Shuffles which are broken into separate halves reveal splats in which
a half is accessed via one index; such operations can be optimized to
use "vrgather.vi".
This optimization could be achieved by adding extra patterns to match
`vrgather_vv_vl` which uses a splat as an index operand, but this patch
instead identifies splat earlier. This way, future optimizations can
build on top of the data gathered here, e.g., to splat-gather dominant
indices and insert any leftovers.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D107449
Use a tail policy operand instead. Inspired by the work in D105092,
but without the intrinsic interface changes.
Reviewed By: frasercrmck
Differential Revision: https://reviews.llvm.org/D106512
This patch adds support for lowering the saturating vector add/sub
intrinsics to RVV instructions, for both fixed-length and
scalable-vector forms alike.
Note that some of the DAG combines are still not triggering for the
scalable-vector tests. These require a bit more work in the DAGCombiner
itself.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D106651
This adds new pseudoinstructions with ForceTailAgnostic set. This
matches what we did for non-widening VMACC. We should move to a
tail policy operand on the pseudos when we expand the intrinsic
interface to include the tail policy.
This adds a DAG combine to detect sext/zext inputs and emit a
new ISD opcode. The extends will either be removed or replaced
with narrower extends.
Isel patterns are used to match add and widening mul to vwmacc
similar to the recently added vmacc patterns.
There's still some work to be to match vmulsu.
We should also rewrite splats that were extended as scalars and
then splatted.
Reviewed By: arcbbb
Differential Revision: https://reviews.llvm.org/D104802
Where the RVV specification writes `vs2, vs1`, our TableGen patterns use
`rs1, rs2`. These differences can easily cause confusion. The VMANDNOT
instruction performs `LHS && !RHS`, and similarly for VMORNOT.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D102606
Limited to splats because we would need to truncate the shift
amount vector otherwise.
I tried to do this with new ISD nodes and a DAG combine to
avoid such a large pattern, but we don't form the splat until
LegalizeDAG and need DAG combine to remove a scalable->fixed->scalable
cast before it becomes visible to the shift node. By the time that
happens we've already visited the truncate node and won't revisit it.
I think I have an idea how to improve i64 on RV32 I'll save for a
follow up.
Reviewed By: frasercrmck
Differential Revision: https://reviews.llvm.org/D102019
Use result_type for the IMPLICIT_DEF in masked vector patterns.
This doesn't matter today because result_type and op_type are
always the same.
Use multiclass inheritance to reduce repeated code.
This patch supports all of the current set of VP integer binary
intrinsics by lowering them to to RVV instructions. It does so by using
the existing RISCVISD *_VL custom nodes as an intermediate layer. Both
scalable and fixed-length vectors are supported by using this method.
One notable change to the existing vector codegen strategy is that
scalable all-ones and all-zeros mask SPLAT_VECTORs are now lowered to
RISCVISD VMSET_VL and VMCLR_VL nodes to match their fixed-length
BUILD_VECTOR counterparts. This allows them to reuse the existing
"all-ones" VL patterns.
To reduce the size of the phabricator diff, some tests are intentionally
left out and will be added later if the patch is accepted.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D101826
This shrinks the immediate that isel table needs to emit for these
instructions. Hoping this allows me to change OPC_EmitInteger to
use a better variable length encoding for representing negative
numbers. Similar to what was done a few months ago for OPC_CheckInteger.
The alternative encoding uses less bytes for negative numbers, but
increases the number of bytes need to encode 64 which was a very
common number in the RISCV table due to SEW=64. By using Log2 this
becomes 6 and is no longer a problem.
This patch adds support for both scalable- and fixed-length vector code
lowering of the llvm.minnum and llvm.maxnum intrinsics to the equivalent
RVV instructions.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D101035
This patch extends the lowering of RVV fixed-length vector shuffles to
avoid the default stack expansion and instead lower to vrgather
instructions.
For "permute"-style shuffles where one vector is swizzled, we can lower
to one vrgather. For shuffles involving two vector operands, we lower to
one unmasked vrgather (or splat, where appropriate) followed by a masked
vrgather which blends in the second half.
On occasion, when it's not possible to create a legal BUILD_VECTOR for
the indices, we use vrgatherei16 instructions with 16-bit index types.
For 8-bit element vectors where we may have indices over 255, we have a
fairly blunt fallback to the stack expansion to avoid custom-splitting
of the vector types.
To enable the selection of masked vrgather instructions, this patch
extends the various RISCVISD::VRGATHER nodes to take a passthru operand.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D100549
This patch adds more optimized codegen for the above SETCC forms,
by matching the '.vi' vector forms when the immediate is a 5-bit signed
immediate plus 1. The immediate can be decremented and the corresponding
SET[U]LE or SET[U]GT forms can be matched.
This work was left as a TODO from D94168.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D100096
This patch adds RVV codegen support for OR/XOR/AND reductions for both
scalable- and fixed-length vector types. There are a few possible
codegen strategies for each -- vmfirst.m, vmsbf.m, and vmsif.m could be
used to some extent -- but the vpopc.m instruction was chosen since it
produces the scalar result in one instruction, after which scalar
instructions can finish off the computation.
The reductions are lowered identically for both scalable- and
fixed-length vectors, although some alternate strategies may be more
optimal on fixed-length vectors since it's cheaper to get the length of
those types.
Other reduction types were not deemed to be relevant for mask vectors.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D100030
This can't use our normal strategy of splatting the scalar and using
a .vv operation instead of .vx.
Instead this patch bitcasts the vector to the equivalent SEW=32
vector and inserts the scalar parts using two vslide1up/down. We
do that unmasked and apply the mask separately at the end with
a vmerge.
For vslide1up there maybe some other options here like getting
i64 into element 0 and using vslideup.vi with this vector as
vd and the original source as vs1. Masking would still need to
be done afterwards.
That idea doesn't work for vslide1down. We need to slidedown and
then insert a single scalar at vl-1 which we could do with a
vslideup, but that assumes vl > 0 which I don't think we can assume.
The i32 double slide1down implemented here is the best I could come
up with and I just made vslide1up consistent.
Reviewed By: frasercrmck
Differential Revision: https://reviews.llvm.org/D99910
It's a bit silly, but it allows us to write stricter type
constraints for isel. There's still some extra type checks in
the generated table due to some type interference limitations
around HWMode.
This patch optimizes the codegen for INSERT_VECTOR_ELT in various ways.
Primarily, it removes the use of vslidedown during lowering, and the
vector element is inserted entirely using vslideup with a custom VL and
slide index.
Additionally, lowering of i64-element vectors on RV32 has been optimized
in several ways. When the 64-bit value to insert is the same as the
sign-extension of the lower 32-bits, the codegen can follow the regular
path. When this is not possible, a new sequence of two i32 vslide1up
instructions is used to get the vector element into a vector. This
sequence was suggested by @craig.topper. From there, the value is slid
into the final position for more consistent lowering across RV32 and
RV64.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D98250
I've left mask registers to a future patch as we'll need
to convert them to full vectors, shuffle, and then truncate.
Reviewed By: frasercrmck
Differential Revision: https://reviews.llvm.org/D97609
I've included tests that require type legalization to split the
vector. The i64 version of these scalarizes on RV32 due to type
legalization visiting the result before the vector type. So we
have to abort our custom expansion to avoid creating target
specific nodes with an illegal type. Then type legalization ends
up scalarizing. We might be able to fix this by doing custom
splitting for large vectors in our handler to get down to a legal
type.
Reviewed By: frasercrmck
Differential Revision: https://reviews.llvm.org/D98102
This patch fixes up one case where the fixed-length-vector VL was
dropped (falling back to VLMAX) when inserting vector elements, as the
code would lower via ISD::INSERT_VECTOR_ELT (at index 0) which loses the
fixed-length vector information.
To this end, a custom node, VMV_S_XF_VL, was introduced to carry the VL
operand through to the final instruction. This node wraps the RVV
vmv.s.x and vmv.s.f instructions, which were being selected by
insert_vector_elt anyway.
There should be no observable difference in scalable-vector codegen.
There is still one outstanding drop from fixed-length VL to VLMAX, when
an i64 element is inserted into a vector on RV32; the splat (which is
custom legalized) has no notion of the original fixed-length vector
type.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D97842
This patch extends the support for scalable-vector int->fp and fp->int
conversions by additionally handling fixed-length vectors.
The existing scalable-vector lowering re-expresses widening/narrowing by
x4+ conversions as standard nodes. The fixed-length vector support slots
in at "the end" of this process by lowering the now equally-sized and
widening/narrowing by x2 nodes to our custom VL versions.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D97374
This patch extends the support for vector FP_ROUND and FP_EXTEND by
including support for fixed-length vector types. Since fixed-length
vectors use "VL" nodes and scalable vectors can use the standard nodes,
there is slightly more to do in the fixed-length case. A helper function
was introduced to try and reduce the divergent paths. It is expected
that this function will similarly come in useful for lowering the
int-to-fp and fp-to-int operations for fixed-length vectors.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D97301
This patch extends support for our custom-lowering of scalable-vector
truncates to include those of fixed-length vectors. It does this by
co-opting the custom RISCVISD::TRUNCATE_VECTOR node and adding mask and
VL operands. This avoids unnecessary duplication of patterns and
inflation of the ISel table.
Some truncates go through CONCAT_VECTORS which currently isn't
efficiently handled, as it goes through the stack. This can be improved
upon in the future.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D97202
This patch adds support for the custom lowering sign- and zero-extension
of fixed-length vector types. It does so through custom nodes. Since the
source and destination types are (necessarily) of different sizes, it is
possible that the source type is legal whilst the larger destination
type isn't. In this case the legalization makes heavy use of
EXTRACT_SUBVECTOR.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D97194
This uses to division by constant optimization to use MULHU/MULHS.
Reviewed By: frasercrmck, arcbbb
Differential Revision: https://reviews.llvm.org/D96934
This patch adds support for fixed-length vector vselect. It does so by
lowering them to a custom unmasked VSELECT_VL node with a vector length
operand.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D96768
This is annoying because the condition code legalization belongs
to LegalizeDAG, but our custom handler runs in Legalize vector ops
which occurs earlier.
This adds some of the mask binary operations so that we can combine
multiple compares that we need for expansion.
I've also fixed up RISCVISelDAGToDAG.cpp to handle copies of masks.
This patch contains a subset of the integer setcc patch as well.
That patch is dependent on the integer binary ops patch. I'll rebase
based on what order the patches go in.
Reviewed By: frasercrmck
Differential Revision: https://reviews.llvm.org/D96567
This patch prepares the RISCV VSLIDEUP and VSLIDEDOWN custom nodes to
ones carrying additional mask and vector-length operands. This is
primarily so they can be used by both systems.
This also takes the opportunity to create some helper functions to deal
with the common task of getting the default (unmasked) VL operands.
Reviewed By: craig.topper, arcbbb
Differential Revision: https://reviews.llvm.org/D96505
I believe I've covered all orderings of splat operands here. Better
canonicalization in lowering might help reduce this. I did not handle
the immediate adjustments needed for set(u)gt/set(u)lt.
Testing here is limited to byte types because the scalable vector
type used for masks for the store is calculated assuming 8 byte
elements. But for the setcc its based on the element count of the
container type for the setcc input. So they don't agree. We'll need
to enhanced D96352 to handle this I think.
Differential Revision: https://reviews.llvm.org/D96443
Unlike scalable vectors, I'm only using a ComplexPattern for
the immediate itself. The vmv_v_x is matched explicitly. We igore
the VL argument when matching a binary operator, but we do check
it when matching splat directly.
I left out tests for vXi64 as they fail on rv32 right now.
Reviewed By: frasercrmck
Differential Revision: https://reviews.llvm.org/D96365
This patch extends the initial fixed-length vector support to include
smin, smax, umin, and umax.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D96491
Fraser Cormack