This patch unifies the two disparate paths for lowering
EXTRACT_SUBVECTOR operations under one roof. Consequently, with this
patch it is possible to support any fixed-length subvector extraction,
not just "cast-like" ones.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D97192
We always create the VL operand using a register, but if we can
determine that it came from an ADDI X0, imm with a sufficiently
small immediate, we can use VSETIVLI.
Reviewed By: frasercrmck
Differential Revision: https://reviews.llvm.org/D97332
I've changed to use VL=1 for slidedown and shifts to avoid extra
element processing that we don't need.
The i64 fixed vector handling on i32 isn't great if the vector type
isn't legal due to an ordering issue in type legalization. If the
vector type isn't legal, we fall back to default legalization
which will bitcast the vector to vXi32 and use two independent extracts.
Doing better will require handling several different cases by
manually inserting insert_subvector/extract_subvector to adjust the type
to a legal vector before emitting custom nodes.
Reviewed By: frasercrmck
Differential Revision: https://reviews.llvm.org/D97319
This patch extends the support for RVV INSERT_SUBVECTOR to cover those
which don't align to a vector register boundary. Like the support for
EXTRACT_SUBVECTOR in D96959, it accomplishes this by extracting the
nearest register-sized subvector (a subregister operation), then sliding
the vector down with VSLIDEDOWN, inserting the subvector to the first
position, and sliding the vector back up again afterwards.
Unlike subvector extraction, for vectors that occupy less than a full
vector register we must preserve the untouched elements. We do this by
lowering to an LMUL=1 INSERT_SUBVECTOR using the above method and
lowering that to a VSLIDEUP with a zero offset. This uses a
tail-undisturbed policy and so has the effect of "sliding in" the
subvector elements while preserving the surrounding ones.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D96972
This should fix the issue reported in D96972.
I don't have a good test case for this without those changes.
Differential Revision: https://reviews.llvm.org/D97082
A previous patch moved the index versions. This moves the rest.
I also removed the custom lowering for VLEFF since we can now
do everything directly in the isel handling.
I had to update getLMUL to handle mask registers to index the
pseudo table correctly for VLE1/VSE1.
This is good for another 15K reduction in llc size.
Reviewed By: frasercrmck
Differential Revision: https://reviews.llvm.org/D97097
This patch extends the support for RVV EXTRACT_SUBVECTOR to cover those
which don't align to a vector register boundary. It accomplishes this by
extracting the nearest register-sized subvector (a subregister
operation), then sliding the vector down with VSLIDEDOWN and extracting
the subvector from the first position (a COPY operation).
Since this procedure involves the use of VSCALE and multiplication, the
handling of such operations is done during lowering to simplify the
implementation and make use of DAG combining. This necessitated moving
some helper functions from RISCVISelDAGToDAG to RISCVTargetLowering.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D96959
We previously used isel patterns for this, but that used quite
a bit of space in the isel table due to OR being associative
and commutative. It also wouldn't handle shifts/ands being in
reversed order.
This generalizes the shift/and matching from GREVI to
take the expected mask table as input so we can reuse it for
SHFLI.
There is no SHFLIW instruction, but we can promote a 32-bit
SHFLI to i64 on RV64. As long as bit 4 of the control bit isn't
set, a 64-bit SHFLI will preserve 33 sign bits if the input had
at least 33 sign bits. ComputeNumSignBits has been updated to
account for that to avoid sext.w in the tests.
Reviewed By: frasercrmck
Differential Revision: https://reviews.llvm.org/D96661
This uses to division by constant optimization to use MULHU/MULHS.
Reviewed By: frasercrmck, arcbbb
Differential Revision: https://reviews.llvm.org/D96934
Due to vXi64 on RV32, I've directly emitted this using _VL ISD
opcodes. If it wasn't for that we could just use fixed vector
BUILD_VECTOR and VSELECT and let those each be legalized.
Reviewed By: frasercrmck
Differential Revision: https://reviews.llvm.org/D96910
The type legalizer can call this code based on the scalar type so
we need to verify the vector type is a scalable vector.
I think due to how type legalization visits nodes, the vector type
will have already been legalized so we don't have an issue with
using MVT here like we did for EXTRACT_VECTOR_ELT.
I've added a test just in case.
The type legalizer is calling this code based on the scalar type so
we need to verify the input type is a scalable vector.
The vector type has also not been legalized yet when this is called
so we need to use EVT for it.
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
Non-splatted non-integer build_vector nodes were mistakenly being
lowered as VID expressions, which should not happen. VID can only be
used to select integer build_vector nodes.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D96718
The patterns mostly follow the scalar counterparts, save for some extra
optimizations to match the vector/scalar forms.
The patch adds a DAGCombine for ISD::FCOPYSIGN to try and reorder
ISD::FNEG around any ISD::FP_EXTEND or ISD::FP_TRUNC of the second
operand. This helps us achieve better codegen to match vfsgnjn.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D96028
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
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
This refines how we determine which masks types are legal and adds
support for loads, stores, and all ones/zeros splats.
I left a fixme in store handling where I think we need to zero
extra bits if the type isn't a multiple of a byte. If I remember
right from X86 there was some case we could have a store of a
1, 2, or 4 bit mask and have a scalar zextload that then expected the
bits to be 0. Its tricky to zero the bits with RVV. We need to do
something like round VL up, zero a register, lower the VL back down,
then do a tail undisturbed move into the zero register. Another
option might be to generate a mask of 1/2/4 bits set with a VL of 8
and use that to mask off the bits.
Reviewed By: frasercrmck
Differential Revision: https://reviews.llvm.org/D96468
The test cases extract a fixed element from a vector and splat it
into a vector. This gets DAG combined into a splat shuffle.
I've used some very wide vectors in the test to make sure we have
at least a couple tests where the element doesn't fit into the
uimm5 immediate of vrgather.vi so we fall back to vrgather.vx.
Reviewed By: frasercrmck
Differential Revision: https://reviews.llvm.org/D96186
This patch optimizes a build_vector "index sequence" and lowers it to
the existing custom RISCVISD::VID node. This pattern is common in
autovectorized code.
The custom node was updated to allow it to be used by both scalable and
fixed-length vectors, thus avoiding pattern duplication.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D96332
Define an option -riscv-vector-bits-max to specify the maximum vector
bits for vectorizer. Loop vectorizer will use the value to check if it
is safe to use the whole vector registers to vectorize the loop.
It is not the optimum solution for loop vectorizing for scalable vector.
It assumed the whole vector registers will be used to vectorize the code.
If it is possible, we should configure vl to do vectorize instead of
using whole vector registers.
We only consider LMUL = 1 in this patch.
This patch just an initial work for loop vectorizer for RISC-V Vector.
Differential Revision: https://reviews.llvm.org/D95659
Building on the fixed vector support from D95705
I've added ISD nodes for vmv.v.x and vfmv.v.f and switched to
lowering the intrinsics to it. This allows us to share the same
isel patterns for both.
This doesn't handle splats of i64 on RV32 yet. The build_vector
gets converted to a vXi32 build_vector+bitcast during type
legalization. Not sure the best way to handle this at the moment.
Differential Revision: https://reviews.llvm.org/D96108
This is an alternative to D95563.
This is modeled after a similar feature for AArch64's SVE that uses
predicated scalable vector instructions.a
Rather than use predication, this patch uses an explicit VL operand.
I've limited it to always use LMUL=1 for now, but we can improve this
in the future.
This requires a bunch of new ISD opcodes to carry the VL operand.
I think we can probably lower intrinsics to these ISD opcodes to
cut down on the size of the isel table. Which is why I've added
patterns for all integer/float types and not just LMUL=1.
I'm only testing one vector width right now, but the width is
programmable via the command line.
Reviewed By: frasercrmck
Differential Revision: https://reviews.llvm.org/D95705
This adds support for commuting operands and converting between
vfmadd and vfmacc to avoid register copies.
To avoid messing up intrinsic behavior, I've added new pseudo
instructions that have the isCommutable flag set. These pseudos also
force a tail agnostic policy. The intrinsic version still use
the tail undisturbed policy.
For best results it looks like we need to start with fmadd and only
pick fmacc if its beneficial. MachineCSE commutes without contraining
the operands and then commutes back if it didn't help with CSE. So
I've made sure that when the operand choice isn't constrained, we
will keep fmadd for MachineCSE and when it does the second commute,
we get back the original instruction.
Reviewed By: frasercrmck
Differential Revision: https://reviews.llvm.org/D95800
This patch adds support for both the fadd reduction intrinsic, in both
the ordered and unordered modes.
The fmin and fmax intrinsics are not currently supported due to a
discrepancy between the LLVM semantics and the RVV ISA behaviour with
regards to signaling NaNs. This behaviour is likely fixed in version 2.3
of the RISC-V F/D/Q extension, but until then the intrinsics can be left
unsupported.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D95870
This patch adds support for the integer reduction intrinsics supported
by RVV. This excludes "mul" which has no corresponding instruction.
The reduction instructions in RVV have slightly complicated type
constraints given they always produce a single "M1" vector register.
They are lowered to custom nodes including the second "scalar" reduction
operand to simplify the patterns and in the hope that they can be useful
for future DAG combines.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D95620
This patch custom-legalizes all integer EXTRACT_VECTOR_ELT nodes where
SEW < XLEN to VMV_S_X nodes to help the compiler infer sign bits from
the result. This allows us to eliminate redundant sign extensions.
For parity, all integer EXTRACT_VECTOR_ELT nodes are legalized this way
so that we don't need TableGen patterns for some and not others.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D95741
We need to add a mask to the shift amount for these operations
to use the FSR/FSL instructions. We were previously doing this
in isel patterns, but custom lowering will make the mask
visible to optimizations earlier.
This patch adds support for the full range of vector int-to-float,
float-to-int, and float-to-float conversions on legal types.
Many conversions are supported natively in RVV so are lowered with
patterns. These include conversions between (element) types of the same
size, and those that are half/double the size of the input. When
conversions take place between types that are less than half or more
than double the size we must lower them using sequences of instructions
which go via intermediate types.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D95447
-Remove the ISD opcode for READ_VL. Just emit the MachineSDNode directly.
-Move segmented fault first only load intrinsic handling completely to
RISCVISelDAGToDAG.cpp and emit the ReadVL MachineSDNode there
instead of lowering to ISD opcodes first.
Remove the RISCVVMVTs namespace because I don't think it provides
a lot of value. If we change the mappings we'd likely have to add
or remove things from the list anyway.
Add a wrapper around addRegisterClass that can determine the
register class from the fixed size of the type.
Reviewed By: frasercrmck, rogfer01
Differential Revision: https://reviews.llvm.org/D95491
This patch fixes some crashes coming from
`RISCVISelLowering::getSetCCResultType`, which would occasionally return
an EVT constructed from an invalid MVT, which has a null Type pointer.
The attached test shows this happening currently for some fixed-length
vectors, which hit this issue when the V extension was enabled, even
though they're not legal types under the V extension. The fix was also
pre-emptively extended to scalable vectors which can't be represented as
an MVT, even though a test case couldn't be found for them.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D95434
239cfbccb0509da1a08d9e746706013b732e646b add support for legalizing
i8/i16 UDIV/UREM/SDIV to use *W instructions. So we need to truncate
to i8/i16 if we're legalizing one of those.
Original patch by @rogfer01.
This patch adds support for insertelt and extractelt operations on
scalable vectors.
Special care must be taken on RV32 when dealing with i64 vectors as
there are no straightforward ways to insert a 64-bit element without a
register of that size. To that end, both are custom-lowered to different
sequences.
Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: Fraser Cormack <fraser@codeplay.com>
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D94615
This makes our i8/i16 codegen more similar to the i32 codegen.
I've also added computeKnownBits support for DIVUW/REMUW so
that we can remove zero extending ANDs from the output. Without
this we end up turning DIVUW/REMUW back into DIVU/REMU via some
isel patterns.
Reviewed By: frasercrmck, luismarques
Differential Revision: https://reviews.llvm.org/D95322
As far as I know 32 bits arguments and returns on RV64 are always
sign extended to i64. So I think we should be taking this into
account around libcalls.
Reviewed By: luismarques
Differential Revision: https://reviews.llvm.org/D95285
This patch adds support for scalable-vector splats in DAGCombiner's
`isConstantOrConstantVector` and `ISD::matchUnaryPredicate` functions,
which enable the SelectionDAG div/rem-by-constant optimizations for
scalable vector types.
It also fixes up one case where the UDIV optimization was generating a
SETCC without first consulting the target for its preferred SETCC result
type.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D94501
These instructions use a portion of the encodings for grevi and
gorci. The full encodings are only supported with Zbp. Note,
rev8 has a different encoding between rv32 and rv64.
Zbb is closer to being finalized that Zbp which has motivated
some decisions in this patch.
I'm treating rev8 and orc.b as separate instructions when
either Zbb or Zbp is enabled. This allows us to print to suggest
that either feature needs to be enabled to support these mnemonics.
I had tried to put HasStdExtZbbAndNotZbp on the Zbb instructions,
but that caused a diagnostic that said Zbp is required if neither
feature is enabled. We should really mention Zbb since its closer
to final.
This does require extra isel patterns for the different cases so
that bswap will always print as rev8 in assembly listing since
we can't use an InstAlias.
llvm-objdump disassembling should always pick the rev8 or orc.b
instructions. llvm-mc parsing and printing text will not convert
the grevi/gorci spellings to rev8/gorc.b. We could probably fix
this with a special case in processInstruction in the assembly
parser if it its important.
Reviewed By: asb, frasercrmck
Differential Revision: https://reviews.llvm.org/D94944
The fault-only-first-load instructions can reduce VL if an element
other than element 0 triggers a memory fault. This can be used to
vectorize loops with data dependent exit conditions like strcmp or
strlen.
This patch adds a VL output to these intrinsics so that the new
VL value can be captured by software. This will be expanded to
'csrr gpr, vl' after the vleff instruction during SelectionDAG.
By doing this with one intrinsic we are able to guarantee that the
csrr reads the VL value produced by the vleff instruction. Having
it as a separate intrinsic would make it impossible to guarantee
ordering without making every other vector intrinsic have side
effects.
The intrinsics are expanded during lowering into two ISD nodes
that are glued together. These ISD nodes will go
through isel separately, but should maintain the glue so that they
get emitted adjacently by InstrEmitter.
I've only ran the chain through the vleff instruction, allowing
the READ_VL to be deleted if it is unused.
Reviewed By: HsiangKai
Differential Revision: https://reviews.llvm.org/D94286
This recommits 71ed4b6ce57d8843ef705af8f98305976a8f107a with
the polarity of some of the pattern corrected.
Original commit message:
The custom expansion of select operations in the RISC-V backend
interferes with the matching of cmov instructions. Legalizing
select when the Zbt extension is available solves that problem.
Reviewed By: luismarques, craig.topper
Differential Revision: https://reviews.llvm.org/D93767
