If we're going to end up expanding anyway, we should do it early
so we don't create extra operations to handle the bytes added by
promotion.
Simlilar was done for BSWAP previously.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D96681
As of the current draft these are no longer being considered
for the bitmanip spec. It wasn't clear what sub extension they
belonged in in the 0.93 spec.
So remove them. They can always be added back if something changes.
Reviewed By: frasercrmck
Differential Revision: https://reviews.llvm.org/D96157
Zext.h will need to come back to Zbb, but that only uses specific
encodings of pack.
Reviewed By: asb, frasercrmck
Differential Revision: https://reviews.llvm.org/D94742
It's not really clear in the spec that these are in Zbp now, but
that's what I've gather from previous commits to the spec. I've
file an issue to get it documented properly.
Reviewed By: asb, frasercrmck
Differential Revision: https://reviews.llvm.org/D94652
A rotate by half the bitwidth swaps the bottom and top half which is the same as one of the MSB GREVI stage.
We have to do this as a special combine because we prefer to keep (rotl/rotr X, BitWidth/2) as a rotate rather than a single stage GREVI.
Differential Revision: https://reviews.llvm.org/D92286
This enables bswap/bitreverse to combine with other GREVI patterns or each other without needing to add more special cases to the DAG combine or new DAG combines.
I've also enabled the existing GREVI combine for GREVIW so that it can pick up the i32 bswap/bitreverse on RV64 after they've been type legalized to GREVIW.
Differential Revision: https://reviews.llvm.org/D92253
Not sure why bswap was treated specially. This also applies to bitreverse
or generic grevi. We can improve this in future patches.
For now I just wanted to get the consistency and the test coverage
as I plan to make some other changes around bswap.
This should result in better utilization of RORIW since we
don't need to look for a SIGN_EXTEND_INREG that may not exist.
Also remove rotl/rotr isel matching to GREVI and just prefer RORI.
This is to keep consistency so we don't have to match ROLW/RORW
to GREVIW as well. I imagine RORI/RORIW performance will be the
same or better than GREVI.
Differential Revision: https://reviews.llvm.org/D91449
DAGCombine doesn't canonicalize rotl/rotr with immediate so we
need patterns for both.
Remove the custom matcher for rotl to RORI and just use a SDNodeXForm
to convert the immediate instead. Doing this gives priority to the
rev32/rev16 versions of grevi over rori since an explicit immediate
is more precise than any immediate. I also added rotr patterns for
rev32/rev16. And removed the (or (shl), (shr)) patterns that should be
combined to rotl by DAG combine.
There is at least one other grev pattern that probably needs a
another rotr pattern, but we need more test coverage first.
Differential Revision: https://reviews.llvm.org/D90575
fshl/fshr intrinsics turn into rotl/rotr ISD opcodes and we don't
have a complete set of patterns.
We pattern match rotl, but we have a custom match for rori that gets
priority. We don't pattern match rotr and we don't have patterns
or custom code for rori from rotr.
This patch provides optimization of bit manipulation operations by
enabling the +experimental-b target feature.
It adds matching of single block patterns of instructions to specific
bit-manip instructions from the permutation subset (zbp subextension) of
the experimental B extension of RISC-V.
It adds also the correspondent codegen tests.
This patch is based on Claire Wolf's proposal for the bit manipulation
extension of RISCV:
https://github.com/riscv/riscv-bitmanip/blob/master/bitmanip-0.92.pdf
Differential Revision: https://reviews.llvm.org/D79871
Craig Topper