Re: [PATCH 2/8] i386: bitops: Rectify bogus "Ir" constraints

From: Andi Kleen
Date: Mon Jul 23 2007 - 12:30:53 EST



> Whoa, thanks for explaining that to me -- I didn't know, obviously. I had
> just written a test program that used "Ir" with an automatic variable
> defined in the inline function (as is the case with these bitops) and
> observed that even when I gave > 32 values, it would still work -- hence
> my conclusion.
>
> However, the patch still stands, does it not? [ I will modify the
> changelog, obviously. ] The thing is that we don't want to limit
> @nr to <= 31 in the first place, or am I wrong again? :-)

These bit operations only allow 8 bit immediates, so 0..255 would
be correct. N might work from the 4.1 docs, but I don't know if it works
in all old supported gccs (3.2+)

However I is definitely not wrong and most bit numbers are small anyways.

-Andi
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