[llvm-commits] [patch] Expose RTLIB/float-softening to targets

[Tim Northover]

Hi Renato,

Thanks for your comments on this too.

On Tuesday 08 Jan 2013 11:22:01 Renato Golin wrote:
> +  return TLI.makeLibCall(DAG, GetFPLibCall(N->getValueType(0),
> +                                           RTLIB::ADD_F32,
> +                                           RTLIB::ADD_F64,
> +                                           RTLIB::ADD_F80,
> +                                           RTLIB::ADD_PPCF128),
> +                         NVT, Ops, 2, false, N->getDebugLoc());
> 
> Shouldn't this (and all other variations) also take into account the IEEE
> variation of long doubles?

It was an active decision not to. AArch64 will not make any use of this code 
so it would be truly untestable as far as I'm aware.

> As far as I can tell (I'm not a diff engine), the main move was
> softenSetCCOperands() and makeLibCall() going to TargetLowering. Your
> description doesn't tell why this is necessary at all and it's hard to
> point it out from the diff, since they're in different files and
> everything appears different, but look similar enough.

It's necessary so that the AArch64 backend can call these functions from 
ISelLowering to handle its IEEE quads.

> If the move was just good, not necessary, it'd be easier to have it in two
> changes: one with the real change (with a small diff) and another with the
> code move (for the sake of simplicity and code organization).

I think that move is the entirity of the change, there is nothing else to 
split off that I can see.

Cheers.

Tim.