Commit Graph

238 Commits

Author SHA1 Message Date
Craig Topper 5c7ec998a9 [RISCV] Fold addiw from (add X, (addiw (lui C1, C2))) into load/store address
This is a followup to D124231.

We can fold the ADDIW in this pattern if we can prove that LUI+ADDI
would have produced the same result as LUI+ADDIW.

This pattern occurs because constant materialization prefers LUI+ADDIW
for all simm32 immediates. Only immediates in the range
0x7ffff800-0x7fffffff require an ADDIW. Other simm32 immediates
work with LUI+ADDI.

Reviewed By: asb

Differential Revision: https://reviews.llvm.org/D124693
2022-05-11 12:47:13 -07:00
Yeting Kuo 4537aae0d5 [RISCV] Make PseudoReadVL have the vtypes of the corresponding VLEFF/VLSEGFF.
The patch make PseudoReadVL have the vtypes of the corresponding VLEFF/VLSEGFF.
It's useful to get the vtypes of locations of PseudoReadVL without finding the
corresponding VLEFF/VLSEGFF.
It could simplify optimizations in RISCVInsertVSETVLI like D123581.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D125199
2022-05-11 14:07:58 +08:00
Zakk Chen 5807e59a0a [RISCV] Fix incorrect codegen for masked vmsge{u}.vx with mask agnostic.
The result was totally wrong.
We could use mask undisturbed result to emulate the mask agnostic result.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D124684
2022-05-02 17:57:29 -07:00
Craig Topper f91690f7db [RISCV] Don't merge addi into load/store address if addi has a FrameIndex operand.
This fixes a crash from D124231.

We can't fold
  (load (add base, (addi src, off1)), off2)
     -> (load (add base, src), off1+off2)
if the src is a FrameIndex. FrameIndex cannot be the operand of an
add.

There was an immediate==0 check that I think was trying to catch
the common case of FrameIndex addis where the immediate is 0, but
they can also appear in non-zero form. Instead explicitly check
for a FrameIndex operand.
2022-04-29 18:22:20 -07:00
Hsiangkai Wang c62b014db9 [RISCV] Merge addi into load/store as there is a ADD between them
This patch adds peephole optimizations for the following patterns:

(load (add base, (addi src, off1)), off2)
   -> (load (add base, src), off1+off2)
(store val, (add base, (addi src, off1)), off2)
   -> (store val, (add base, src), off1+off2)

Differential Revision: https://reviews.llvm.org/D124231
2022-04-29 04:33:05 +00:00
ShihPo Hung 6b55f133fb [RISCV][RVV] Select unmasked TU RVV pseudos in a DAG post-process
Following D118810 that reduced the size of ISel table,
this patch optimizes allone-masked RVV pseudos with TU policy and
swap them out to their unmasked TU pseudos.

Since the UNDEF merge operand is not preserved, we turn it into TA
pseudo regardless of the policy operand.

Reviewed By: craig.topper, frasercrmck
Differential Revision: https://reviews.llvm.org/D121881
2022-04-26 20:14:54 -07:00
Lian Wang 3100893f63 [RISCV] Remove sext_inreg+riscv_grev/riscv_gorc isel patterns
Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D123565
2022-04-14 08:16:32 +00:00
Craig Topper 1903b99154 [RISCV] Always select (and (srl X, C), Mask) as (srli (slli X, C2), C3).
SLLI is always compressible to C.SLLI as long as the source and dest
register is the same.

ANDI and SRLI are only compressible if the register is x8-x15. By
using SLLI we have a better chance of generating shorter code.

I had to exclude one exclusion for the BEXTI case so that it's
pattern match could still fire.

Reviewed By: luismarques

Differential Revision: https://reviews.llvm.org/D123336
2022-04-08 09:04:04 -07:00
Craig Topper 4477500533 [RISCV] ISel (and (shift X, C1), C2)) to shift pair in more cases
Previously, these isel optimizations were disabled if the AND could
be selected as a ANDI instruction. This patch disables the optimizations
only if the immediate is valid for C.ANDI. If we can't use C.ANDI,
we might be able to compress the shift instructions instead.

I'm not checking the C extension since we have relatively poor test
coverage of the C extension. Without C extension the code size
should be equal. My only concern would be if the shift+andi had
better latency/throughput on a particular CPU.

I did have to add a peephole to match SRLIW if the input is zexti32
to prevent a regression in rv64zbp.ll.

Reviewed By: luismarques

Differential Revision: https://reviews.llvm.org/D122701
2022-03-30 11:46:42 -07:00
Zakk Chen b578330754 [RISCV] Use maskedoff to decide mask policy for masked compare and vmsbf/vmsif/vmsof.
masked compare and vmsbf/vmsif/vmsof are always tail agnostic, we could
check maskedoff value to decide mask policy rather than have a addtional
policy operand.

Reviewed By: craig.topper, arcbbb

Differential Revision: https://reviews.llvm.org/D122456
2022-03-29 18:05:33 -07:00
Zakk Chen 10b2760da0 Revert "[RISCV] Add policy operand for masked compare and vmsbf/vmsif/vmsof IR"
This reverts commit 10fd2822b7.

I have a better implementation for those operations without the
additional policy operand.
masked compare and vmsbf/vmsif/vmsof are always tail agnostic so we could
assume undef maskedoff is mask agnostic.

Differential Revision: https://reviews.llvm.org/D122455
2022-03-29 18:05:33 -07:00
Zakk Chen 10fd2822b7 [RISCV] Add policy operand for masked compare and vmsbf/vmsif/vmsof IR
intrinsics.

Those operations are updated under a tail agnostic policy, but they
could have mask agnostic or undisturbed.

Reviewed By: rogfer01

Differential Revision: https://reviews.llvm.org/D120228
2022-03-22 07:47:21 -07:00
Craig Topper 2e10671ec7 [RISCV] Improve detection of when to skip (and (srl x, c2) c1) -> (srli (slli x, c3-c2), c3) isel.
We have a special case to skip this transform if c1 is 0xffffffff
and x is sext_inreg in order to use sraiw+zext.w. But we were only
checking that we have a sext_inreg opcode, not how many bits are
being sign extended.

This commit adds a check that it is a sext_inreg from i32 so we know for
sure that an sraiw can be created.
2022-03-16 14:54:34 -07:00
Zakk Chen 3be907621f [RISCV] Fix incorrect optimization for masked vmsgeu.vi with 0 immediate.
vmsgeu.vi with 0 is always true, but in the masked with mask undisturbed
policy, we still need to keep inactive elelemt which come from maskedoff.

We could return mask directly if it's mask agnostic policy in the future.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D121080
2022-03-06 19:22:35 -08:00
Zakk Chen 33b61c5678 [RISCV] Fix incorrect codegen introduced by D119688.
We should not emit a tail agnostic vlse for a tail undisturbed vmv.s.x

In D119688:
-    if (IsScalarMove && !Node->getOperand(0).isUndef())
+    bool HasPassthruOperand = Node->getOpcode() != ISD::SPLAT_VECTOR;
+    if (HasPassthruOperand && !IsScalarMove &&
!Node->getOperand(0).isUndef())
       break;

The IsScalarMove check in the if statement had been changed.

Differential Revision: https://reviews.llvm.org/D120963
2022-03-05 06:10:26 -08:00
Lian Wang db85cd729a [RISCV] Add FMV_W_X and FMV_H_X instrutions to hasAllNBitUsers
Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D120699
2022-03-01 08:13:59 +00:00
Chenbing Zheng 7f811ce127 [RISCV] Optimize (sext.w, srli) to sraiw with Zba.
In this patch, we add a more narrower exclusion for
zeroext (srl x) -> srli (slli x), so that it provides an opportunity
for the selection of sraiw.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D120467
2022-02-28 10:34:35 +08:00
Haocong.Lu 865fe131f8 [RISCV] Fix a mistake in PostprocessISelDAG
With the condition N->use_empty(), the root node of DAG always
misses peephole optimization. So a dummy node is needed.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D119934
2022-02-25 12:38:31 +00:00
Craig Topper 954fe404ab [RISCV] Fix incorrect MemOperand copy converting splat+load to vlse.
Due to an incorrect copy/paste from load intrinsic handling we
checked if the splat node was a MemSDNode which of course it isn't.

Instead get the MemOperand from the LoadSDNode for the source of
the splat.

This enables LICM to see the load is loop invariant and hoist it
out of the loop.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D120014
2022-02-17 08:15:50 -08:00
Zakk Chen eeb7754f68 [RISCV] Add the passthru operand for vmv.vv/vmv.vx/vfmv.vf IR intrinsics.
Add the passthru operand for
VMV_V_X_VL, VFMV_V_F_VL and SPLAT_VECTOR_SPLIT_I64_VL also.

The goal is support tail and mask policy in RVV builtins.
We focus on IR part first.
If the passthru operand is undef, we use tail agnostic, otherwise
use tail undisturbed.

Reviewed By: rogfer01

Differential Revision: https://reviews.llvm.org/D119688
2022-02-17 06:38:14 -08:00
Fangrui Song 8eb750189c [RISCV] Fix -Wunused-variable in -DLLVM_ENABLE_ASSERTIONS=off builds 2022-02-10 20:10:12 -08:00
Craig Topper b861ddf365 [RISCV] Move the creation of VLMaxSentinel to isel. Use X0 during lowering.
The VLMaxSentinel is represented as TargetConstant, but that's included
in isa<ConstantSDNode>. To keep constant VLs and VLMax separate as long
as possible, use the X0 register during lowering and only convert to
VLMaxSentinel during isel.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D118845
2022-02-10 09:28:44 -08:00
Fraser Cormack fd43d99c93 [RISCV] Pre-process FP SPLAT_VECTOR to RISCVISD::VFMV_V_F_VL
This patch builds on top of D119197 to canonicalize floating-point
SPLAT_VECTOR as RISCVISD::VFMV_V_F_VL as a pre-process ISel step.

This primarily benefits scalable-vector VP code, where our VP patterns
only match VFMV_V_F_VL to reduce the burden on our ISel patterns, but
where at the same time, scalable-vector code doesn't custom-legalize
SPLAT_VECTOR.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D117670
2022-02-10 09:56:00 +00:00
Craig Topper c45c1b130b [RISCV] Teach RISCVDAGToDAGISel::selectShiftMask to replace sub from constant with neg.
If the shift amount is (sub C, X) where C is 0 modulo the size of
the shift, we can replace it with neg or negw.

Similar is is done for AArch64 and X86.

Reviewed By: khchen

Differential Revision: https://reviews.llvm.org/D119089
2022-02-09 12:33:01 -08:00
Craig Topper e305b1de7e [RISCV] Pre-process integer ISD::SPLAT_VECTOR to RISCISD::VMV_V_X_VL before isel.
This allows us to remove some isel patterns that exist for both
operations. Saving nearly 3000 bytes from the isel table.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D119197
2022-02-09 08:10:21 -08:00
Fraser Cormack 6449bea508 [RISCV] Select unmasked RVV pseudos in a DAG post-process
This patch drops TableGen patterns matching all-ones masked RVV pseudos
in the case where there are fallback patterns matching the generic
masked forms to "_MASK" pseudos. This optimization is now performed with
a SelectionDAG post-processing step which peephole-optimizes these same
pseudos with all-ones masks and swaps them out to their unmasked
pseudos.

This cuts our generated ISel table down by around ~5% (~110kB) in lieu
of a far smaller auto-generated table to help with the peephole.

This only targets our custom RISCVISD::*_VL binary operator nodes, which
use the one form for both masked and unmasked variants. A similar
approach could be used for our intrinsics but we'd need to do some work,
e.g., to represent unmasked intrinsics as true-masked intrinsics at the
IR or ISel level. At a rough estimate, this could save us a further 9%
on the size of our ISel table for the binary intrinsic patterns alone.

There is no observable impact on our tests.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D118810
2022-02-09 07:50:15 +00:00
Craig Topper 5f35009996 [RISCV] Remove a ComputeNumSignBits call from an isel special case.
Only isel (and (srl (sexti32 Y), c2), c1) -> (srliw (sraiw Y, 31), c3 - 32)
when there is a sext_inreg present. Don't both checking for Y
having 32 sign bits.
2022-02-04 23:26:53 -08:00
Craig Topper d752ea9a72 [RISCV] Remove exclusions for zext.h/zext.w from our (and (srl X, C1), C2) selection code.
This code tries to replace the pattern with a pair of shifts, but
we were excluding if the And could be a zext.h or zext.w. The SLLI/SRL
pair is more compressible and doesn't come with much down side.

We do regress one test case in rv64i-exhaustive-w-insts.ll but we
can probably add a narrower exclusion for that case.
2022-02-04 17:10:48 -08:00
Craig Topper 2349fb0312 [RISCV] Remove RISCVISD::SPLAT_VECTOR_I64 in favor of RISCVISD::VMV_V_X_VL.
SPLAT_VECTOR_I64 has the same semantics as RISCVISD::VMV_V_X_VL, it
just assumed VLMax instead of carrying a VL operand.

Include order of RISCVInstrInfoVSDPatterns.td and RISCVInstrInfoVVLPatterns.td
has been swapped to avoid moving riscv_vmv_v_x_vl into
RISCVInstrInfoVSDPatterns.td and to allow moving other "_vl" SDNodes back to
RISCVInstrInfoVVLPatterns.td

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D118841
2022-02-03 08:30:25 -08:00
Craig Topper f1720abb54 [RISCV] Cleanup some places that assumed VLMaxSentinel and -1 constant mean the same thing. NFCI
VLMaxSentintel happens to be represented as -1 TargetConstant. A user
provided -1 would be an ISD::Constant. We shouldn't assume that they
are the same thing. I'm still not entirely convinced that we should be
treating -1 from the user as VLMAX.

Also fix one place that failed to use XLenVT for the VLMaxSentinel,
using MVT::i64 in code that only executes on RV32.
2022-02-02 12:23:12 -08:00
Alex Bradbury 588f121ada [RISCV][NFC] Make Zb* instruction naming match the convention used elsewhere in the RISC-V backend
Where the instruction mnemonic contains a dot, we name the corresponding
instruction in the .td file using a _ in the place of the dot. e.g. LR_W
rather than LRW. This commit updates RISCVInstrInfoZb.td to follow that
convention.
2022-01-28 15:20:37 +00:00
Zakk Chen 9273378b85 [RISCV] Add the passthru operand for RVV nomask load intrinsics.
The goal is support tail and mask policy in RVV builtins.
We focus on IR part first.
If the passthru operand is undef, we use tail agnostic, otherwise
use tail undisturbed.

Co-Authored-by: Hsiangkai Wang <Hsiangkai@gmail.com>

Reviewers: craig.topper, frasercrmck

Differential Revision: https://reviews.llvm.org/D117647
2022-01-25 17:31:36 -08:00
Fraser Cormack d42678b453 [RISCV] Add side-effect-free vsetvli intrinsics
This patch introduces new intrinsics that enable the use of vsetvli in
contexts where only the returned vector length is of interest. The
pre-existing intrinsics are marked with side-effects, which prevents
even trivial optimizations on/across them.

These intrinsics are intended to be used in situations where the vector
length is fed in turn to RVV intrinsics or to vector-predication
intrinsics during loop vectorization, for example. Those codegen paths
ensure that instructions are generated with their own implicit vsetvli,
so the vector length and vtype can be relied upon to be correct.

No corresponding C builtins are planned at this stage, though that is a
possibility for the future if the need arises.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D117910
2022-01-24 13:52:08 +00:00
Chenbing.Zheng 9ea772ff81 [RISCV] Block vmsgeu.vi with 0 immediate in Isel
For vmsgeu.vi with 0, we know this is always true. So we can replace
it with vmset.m (unmasked) or vmset.m+vmand.mm (masked).

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D116584
2022-01-11 03:04:44 +00:00
jacquesguan d0554ae4cf [RISCV] Select vl op to X0 when it is equal to ~0.
Now the backend will select ~0 vl to a register and load instruction, we could use X0 to replace it.

Differential Revision: https://reviews.llvm.org/D116798
2022-01-11 10:56:25 +08:00
jacquesguan b607cd3928 [RISCV] Use vmv.s.x to build one element splat vector.
When we want to create an splat vector that only the first element is initialized, we could use vmv.s.x or vfmv.s.f to build it.

Differential Revision: https://reviews.llvm.org/D116277
2022-01-11 10:21:18 +08:00
Craig Topper b645bcd98a [RISCV] Generalize (srl (and X, 0xffff), C) -> (srli (slli X, (XLen-16), (XLen-16) + C) optimization.
This can be generalized to (srl (and X, C2), C) ->
(srli (slli X, (XLen-C3), (XLen-C3) + C). Where C2 is a mask with
C3 trailing ones.

This can avoid constant materialization for C2. This is beneficial
even when C2 can be selected to ANDI because the SLLI can become
C.SLLI, but C.ANDI cannot cover all the immediates of ANDI.

This also enables CSE in some cases of i8 sdiv by constant codegen.
2022-01-09 23:37:10 -08:00
Craig Topper 296e8cae5c [RISCV] Isel (sra (sext_inreg X, i16), C) -> (srai (slli X, (XLen-16), (XLen-16) + C).
Similar for (sra (sext_inreg X, i8), C).

With Zbb, sext_inreg of i8 and i16 are legal for sext.b and sext.h.
This transform makes the Zbb codegen the same as without Zbb. The
shifts are more compressible. This also exposes an opportunity for
CSE with another slli in the i16 sdiv by constant codegen.
2022-01-09 21:23:43 -08:00
jacquesguan 6b8362eb8d [RISCV] Disable EEW=64 for index values when XLEN=32.
Disable EEW=64 for vector index load/store when XLEN=32.

Differential Revision: https://reviews.llvm.org/D106518
2022-01-10 10:51:27 +08:00
Craig Topper 2dd52f840b [RISCV] Fold (srl (and X, 0xffff), C)->(srli (slli X, (XLen-16), (XLen-16) + C) even with Zbb/Zbp.
We can use zext.h with Zbb, but srli/slli may offer more opportunities
for compression.
2022-01-09 18:42:03 -08:00
Craig Topper fd992aac19 [RISCV] Use macros to reduce repetive switch cases. NFC
These 3 switches map LMUL enum to instruction names. These follow
a regular pattern. Use a macro to reduce the number of source code
lines.

Reviewed By: arcbbb

Differential Revision: https://reviews.llvm.org/D116631
2022-01-05 09:00:48 -08:00
wangpc 41454ab256 [RISCV] Use constant pool for large integers
For large integers (for example, magic numbers generated by
TargetLowering::BuildSDIV when dividing by constant), we may
need about 4~8 instructions to build them.
In the same time, it just takes two instructions to load
constants (with extra cycles to access memory), so it may be
profitable to put these integers into constant pool.

Reviewed By: asb, craig.topper

Differential Revision: https://reviews.llvm.org/D114950
2021-12-31 14:48:48 +08:00
Craig Topper 015ff729cb [RISCV] Add a few more instructions to hasAllNBitUsers. 2021-12-29 09:17:47 -08:00
Craig Topper 7598ac5ec5 [RISCV] Convert (splat_vector (load)) to vlse with 0 stride.
We already do this for splat nodes that carry a VL, but not for
splats that use VLMAX.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D115483
2021-12-14 09:14:03 -08:00
Craig Topper 6f7de819b9 [RISCV] Use MULHU for more division by constant cases.
D113805 improved handling of i32 divu/remu on RV64. The basic idea
from that can be extended to (mul (and X, C2), C1) where C2 is any
mask constant.

We can replace the and with an SLLI by shifting by the number of
leading zeros in C2 if we also shift C1 left by XLen - lzcnt(C1)
bits. This will give the full product XLen additional trailing zeros,
putting the result in the output of MULHU. If we can't use ANDI,
ZEXT.H, or ZEXT.W, this will avoid materializing C2 in a register.

The downside is it make take 1 additional instruction to create C1.
But since that's not on the critical path, it can hopefully be
interleaved with other operations.

The previous tablegen pattern is replaced by custom isel code.

Reviewed By: asb

Differential Revision: https://reviews.llvm.org/D115310
2021-12-09 09:10:14 -08:00
Zakk Chen 0649dfebba [RISCV] Rename some assembler mnemonic and intrinsic functions for RVV 1.0.
Rename vpopc/vmandnot/vmornot to vcpop/vmandn/vmorn assembler mnemonic.

Reviewed By: frasercrmck, jrtc27, craig.topper

Differential Revision: https://reviews.llvm.org/D111062
2021-11-04 10:08:01 -07:00
Craig Topper 1387483e72 [RISCV] Replace most uses of RISCVSubtarget::hasStdExtV. NFCI
Add new hasVInstructions() which is currently equivalent.

Replace vector uses of hasStdExtZfh/F/D with new vector specific
versions. The vector spec no longer requires that the vectors implement the
same types as scalar. It only requires that the scalar type is
the maximum size the vectors can support. This is currently
implemented using the scalar rule we were using before.

Add new hasVInstructionsI64() begin using to qualify code that
requires i64 vector elements.

This is all NFC for now, but we can start using this to better
implement D112408 which introduces the Zve extensions.

Reviewed By: frasercrmck, eopXD

Differential Revision: https://reviews.llvm.org/D112496
2021-10-27 19:33:48 -07:00
Ben Shi 4fe5ab4b00 [RISCV] Optimize immediate materialisation with SH*ADD
Use SH1ADD/SH2ADD/SH3ADD along with LUI+ADDI to compose int32*3,
int32*5 and int32*9.

Reviewed By: craig.topper, luismarques

Differential Revision: https://reviews.llvm.org/D111484
2021-10-15 06:46:41 +00:00
Hsiangkai Wang 80a6456306 [RISCV] Update to vlm.v and vsm.v according to v1.0-rc1.
vle1.v  -> vlm.v
vse1.v  -> vsm.v

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D106044
2021-10-05 21:49:54 +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 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
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 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
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
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
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
Craig Topper 3f9b37ccb1 [RISCV] Remove sext_inreg+add/sub/mul/shl isel patterns.
Let the sext_inreg be selected to sext.w. Remove unneeded sext.w
during PostProcessISelDAG.

This gives opportunities for some other isel patterns to match
like the ADDIPair or matching mul with immediate to shXadd.

This becomes possible after D107658 started selecting W instructions
based on users. The sext.w will be considered a W user so isel
will often select a W instruction for the sext.w input and we can
just remove the sext.w. Otherwise we can combine the sext.w with
a ADD/SUB/MUL/SLLI to create a new W instruction in parallel
to the the original instruction.

Reviewed By: luismarques

Differential Revision: https://reviews.llvm.org/D107708
2021-08-18 11:07:11 -07:00
Craig Topper 20e6265873 [RISCV] Improve constant materialization for stores of i16 or i32 negative constants.
DAGCombiner::visitStore can clear the upper bits of constants
used by stores. This leads prevents them from being recognized as
sign extended negative values making them more expensive to
materialize.

This patch uses the hasAllNBitUsers method from D107658 to make
a negative constant if none of the users care about the upper bits.

Reviewed By: luismarques

Differential Revision: https://reviews.llvm.org/D108052
2021-08-18 10:25:12 -07:00
Craig Topper d9ba1a9c5c [RISCV] Teach isel to select ADDW/SUBW/MULW/SLLIW when only the lower 32-bits are used.
We normally select these when the root node is a sext_inreg, but
SimplifyDemandedBits can sometimes bypass the sext_inreg for some
users. This can create situation where sext_inreg+add/sub/mul/shl
is selected to a W instruction, and then the add/sub/mul/shl is
separately selected to a non-W instruction with the same inputs.

This patch tries to detect when it would still be ok to use a W
instruction without the sext_inreg by checking the direct users.
This can allow the W instruction to CSE with one created for a
sext_inreg+add/sub/mul/shl. To minimize complexity and cost of
checking, we make no attempt to determine if the CSE will happen
and just always use a W instruction when we can.

Differential Revision: https://reviews.llvm.org/D107658
2021-08-18 10:22:00 -07:00
Craig Topper 98d4adc2d1 [RISCV] Add custom isel to select (and (srl X, C1), C2) and (and (shl X, C1), C2)
Replace some existing isel patterns that are covered by the new
code. SLLIUWPat has been removed in favor of folding its root case
into the new code. The other uses in isel patterns for shXadd.uw
have been switched to using hardcoded AND masks.

This is based on the original version of D49585 from ARM. The final
version of that was made a DAG combine, but I've chosen to keep it
as custom isel. I'm not convinced DAG combine is as good with
shift pairs as it is with and+shift. I saw some issues optimizing
the shifts created by vscale lowering if an and isn't created for
from a shift pair.

Reviewed By: luismarques

Differential Revision: https://reviews.llvm.org/D106230
2021-07-20 08:53:55 -07:00
Craig Topper 4dbb788068 [RISCV] Teach constant materialization that it can use zext.w at the end with Zba to reduce number of instructions.
If the upper 32 bits are zero and bit 31 is set, we might be able to
use zext.w to fill in the zeros after using an lui and/or addi.

Most of this patch is plumbing the subtarget features into the constant
materialization.

Reviewed By: luismarques

Differential Revision: https://reviews.llvm.org/D105509
2021-07-16 09:35:56 -07:00
Craig Topper a37cf17834 [RISCV] Add explicit copy to V0 in the masked vmsge(u).vx intrinsic handling.
This is consistent with our other masked vector instructions.
Previously we found cases where not doing this broke fast reg
alloc.
2021-06-23 08:04:42 -07:00
Craig Topper 420bd5ee8e [RISCV] Use ComputeNumSignBits/MaskedValueIsZero in RISCVDAGToDAGISel::selectSExti32/selectZExti32.
This helps us select W instructions in more cases. Most of the
affected tests have had the sign_extend_inreg or AND folded into
sextload/zextload.

Differential Revision: https://reviews.llvm.org/D104079
2021-06-10 19:06:45 -07:00
Craig Topper 7c4e9a6826 [RISCV] Use 0 for Log2SEW for vle1/vse1 intrinsics to enable vsetvli optimization.
Missed in D103299.
2021-06-07 22:41:14 -07:00
Craig Topper 9b92ae01ee [RISCV] Store Log2 of EEW in the vector load/store intrinsic to pseudo lookup tables. NFCI
This uses 3 bits of data instead of 7. I'm wondering if we can use
bitfields for the lookup table key where this would matter.

I also name the shift_amount template to log2 since it is used
with more than just an srl now.
2021-06-07 15:47:45 -07:00
Craig Topper c653711fd3 [RISCV] Teach vsetvli insertion pass that operations on masks don't care about SEW/LMUL.
All that really matters is that the VLMAX of the preceding
instructions is the same as the VLMAX required by the mask
operation.

Also update the vmsge(u) handling to use the SEW/LMUL we use for
other mask register operations. We were matching it to the compare
before. Some cases will be improve if we fix masked compares to
use tail agnostic policy. I think they ignore the tail policy
anyway.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D103299
2021-06-04 09:17:46 -07:00
Craig Topper 9065118b64 [RISCV] Optimize SEW=64 shifts by splat on RV32.
SEW=64 shifts only uses the log2(64) bits of shift amount. If we're
splatting a 64 bit value in 2 parts, we can avoid splatting the
upper bits and just let the low bits be sign extended. They won't
be read anyway.

For the purposes of SelectionDAG semantics of the generic ISD opcodes,
if hi was non-zero or bit 31 of the low is 1, the shift was already
undefined so it should be ok to replace high with sign extend of low.

In order do be able to find the split i64 value before it becomes
a stack operation, I added a new ISD opcode that will be expanded
to the stack spill in PreprocessISelDAG. This new node is conceptually
similar to BuildPairF64, but I expanded earlier so that we could
go through regular isel to get the right VLSE opcode for the LMUL.
BuildPairF64 is expanded in a CustomInserter.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D102521
2021-05-26 10:23:32 -07:00
Craig Topper 0a34ff8bcb [RISCV] Replace AddiPair ComplexPattern with a PatLeaf. NFC
The ComplexPattern is looking for an immediate in a certain range
that has a single use. This can be handled with a PatLeaf since
we aren't matching multiple patterns or checking any complicated
relationships between nodes.

This shrinks the isel table a little bit since tablegen no longer
has to generate patterns with commuted operands. With the PatLeaf,
tablegen can see we're matching an immediate which should always
be on the right hand side of add.

Reviewed By: benshi001

Differential Revision: https://reviews.llvm.org/D102510
2021-05-16 12:17:52 -07:00
Craig Topper 9c345407b4 [RISCV] Remove RISCVII:VSEW enum. Make encodeVYPE operate directly on SEW.
The VSEW encoding isn't a useful value to pass around. It's better
to use SEW or log2(SEW) directly. The only real ugliness is that
the vsetvli IR intrinsics use the VSEW encoding, but it's easy
enough to decode that when the intrinsic is processed.
2021-05-12 13:19:08 -07:00
Evandro Menezes 3a64b7080d [RISCV] Move instruction information into the RISCVII namespace (NFC)
Move instruction attributes into the `RISCVII` namespace and add associated helper functions.

Differential Revision: https://reviews.llvm.org/D102268
2021-05-11 16:32:42 -05:00
Craig Topper 191ffda3f7 [RISCV] Remove unused ComplexPatterns. NFC 2021-05-06 12:17:41 -07:00
Craig Topper ba63cdb8f2 [RISCV] Store SEW in RISCV vector pseudo instructions in log2 form.
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.
2021-05-02 12:09:20 -07:00
Craig Topper ce09dd54e6 [RISCV] Select 5 bit immediate for VSETIVLI during isel rather than peepholing in the custom inserter.
This adds a special operand type that is allowed to be either
an immediate or register. By giving it a unique operand type the
machine verifier will ignore it.

This perturbs a lot of tests but mostly it is just slightly different
instruction orders. Something bad did happen to some min/max reduction
tests. We're spilling vector registers when we weren't before.

Reviewed By: khchen

Differential Revision: https://reviews.llvm.org/D101246
2021-04-27 14:38:16 -07:00
Craig Topper e2cd92cb9b [RISCV] Match splatted load to scalar load + splat. Form strided load during isel.
This modifies my previous patch to push the strided load formation
to isel. This gives us opportunity to fold the splat into a .vx
operation first. Using a scalar register and a .vx operation reduces
vector register pressure which can be important for larger LMULs.

If we can't fold the splat into a .vx operation, then it can make
sense to use a strided load to free up the vector arithmetic
ALU to do actual arithmetic rather than tying it up with vmv.v.x.

Reviewed By: khchen

Differential Revision: https://reviews.llvm.org/D101138
2021-04-26 13:32:03 -07:00
Craig Topper baa107f018 [RISCV] Only expose one interface for getContainerForFixedLengthVector in the RISCVTargetLowering class
We can have RISCVISelDAGToDAG.cpp call the VT only version by
finding the RISCVTargetLowering object via the Subtarget.

Make the static versions just global static functions in
RISCVISelLowering that can be called by static functions in that
file.
2021-04-23 15:06:10 -07:00
Craig Topper e01c419ecd [RISCV] Add IR intrinsics for vmsge(u).vv/vx/vi.
These instructions don't really exist, but we have ways we can
emulate them.

.vv will swap operands and use vmsle().vv. .vi will adjust the
immediate and use .vmsgt(u).vi when possible. For .vx we need to
use some of the multiple instruction sequences from the V extension
spec.

For unmasked vmsge(u).vx we use:
  vmslt{u}.vx vd, va, x; vmnand.mm vd, vd, vd

For cases where mask and maskedoff are the same value then we have
vmsge{u}.vx v0, va, x, v0.t which is the vd==v0 case that
requires a temporary so we use:
  vmslt{u}.vx vt, va, x; vmandnot.mm vd, vd, vt

For other masked cases we use this sequence:
  vmslt{u}.vx vd, va, x, v0.t; vmxor.mm vd, vd, v0
We trust that register allocation will prevent vd in vmslt{u}.vx
from being v0 since v0 is still needed by the vmxor.

Differential Revision: https://reviews.llvm.org/D100925
2021-04-22 10:44:38 -07:00
Ben Shi 30e2c7be99 [RISCV] Refactor an optimization of addition with immediate
Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D100769
2021-04-20 18:04:25 +08:00
Fraser Cormack d737c47137 [RISCV] Support vector SET[U]LT and SET[U]GE with splatted immediates
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
2021-04-12 18:36:45 +01:00
Craig Topper ff902080a9 [RISCV] Use SLLI/SRLI instead of SLLIW/SRLIW for (srl (and X, 0xffff), C) custom isel on RV64.
We don't need the sign extending behavior here and SLLI/SRLI
are able to compress to C.SLLI/C.SRLI.
2021-04-11 13:59:51 -07:00
Craig Topper bc0e052730 [RISCV] Teach targetShrinkDemandedConstant to preserve (and X, 0xffff) when zext.h is supported.
Similar to what we do for zext.w.

Disable the (srl (and X, 0xffff), C) custom isel when zext.h is
available.
2021-04-11 10:03:35 -07:00
Craig Topper 9895285191 [RISCV] Replace 'return ReplaceNode' with 'ReplaceNode; return;' NFC
ReplaceNode is a void function as is the function that we were
doing this in. While this is valid code, it was a bit confusing.
2021-04-07 12:18:41 -07:00
Craig Topper 3ae03f67fe [RISCV] Add helper function to share some of the code for isel of vector load/store intrinsics.
Many of the operands are handled the same or in the same order
for all these intrinsics. Factor out the code for selecting and
pushing them into the Operands vector.

Differential Revision: https://reviews.llvm.org/D99923
2021-04-06 09:54:24 -07:00
Craig Topper cb1028a0b9 [RISCV] When custom iseling masked stores, copy the mask into V0 instead of virtual register.
I missed a few intrinsics in 3dd4aa7d09
when I did this for masked loads and masked segment loads/stores.

Found while trying to share more code between these custom isel
functions.
2021-04-05 21:28:32 -07:00
Craig Topper d61b40ed27 [RISCV] Improve 64-bit integer materialization for some cases.
This adds a new integer materialization strategy mainly targeted
at 64-bit constants like 0xffffffff where there are 32 or more trailing
ones with leading zeros. We can materialize these by using an addi -1
and srli to restore the leading zeros. This matches what gcc does.

I haven't limited to just these cases though. The implementation
here takes the constant, shifts out all the leading zeros and
shifts ones into the LSBs, creates the new sequence, adds an srli,
and checks if this is shorter than our original strategy.

I've separated the recursive portion into a standalone function
so I could append the new strategy outside of the recursion. Since
external users are no longer using the recursive function, I've
cleaned up the external interface to return the sequence instead of
taking a vector by reference.

Reviewed By: asb

Differential Revision: https://reviews.llvm.org/D98821
2021-04-01 09:12:52 -07:00
Craig Topper 3dd4aa7d09 [RISCV] When custom iseling masked loads/stores, copy the mask into V0 instead of virtual register.
This matches what we do in our isel patterns. In our internal
testing we've found this is needed to make the fast register
allocator happy at -O0. Otherwise it may assign V0 to an earlier
operand and find itself with no registers left when it reaches
the mask operand. By using V0 explicitly, the fast register allocator
will see it when it checks for phys register usages before it
starts allocating vregs. I'll try to update this with a test case.

Unfortunately, this does appear to prevent some instruction reordering
by the pre-RA scheduler which leads to the increased spills seen in
some tests. I suspect that problem could already occur for other
instructions that already used V0 directly.

There's a lot of repeated code here that could do with some
wrapper functions. Not sure if that should be at the level of the
new code that deals with V0. That would require multiple output
parameters to pass the glue, chain and register back. Maybe it
should be at a higher level over the entire set of push_backs.

Reviewed By: frasercrmck, HsiangKai

Differential Revision: https://reviews.llvm.org/D99367
2021-03-29 10:20:43 -07:00
Craig Topper 5a18c576c4 [RISCV] Don't call CheckAndMask from selectZExti32.
Now that targetShrinkDemandedConstant preserves 0xffffffff masks we
shouldn't need to call computeKnownBits here.
2021-03-25 22:07:41 -07:00
Craig Topper c40cea6f08 [RISCV] Teach targetShrinkDemandedConstant to preserve (and X, 0xffffffff).
We look for this pattern frequently in isel patterns so its a
good idea to try to preserve it.

This also let's us remove our special isel handling for srliw
and use a direct pattern match of (srl (and X, 0xffffffff), C)
since no bits will be removed from the and mask.

Differential Revision: https://reviews.llvm.org/D99042
2021-03-25 09:03:25 -07:00
Craig Topper 839a46d88f [RISCV] Use selectImm for RV32. NFC
Previously we used selectImm for RV64 and isel patterns for
RV32. This should be NFC, but will allow RV32 and RV64 to share
improvements in the future. For example, it might be useful to
use BSETI from Zbs to make single bit constants.

Reviewed By: luismarques

Differential Revision: https://reviews.llvm.org/D98877
2021-03-23 08:57:15 -07:00
Craig Topper 92b39c6907 [RISCV] Use getTargetExtractSubreg and getTargetInsertSubreg to simplify some code. NFCI 2021-03-17 12:10:19 -07:00
Fraser Cormack 8e7ceffd0b [RISCV] Fix crash when inserting large fixed-length subvectors
This patch addresses a compiler crash resulting from passing a
fixed-length type to one that expects scalable vector types. An
assertion was added to prevent this regressing in the future.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D97868
2021-03-04 09:27:16 +00:00
Fraser Cormack 4ea734e6ec [RISCV] Unify scalable- and fixed-vector INSERT_SUBVECTOR lowering
This patch unifies the two disparate paths for lowering INSERT_SUBVECTOR
operations under one roof. Consequently, with this patch it is possible to
support any fixed-length subvector insertion, not just "cast-like" ones.

As before, support for the insertion of mask vectors will come in a
separate patch.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D97543
2021-03-01 11:38:47 +00:00
Craig Topper b183cbfacd [RISCV] Call SelectBaseAddr on the base pointer in the custom isel for vector loads and stores.
This will allow FrameIndex as the base address instead of
emitting a separate ADDI from isel. eliminateFrameIndex will likely turn
it back into an ADDI, but this makes things consistent with the
SDPatterns and VLPatterns.

I only tested one case for simplicity. I can test more if reviewers
want.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D97221
2021-02-26 11:38:23 -08:00
Fraser Cormack 821f8bb29a [RISCV] Unify scalable- and fixed-vector EXTRACT_SUBVECTOR lowering
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
2021-02-25 11:46:57 +00:00
Craig Topper 159f78fc2f [RISCV] Reuse existing SDLoc and XLenVT in the switch in RISCVISelDAGToDAG::Select. NFC
A SDLoc and XLenVT were already created above the switch.
2021-02-24 21:39:00 -08:00
Craig Topper 9bde29629d [RISCV] Use a ComplexPattern for zexti32 to match sexti32.
We just started using a ComplexPattern for sexti32. This updates
zexti32 to match.

Reviewed By: luismarques

Differential Revision: https://reviews.llvm.org/D97231
2021-02-24 16:06:29 -08:00
Fraser Cormack dd68f3cf28 [RISCV] Support insertion of misaligned subvectors
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
2021-02-23 10:31:06 +00:00
Craig Topper 3231607ce9 [RISCV] Have sexti32 also recognize AssertZExt from types smaller than i32.
An i64 AssertZExt from a type smaller than i32 has at least 33
leading zeros which mean it has at least 33 sign bits.

Since we have a couple patterns that use two sexti32, I've
switched to a ComplexPattern so tablegen didn't have to generate
9 different permutations.

As noted in the FIXME, maybe we should just call computeNumSignBits,
but we don't have tests that benefit from that yet.

Reviewed By: luismarques

Differential Revision: https://reviews.llvm.org/D97130
2021-02-22 14:56:22 -08:00
Craig Topper 1cd2a5a7da [RISCV] Add isel support for bitcasts between fixed vector types.
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
2021-02-22 12:05:46 -08:00