Messages in this thread Patch in this message | | | Date | Fri, 11 Jun 2021 22:17:34 +0300 | From | Alexey Dobriyan <> | Subject | [PATCH] lib: uninline simple_strtoull() |
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Gcc inlines simple_strtoull() too agressively.
Given that all 4 signatures match, everything very efficiently calls or tailcalls into simple_strtoull():
ffffffff81da0240 <simple_strtoll>: ffffffff81da0240: 80 3f 2d cmp BYTE PTR [rdi],0x2d ffffffff81da0243: 74 05 je ffffffff81da024a <simple_strtoll+0xa> ffffffff81da0245: e9 76 ff ff ff jmp simple_strtoull ffffffff81da024a: 48 83 c7 01 add rdi,0x1 ffffffff81da024e: e8 6d ff ff ff call simple_strtoull ffffffff81da0253: 48 f7 d8 neg rax ffffffff81da0256: c3 ret
Space savings (on F34-ish .config)
add/remove: 0/0 grow/shrink: 1/3 up/down: 52/-313 (-261) Function old new delta vsscanf 2167 2219 +52 simple_strtoul 72 2 -70 simple_strtoll 143 23 -120 simple_strtol 143 20 -123
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> ---
lib/vsprintf.c | 1 + 1 file changed, 1 insertion(+)
--- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -61,6 +61,7 @@ * * This function has caveats. Please use kstrtoull instead. */ +noinline unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base) { unsigned long long result;
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