Messages in this thread | | | Date | Fri, 15 Jul 2011 17:14:33 -0700 | From | Jeremy Fitzhardinge <> | Subject | Re: [PATCH RFC 0/7] x86: convert ticketlocks to C and remove duplicate code |
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On 07/15/2011 04:06 PM, H. Peter Anvin wrote: > On 07/15/2011 10:24 AM, Jeremy Fitzhardinge wrote: >> I posted a bug about gcc not generating cmp %ah, %al in this case, but the general consensus was that >> it's not a good choice on current Intel chips, because it causes a partial word stall, and that the >> current generated code is better. (And gcc can generate "cmp %Xh, %Xl" if it wants to - see below.) >> > Which version of gcc is this, and also, do you have the gcc bug report > number? I was talking to H.J. and he said he thought it sounded strange.
gcc version 4.6.0 20110530 (Red Hat 4.6.0-9) (GCC)
It's bug 47556.
J
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