[PATCH] Add ISD::FROUND for libm round()

Hal Finkel hfinkel at anl.gov
Wed Aug 7 15:51:36 PDT 2013


----- Original Message -----
> LGTM.

r187926. Thanks!

 -Hal

> 
> 
> 
> On Jul 23, 2013, at 4:05 PM, Hal Finkel < hfinkel at anl.gov > wrote:
> 
> 
> 
> Ping.
> 
> -Hal
> 
> ----- Original Message -----
> 
> 
> ----- Original Message -----
> 
> 
> Hi Hal,
> 
> 
> I think that the round intrinsic should support all of the popular
> rounding mode, and not only nearest integer.
> 
> I agree, and we do currently, except for the round-away-from-zero
> mode of round(). In libm, the different rounding modes have
> different function calls, and we currently support (have the ability
> to custom lower):
> FCEIL, FTRUNC, FRINT, FNEARBYINT, FFLOOR,
> 
> which correspond to:
> ceil - smallest integral value not less than
> trunc - round to integer, towards zero
> floor - largest integral value not greater than
> rint/nearbyint - round to nearest integer using the current
> rounding mode (which is normally ties-to-even)
> 
> and now I'd like to add the remaining one:
> round - round to nearest integer, away from zero
> 
> Thanks again,
> Hal
> 
> 
> 
> 
> 
> Thanks,
> Nadav
> 
> 
> 
> On Jul 7, 2013, at 9:04 PM, Hal Finkel < hfinkel at anl.gov > wrote:
> 
> 
> 
> Hello!
> 
> round() has been feeling a little left out; all of its friends
> (like
> rint() and nearbyint()) have their own ISD nodes, and round()
> doesn't. Recent PowerPC cores have an instruction for round(), and
> so I'd like to correct this injustice and add ISD::FROUND.
> 
> For the most part, this is extremely straightforward. I've added an
> intrinsic and matching ISD node just like those for nearbyint() and
> friends. The SelectionDAG pattern I've named frnd (because
> ISD::FP_ROUND has already claimed fround); obviously we can use a
> different name if someone has a better suggestion. Please review.
> 
> Thanks again,
> Hal
> 
> --
> Hal Finkel
> Assistant Computational Scientist
> Leadership Computing Facility
> Argonne National Laboratory
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> 
> --
> Hal Finkel
> Assistant Computational Scientist
> Leadership Computing Facility
> Argonne National Laboratory
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
> 
> 
> --
> Hal Finkel
> Assistant Computational Scientist
> Leadership Computing Facility
> Argonne National Laboratory
> 

-- 
Hal Finkel
Assistant Computational Scientist
Leadership Computing Facility
Argonne National Laboratory



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