Messages in this thread | | | Date | Wed, 19 Aug 2009 11:56:41 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH] x86: make use of inc/dec conditional |
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On Wed, 19 Aug 2009, Jan Beulich wrote:
> >>> Thomas Gleixner <tglx@linutronix.de> 19.08.09 11:06 >>> > >You still do not tell on which machines the INC/DEC instructions > >should be avoided and why. GCC avoiding it is not a convincing > >argument. > > On Pentium4 (Prescott/Nocona) inc/dec not modifying the carry flag cause > an extra instruction dependency on EFLAGS, and hence extra latency in > when the instruction can be scheduled for execution.
Do we really care that much about those electronic heaters which are scheduled for darwinistic extinction since their introduction ?
Thanks,
tglx
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