Messages in this thread | | | Date | Wed, 14 Aug 2002 23:11:40 +0200 | From | Willy Tarreau <> | Subject | Re: [patch 4/21] fix ARCH_HAS_PREFETCH |
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On Wed, Aug 14, 2002 at 01:58:41PM -0700, H. Peter Anvin wrote: > Willy Tarreau wrote: > > This way, some loops could be optimized, and the developpers could explicitely > > tell the compiler when they need to prevent any optimization. > > > > #define __nop() asm volatile("")
and if you want to pass arguments, to guarantee that no optimization will be done, even on loop constants ? eg: for (i = 0; i < N; i++) { j++; __nop(); }
-> might be optimized this way : j = N; for (i = 0; i < N; i++) { __nop(); }
Perhaps using a volatile for j ?
Cheers, Willy - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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