x86 & generic: change to __builtin_prefetch() (ab483570) · Commits · 戴 / test

gcc 3.2+ supports __builtin_prefetch, so it's possible to use it on all architectures. Change the generic fallback in linux/prefetch.h to use it instead of noping it out. gcc should do the right thing when the architecture doesn't support prefetching Undefine the x86-64 inline assembler version and use the fallback. Signed-off-by:

Andi Kleen <ak@suse.de> Signed-off-by:

Ingo Molnar <mingo@elte.hu> Signed-off-by:

Thomas Gleixner <tglx@linutronix.de>

include/asm-x86/processor_64.h

+0 −6

Original line number	Diff line number	Diff line
		@@ -390,12 +390,6 @@ static inline void sync_core(void)
		asm volatile("cpuid" : "=a" (tmp) : "0" (1) : "ebx","ecx","edx","memory");
		}

		#define ARCH_HAS_PREFETCH
		static inline void prefetch(void *x)
		{
		asm volatile("prefetcht0 (%0)" :: "r" (x));
		}

		#define ARCH_HAS_PREFETCHW 1
		static inline void prefetchw(void *x)
		{

include/linux/prefetch.h

+2 −7

Original line number	Diff line number	Diff line
		@@ -34,17 +34,12 @@

		*/

		/*
		* These cannot be do{}while(0) macros. See the mental gymnastics in
		* the loop macro.
		*/

		#ifndef ARCH_HAS_PREFETCH
		static inline void prefetch(const void *x) {;}
		#define prefetch(x) __builtin_prefetch(x)
		#endif

		#ifndef ARCH_HAS_PREFETCHW
		static inline void prefetchw(const void *x) {;}
		#define prefetchw(x) __builtin_prefetch(x,1)
		#endif

		#ifndef ARCH_HAS_SPINLOCK_PREFETCH

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