[Libclc-dev] [PATCH 4/4] rootn: Port from amd_builtins

[Jan Vesely via Libclc-dev]

On Thu, 2018-01-18 at 20:33 +0100, Jeroen Ketema wrote:
> > On 18 Jan 2018, at 00:49, Jan Vesely <jan.vesely at rutgers.edu> wrote:
> > 
> > On Thu, 2018-01-18 at 00:39 +0100, Jeroen Ketema wrote:
> > > Hi Jan,
> > > 
> > > Triggered by your patch below, I started looking a bit more closely at __clc_fp32_subnormals_supported.
> > > Am I correct that this function currently always returns false no matter the target? Or does some
> > > override occur somewhere?
> > 
> > Looks like it. Tom might be better qualified to answer this.
> > The original idea was to link default or disabled to select proper
> > operation at kernel link time, but it looks likes it only applies to
> > fp64.
> > That is weird since fp64 denormals are required by specs. I'd say we
> > can drop the entire mechanism.
> 
> That’s not totally true. Check out the cl-denorms-are-zero option.

sorry, this one slipped under my radar. You're right. The mechanism was
aimed at AMD gpus that only care about fp64 denormals (fp32 denorms are
preferred disabled for performance/compliance reasons).
I don't mind someone reworking it to be more general (and idealy in CLC
instead of llvm ir).

regards,
Jan

> 
> Jeroen
> 
> > 
> > Jan
> > 
> > > 
> > > Thanks,
> > > 
> > > Jeroen
> > > 
> 
> 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 488 bytes
Desc: This is a digitally signed message part
URL: <http://lists.llvm.org/pipermail/libclc-dev/attachments/20180131/a38ced9e/attachment.sig>