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

Andy Shevchenko <andy.shevchenko@xxxxxxxxx> · Thu, 1 Apr 2021 11:37:45 +0300

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






