[PATCH] More direct types in PowerPC AltiVec instructions

[Bill Schmidt]

Hi Uli,

OK, excellent!  It seems I didn't look far enough at the vector
logicals.  With the shuffles, I think I made the mistake of trying to
mess with the fragment definitions (like vpkuhum_shuffle).  Looks like
if you leave those alone, the v16i8 works throughout as your patch
shows.

The patch LGTM.  Thanks!

Bill

On Wed, 2013-04-03 at 15:47 +0200, Ulrich Weigand wrote:
> Hi Bill,
> 
> in you commit message for r178277 you wrote:
> 
> >I have not been able to do anything for the
> >following classes of instructions:
> 
> >(1) Vector logicals.  These don't have corresponding intrinsics and
> >don't have a single obvious vector type.  So far as I can tell I need
> >to leave these as VRRC.  Affected instructions are:  VAND, VANDC,
> >VNOR, VOR, VXOR, V_SET0.
> 
> >(2) Instructions that make use of vector shuffle.  The selection code
> >promotes all shuffles to v16i8, so any pattern that matches on a
> >shuffle is constrained.  I haven't found any way to make the patterns
> >match on their natural types, so I plan to leave these as VRRC.
> >Affected instructions are:  VMRG*, VSPLTB, VSPLTH, VSPLTW, VPKUHUM,
> >VPKUWUM.
> 
> From looking at the generated .inc files, it seems TableGen does
> actually choose specific types to match.  In the cases listed
> under (1), this is always v4i32, while in the cases listed
> under (2), it is always v16i8.
> 
> Using the attached patch replaces the remaining uses of VRRC in
> ISEL DAG patterns by those types; the generated .inc files are
> completely identical (except for comments), and thus no change
> in code generation is expected.
> 
> I think for clarity it would make sense to apply this patch;
> after all, this is what will actually be matched ...
> 
> Thoughts?
> 
> 
> B.t.w. if the patch is applied, the only remaining uses of
> VRRC in a pattern are the bitconvert Pat pattern.  I was
> unable to rewrite those to use types without getting
> TableGen errors.
> 
> Bye,
> Ulrich
> 
> 
> (See attached file: diff-llvm-moredirecttypes)