[PATCH] R600: Add intrinsics for math helper instructions

[Tom Stellard]

On Mon, Jun 23, 2014 at 10:59:54AM -0700, Matt Arsenault wrote:
> On 06/23/2014 09:04 AM, Tom Stellard wrote:
> >On Sun, Jun 22, 2014 at 04:17:16PM -0700, Matt Arsenault wrote:
> >>On Jun 17, 2014, at 7:10 AM, Tom Stellard <tom at stellard.net> wrote:
> >>
> >>>I think we should replace the r600 in the builtin name with amdgpu, this will
> >>>prevent some confusion about what hardware is supported on.
> >>I found a problem with this. getIntrinsicForGCCBuiltin / Clang uses Triple::getArchTypePrefix(), which is “r600” when looking for the GCCBuiltin. It never finds the ones with AMDGPU as the target prefix, so to support both of these prefixes clang would need to specially handle these to support both __builtin prefixes
> >I normally don't care so much about naming, but in this case I would really
> >like the builtins to use the amdgpu prefix, because r600 is really confusing.
> >What other options do we have.  Could we add an amdgpu triple?  Can we
> >change the getArchTypePrefix() function to return "amdgpu"?
> The other problem is TargetPrefix also needs to be changed from
> "AMDGPU" to "amdgpu"
> I think we could do a combination of these things:
> 
> 1. Rename the "AMDGPU" target prefixed intrinsics to "amdgpu"

Is there any particular reason this needs to be lowercase ?

> 2. Change the triple, and rename all r600 intrinsics to be amdgpu,
> and move them under the amdgpu target prefix

Do you know what impact changing the triple will have?  Can we keep the old one too?

> 3. Refactor the code in clang handling GCCBuiltin lookups into a
> function, so in the special case R600 intrinsics function can also
> lookup GCCBuiltins with the second prefix

The intrinsics defined in IntrinsicsR600.td are never used as builtins,
so we can move them into lib/Target/R600 if this would make things easier.


-Tom