Change __ffs return value from 'int' to 'unsigned long' as it
is done in other implementations (like asm-generic, x86, etc...)
to avoid build-time warnings in places where type is strictly
checked.
As __ffs may return values in [0-31] interval changing return
type to unsigned is valid.
Signed-off-by: Eugeniy Paltsev <[email protected]>
---
arch/arc/include/asm/bitops.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/arc/include/asm/bitops.h b/arch/arc/include/asm/bitops.h
index 8da87feec59a..99e6d8948f4a 100644
--- a/arch/arc/include/asm/bitops.h
+++ b/arch/arc/include/asm/bitops.h
@@ -340,7 +340,7 @@ static inline __attribute__ ((const)) int __fls(unsigned long x)
/*
* __ffs: Similar to ffs, but zero based (0-31)
*/
-static inline __attribute__ ((const)) int __ffs(unsigned long word)
+static inline __attribute__ ((const)) unsigned long __ffs(unsigned long word)
{
if (!word)
return word;
@@ -400,9 +400,9 @@ static inline __attribute__ ((const)) int ffs(unsigned long x)
/*
* __ffs: Similar to ffs, but zero based (0-31)
*/
-static inline __attribute__ ((const)) int __ffs(unsigned long x)
+static inline __attribute__ ((const)) unsigned long __ffs(unsigned long x)
{
- int n;
+ unsigned long n;
asm volatile(
" ffs.f %0, %1 \n" /* 0:31; 31(Z) if src 0 */
--
2.14.5
On 12/13/18 7:43 AM, Eugeniy Paltsev wrote:
> Change __ffs return value from 'int' to 'unsigned long' as it
> is done in other implementations (like asm-generic, x86, etc...)
> to avoid build-time warnings in places where type is strictly
> checked.
>
> As __ffs may return values in [0-31] interval changing return
> type to unsigned is valid.
>
> Signed-off-by: Eugeniy Paltsev <[email protected]>
Can you please paste a couple of lines of offending output !
-Vineet
Hi Vineet,
On Thu, 2018-12-13 at 18:23 +0000, Vineet Gupta wrote:
> On 12/13/18 7:43 AM, Eugeniy Paltsev wrote:
> > Change __ffs return value from 'int' to 'unsigned long' as it
> > is done in other implementations (like asm-generic, x86, etc...)
> > to avoid build-time warnings in places where type is strictly
> > checked.
> >
> > As __ffs may return values in [0-31] interval changing return
> > type to unsigned is valid.
> >
> > Signed-off-by: Eugeniy Paltsev <[email protected]>
>
> Can you please paste a couple of lines of offending output !
---------------------------------->8---------------------------------
CC mm/nobootmem.o
In file included from ./include/asm-generic/bug.h:18:0,
from ./arch/arc/include/asm/bug.h:32,
from ./include/linux/bug.h:5,
from ./include/linux/mmdebug.h:5,
from ./include/linux/gfp.h:5,
from ./include/linux/slab.h:15,
from mm/nobootmem.c:14:
mm/nobootmem.c: In function ‘__free_pages_memory’:
./include/linux/kernel.h:845:29: warning: comparison of distinct pointer types lacks a cast
(!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
^
./include/linux/kernel.h:859:4: note: in expansion of macro ‘__typecheck’
(__typecheck(x, y) && __no_side_effects(x, y))
^~~~~~~~~~~
./include/linux/kernel.h:869:24: note: in expansion of macro ‘__safe_cmp’
__builtin_choose_expr(__safe_cmp(x, y), \
^~~~~~~~~~
./include/linux/kernel.h:878:19: note: in expansion of macro ‘__careful_cmp’
#define min(x, y) __careful_cmp(x, y, <)
^~~~~~~~~~~~~
mm/nobootmem.c:104:11: note: in expansion of macro ‘min’
order = min(MAX_ORDER - 1UL, __ffs(start));
^~~
---------------------------------->8---------------------------------
>
> -Vineet
--
Eugeniy Paltsev