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Pekka J Enberg wrote: > On Wed, 26 Apr 2006, Kyle Moffett wrote: > >>Here's code that I've found works as well as can be expected under both GCC 3 >>and GCC 4. If xp is a known-NULL constant the whole function will be >>optimized out completely. If xp is known-not-NULL, then it will optimize to a >>kfree function without the null check. Otherwise it optimizes to call the >>out-of-line version. > > > Wouldn't it be better to simply remove calls to kfree() with known > NULL constant? Yes, but this will optimise away the check for known non-NULL. At the cost of icache footprint. I think unmeasurable micro-optimisations that go against historic CPU trends (eg. size for speed) aren't worth wasting too much sleep over. If it is a 0.0001% speedup today, it'll be a 0.0001% slowdown tomorrow :) -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com - 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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