diff mbox series

[1/2] linux/kernel.h: use 'short' to define USHRT_MAX, SHRT_MAX, SHRT_MIN

Message ID 1549123585-13800-1-git-send-email-yamada.masahiro@socionext.com
State Superseded
Headers show
Series [1/2] linux/kernel.h: use 'short' to define USHRT_MAX, SHRT_MAX, SHRT_MIN | expand

Commit Message

Masahiro Yamada Feb. 2, 2019, 4:06 p.m. UTC
The log of commit 44f564a4bf6a ("ipc: add definitions of USHORT_MAX
and others") did not explain why it used (s16) and (u16) instead of
(short) and (unsigned short).

Let's use (short) and (unsigned short), which is more sensible, and
more consistent with the other MAX/MIN defines.

As you see in include/uapi/asm-generic/int-ll64.h, s16/u16 are
typedef'ed as signed/unsigned short. So, this commit does not have
a functional change.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Zhang Yanmin <yanmin.zhang@intel.com>
---

 include/linux/kernel.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

-- 
2.7.4

Comments

Alexey Dobriyan Feb. 2, 2019, 4:31 p.m. UTC | #1
On Sun, Feb 03, 2019 at 01:06:24AM +0900, Masahiro Yamada wrote:
> The log of commit 44f564a4bf6a ("ipc: add definitions of USHORT_MAX

> and others") did not explain why it used (s16) and (u16) instead of

> (short) and (unsigned short).

> 

> Let's use (short) and (unsigned short), which is more sensible, and

> more consistent with the other MAX/MIN defines.

> 

> As you see in include/uapi/asm-generic/int-ll64.h, s16/u16 are

> typedef'ed as signed/unsigned short. So, this commit does not have

> a functional change.


> -#define USHRT_MAX	((u16)(~0U))

> -#define SHRT_MAX	((s16)(USHRT_MAX>>1))

> -#define SHRT_MIN	((s16)(-SHRT_MAX - 1))

> +#define USHRT_MAX	((unsigned short)(~0U))

					 ^   ^
					 +---+
					   unnecessary ()
> +#define SHRT_MAX	((short)(USHRT_MAX>>1))

> +#define SHRT_MIN	((short)(-SHRT_MAX - 1))


"short" and "unsigned short" are probably the most useless C types.
I doubt their usage should be promoted.
Alexey Dobriyan Feb. 2, 2019, 4:36 p.m. UTC | #2
On Sat, Feb 02, 2019 at 07:31:05PM +0300, Alexey Dobriyan wrote:
> On Sun, Feb 03, 2019 at 01:06:24AM +0900, Masahiro Yamada wrote:

> > The log of commit 44f564a4bf6a ("ipc: add definitions of USHORT_MAX

> > and others") did not explain why it used (s16) and (u16) instead of

> > (short) and (unsigned short).

> > 

> > Let's use (short) and (unsigned short), which is more sensible, and

> > more consistent with the other MAX/MIN defines.

> > 

> > As you see in include/uapi/asm-generic/int-ll64.h, s16/u16 are

> > typedef'ed as signed/unsigned short. So, this commit does not have

> > a functional change.

> 

> > -#define USHRT_MAX	((u16)(~0U))

> > -#define SHRT_MAX	((s16)(USHRT_MAX>>1))

> > -#define SHRT_MIN	((s16)(-SHRT_MAX - 1))

> > +#define USHRT_MAX	((unsigned short)(~0U))

> 					 ^   ^

> 					 +---+

> 					   unnecessary ()

> > +#define SHRT_MAX	((short)(USHRT_MAX>>1))

> > +#define SHRT_MIN	((short)(-SHRT_MAX - 1))

> 

> "short" and "unsigned short" are probably the most useless C types.

> I doubt their usage should be promoted.


OTOH, U16_MAX etc exist and cast to u16, so using "short" would be
the right thing to do.
Masahiro Yamada Feb. 3, 2019, 1:09 a.m. UTC | #3
On Sun, Feb 3, 2019 at 1:33 AM Alexey Dobriyan <adobriyan@gmail.com> wrote:
>

> On Sun, Feb 03, 2019 at 01:06:24AM +0900, Masahiro Yamada wrote:

> > The log of commit 44f564a4bf6a ("ipc: add definitions of USHORT_MAX

> > and others") did not explain why it used (s16) and (u16) instead of

> > (short) and (unsigned short).

> >

> > Let's use (short) and (unsigned short), which is more sensible, and

> > more consistent with the other MAX/MIN defines.

> >

> > As you see in include/uapi/asm-generic/int-ll64.h, s16/u16 are

> > typedef'ed as signed/unsigned short. So, this commit does not have

> > a functional change.

>

> > -#define USHRT_MAX    ((u16)(~0U))

> > -#define SHRT_MAX     ((s16)(USHRT_MAX>>1))

> > -#define SHRT_MIN     ((s16)(-SHRT_MAX - 1))

> > +#define USHRT_MAX    ((unsigned short)(~0U))

>                                          ^   ^

>                                          +---+

>                                            unnecessary ()



Thanks, I will remove it in v2.




> > +#define SHRT_MAX     ((short)(USHRT_MAX>>1))

> > +#define SHRT_MIN     ((short)(-SHRT_MAX - 1))

>

> "short" and "unsigned short" are probably the most useless C types.

> I doubt their usage should be promoted.




-- 
Best Regards
Masahiro Yamada
diff mbox series

Patch

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 8f0e68e..110bac1 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -16,9 +16,9 @@ 
 #include <asm/byteorder.h>
 #include <uapi/linux/kernel.h>
 
-#define USHRT_MAX	((u16)(~0U))
-#define SHRT_MAX	((s16)(USHRT_MAX>>1))
-#define SHRT_MIN	((s16)(-SHRT_MAX - 1))
+#define USHRT_MAX	((unsigned short)(~0U))
+#define SHRT_MAX	((short)(USHRT_MAX>>1))
+#define SHRT_MIN	((short)(-SHRT_MAX - 1))
 #define INT_MAX		((int)(~0U>>1))
 #define INT_MIN		(-INT_MAX - 1)
 #define UINT_MAX	(~0U)