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@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/proc/util.c b/fs/proc/util.c
index c29aa49..b161cfa 100644
--- a/fs/proc/util.c
+++ b/fs/proc/util.c
@@ -8,7 +8,7 @@ unsigned name_to_int(const struct qstr *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 *qstr)
goto out;
n *= 10;
n += c;
- }
+ } while (--len > 0);
return n;
out:
return ~0U;