[PATCH] D82182: [AArch64][SVE] Add bfloat16 support to perm and select intrinsics

[Cullen Rhodes via Phabricator via llvm-commits]

c-rhodes marked an inline comment as done.
c-rhodes added inline comments.


================
Comment at: clang/include/clang/Basic/arm_sve.td:1115
 
+let ArchGuard = "defined(__ARM_FEATURE_SVE_BF16)" in {
+def SVREV_BF16    : SInst<"svrev[_{d}]",    "dd",   "b", MergeNone, "aarch64_sve_rev">;
----------------
c-rhodes wrote:
> fpetrogalli wrote:
> > c-rhodes wrote:
> > > c-rhodes wrote:
> > > > fpetrogalli wrote:
> > > > > nit: could create a multiclass here like @sdesmalen have done in https://reviews.llvm.org/D82187, seems quite a nice way to keep the definition of the intrinsics together (look for `multiclass StructLoad`, for example)
> > > > it might be a bit tedious having separate multiclasses, what do you think about:
> > > > ```multiclass SInstBF16<string n, string p, string t, MergeType mt, string i = "",
> > > >                      list<FlagType> ft = [], list<ImmCheck> ch = []> {
> > > >   def : SInst<n, p, t, mt, i, ft, ch>;
> > > >   let ArchGuard = "defined(__ARM_FEATURE_SVE_BF16)" in {
> > > >     def : SInst<n, p, "b", mt, i, ft, ch>;
> > > >   }
> > > > }
> > > > 
> > > > defm SVREV    : SInstBF16<"svrev[_{d}]",    "dd",   "csilUcUsUiUlhfd", MergeNone, "aarch64_sve_rev">;
> > > > defm SVSEL    : SInstBF16<"svsel[_{d}]",    "dPdd", "csilUcUsUiUlhfd", MergeNone, "aarch64_sve_sel">;
> > > > defm SVSPLICE : SInstBF16<"svsplice[_{d}]", "dPdd", "csilUcUsUiUlhfd", MergeNone, "aarch64_sve_splice">;
> > > > defm SVTRN1   : SInstBF16<"svtrn1[_{d}]",   "ddd",  "csilUcUsUiUlhfd", MergeNone, "aarch64_sve_trn1">;
> > > > defm SVTRN2   : SInstBF16<"svtrn2[_{d}]",   "ddd",  "csilUcUsUiUlhfd", MergeNone, "aarch64_sve_trn2">;
> > > > defm SVUZP1   : SInstBF16<"svuzp1[_{d}]",   "ddd",  "csilUcUsUiUlhfd", MergeNone, "aarch64_sve_uzp1">;
> > > > defm SVUZP2   : SInstBF16<"svuzp2[_{d}]",   "ddd",  "csilUcUsUiUlhfd", MergeNone, "aarch64_sve_uzp2">;
> > > > defm SVZIP1   : SInstBF16<"svzip1[_{d}]",   "ddd",  "csilUcUsUiUlhfd", MergeNone, "aarch64_sve_zip1">;
> > > > defm SVZIP2   : SInstBF16<"svzip2[_{d}]",   "ddd",  "csilUcUsUiUlhfd", MergeNone, "aarch64_sve_zip2">;```
> > > > 
> > > > ?
> > > I've played around with this and it works great for instructions guarded on a single feature flag but falls apart for the .Q forms that also require `__ARM_FEATURE_SVE_MATMUL_FP64`. I suspect there's a nice way of handling it in tablegen by passing the features as a list of strings and joining them but I spent long enough trying to get that to work so I'm going to keep it simple for now.
> > > it might be a bit tedious having separate multiclasses, what do you think about:
> > 
> > Sorry I think I misunderstood you when we last discussed this. I didn't mean to write a multiclass that would work for ALL intrinsics that uses regular types and bfloats.... I just meant to merge together those who were using the same archguard and that you are adding in this patch.
> > 
> > I think you could keep both macros in a single ArchGuard string:
> > 
> > ```
> > multiclass SInstPerm<string n, string p, MergeType mt, string i> {
> >   def : SInst<n, p, "csilUcUsUiUlhfd",  mt, i>;
> >   let ArchGuard = "defined(__ARM_FEATURE_SVE_BF16)" in {
> >     def : SInst<n, p, "b", mt, i>;
> >   }
> > }
> > 
> > defm SVREV    : SInstPerm<"svrev[_{d}]",    "dd",    MergeNone, "aarch64_sve_rev">;
> > ...
> > 
> > multiclass SInstPermMatmul<string n, string p, MergeType mt, string i> {
> >   def : SInst<n, p, "csilUcUsUiUlhfd",  mt, i>;
> >   let ArchGuard = "defined(__ARM_FEATURE_SVE_BF16) && defined(__ARM_FEATURE_SVE_MATMUL_FP64)" in {
> >     def : SInst<n, p, "b", mt, i>;
> >   }
> > }
> > 
> > def SVTRN1Q : SInstPermMatmul ...
> > ...
> > ```
> Sure, I understood you meant separate multiclasses for each intrinsic / group similar to what Sander implemented for structured loads / stores but I thought it would be quite abit of extra code to implement that, hence why I proposed a single multiclass that could handle this. I've experimented with the `SInstBF16` multiclass I mentioned above and have it working with an extra arg for arch features. I'll create a follow up patch and if people are happy with it we'll move forward with that, otherwise I'm happy to implement your suggestion.
> I'll create a follow up patch

https://reviews.llvm.org/D82450


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D82182/new/

https://reviews.llvm.org/D82182