| Message ID | bc92eb1507448731163ae67fc888668d327f9168.1477669745.git.stillcompiling@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Joshua,
[auto build test WARNING on linus/master]
[also build test WARNING on v4.9-rc2 next-20161028]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
[Suggest to use git(>=2.9.0) format-patch --base=<commit> (or --base=auto for convenience) to record what (public, well-known) commit your patch series was built on]
[Check https://git-scm.com/docs/git-format-patch for more information]
url: https://github.com/0day-ci/linux/commits/Joshua-Clayton/lib-add-bitrev8x4/20161029-012535
config: arm-s5pv210_defconfig (attached as .config)
compiler: arm-linux-gnueabi-gcc (Debian 6.1.1-9) 6.1.1 20160705
reproduce:
wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=arm
All warnings (new ones prefixed by >>):
In file included from include/linux/bitrev.h:7:0,
from include/linux/crc32.h:9,
from lib/crc32.c:29:
arch/arm/include/asm/bitrev.h: In function '__arch_bitrev8x4':
>> arch/arm/include/asm/bitrev.h:23:1: warning: no return statement in function returning non-void [-Wreturn-type]
}
^
vim +23 arch/arm/include/asm/bitrev.h
7 return x;
8 }
9
10 static __always_inline __attribute_const__ u16 __arch_bitrev16(u16 x)
11 {
12 return __arch_bitrev32((u32)x) >> 16;
13 }
14
15 static __always_inline __attribute_const__ u8 __arch_bitrev8(u8 x)
16 {
17 return __arch_bitrev32((u32)x) >> 24;
18 }
19
20 static __always_inline __attribute_const__ u32 __arch_bitrev8x4(u32 x)
21 {
22 __asm__ ("rbit %0, %1; rev %0, %0" : "=r" (x) : "r" (x));
> 23 }
24
25 #endif
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
diff --git a/arch/arm/include/asm/bitrev.h b/arch/arm/include/asm/bitrev.h index ec291c3..6d2e9ca 100644 --- a/arch/arm/include/asm/bitrev.h +++ b/arch/arm/include/asm/bitrev.h @@ -17,4 +17,9 @@ static __always_inline __attribute_const__ u8 __arch_bitrev8(u8 x) return __arch_bitrev32((u32)x) >> 24; } +static __always_inline __attribute_const__ u32 __arch_bitrev8x4(u32 x) +{ + __asm__ ("rbit %0, %1; rev %0, %0" : "=r" (x) : "r" (x)); +} + #endif diff --git a/include/linux/bitrev.h b/include/linux/bitrev.h index fb790b8..b1cfa1a 100644 --- a/include/linux/bitrev.h +++ b/include/linux/bitrev.h @@ -9,6 +9,7 @@ #define __bitrev32 __arch_bitrev32 #define __bitrev16 __arch_bitrev16 #define __bitrev8 __arch_bitrev8 +#define __bitrev8x4 __arch_bitrev8x4 #else extern u8 const byte_rev_table[256]; @@ -27,6 +28,14 @@ static inline u32 __bitrev32(u32 x) return (__bitrev16(x & 0xffff) << 16) | __bitrev16(x >> 16); } +static inline u32 __bitrev8x4(u32 x) +{ + return(__bitrev8(x & 0xff) | + (__bitrev8((x >> 8) & 0xff) << 8) | + (__bitrev8((x >> 16) & 0xff) << 16) | + (__bitrev8((x >> 24) & 0xff) << 24)); +} + #endif /* CONFIG_HAVE_ARCH_BITREVERSE */ #define __constant_bitrev32(x) \ @@ -50,6 +59,15 @@ static inline u32 __bitrev32(u32 x) __x; \ }) +#define __constant_bitrev8x4(x) \ +({ \ + u32 __x = x; \ + __x = ((__x & (u32)0xF0F0F0F0UL) >> 4) | ((__x & (u32)0x0F0F0F0FUL) << 4); \ + __x = ((__x & (u32)0xCCCCCCCCUL) >> 2) | ((__x & (u32)0x33333333UL) << 2); \ + __x = ((__x & (u32)0xAAAAAAAAUL) >> 1) | ((__x & (u32)0x55555555UL) << 1); \ + __x; \ +}) + #define __constant_bitrev8(x) \ ({ \ u8 __x = x; \ @@ -75,6 +93,14 @@ static inline u32 __bitrev32(u32 x) __bitrev16(__x); \ }) +#define bitrev8x4(x) \ +({ \ + u32 __x = x; \ + __builtin_constant_p(__x) ? \ + __constant_bitrev8x4(__x) : \ + __bitrev8x4(__x); \ +}) + #define bitrev8(x) \ ({ \ u8 __x = x; \
Add a function to reverse bytes within a 32 bit word. This function is more efficient than using the 8 bit version when iterating over an array Signed-off-by: Joshua Clayton <stillcompiling@gmail.com> --- arch/arm/include/asm/bitrev.h | 5 +++++ include/linux/bitrev.h | 26 ++++++++++++++++++++++++++ 2 files changed, 31 insertions(+)