Hi Giacomo, Thanks for your suggestion. Regarding a different decoder flavour, I could not find the commit d3d15974, is it in the gem5 repo?
Regards, -- Fernando A. Endo, Post-doc INRIA Rennes-Bretagne Atlantique France 2016-10-14 17:02 GMT+02:00 Giacomo Gabrielli <[email protected]>: > Hi Fernando, > Thanks for your contribution. > In general, I’d say that these instructions tend to capture common > patterns that could map well to a “fast-path” implementation. > Cracking them in a conservative way might end up jeopardising their goal, > as more aggressive implementations could be possible, so I’d recommend to > leave the default “vanilla” implementation as it is and avoid cracking. > The other option could be to include your changes as a decoder flavour - > see commit d3d15974 - and leave the non-cracked version as default choice. > > Thanks, > Giacomo > > > > > > On 14/10/2016, 14:26, "gem5-dev on behalf of Fernando Endo" < > [email protected] on behalf of [email protected]> wrote: > > >Hello all, > > > >I'd like to know if the following patch may interest the community. > > > >I split conditionally executed AArch64 instructions into two or three > uops, > >in order to use at most 3 register file ports, instead of 4 in the current > >code. The vast majority if not all AArch64 uops use up to 3 RF ports. > > > >More specifically: > > > >CSEL (and similarly CSINC, CSINV, CSNEG FCSEL) are split as follows: > >CSEL Rd, Rn, Rm, cond > >uop 1: (cond) ? Tmp0 = Rn : 0 > >uop 2: (!cond) ? Tmp1 = Rm : 0 > >uop 3: Rd = Tmp0 + Tmp1 > > > >CCMN (and similarly CCMP, FCCMP) are split as: > >CCMP Rn, Rm, #imm, cond > >uop 1: Tmp_nzcv = CMP Rn, Rm > >uop 2: (cond) ? nzcv = Tmp_nzcv : #imm > > > >Just asking because the patch works in my branch, I didn't rebase/test > over > >gem5 mainstream. > > > >Regards, > > > >-- > >Fernando A. Endo, Post-doc > > > >INRIA Rennes-Bretagne Atlantique > >France > >_______________________________________________ > >gem5-dev mailing list > >[email protected] > >http://m5sim.org/mailman/listinfo/gem5-dev > IMPORTANT NOTICE: The contents of this email and any attachments are > confidential and may also be privileged. If you are not the intended > recipient, please notify the sender immediately and do not disclose the > contents to any other person, use it for any purpose, or store or copy the > information in any medium. Thank you. > _______________________________________________ > gem5-dev mailing list > [email protected] > http://m5sim.org/mailman/listinfo/gem5-dev > _______________________________________________ gem5-dev mailing list [email protected] http://m5sim.org/mailman/listinfo/gem5-dev
