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Re: i386.md splits 1
- To: Jan Hubicka <hubicka at atrey dot karlin dot mff dot cuni dot cz>
- Subject: Re: i386.md splits 1
- From: Jeffrey A Law <law at cygnus dot com>
- Date: Mon, 26 Oct 1998 16:12:35 -0700
- cc: Richard Henderson <rth at cygnus dot com>, egcs-patches at cygnus dot com
- Reply-To: law at cygnus dot com
In message <19981002124128.51289@atrey.karlin.mff.cuni.cz>you write:
> > > + (define_insn "ashrsi3_31"
> > > + [(set (match_operand:SI 0 "nonimmediate_operand" "=rm,d")
> > > + (ashiftrt:SI (match_operand:SI 1 "nonimmediate_operand" "0,a")
> > > + (const_int 31)))]
> > > + "ix86_cpu != PROCESSOR_PENTIUM || optimize_size"
> > > + "@
> > > + sar%L0 $31,%0
> > > + cltd")
> >
> > Do you really want to limit this pattern to the pentium?
> Yes. At pentium ctld takes two cycles, as mov/sar combination does.
> But mov/sar combination is pairable, so it usually results in faster (and l
> onger) code.
What about pentiumpro? Seems like that pattern would be used on the PPro.
Does anyone know what the right thing to do for PPro is?
jeff