= mask;
val2 |= mask; val2 |= mask;
return val1 == val2; return val1 == val2;
} }
else FASTFLOAT_IF_CONSTEXPR17(sizeof(UC) == 4) { else FASTFLOAT_IF_CONSTEXPR17(sizeof(UC) == 4) {
std::memcpy(&val1, actual_mixedcase, 2 * sizeof(UC)); ::memcpy(&val1, actual_mixedcase, 2 * sizeof(UC));
std::memcpy(&val2, expected_lowercase, 2 * sizeof(UC)); ::memcpy(&val2, expected_lowercase, 2 * sizeof(UC));
val1 |= mask; val1 |= mask;
if (val1 != val2) { if (val1 != val2) {
return false; return false;
@ -378,7 +378,7 @@ fastfloat_strncasecmp5(UC const *actual_mixedcase,
} }
} }
} else { } else {
uint64_t val1, val2; uint64_t val1{0}, val2{0};
FASTFLOAT_IF_CONSTEXPR17(sizeof(UC) == 1) { FASTFLOAT_IF_CONSTEXPR17(sizeof(UC) == 1) {
constexpr uint64_t mask = 0x2020202020202020; constexpr uint64_t mask = 0x2020202020202020;
std::memcpy(&val1, actual_mixedcase, 5 * sizeof(UC)); std::memcpy(&val1, actual_mixedcase, 5 * sizeof(UC));
@ -413,9 +413,6 @@ fastfloat_strncasecmp5(UC const *actual_mixedcase,
} }
return (actual_mixedcase[4] | 32) == (expected_lowercase[4]); return (actual_mixedcase[4] | 32) == (expected_lowercase[4]);
} }
else {
return false;
}
} }
return true; return true;
@ -433,6 +430,7 @@ fastfloat_strncasecmp(UC const *actual_mixedcase, UC const *expected_lowercase,
} }
} }
} else { } else {
uint64_t val1{0}, val2{0};
uint64_t mask; uint64_t mask;
FASTFLOAT_IF_CONSTEXPR17(sizeof(UC) == 1) { mask = 0x2020202020202020; } FASTFLOAT_IF_CONSTEXPR17(sizeof(UC) == 1) { mask = 0x2020202020202020; }
else FASTFLOAT_IF_CONSTEXPR17(sizeof(UC) == 2) { else FASTFLOAT_IF_CONSTEXPR17(sizeof(UC) == 2) {
@ -441,16 +439,12 @@ fastfloat_strncasecmp(UC const *actual_mixedcase, UC const *expected_lowercase,
else FASTFLOAT_IF_CONSTEXPR17(sizeof(UC) == 4) { else FASTFLOAT_IF_CONSTEXPR17(sizeof(UC) == 4) {
mask = 0x0000002000000020; mask = 0x0000002000000020;
} }
else {
return false;
}
constexpr uint_fast8_t sz{8 / (sizeof(UC))}; constexpr uint_fast8_t sz{8 / (sizeof(UC))};
for (uint_fast8_t i = 0; i != length; i += sz) { for (uint_fast8_t i = 0; i < length; i += sz) {
uint64_t val1{0}; val1 = val2 = 0;
uint64_t val2{0};
sz = std::min(sz, length - i); sz = std::min(sz, length - i);
::memcpy(&val1, actual_mixedcase + i, sz * sizeof(UC)); std::memcpy(&val1, actual_mixedcase + i, sz * sizeof(UC));
::memcpy(&val2, expected_lowercase + i, sz * sizeof(UC)); std::memcpy(&val2, expected_lowercase + i, sz * sizeof(UC));
val1 |= mask; val1 |= mask;
val2 |= mask; val2 |= mask;
if (val1 != val2) { if (val1 != val2) {

4
include/fast_float/parse_number.h
View File

@ -16,7 +16,7 @@ namespace fast_float {
namespace detail { namespace detail {
#ifndef FASTFLOAT_ONLY_POSITIVE_C_NUMBER_WO_INF_NAN #ifndef FASTFLOAT_ONLY_POSITIVE_C_NUMBER_WO_INF_NAN
/** /**
* Special case +inf, -inf, nan, infinity, -infinity. * Special case inf, +inf, -inf, nan, infinity, -infinity.
* The case comparisons could be made much faster given that we know that the * The case comparisons could be made much faster given that we know that the
* strings a null-free and fixed. * strings a null-free and fixed.
**/ **/
@ -46,7 +46,7 @@ from_chars_result_t<UC>
// Check for possible nan(n-char-seq-opt), C++17 20.19.3.7, // Check for possible nan(n-char-seq-opt), C++17 20.19.3.7,
// C11 7.20.1.3.3. At least MSVC produces nan(ind) and nan(snan). // C11 7.20.1.3.3. At least MSVC produces nan(ind) and nan(snan).
if (first != last && *first == UC('(')) { if (first != last && *first == UC('(')) {
for (UC const *ptr = first + 1; ptr != last; ++ptr) { for (auto const *ptr = first + 1; ptr != last; ++ptr) {
if (*ptr == UC(')')) { if (*ptr == UC(')')) {
answer.ptr = ptr + 1; // valid nan(n-char-seq-opt) answer.ptr = ptr + 1; // valid nan(n-char-seq-opt)
break; break;