Commit Graph

16 Commits

Author SHA1 Message Date
Craig Topper 83c92fdeda [RISCV] Move pack instructions to Zbp extension only.
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
2021-01-22 12:49:10 -08:00
Craig Topper 5ae92f1e11 [RISCV] Change zext.w to be an alias of add.uw rd, rs1, x0 instead of pack.
This didn't make it into the published 0.93 spec, but it was the
intention.

But it is in the tex source as of this commit
d172f029c0

This means zext.w now requires Zba. Not sure if we should still use
pack if Zbp is enabled and Zba isn't. I'll leave that for the future
when pack is closer to being final.

Reviewed By: asb, frasercrmck

Differential Revision: https://reviews.llvm.org/D94736
2021-01-22 12:49:10 -08:00
Craig Topper 249d7de119 [RISCV] Don't print zext.b alias.
This alias for andi x, 255 was recently added to the spec. If we
print it, code we output can't be compiled with -fno-integrated-as
unless the GNU assembler is also a version that supports alias.

Reviewed By: lenary

Differential Revision: https://reviews.llvm.org/D93826
2021-01-05 10:41:08 -08:00
Sam Elliott 12406ade06 [RISCV] Add (Proposed) Assembler Extend Pseudo-Instructions
There is an in-progress proposal for the following pseudo-instructions
in the assembler, to complement the existing `sext.w` rv64i instruction:
- sext.b
- sext.h
- zext.b
- zext.h
- zext.w

The `.b` and `.h` variants are available with rv32i and rv64i, and `zext.w` is
only available with `rv64i`.

These are implemented primarily as pseudo-instructions, as these instructions
expand to multiple real instructions. In the case of `zext.b`, this expands to a
single rv32/64i instruction, so it is implemented with an InstAlias (like
`sext.w` is on rv64i).

The proposal is available here: https://github.com/riscv/riscv-asm-manual/pull/61

Reviewed By: asb

Differential Revision: https://reviews.llvm.org/D92793
2020-12-10 19:25:51 +00:00
Craig Topper 78767b7f8e [RISCV] Add RISCVISD::ROLW/RORW use those for custom legalizing i32 rotl/rotr on RV64IZbb.
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
2020-11-20 10:25:47 -08:00
Craig Topper 67fa016ac1 [RISCV] Add RORW/ROLW/RORIW/ROLIW test cases that don't sign extend the result. NFC
This shows that we currently fail to select RORIW/ROLIW.
2020-11-13 10:59:32 -08:00
Craig Topper a59076006b [RISCV] Add isel patterns for using PACK for zext.h and zext.w.
Differential Revision: https://reviews.llvm.org/D91024
2020-11-09 10:13:45 -08:00
Craig Topper 857563eaf0 [RISCV] Check all 64-bits of the mask in SelectRORIW.
We need to ensure the upper 32 bits of the mask are zero.
So that the srl shifts zeroes into the lower 32 bits.

Differential Revision: https://reviews.llvm.org/D90585
2020-11-04 10:15:30 -08:00
Craig Topper 00eff96e1d [RISCV] Add missing patterns for rotr with immediate for Zbb/Zbp extensions.
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
2020-11-03 10:04:52 -08:00
Craig Topper 9ac2910093 [RISCV] Make SelectRORIW handle the commutability of OR.
The SHL and SRL could be in opposite order so account for that.

Differential Revision: https://reviews.llvm.org/D90586
2020-11-02 09:32:54 -08:00
Craig Topper 7142ec3aaf [RISCV] When matching RORIW, make sure the same input is given to both shifts.
The code is looking for (sext_inreg (or (shl X, C2), (shr (and Y, C3), C1))).
We need to ensure X and Y are the same.

Differential Revision: https://reviews.llvm.org/D90580
2020-11-02 09:12:40 -08:00
Craig Topper db2d4417fa [RISCV] Add a test case for another issue in SelectRORIW. NFC
When validating C3 in (sext_inreg (or (shl X, C2), (shr (and Y, C3), C1)), i32)
we are truncating it to 32 bits before checking its value. We need
to check all 64 bits.
2020-11-01 22:36:14 -08:00
Craig Topper 530bc22f28 [RISCV] Add a test case to show a bug in SelectRORIW. NFC
The function is matching (sext_inreg (or (shl X, C2), (shr (and Y, C3), C1))),
with appropriate checks for the constants to be a rotate. But it
fails to check that X and Y are the same which is also necessary.
2020-11-01 20:30:55 -08:00
Craig Topper 090e8472ae [RISCV] Add tests to show missed opportunities to use rori for fshr intrinsic with same inputs. NFC
The fshr intrinsic with same inputs produces rotr ISD node. The
fshl intrinsic produces rotl ISD node.

There were only test cases and isel patterns for the fshl/rotl case.
This patch adds fshr/rotr test cases.
2020-11-01 12:25:47 -08:00
Jay Foad 0819a6416f [SelectionDAG] Better legalization for FSHL and FSHR
In SelectionDAGBuilder always translate the fshl and fshr intrinsics to
FSHL and FSHR (or ROTL and ROTR) instead of lowering them to shifts and
ORs. Improve the legalization of FSHL and FSHR to avoid code quality
regressions.

Differential Revision: https://reviews.llvm.org/D77152
2020-08-21 10:32:49 +01:00
lewis-revill 6144f0a1e5 [RISCV] Add matching of codegen patterns to RISCV Bit Manipulation Zbbp asm instructions
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 belonging to both the permutation and the base
subsets 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/D79873
2020-07-15 12:19:34 +01:00