paulwalker-arm added inline comments.
================
Comment at: llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp:119-131
-Optional<unsigned> RISCVTTIImpl::getMaxVScale() const {
- // There is no assumption of the maximum vector length in V specification.
- // We use the value specified by users as the maximum vector length.
- // This function will use the assumed maximum vector length to get the
- // maximum vscale for LoopVectorizer.
- // If users do not specify the maximum vector length, we have no way to
- // know whether the LoopVectorizer is safe to do or not.
----------------
bsmith wrote:
> I'm not sure that RISCV have made a commitment to use the vscale_range
> attribute yet have they? In either case I think they should be involved in a
> change like this.
Perhaps it's worth this patch not removing getMaxVScale just yet but rather
just AArch64's implementation? There would only need to be a minor change to
LoopVectorize.cpp along the lines of `if (!MaxVScale &&
TheFunction->hasFnAttribute(Attribute::VScaleRange...`. That way getMaxVScale
can be removed if/when no one needs it, which I hope is not too far away.
If there is agreement to remove it then I imagine code similar to what you've
done for SVE in CodeGenFunction.cpp will be needed for RISCV otherwise the
patch will cause a regression in functionality.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D106277/new/
https://reviews.llvm.org/D106277
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
