diff options
| author | Alexey Dobriyan <adobriyan@gmail.com> | 2023-10-27 17:13:58 +0300 |
|---|---|---|
| committer | Petr Mladek <pmladek@suse.com> | 2023-11-01 15:55:39 +0100 |
| commit | 72fcce70faf06dd7442bf0b41b71f071d7fa29a4 (patch) | |
| tree | 9fd2191e260b19a7682517db62b6ab33595d8cd5 /lib | |
| parent | 3f6074cf467f6c2beb7db0b0d685fb53f25ae9aa (diff) | |
| download | lwn-72fcce70faf06dd7442bf0b41b71f071d7fa29a4.tar.gz lwn-72fcce70faf06dd7442bf0b41b71f071d7fa29a4.zip | |
vsprintf: uninline simple_strntoull(), reorder arguments
* uninline simple_strntoull(),
gcc overinlines and this function is not performance critical
* reorder arguments, so that appending INT_MAX as 4th argument
generates very efficient tail call
Space savings:
add/remove: 1/0 grow/shrink: 0/3 up/down: 27/-179 (-152)
Function old new delta
simple_strntoll - 27 +27
simple_strtoull 15 10 -5
simple_strtoll 41 7 -34
vsscanf 1930 1790 -140
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/all/82a2af6e-9b6c-4a09-89d7-ca90cc1cdad1@p183/
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/vsprintf.c | 25 |
1 files changed, 12 insertions, 13 deletions
diff --git a/lib/vsprintf.c b/lib/vsprintf.c index afb88b24fa74..3e3733a7084f 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -60,7 +60,8 @@ bool no_hash_pointers __ro_after_init; EXPORT_SYMBOL_GPL(no_hash_pointers); -static noinline unsigned long long simple_strntoull(const char *startp, size_t max_chars, char **endp, unsigned int base) +noinline +static unsigned long long simple_strntoull(const char *startp, char **endp, unsigned int base, size_t max_chars) { const char *cp; unsigned long long result = 0ULL; @@ -95,7 +96,7 @@ static noinline unsigned long long simple_strntoull(const char *startp, size_t m noinline unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base) { - return simple_strntoull(cp, INT_MAX, endp, base); + return simple_strntoull(cp, endp, base, INT_MAX); } EXPORT_SYMBOL(simple_strtoull); @@ -130,8 +131,8 @@ long simple_strtol(const char *cp, char **endp, unsigned int base) } EXPORT_SYMBOL(simple_strtol); -static long long simple_strntoll(const char *cp, size_t max_chars, char **endp, - unsigned int base) +noinline +static long long simple_strntoll(const char *cp, char **endp, unsigned int base, size_t max_chars) { /* * simple_strntoull() safely handles receiving max_chars==0 in the @@ -140,9 +141,9 @@ static long long simple_strntoll(const char *cp, size_t max_chars, char **endp, * and the content of *cp is irrelevant. */ if (*cp == '-' && max_chars > 0) - return -simple_strntoull(cp + 1, max_chars - 1, endp, base); + return -simple_strntoull(cp + 1, endp, base, max_chars - 1); - return simple_strntoull(cp, max_chars, endp, base); + return simple_strntoull(cp, endp, base, max_chars); } /** @@ -155,7 +156,7 @@ static long long simple_strntoll(const char *cp, size_t max_chars, char **endp, */ long long simple_strtoll(const char *cp, char **endp, unsigned int base) { - return simple_strntoll(cp, INT_MAX, endp, base); + return simple_strntoll(cp, endp, base, INT_MAX); } EXPORT_SYMBOL(simple_strtoll); @@ -3648,13 +3649,11 @@ int vsscanf(const char *buf, const char *fmt, va_list args) break; if (is_sign) - val.s = simple_strntoll(str, - field_width >= 0 ? field_width : INT_MAX, - &next, base); + val.s = simple_strntoll(str, &next, base, + field_width >= 0 ? field_width : INT_MAX); else - val.u = simple_strntoull(str, - field_width >= 0 ? field_width : INT_MAX, - &next, base); + val.u = simple_strntoull(str, &next, base, + field_width >= 0 ? field_width : INT_MAX); switch (qualifier) { case 'H': /* that's 'hh' in format */ |