Commit Graph

1388 Commits

Author SHA1 Message Date
Craig Topper a21c557955 [RISCV] Remove Zbproposedc extension
This consists of 3 compressed instructions, c.not, c.neg, and c.zext.w.
I believe these have been picked up by the Zce effort using different
encodings. I don't think it makes sense to keep them in bitmanip. It
will eventually cause a conflict if/when Zce is implemented in llvm.

Differential Revision: https://reviews.llvm.org/D110871
2021-09-30 14:23:05 -07:00
Craig Topper a2a07e8db3 [RISCV] Fold store of vmv.x.s to a vse with VL=1.
This can avoid a loss of decoupling with the scalar unit on cores
with decoupled scalar and vector units.

We should support FP too, but those use extract_element and not a
custom ISD node so it is a little different. I also left a FIXME
in the test for i64 extract and store on RV32.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D109482
2021-09-27 09:54:46 -07:00
Craig Topper 933182e948 [RISCV] Improve support for forming widening multiplies when one input is a scalar splat.
If one input of a fixed vector multiply is a sign/zero extend and
the other operand is a splat of a scalar, we can use a widening
multiply if the scalar value has sufficient sign/zero bits.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D110028
2021-09-27 09:37:07 -07:00
Fraser Cormack d48f6df1f8 [RISCV] Create the correct mask type when lowering EXTRACT_VECTOR_ELT
This particular case was creating a `VMSET_VL` using the old
fixed-length type in order to pass a mask to other custom nodes
operating on the scalable container type. This kind of thing wasn't
caught for us; I only noticed when experimenting with odd-length
vectors, where it was trying to generate an invalid `v3i1` MVT.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D110420
2021-09-27 09:43:40 +01:00
Kazu Hirata c4ae4a745d [RISCV] Remove redundant declaration RISCVMnemonicSpellCheck (NFC)
Note that RISCVMnemonicSpellCheck is defined in
RISCVGenAsmMatcher.inc, which RISCVAsmParser.cpp includes.

Identified with readability-redundant-declaration.
2021-09-26 09:26:57 -07:00
Jim Lin ed687c0211 [RISCV] Fix incorrect operand type of inst alias for InstR4
Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D110381
2021-09-25 11:25:12 +08:00
Craig Topper 715cf6ffb9 [RISCV] Add another isel optimization for (and (shl X, c2), c1).
Where c1 is a shifted mask with 32-c2 leading zeros and c3 trailing
zeros and c3>c2. We can select it as (slli (srliw X, c3-c2), c3).
2021-09-24 15:10:25 -07:00
Hsiangkai Wang 7d39a8a921 [RISCV] (1/2) Add the tail policy argument to builtins/intrinsics.
Add the tail policy argument to LLVM IR intrinsics. There are two policies for tail elements. Tail agnostic means users do not care about the values in the tail elements and tail undisturbed means the values in the tail elements need to be kept after the operation. In order to let users control the tail policy, we add an additional argument at the end of the argument list.

For unmasked operations, we have no maskedoff and the tail policy is always tail agnostic. If users want to keep tail elements under unmasked operations, they could use all one mask in the masked operations to do it. So, we only add the additional argument for masked operations for most cases. There are exceptions listed below.

In this patch, we do not handle the following cases to reduce the complexity of the patch. There could be two separate patches for them.

* Use dest argument to control tail policy
vmerge.vvm/vmerge.vxm/vmerge.vim (add _t builtins with additional dest argument)
vfmerge.vfm (add _t builtins with additional dest argument)
vmv.v.v (add _t builtins with additional dest argument)
vmv.v.x (add _t builtins with additional dest argument)
vmv.v.i (add _t builtins with additional dest argument)
vfmv.v.f (add _t builtins with additional dest argument)
vadc.vvm/vadc.vxm/vadc.vim (add _t builtins with additional dest argument)
vsbc.vvm/vsbc.vxm (add _t builtins with additional dest argument)

* Always has tail argument for masked/unmasked intrinsics
Vector Single-Width Integer Multiply-Add Instructions (add _t and _mt builtins)
Vector Widening Integer Multiply-Add Instructions (add _t and _mt builtins)
Vector Single-Width Floating-Point Fused Multiply-Add Instructions (add _t and _mt builtins)
Vector Widening Floating-Point Fused Multiply-Add Instructions (add _t and _mt builtins)
Vector Reduction Operations (add _t and _mt builtins)
Vector Slideup Instructions (add _t and _mt builtins)
Vector Slidedown Instructions (add _t and _mt builtins)

Discussion: https://github.com/riscv/rvv-intrinsic-doc/pull/101

Differential Revision: https://reviews.llvm.org/D105092
2021-09-24 17:09:50 +08:00
Craig Topper 40b230f685 [RISCV] Limit transformAddImmMulImm to prevent an infinite loop.
This fixes an issue reported in D108607.
2021-09-23 15:53:11 -07:00
Craig Topper 70f50114f3 [RISCV] Add another isel optimization for (and (shl x, c2), c1)
Turn (and (shl x, c2), c1) -> (slli (srli x, c3-c2), c3) if c1 is a
shifted mask with no leading zeros and c3 trailing zeros where c3
is greater than c2.
2021-09-23 14:18:07 -07:00
Craig Topper 4a69551d66 [RISCV] Add more isel optimizations for (and (shr x, c2), c1).
Turn (and (shr x, c2), c1) -> (slli (srli x, c2+c3), c3) if c1 is a
shifted mask with c2 leading zeros and c3 trailing zeros.

When the leading zeros is C2+32 we can use SRLIW in place of SRLI.
2021-09-23 11:29:04 -07:00
Jim Lin fbacf5ad38 [RISCV] Add missing op type OPERAND_UIMM2, OPERAND_UIMM3 and OPERAND_UIMM7 for verifyInstruction
Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D110307
2021-09-23 19:30:46 +08:00
Fraser Cormack e7c879a69d [RISCV][VP] Add support for VP_REDUCE_* operations
This patch adds codegen support for lowering the vector-predicated
reduction intrinsics to RVV instructions. The process is similar to that
of the other reduction intrinsics, save for the fact that every VP
reduction has a start value. We reuse the existing custom "VL" nodes,
adding extra patterns where required to handle non-true masks.

To support these nodes, the `RISCVISD::VECREDUCE_*_VL` nodes have been
given an explicit "merge" operand. This is to faciliate the VP
reductions, where we must be careful to ensure that even if no operation
is performed (when VL=0) we still produce the start value. The RVV
reductions don't update the destination register under these conditions,
so we tie the splatted start value to the output register.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D107657
2021-09-23 11:11:05 +01:00
Jay Foad 6cef28ed2d [TII] Remove the MFI argument to convertToThreeAddress. NFC.
This simplifies the API and addresses a FIXME in
TwoAddressInstructionPass::convertInstTo3Addr.

Differential Revision: https://reviews.llvm.org/D110229
2021-09-23 08:58:46 +01:00
Craig Topper f0a422f935 [RISCV] Add fcvt.s.w(u)/fcvt.d.w(u)/fcvt.h.w(u) to hasAllNBitUsers
These instructions only read the lower 32 bits of their input.
2021-09-22 14:24:26 -07:00
Craig Topper b33a1cc05b [RISCV] Optimize vp.store with an all ones mask to avoid a vmset.
We can use riscv_vse intrinsic instead of riscv_vse_mask. The code here
is based on similar code for handling masked.scatter and vp.scatter.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D110206
2021-09-22 09:12:47 -07:00
Craig Topper 7c975665b4 [RISCV] Make some arrays of constants 'static const'. NFC
This helps the compiler generate better code.
2021-09-21 10:52:47 -07:00
Craig Topper aeb63d464f [RISCV] Teach RISCVTargetLowering::shouldSinkOperands to sink splats for and/or/xor.
This requires a minor change to CodeGenPrepare to ensure that
shouldSinkOperands will be called for And.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D110106
2021-09-21 10:07:29 -07:00
Ben Shi b3052013b4 [RISCV] Optimize (add (mul x, c0), c1)
Optimize (add (mul x, c0), c1) -> (ADDI (MUL (ADDI, c1/c0), c0), c1%c0),
if c1/c0 and c1%c0 are simm12, while c1 is not.

Optimize (add (mul x, c0), c1) -> (MUL (ADDI, c1/c0), c0),
if c1%c0 is zero, and c1/c0 is simm12 while c1 is not.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D108607
2021-09-21 14:13:14 +00:00
Craig Topper a95ba81073 [RISCV] Teach RISCVTargetLowering::shouldSinkOperands to sink splats for FMA.
If either of the multiplicands is a splat, we can sink it to use
vfmacc.vf or similar.
2021-09-20 11:49:50 -07:00
Craig Topper 04ab6c85ef [RISCV] Teach RISCVTargetLowering::shouldSinkOperands to sink splats for FAdd/FSub/FMul/FDiv. 2021-09-20 10:25:46 -07:00
Craig Topper d85e347a28 [RISCV] Add a pass to recognize VLS strided loads/store from gather/scatter.
For strided accesses the loop vectorizer seems to prefer creating a
vector induction variable with a start value of the form
<i32 0, i32 1, i32 2, ...>. This value will be incremented each
loop iteration by a splat constant equal to the length of the vector.
Within the loop, arithmetic using splat values will be done on this
vector induction variable to produce indices for a vector GEP.

This pass attempts to dig through the arithmetic back to the phi
to create a new scalar induction variable and a stride. We push
all of the arithmetic out of the loop by folding it into the start,
step, and stride values. Then we create a scalar GEP to use as the
base pointer for a strided load or store using the computed stride.
Loop strength reduce will run after this pass and can do some
cleanups to the scalar GEP and induction variable.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D107790
2021-09-20 09:39:44 -07:00
Ben Shi dee5a8ca32 [RISCV] Optimize (add (shl x, c0), (shl y, c1)) with SH*ADD
Optimize (add (shl x, c0), (shl y, c1)) ->
         (SLLI (SH*ADD x, y), c1), if c0-c1 == 1/2/3.

Reviewed By: craig.topper, luismarques

Differential Revision: https://reviews.llvm.org/D108916
2021-09-19 16:35:12 +08:00
Craig Topper 73e5b9ea90 [RISCV] Select (srl (sext_inreg X, i32), uimm5) to SRAIW if only lower 32 bits are used.
SimplifyDemandedBits can turn srl into sra if the bits being shifted
in aren't demanded. This patch can recover the original sra in some cases.

I've renamed the tablegen class for detecting W users since the "overflowing operator"
term I originally borrowed from Operator.h does not include srl.

Reviewed By: luismarques

Differential Revision: https://reviews.llvm.org/D109162
2021-09-16 11:03:35 -07:00
Jim Lin f29336104d [RISCV] Rename prefix `FeatureExt*` to `FeatureStdExt*` for all sub-extension
Rename prefix `FeatureExt*` to `FeatureStdExt*` for all sub-extension for consistency

Reviewed By: HsiangKai, asb

Differential Revision: https://reviews.llvm.org/D108187
2021-09-13 16:24:15 +08:00
Craig Topper 283879793d [RISCV] Initial support .insn directive for the assembler.
This allows for a custom encoding to be emitted. It can also be
used with inline assembly to allow the custom instruction to be
register allocated like other instructions.

I initially started from SystemZ's implementation, but some of
the formats allow operands to be specified in multiple ways so I
had to add support for matching different operand class lists for
the same format. That implementation is a simplified version of
what is emitted by tablegen for regular instructions.

I've left out the compressed formats. And I haven't supported the
named opcodes like LUI or OP_IMM_32. Those can be added in future
patches.

Documentation can be found here https://sourceware.org/binutils/docs-2.37/as/RISC_002dV_002dFormats.html

Reviewed By: jrtc27, MaskRay

Differential Revision: https://reviews.llvm.org/D108602
2021-09-12 15:56:12 -07:00
Craig Topper 1b736bda3b [RISCV] Enable CGP to sink splat operands of Add/Sub/Mul/Shl/LShr/AShr
LICM may have pulled out a splat, but with .vx instructions we
can fold it into an operation.

This patch enables CGP to reverse the LICM transform and move the
splat back into the loop.

I've started with the commutable integer operations and shifts, but we can
extend this with more operations in future patches.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D109394
2021-09-10 09:04:01 -07:00
Craig Topper 6c7cadb8c1 [RISCV] Teach vsetvli insertion that stores don't use the policy bits in vtype.
This can avoid a vsetvl after a tail undisturbed operation.

Differential Revision: https://reviews.llvm.org/D109549
2021-09-10 09:03:20 -07:00
Craig Topper 9af8f1b18e [SelectionDAG] Add isZero/isAllOnes methods to ConstantSDNode.
Soft deprecrate isNullValue/isAllOnesValue and update in tree
callers. This matches the changes to the APInt interface from
D109483.

Reviewed By: lattner

Differential Revision: https://reviews.llvm.org/D109535
2021-09-09 13:28:30 -07:00
Alexander Pivovarov 4bc8dbe0ca [RISCV] Add SiFive cores E and S series
Add SiFive cores E20, E21, E24, E34, S21, S54 and S76

Differential Revision: https://reviews.llvm.org/D109260
2021-09-08 23:59:04 -07:00
Yvan Roux 261cbe98c3 [RISCV] Fix Machine Outliner jump table handling.
Don't outline machine instructions which are using jump table indexes
since they are materialized as local labels (like the already handled
case of constant pools).

Reviewed By: paquette

Differential Revision: https://reviews.llvm.org/D109436
2021-09-09 07:32:30 +02:00
Craig Topper a574f0e0c3 [RISCV] Disable use of i128 shift libcalls on RV32.
Since i128 isn't a legal C type on RV32, I don't believe
libgcc implements these functions for RV32. compiler-rt
does implement them because i128 support is enabled
in order to handle long double.

This is consistent with 32-bit X86 and ARM.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D109383
2021-09-08 14:26:07 -07:00
Craig Topper aca14c8cf1 [RISCV] Remove unused tablegen template parameters. NFC
Identified in D109359
2021-09-08 10:01:42 -07:00
Craig Topper b04c09c07c [RISCV] Use V0 instead of VMV0: for mask vectors in isel patterns.
This is consistent with the RVV intrinsic patterns. This has been
shown to prevent some "ran out of registers" errors in our internal
testing.

Unfortunately, there are some regressions on LMUL=8 tests in here.
I think the lack of registers with LMUL=8 just makes it very hard
to schedule correctly.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D109245
2021-09-08 09:46:21 -07:00
Craig Topper 1f16191906 [RISCV] Add an GPR def to the Zvlseg SPILL/RELOAD pseudos
The expansion of these pseudos creates ADD instructions. Those
ADDs modify a GPR so that it is no longer contains the same value
as the input base pointer. Therefore, I believe we should have a
GPR as a Def on these instructions and expansion should get the
destination register for the ADDs from that operand.

At least in our tests here this works out so that register
scavenging picks the same register as the base pointer.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D109405
2021-09-08 09:23:33 -07:00
Kazu Hirata 5c6338de16 [RISCV] Fix "set but not used" warnings 2021-09-07 09:19:31 -07:00
Peter Smith e63455d5e0 [MC] Use local MCSubtargetInfo in writeNops
On some architectures such as Arm and X86 the encoding for a nop may
change depending on the subtarget in operation at the time of
encoding. This change replaces the per module MCSubtargetInfo retained
by the targets AsmBackend in favour of passing through the local
MCSubtargetInfo in operation at the time.

On Arm using the architectural NOP instruction can have a performance
benefit on some implementations.

For Arm I've deleted the copy of the AsmBackend's MCSubtargetInfo to
limit the chances of this causing problems in the future. I've not
done this for other targets such as X86 as there is more frequent use
of the MCSubtargetInfo and it looks to be for stable properties that
we would not expect to vary per function.

This change required threading STI through MCNopsFragment and
MCBoundaryAlignFragment.

I've attempted to take into account the in tree experimental backends.

Differential Revision: https://reviews.llvm.org/D45962
2021-09-07 15:46:19 +01:00
Fraser Cormack a823bdf3ab [RISCV][VP] Custom lower VP_STORE and VP_LOAD
This patch adds support for the vector-predicated `VP_STORE` and
`VP_LOAD` nodes. We do this in the same way we lower `MSTORE` and
`MLOAD`: to regular load/store instructions via intrinsics.

One necessary change was made to `SelectionDAGLegalize` so that
`VP_STORE` nodes' operation actions are taken from the stored "value"
operands, in the same vein as `STORE` or `MSTORE`.

Reviewed By: craig.topper, rogfer01

Differential Revision: https://reviews.llvm.org/D108999
2021-09-07 10:53:25 +01:00
Fraser Cormack f4dee8cb82 [RISCV][VP] Custom lower VP_SCATTER and VP_GATHER
This patch adds support for the `VP_SCATTER` and `VP_GATHER` nodes by
lowering them to RVV's `vsox`/`vlux` instructions, respectively. This
process is almost identical to the existing `MSCATTER`/`MGATHER` support.

One extra change was made to `SelectionDAGLegalize` so that
`VP_SCATTER`'s operation action is derived from its stored "value"
operand rather than its return type (which is always the chain).

Reviewed By: craig.topper, rogfer01

Differential Revision: https://reviews.llvm.org/D108987
2021-09-07 10:43:07 +01:00
Craig Topper 75620fadf5 [RISCV] Change how we encode AVL operands in vector pseudoinstructions to use GPRNoX0.
This patch changes the register class to avoid accidentally setting
the AVL operand to X0 through MachineIR optimizations.

There are cases where we really want to use X0, but we can't get that
past the MachineVerifier with the register class as GPRNoX0. So I've
use a 64-bit -1 as a sentinel for X0. All other immediate values should
be uimm5. I convert it to X0 at the earliest possible point in the VSETVLI
insertion pass to avoid touching the rest of the algorithm. In
SelectionDAG lowering I'm using a -1 TargetConstant to hide it from
instruction selection and treat it differently than if the user
used -1. A user -1 should be selected to a register since it doesn't
fit in uimm5.

This is the rest of the changes started in D109110. As mentioned there,
I don't have a failing test from MachineIR optimizations anymore.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D109116
2021-09-03 09:19:25 -07:00
Alexander Pivovarov 6cd4b508a8 [RISCV] Add SiFive core S51
Add SiFive core s51 as rv64imac RocketModel

Reviewed-By: MaskRay, evandro
Differential Revision: https://reviews.llvm.org/D108886
2021-09-02 18:45:25 -07:00
Alexander Pivovarov 1104e3258b Fix typo in RISCVMatInt.cpp comments 2021-09-02 18:11:09 -07:00
Craig Topper b5fd6b46f5 [RISCV] Teach instruction selection to elide sext.w in some cases.
If a sext_inreg is up for isel, and all its users are W instructions,
we can skip emitting the sext_inreg. This helpful if the producing
instruction can't become a W instruction.

Reviewed By: asb

Differential Revision: https://reviews.llvm.org/D108966
2021-09-02 07:54:34 -07:00
Evandro Menezes 5ebdb07e7e [RISCV] Enable shrink wrap by default
Differential Revision: https://reviews.llvm.org/D109037
2021-09-02 09:47:58 -05:00
Craig Topper e4e69ba4d1 [RISCV] Split PseudoVSETVLI into 2 instructions to allow different register classes for rs1.
X0 has special meaning for vsetvli, we need to make sure we never
create it a vsetvli that uses it by accident. This could happen
if the register coalescer coalesces a copy from X0 into this
instruction.

This patch splits the instruction so that we can have GPRNoX0
register class to use for the cases where we don't want the source
to be X0. The verifier won't let us explicitly use X0 on a GPRNoX0
operand so we need a separate pseudo for those cases.

I don't currently have a failing example for this. There was a
failure in D107957, but the coalescable copy from that example
should have been optimized away much earlier so I've fixed that.

This is not a complete fix. We still need to prevent the same
possible issue on the AVL operand of all of the vector instruction
pseudos. I don't want to make two versions of all of those so we
need to find a different solution for those. I have an idea I'm
going to try.

Differential Revision: https://reviews.llvm.org/D109110
2021-09-02 07:45:31 -07:00
Alexander Pivovarov 4b04d54206 [RISCV] Fix typo in RISCVSchedSiFive7.td
Fix typo in "microarchitecure".

Differential Revision: https://reviews.llvm.org/D109006
2021-09-01 16:39:48 -05:00
Craig Topper ccbb4c8b4f [RISCV] Fold (RISCVISD::SELECT_CC X, Y, CC, Z, Z) -> Z.
If the true and false values are the same, we don't need a SELECT_CC.

This would normally be folded before a select is legalized to
select_cc. The test case exploits the late legalization of vscale
to trigger a case where they become identical after legalization.

This works around an issue found on a test case in D107957. In that
case the true/false values were both eventually 0 and the select was
used by a vector AVL operand. The select_cc got expanded to control
flow and a phi, but the phi inputs were both copies from X0. MachineIR
optimizations simplified this to a single copy from X0 going into the
vector instruction. This became the input of a vsetvli after vsetvli
insertion. Then register coalescing folded the copy into the vsetvli.
X0 as the source of a vsetvli is a special encoding and should not be
created by coalesing. We need to fix our vsetvli handling to make sure
this can never happen any other way, but removing the unneeded select
is still a worthwhile optimization.
2021-09-01 12:37:52 -07:00
Luke a78dd726f4 [SLP][RISCV] Implement unsigned getMinVectorRegisterBitWidth() for RISCV
Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D108973
2021-09-01 14:25:15 +08:00
Nick Desaulniers e9b3f25730 [RISCVISelLowering] avoid emitting libcalls to __mulodi4() and __multi3()
Similar to D108842, D108844, D108926, D108928, and D108936.

__has_builtin(builtin_mul_overflow) returns true for 32b RISCV targets,
but Clang is deferring to compiler RT when encountering long long types.

If the semantics of __has_builtin mean "the compiler resolves these,
always" then we shouldn't conditionally emit a libcall.

Link: https://bugs.llvm.org/show_bug.cgi?id=28629

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D108939
2021-08-31 11:23:56 -07:00
Nikita Popov c1b7540645 [TTI] Sink IVDescriptors.h include (NFC)
Forward declare RecurrenceDescriptor and include IVDescritor.h
only in implementation code that actually needs it.
2021-08-30 22:41:58 +02:00