On 2014/05/12 13:41:36, Yang wrote:
On 2014/05/12 13:00:47, Yang wrote:
> On 2014/05/12 12:55:45, Sven Panne wrote:
> >
https://codereview.chromium.org/275253004/diff/1/src/ia32/assembler-ia32.h
> > File src/ia32/assembler-ia32.h (left):
> >
> >
>
https://codereview.chromium.org/275253004/diff/1/src/ia32/assembler-ia32.h#oldcode726
> > src/ia32/assembler-ia32.h:726: void cmov(Condition cc, Register dst,
Register
> > src) {
> > On 2014/05/12 12:40:32, titzer wrote:
> > > Please don't remove these from the MacroAssembler!
> >
> > Whatever uses that should consider *not* using it. ;-) This introduces
data
> > dependencies, and normally modern processors are better off using
> caveman-style
> > conditional branches + normal loads.
>
> Of course I could change them into true macros: cmov would internally
use
jump
> and mov.
So... what do we want now? Use cmov where possible, or never use cmov? In
either
case, we would require cmov-support anyways. By now I have a CL for either
option under review...
I view the assembler is a grab bag of all the things the machine can do.
I am neutral on the usage of CMOV; I just don't want to see them removed
from
the Assembler, because there are sometimes good reasons to use them. If you
remove current uses, then maybe we need them later again. When that happens
someone puts them back in, then sometime later someone changes that code,
notices the methods are dead again, removes them again, on and on...
https://codereview.chromium.org/275253004/
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