2024-03-25 12:17:32

by Adrian Hunter

Subject: [PATCH V2 04/19] math64: Tidy mul_u64_u32_shr()

Put together declaration and initialization of local variables.

Suggested-by: Thomas Gleixner <[email protected]>
Signed-off-by: Adrian Hunter <[email protected]>
---
include/linux/math64.h | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/include/linux/math64.h b/include/linux/math64.h
index bf74478926d4..fd13622b2056 100644
--- a/include/linux/math64.h
+++ b/include/linux/math64.h
@@ -179,16 +179,12 @@ static __always_inline u64 mul_u64_u64_shr(u64 a, u64 mul, unsigned int shift)
#ifndef mul_u64_u32_shr
static __always_inline u64 mul_u64_u32_shr(u64 a, u32 mul, unsigned int shift)
{
- u32 ah, al;
+ u32 ah = a >> 32, al = a;
u64 ret;

- al = a;
- ah = a >> 32;
-
ret = mul_u32_u32(al, mul) >> shift;
if (ah)
ret += mul_u32_u32(ah, mul) << (32 - shift);
-
return ret;
}
#endif /* mul_u64_u32_shr */
--
2.34.1

2024-04-08 13:13:56

by tip-bot2 for Tony Luck

Subject: [tip: timers/core] math64: Tidy up mul_u64_u32_shr()

The following commit has been merged into the timers/core branch of tip:

Commit-ID: 5e5e51422cd189bc1b627f619f0f99324e6e4de9
Gitweb: https://git.kernel.org/tip/5e5e51422cd189bc1b627f619f0f99324e6e4de9
Author: Adrian Hunter <[email protected]>
AuthorDate: Mon, 25 Mar 2024 08:40:08 +02:00
Committer: Thomas Gleixner <[email protected]>
CommitterDate: Mon, 08 Apr 2024 15:03:06 +02:00

math64: Tidy up mul_u64_u32_shr()

Put together declaration and initialization of local variables.

Suggested-by: Thomas Gleixner <[email protected]>
Signed-off-by: Adrian Hunter <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

---
include/linux/math64.h | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/include/linux/math64.h b/include/linux/math64.h
index bf74478..fd13622 100644
--- a/include/linux/math64.h
+++ b/include/linux/math64.h
@@ -179,16 +179,12 @@ static __always_inline u64 mul_u64_u64_shr(u64 a, u64 mul, unsigned int shift)
#ifndef mul_u64_u32_shr
static __always_inline u64 mul_u64_u32_shr(u64 a, u32 mul, unsigned int shift)
{
- u32 ah, al;
+ u32 ah = a >> 32, al = a;
u64 ret;

- al = a;
- ah = a >> 32;
-
ret = mul_u32_u32(al, mul) >> shift;
if (ah)
ret += mul_u32_u32(ah, mul) << (32 - shift);
-
return ret;
}
#endif /* mul_u64_u32_shr */

2024-04-24 15:17:12

by Peter Zijlstra

Subject: Re: [PATCH V2 04/19] math64: Tidy mul_u64_u32_shr()

On Mon, Mar 25, 2024 at 08:40:08AM +0200, Adrian Hunter wrote:
> Put together declaration and initialization of local variables.
>
> Suggested-by: Thomas Gleixner <[email protected]>
> Signed-off-by: Adrian Hunter <[email protected]>
> ---

Nothing wrong with this patch, but it is highly unlikely this code is
actually tested much. Most (sane) architectures will use the __int128
version.

> include/linux/math64.h | 6 +-----
> 1 file changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/include/linux/math64.h b/include/linux/math64.h
> index bf74478926d4..fd13622b2056 100644
> --- a/include/linux/math64.h
> +++ b/include/linux/math64.h
> @@ -179,16 +179,12 @@ static __always_inline u64 mul_u64_u64_shr(u64 a, u64 mul, unsigned int shift)
> #ifndef mul_u64_u32_shr
> static __always_inline u64 mul_u64_u32_shr(u64 a, u32 mul, unsigned int shift)
> {
> - u32 ah, al;
> + u32 ah = a >> 32, al = a;
> u64 ret;
>
> - al = a;
> - ah = a >> 32;
> -
> ret = mul_u32_u32(al, mul) >> shift;
> if (ah)
> ret += mul_u32_u32(ah, mul) << (32 - shift);
> -
> return ret;
> }
> #endif /* mul_u64_u32_shr */
> --
> 2.34.1
>