From: Alexey Dobriyan <adobriyan@xxxxxxxxx> Subject: proc: use do-while in name_to_int() Gcc doesn't know that "len" is guaranteed to be >=1 by dcache and generates standard while-loop prologue duplicating loop condition. add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-27 (-27) function old new delta name_to_int 104 77 -27 Link: http://lkml.kernel.org/r/20170912195213.GB17730@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/proc/util.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff -puN fs/proc/util.c~proc-use-do-while-in-name_to_int fs/proc/util.c --- a/fs/proc/util.c~proc-use-do-while-in-name_to_int +++ a/fs/proc/util.c @@ -8,7 +8,7 @@ unsigned name_to_int(const struct qstr * if (len > 1 && *name == '0') goto out; - while (len-- > 0) { + do { unsigned c = *name++ - '0'; if (c > 9) goto out; @@ -16,7 +16,7 @@ unsigned name_to_int(const struct qstr * goto out; n *= 10; n += c; - } + } while (--len > 0); return n; out: return ~0U; _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
