Re: [PATCH 07/12] lib: inline _find_next_bit() wrappers

[Andy Shevchenko]

On Thu, Apr 1, 2021 at 3:42 AM Yury Norov <yury.norov@xxxxxxxxx> wrote:
>
> lib/find_bit.c declares five single-line wrappers for _find_next_bit().
> We may turn those wrappers to inline functions. It eliminates unneeded
> function calls and opens room for compile-time optimizations.

Acked-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>

> Signed-off-by: Yury Norov <yury.norov@xxxxxxxxx>
> Acked-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
> ---
>  include/asm-generic/bitops/find.h | 28 ++++++++++++----
>  include/asm-generic/bitops/le.h   | 17 +++++++---
>  lib/find_bit.c                    | 56 ++-----------------------------
>  3 files changed, 37 insertions(+), 64 deletions(-)
>
> diff --git a/include/asm-generic/bitops/find.h b/include/asm-generic/bitops/find.h
> index 9fdf21302fdf..7ad70dab8e93 100644
> --- a/include/asm-generic/bitops/find.h
> +++ b/include/asm-generic/bitops/find.h
> @@ -2,6 +2,10 @@
>  #ifndef _ASM_GENERIC_BITOPS_FIND_H_
>  #define _ASM_GENERIC_BITOPS_FIND_H_
>
> +extern unsigned long _find_next_bit(const unsigned long *addr1,
> +               const unsigned long *addr2, unsigned long nbits,
> +               unsigned long start, unsigned long invert, unsigned long le);
> +
>  #ifndef find_next_bit
>  /**
>   * find_next_bit - find the next set bit in a memory region
> @@ -12,8 +16,12 @@
>   * Returns the bit number for the next set bit
>   * If no bits are set, returns @size.
>   */
> -extern unsigned long find_next_bit(const unsigned long *addr, unsigned long
> -               size, unsigned long offset);
> +static inline
> +unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
> +                           unsigned long offset)
> +{
> +       return _find_next_bit(addr, NULL, size, offset, 0UL, 0);
> +}
>  #endif
>
>  #ifndef find_next_and_bit
> @@ -27,9 +35,13 @@ extern unsigned long find_next_bit(const unsigned long *addr, unsigned long
>   * Returns the bit number for the next set bit
>   * If no bits are set, returns @size.
>   */
> -extern unsigned long find_next_and_bit(const unsigned long *addr1,
> +static inline
> +unsigned long find_next_and_bit(const unsigned long *addr1,
>                 const unsigned long *addr2, unsigned long size,
> -               unsigned long offset);
> +               unsigned long offset)
> +{
> +       return _find_next_bit(addr1, addr2, size, offset, 0UL, 0);
> +}
>  #endif
>
>  #ifndef find_next_zero_bit
> @@ -42,8 +54,12 @@ extern unsigned long find_next_and_bit(const unsigned long *addr1,
>   * Returns the bit number of the next zero bit
>   * If no bits are zero, returns @size.
>   */
> -extern unsigned long find_next_zero_bit(const unsigned long *addr, unsigned
> -               long size, unsigned long offset);
> +static inline
> +unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size,
> +                                unsigned long offset)
> +{
> +       return _find_next_bit(addr, NULL, size, offset, ~0UL, 0);
> +}
>  #endif
>
>  #ifdef CONFIG_GENERIC_FIND_FIRST_BIT
> diff --git a/include/asm-generic/bitops/le.h b/include/asm-generic/bitops/le.h
> index 188d3eba3ace..21305f6cea0b 100644
> --- a/include/asm-generic/bitops/le.h
> +++ b/include/asm-generic/bitops/le.h
> @@ -2,6 +2,7 @@
>  #ifndef _ASM_GENERIC_BITOPS_LE_H_
>  #define _ASM_GENERIC_BITOPS_LE_H_
>
> +#include <asm-generic/bitops/find.h>
>  #include <asm/types.h>
>  #include <asm/byteorder.h>
>
> @@ -32,13 +33,21 @@ static inline unsigned long find_first_zero_bit_le(const void *addr,
>  #define BITOP_LE_SWIZZLE       ((BITS_PER_LONG-1) & ~0x7)
>
>  #ifndef find_next_zero_bit_le
> -extern unsigned long find_next_zero_bit_le(const void *addr,
> -               unsigned long size, unsigned long offset);
> +static inline
> +unsigned long find_next_zero_bit_le(const void *addr, unsigned
> +               long size, unsigned long offset)
> +{
> +       return _find_next_bit(addr, NULL, size, offset, ~0UL, 1);
> +}
>  #endif
>
>  #ifndef find_next_bit_le
> -extern unsigned long find_next_bit_le(const void *addr,
> -               unsigned long size, unsigned long offset);
> +static inline
> +unsigned long find_next_bit_le(const void *addr, unsigned
> +               long size, unsigned long offset)
> +{
> +       return _find_next_bit(addr, NULL, size, offset, 0UL, 1);
> +}
>  #endif
>
>  #ifndef find_first_zero_bit_le
> diff --git a/lib/find_bit.c b/lib/find_bit.c
> index f67f86fd2f62..b03a101367f8 100644
> --- a/lib/find_bit.c
> +++ b/lib/find_bit.c
> @@ -29,7 +29,7 @@
>   *    searching it for one bits.
>   *  - The optional "addr2", which is anded with "addr1" if present.
>   */
> -static unsigned long _find_next_bit(const unsigned long *addr1,
> +unsigned long _find_next_bit(const unsigned long *addr1,
>                 const unsigned long *addr2, unsigned long nbits,
>                 unsigned long start, unsigned long invert, unsigned long le)
>  {
> @@ -68,37 +68,7 @@ static unsigned long _find_next_bit(const unsigned long *addr1,
>
>         return min(start + __ffs(tmp), nbits);
>  }
> -#endif
> -
> -#ifndef find_next_bit
> -/*
> - * Find the next set bit in a memory region.
> - */
> -unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
> -                           unsigned long offset)
> -{
> -       return _find_next_bit(addr, NULL, size, offset, 0UL, 0);
> -}
> -EXPORT_SYMBOL(find_next_bit);
> -#endif
> -
> -#ifndef find_next_zero_bit
> -unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size,
> -                                unsigned long offset)
> -{
> -       return _find_next_bit(addr, NULL, size, offset, ~0UL, 0);
> -}
> -EXPORT_SYMBOL(find_next_zero_bit);
> -#endif
> -
> -#if !defined(find_next_and_bit)
> -unsigned long find_next_and_bit(const unsigned long *addr1,
> -               const unsigned long *addr2, unsigned long size,
> -               unsigned long offset)
> -{
> -       return _find_next_bit(addr1, addr2, size, offset, 0UL, 0);
> -}
> -EXPORT_SYMBOL(find_next_and_bit);
> +EXPORT_SYMBOL(_find_next_bit);
>  #endif
>
>  #ifndef find_first_bit
> @@ -157,28 +127,6 @@ unsigned long find_last_bit(const unsigned long *addr, unsigned long size)
>  EXPORT_SYMBOL(find_last_bit);
>  #endif
>
> -#ifdef __BIG_ENDIAN
> -
> -#ifndef find_next_zero_bit_le
> -unsigned long find_next_zero_bit_le(const void *addr, unsigned
> -               long size, unsigned long offset)
> -{
> -       return _find_next_bit(addr, NULL, size, offset, ~0UL, 1);
> -}
> -EXPORT_SYMBOL(find_next_zero_bit_le);
> -#endif
> -
> -#ifndef find_next_bit_le
> -unsigned long find_next_bit_le(const void *addr, unsigned
> -               long size, unsigned long offset)
> -{
> -       return _find_next_bit(addr, NULL, size, offset, 0UL, 1);
> -}
> -EXPORT_SYMBOL(find_next_bit_le);
> -#endif
> -
> -#endif /* __BIG_ENDIAN */
> -
>  unsigned long find_next_clump8(unsigned long *clump, const unsigned long *addr,
>                                unsigned long size, unsigned long offset)
>  {
> --
> 2.25.1
>


-- 
With Best Regards,
Andy Shevchenko