diff mbox series

[4/6] lib: inline _find_next_bit() wrappers

Message ID 20210121000630.371883-5-yury.norov@gmail.com (mailing list archive)
State New, archived
Headers show
Series lib/find_bit: fast path for small bitmaps | expand

Commit Message

Yury Norov Jan. 21, 2021, 12:06 a.m. UTC 
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.

Signed-off-by: Yury Norov <yury.norov@gmail.com>
---
 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(-)

Comments

Andy Shevchenko Jan. 21, 2021, 10:28 a.m. UTC | #1 
On Wed, Jan 20, 2021 at 04:06:28PM -0800, Yury Norov 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.

...

> --- a/include/asm-generic/bitops/le.h
> +++ b/include/asm-generic/bitops/le.h
> @@ -4,6 +4,7 @@
>  
>  #include <asm/types.h>
>  #include <asm/byteorder.h>
> +#include <asm-generic/bitops/find.h>

I'm wondering if generic header inclusion should go before arch-dependent ones.

...

> -#ifndef find_next_bit

> -#ifndef find_next_zero_bit

> -#if !defined(find_next_and_bit)

> -#ifndef find_next_zero_bit_le

> -#ifndef find_next_bit_le

Shouldn't you leave these in new wrappers as well?
Yury Norov Jan. 29, 2021, 6:41 a.m. UTC | #2 
On Thu, Jan 21, 2021 at 2:27 AM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> On Wed, Jan 20, 2021 at 04:06:28PM -0800, Yury Norov 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.
>
> ...
>
> > --- a/include/asm-generic/bitops/le.h
> > +++ b/include/asm-generic/bitops/le.h
> > @@ -4,6 +4,7 @@
> >
> >  #include <asm/types.h>
> >  #include <asm/byteorder.h>
> > +#include <asm-generic/bitops/find.h>
>
> I'm wondering if generic header inclusion should go before arch-dependent ones.
>
> ...
>
> > -#ifndef find_next_bit
>
> > -#ifndef find_next_zero_bit
>
> > -#if !defined(find_next_and_bit)
>
> > -#ifndef find_next_zero_bit_le
>
> > -#ifndef find_next_bit_le
>
> Shouldn't you leave these in new wrappers as well?
>
> --
> With Best Regards,
> Andy Shevchenko

Could you please elaborate? Wrappers in find.h are protected, functions
in lib/find_bit.c too. Maybe I misunderstood you?..
diff mbox series

Patch

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..4cf44ea16ec0 100644
--- a/include/asm-generic/bitops/le.h
+++ b/include/asm-generic/bitops/le.h
@@ -4,6 +4,7 @@ 
 
 #include <asm/types.h>
 #include <asm/byteorder.h>
+#include <asm-generic/bitops/find.h>
 
 #if defined(__LITTLE_ENDIAN)
 
@@ -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)
 {