From: Peter Zijlstra <[email protected]> Enable __int128 usage when available, if not, provide asm versions of mul_u64_u64 and add_u128.
Cc: Ingo Molnar <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Linus Torvalds <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/n/[email protected] --- arch/x86/include/asm/math128.h | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) create mode 100644 arch/x86/include/asm/math128.h diff --git a/arch/x86/include/asm/math128.h b/arch/x86/include/asm/math128.h new file mode 100644 index 0000000..c0e2a6c --- /dev/null +++ b/arch/x86/include/asm/math128.h @@ -0,0 +1,39 @@ +#ifndef _ASM_MATH128_H +#define _ASM_MATH128_H + +#ifdef CONFIG_X86_64 + +#ifdef __SIZEOF_INT128__ +#define ARCH_HAS_INT128 +#endif + +#ifndef ARCH_HAS_INT128 + +static inline u128 mul_u64_u64(u64 a, u64 b) +{ + u128 res; + + asm("mulq %2" + : "=a" (res.lo), "=d" (res.hi) + : "rm" (b), "0" (a)); + + return res; +} +#define mul_u64_u64 mul_u64_u64 + +static inline u128 add_u128(u128 a, u128 b) +{ + u128 res; + + asm("addq %2,%0;\n" + "adcq %3,%1;\n" + : "=rm" (res.lo), "=rm" (res.hi) + : "r" (b.lo), "r" (b.hi), "0" (a.lo), "1" (a.hi)); + + return res; +} +#define add_u128 add_u128 + +#endif /* ARCH_HAS_INT128 */ +#endif /* CONFIG_X86_64 */ +#endif /* _ASM_MATH128_H */ -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
