[PATCH 2/2] proc: use do-while in name_to_int()

From: Alexey Dobriyan
Date: Tue Sep 12 2017 - 15:52:27 EST


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


Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
---

fs/proc/util.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- 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;