diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-05-18 16:17:01 (GMT) |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-05-18 16:17:01 (GMT) |
commit | cb41838bbc4403f7270a94b93a9a0d9fc9c2e7ea (patch) | |
tree | 0f359975ccad4ac72e86b8edf1924c076e74bd89 /arch/x86/include/asm | |
parent | 98f01720cbe3e2eb719682777049b6514e9db556 (diff) | |
parent | c59bd5688299cddb71183e156e7a3c1409b90df2 (diff) | |
download | linux-fsl-qoriq-cb41838bbc4403f7270a94b93a9a0d9fc9c2e7ea.tar.xz |
Merge branch 'core-hweight-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-hweight-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, hweight: Use a 32-bit popcnt for __arch_hweight32()
arch, hweight: Fix compilation errors
x86: Add optimized popcnt variants
bitops: Optimize hweight() by making use of compile-time evaluation
Diffstat (limited to 'arch/x86/include/asm')
-rw-r--r-- | arch/x86/include/asm/alternative.h | 9 | ||||
-rw-r--r-- | arch/x86/include/asm/arch_hweight.h | 61 | ||||
-rw-r--r-- | arch/x86/include/asm/bitops.h | 4 |
3 files changed, 70 insertions, 4 deletions
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h index 92a9033..03b6bb5 100644 --- a/arch/x86/include/asm/alternative.h +++ b/arch/x86/include/asm/alternative.h @@ -42,9 +42,6 @@ #define LOCK_PREFIX "" #endif -/* This must be included *after* the definition of LOCK_PREFIX */ -#include <asm/cpufeature.h> - struct alt_instr { u8 *instr; /* original instruction */ u8 *replacement; @@ -99,6 +96,12 @@ static inline int alternatives_text_reserved(void *start, void *end) ".previous" /* + * This must be included *after* the definition of ALTERNATIVE due to + * <asm/arch_hweight.h> + */ +#include <asm/cpufeature.h> + +/* * Alternative instructions for different CPU types or capabilities. * * This allows to use optimized instructions even on generic binary diff --git a/arch/x86/include/asm/arch_hweight.h b/arch/x86/include/asm/arch_hweight.h new file mode 100644 index 0000000..9686c3d --- /dev/null +++ b/arch/x86/include/asm/arch_hweight.h @@ -0,0 +1,61 @@ +#ifndef _ASM_X86_HWEIGHT_H +#define _ASM_X86_HWEIGHT_H + +#ifdef CONFIG_64BIT +/* popcnt %edi, %eax -- redundant REX prefix for alignment */ +#define POPCNT32 ".byte 0xf3,0x40,0x0f,0xb8,0xc7" +/* popcnt %rdi, %rax */ +#define POPCNT64 ".byte 0xf3,0x48,0x0f,0xb8,0xc7" +#define REG_IN "D" +#define REG_OUT "a" +#else +/* popcnt %eax, %eax */ +#define POPCNT32 ".byte 0xf3,0x0f,0xb8,0xc0" +#define REG_IN "a" +#define REG_OUT "a" +#endif + +/* + * __sw_hweightXX are called from within the alternatives below + * and callee-clobbered registers need to be taken care of. See + * ARCH_HWEIGHT_CFLAGS in <arch/x86/Kconfig> for the respective + * compiler switches. + */ +static inline unsigned int __arch_hweight32(unsigned int w) +{ + unsigned int res = 0; + + asm (ALTERNATIVE("call __sw_hweight32", POPCNT32, X86_FEATURE_POPCNT) + : "="REG_OUT (res) + : REG_IN (w)); + + return res; +} + +static inline unsigned int __arch_hweight16(unsigned int w) +{ + return __arch_hweight32(w & 0xffff); +} + +static inline unsigned int __arch_hweight8(unsigned int w) +{ + return __arch_hweight32(w & 0xff); +} + +static inline unsigned long __arch_hweight64(__u64 w) +{ + unsigned long res = 0; + +#ifdef CONFIG_X86_32 + return __arch_hweight32((u32)w) + + __arch_hweight32((u32)(w >> 32)); +#else + asm (ALTERNATIVE("call __sw_hweight64", POPCNT64, X86_FEATURE_POPCNT) + : "="REG_OUT (res) + : REG_IN (w)); +#endif /* CONFIG_X86_32 */ + + return res; +} + +#endif diff --git a/arch/x86/include/asm/bitops.h b/arch/x86/include/asm/bitops.h index 02b47a6..545776e 100644 --- a/arch/x86/include/asm/bitops.h +++ b/arch/x86/include/asm/bitops.h @@ -444,7 +444,9 @@ static inline int fls(int x) #define ARCH_HAS_FAST_MULTIPLIER 1 -#include <asm-generic/bitops/hweight.h> +#include <asm/arch_hweight.h> + +#include <asm-generic/bitops/const_hweight.h> #endif /* __KERNEL__ */ |