Messages in this thread | | | Subject | Re: Is -fno-strict-aliasing still needed? | From | Andreas Schwab <> | Date | Tue, 11 Feb 2003 10:45:19 +0100 |
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Horst von Brand <brand@jupiter.cs.uni-dortmund.de> writes:
|> Andreas Schwab <schwab@suse.de> said: |> > Horst von Brand <brand@jupiter.cs.uni-dortmund.de> writes: |> > |> > |> Art Haas <ahaas@airmail.net> said: |> > |> > I ask because I've just built a kernel without using that flag - |> > |> > linus-2.5 BK from this morning, probably missing the 2.5.60 release by |> > |> > a few hours. |> > |> |> > |> The problem with strict aliasing is that it allows the compiler to assume |> > |> that in: |> > |> |> > |> void somefunc(int *foo, int *bar) |> > |> |> > |> foo and bar will _*never*_ point to the same memory area |> > |> > This is wrong. Only if they are declared restrict. |> |> ... can they point to the same area. That is exactly the problem: If you do |> nothing, the language definition assumes the programmer made sure (LOL!) |> that they don't point the same way.
Why are you insisting on spreading misinformation?
Pointers that are _not_ declared as restricted can alias _any_ other non-restricted pointer of the same target type.
Andreas.
-- Andreas Schwab, SuSE Labs, schwab@suse.de SuSE Linux AG, Deutschherrnstr. 15-19, D-90429 Nürnberg Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different." - 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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