2084 Commits

Author SHA1 Message Date
Fraser Cormack
fde2466171 [SelectionDAG] Support scalable-vector splats in more cases
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
2021-01-25 10:58:15 +00:00
Jay Foad
868da2ea93 [SelectionDAG] Remove an early-out from computeKnownBits for smin/smax
Even if we know nothing about LHS, it can still be useful to know that
smax(LHS, RHS) >= RHS and smin(LHS, RHS) <= RHS.

Differential Revision: https://reviews.llvm.org/D87145
2021-01-14 18:15:17 +00:00
Jay Foad
517196e569 [Analysis,CodeGen] Make use of KnownBits::makeConstant. NFC.
Differential Revision: https://reviews.llvm.org/D94588
2021-01-14 14:02:43 +00:00
Kerry McLaughlin
2170e0ee60 [SVE][CodeGen] CTLZ, CTTZ & CTPOP operations (predicates)
Canonicalise the following operations in getNode() for predicate types:
 - CTLZ(Pred)  -> bitwise_NOT(Pred)
 - CTTZ(Pred)  -> bitwise_NOT(Pred)
 - CTPOP(Pred) -> Pred

Reviewed By: david-arm

Differential Revision: https://reviews.llvm.org/D94428
2021-01-13 12:24:54 +00:00
Craig Topper
df74c001fa [DAGCombiner] Replace static helper function isConstantFPBuildVectorOrConstantFP with the identical version in SelectionDAG. NFC 2021-01-11 23:41:40 -08:00
Craig Topper
f9ef3a6003 [SelectionDAG] Make isConstantIntBuildVectorOrConstantInt and isConstantFPBuildVectorOrConstantFP methods const. 2021-01-11 23:26:53 -08:00
Fraser Cormack
41d06095b0 [SelectionDAG] Teach isConstOrConstSplat about ISD::SPLAT_VECTOR
This improves llvm::isConstOrConstSplat by allowing it to analyze
ISD::SPLAT_VECTOR nodes, in order to allow more constant-folding of
operations using scalable vector types.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D94168
2021-01-09 20:54:34 +00:00
Fraser Cormack
de373ef779 [SelectionDAG] Extend immAll(Ones|Zeros)V to handle ISD::SPLAT_VECTOR
The TableGen immAllOnesV and immAllZerosV helpers implicitly wrapped the
ISD::isBuildVectorAll(Ones|Zeros) helper functions. This was inhibiting
their use for targets such as RISC-V which use ISD::SPLAT_VECTOR. In
particular, RISC-V had to define its own 'vnot' fragment.

In order to extend the scope of these nodes to include support for
ISD::SPLAT_VECTOR, two new ISD predicate functions have been introduced:
ISD::isConstantSplatVectorAll(Ones|Zeros). These effectively supersede
the older "isBuildVector" predicates, which are now simple wrappers for
the new functions. They pass a defaulted boolean toggle which preserves
the old behaviour. It is hoped that in time all call-sites can be ported
to the "isConstantSplatVector" functions.

While the use of ISD::isBuildVectorAll(Ones|Zeros) has not changed, the
behaviour of the TableGen immAll(Ones|Zeros)V **has**. To test the new
functionality, the custom RISC-V TableGen fragment has been removed and
replaced with the built-in 'vnot'. To test their use as pattern-roots, two
splat patterns have been updated accordingly.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D94223
2021-01-09 17:05:31 +00:00
Simon Moll
611d3c63f3 [VP] ISD helper functions [VE] isel for vp_add, vp_and
This implements vp_add, vp_and for the VE target by lowering them to the
VVP_* layer. We also add helper functions for VP SDNodes (isVPSDNode,
getVPMaskIdx, getVPExplicitVectorLengthIdx).

Reviewed By: kaz7

Differential Revision: https://reviews.llvm.org/D93766
2021-01-08 14:29:45 +01:00
Fraser Cormack
9a1ac97d3a [CodeGen] Format SelectionDAG::getConstant methods (NFC) 2021-01-05 12:59:46 +00:00
Kazu Hirata
1e3ed09165 [CodeGen] Use llvm::append_range (NFC) 2020-12-28 19:55:16 -08:00
Simon Pilgrim
cdb692ee0c [X86] Add X86ISD::SUBV_BROADCAST_LOAD and begin removing X86ISD::SUBV_BROADCAST (PR38969)
Subvector broadcasts are only load instructions, yet X86ISD::SUBV_BROADCAST treats them more generally, requiring a lot of fallback tablegen patterns.

This initial patch replaces constant vector lowering inside lowerBuildVectorAsBroadcast with direct X86ISD::SUBV_BROADCAST_LOAD loads which helps us merge a number of equivalent loads/broadcasts.

As well as general plumbing/analysis additions for SUBV_BROADCAST_LOAD, I needed to wrap SelectionDAG::makeEquivalentMemoryOrdering so it can handle result chains from non generic LoadSDNode nodes.

Later patches will continue to replace X86ISD::SUBV_BROADCAST usage.

Differential Revision: https://reviews.llvm.org/D92645
2020-12-17 10:25:25 +00:00
Justin Bogner
e6a1187dd8 Limit the recursion depth of SelectionDAG::isSplatValue()
This method previously always recursively checked both the left-hand
side and right-hand side of binary operations for splatted (broadcast)
vector values to determine if the parent DAG node is a splat.

Like several other SelectionDAG methods, limit the recursion depth to
MaxRecursionDepth (6). This prevents stack overflow.
See also https://issuetracker.google.com/173785481

Patch by Nicolas Capens. Thanks!

Differential Revision: https://reviews.llvm.org/D92421
2020-12-09 10:35:07 -08:00
Kerry McLaughlin
4519ff4b6f [SVE][CodeGen] Add the ExtensionType flag to MGATHER
Adds the ExtensionType flag, which reflects the LoadExtType of a MaskedGatherSDNode.
Also updated SelectionDAGDumper::print_details so that details of the gather
load (is signed, is scaled & extension type) are printed.

Reviewed By: sdesmalen

Differential Revision: https://reviews.llvm.org/D91084
2020-12-09 11:19:08 +00:00
Kerry McLaughlin
f6dd32fd35 [SVE][CodeGen] Lower scalable masked gathers
Lowers the llvm.masked.gather intrinsics (scalar plus vector addressing mode only)

Changes in this patch:
- Add custom lowering for MGATHER, using getGatherVecOpcode() to choose the appropriate
  gather load opcode to use.
- Improve codegen with refineIndexType/refineUniformBase, added in D90942
- Tests added for gather loads with 32 & 64-bit scaled & unscaled offsets.

Reviewed By: sdesmalen

Differential Revision: https://reviews.llvm.org/D91092
2020-12-07 12:20:41 +00:00
Simon Pilgrim
9cf4f493a7 [DAG] Move SelectionDAG implementation to KnownBits::setInReg(). NFCI. 2020-12-04 18:09:08 +00:00
Kazu Hirata
7a4af2a8e7 [SelectionDAG] Use is_contained (NFC) 2020-12-02 19:09:45 -08:00
Kerry McLaughlin
4bee3197f6 [SVE][CodeGen] Extend isConstantSplatValue to support ISD::SPLAT_VECTOR
Updated the affected scalable_of_scalable tests in sve-gep.ll, as isConstantSplatValue now returns true in DAGCombiner::visitMUL and folds `(mul x, 1) -> x`

Reviewed By: sdesmalen

Differential Revision: https://reviews.llvm.org/D91363
2020-11-26 11:19:40 +00:00
Kai Luo
8e6d92026c [DAG][PowerPC] Fix dropped nsw flag in SimplifySetCC by adding doesNodeExist helper
`SimplifySetCC` invokes `getNodeIfExists` without passing `Flags` argument and `getNodeIfExists` uses a default `SDNodeFlags` to intersect the original flags, as a consequence, flags like `nsw` is dropped. Added a new helper function `doesNodeExist` to check if a node exists without modifying its flags.

Reviewed By: #powerpc, nemanjai

Differential Revision: https://reviews.llvm.org/D89938
2020-11-25 04:39:03 +00:00
Hongtao Yu
d0e42037bf [CSSPGO] MIR target-independent pseudo instruction for pseudo-probe intrinsic
This change introduces a MIR target-independent pseudo instruction corresponding to the IR intrinsic llvm.pseudoprobe for pseudo-probe block instrumentation. Please refer to https://reviews.llvm.org/D86193 for the whole story.

An `llvm.pseudoprobe` intrinsic call will be lowered into a target-independent operation named `PSEUDO_PROBE`. Given the following instrumented IR,

```
define internal void @foo2(i32 %x, void (i32)* %f) !dbg !4 {
bb0:
   %cmp = icmp eq i32 %x, 0
   call void @llvm.pseudoprobe(i64 837061429793323041, i64 1)
   br i1 %cmp, label %bb1, label %bb2
bb1:
   call void @llvm.pseudoprobe(i64 837061429793323041, i64 2)
   br label %bb3
bb2:
   call void @llvm.pseudoprobe(i64 837061429793323041, i64 3)
   br label %bb3
bb3:
   call void @llvm.pseudoprobe(i64 837061429793323041, i64 4)
   ret void
}
```
the corresponding MIR is shown below. Note that block `bb3` is duplicated into `bb1` and `bb2` where its probe is duplicated too. This allows for an accurate execution count to be collected for `bb3`, which is basically the sum of the counts of `bb1` and `bb2`.

```
bb.0.bb0:
   frame-setup PUSH64r undef $rax, implicit-def $rsp, implicit $rsp
   TEST32rr killed renamable $edi, renamable $edi, implicit-def $eflags
   PSEUDO_PROBE 837061429793323041, 1, 0
   $edi = MOV32ri 1, debug-location !13; test.c:0
   JCC_1 %bb.1, 4, implicit $eflags

bb.2.bb2:
   PSEUDO_PROBE 837061429793323041, 3, 0
   PSEUDO_PROBE 837061429793323041, 4, 0
   $rax = frame-destroy POP64r implicit-def $rsp, implicit $rsp
   RETQ

bb.1.bb1:
   PSEUDO_PROBE 837061429793323041, 2, 0
   PSEUDO_PROBE 837061429793323041, 4, 0
   $rax = frame-destroy POP64r implicit-def $rsp, implicit $rsp
   RETQ
```

The target op PSEUDO_PROBE will be converted into a piece of binary data by the object emitter with no machine instructions generated. This is done in a different patch.

Reviewed By: wmi

Differential Revision: https://reviews.llvm.org/D86495
2020-11-20 10:52:43 -08:00
Kazu Hirata
2583d8eb08 [CodeGen] Use llvm::is_contained (NFC) 2020-11-19 22:07:56 -08:00
Simon Pilgrim
8996742741 [KnownBits] Add KnownBits::makeConstant helper. NFCI.
Helper for cases where we need to create a KnownBits from a (fully known) constant value.
2020-11-12 16:16:04 +00:00
Simon Pilgrim
1a62ca65c1 [KnownBits] Add KnownBits::commonBits helper. NFCI.
We have a frequent pattern where we're merging two KnownBits to get the common/shared bits, and I just fell for the gotcha where I tried to use the & operator to merge them........
2020-11-11 12:15:54 +00:00
Kerry McLaughlin
170947a5de [SVE][CodeGen] Lower scalable masked scatters
Lowers the llvm.masked.scatter intrinsics (scalar plus vector addressing mode only)

Changes included in this patch:
 - Custom lowering for MSCATTER, which chooses the appropriate scatter store opcode to use.
    Floating-point scatters are cast to integer, with patterns added to match FP reinterpret_casts.
 - Added the getCanonicalIndexType function to convert redundant addressing
   modes (e.g. scaling is redundant when accessing bytes)
 - Tests with 32 & 64-bit scaled & unscaled offsets

Reviewed By: sdesmalen

Differential Revision: https://reviews.llvm.org/D90941
2020-11-11 11:50:22 +00:00
Kerry McLaughlin
ffbbfc76ca [SVE][CodeGen] Add the isTruncatingStore flag to MSCATTER
This patch adds the IsTruncatingStore flag to MaskedScatterSDNode, set by getMaskedScatter().
Updated SelectionDAGDumper::print_details for MaskedScatterSDNode to print
the details of masked scatters (is truncating, signed or scaled).

This is the first in a series of patches which adds support for scalable masked scatters

Reviewed By: sdesmalen

Differential Revision: https://reviews.llvm.org/D90939
2020-11-11 10:58:24 +00:00
Simon Pilgrim
bf04e34383 [DAG] computeKnownBits - Replace ISD::SREM handling with KnownBits::srem to reduce code duplication 2020-11-05 17:12:58 +00:00
Simon Pilgrim
e237d56b43 [KnownBits] Move ValueTracking/SelectionDAG UREM KnownBits handling to KnownBits::urem. NFCI.
Both these have the same implementation - so move them to a single KnownBits copy.

GlobalISel will be able to use this as well with minimal effort.
2020-11-05 14:30:59 +00:00
Simon Pilgrim
32bee18b84 [KnownBits] Move ValueTracking/SelectionDAG UDIV KnownBits handling to KnownBits::udiv. NFCI.
Both these have the same implementation - so move them to a single KnownBits copy.

GlobalISel will be able to use this as well with minimal effort.
2020-11-05 13:42:42 +00:00
Cameron McInally
c126eb7529 [SelectionDAG] Add legalizations for VECREDUCE_SEQ_FMUL
Hook up legalizations for VECREDUCE_SEQ_FMUL. This is following up on the VECREDUCE_SEQ_FADD work from D90247.

Differential Revision: https://reviews.llvm.org/D90644
2020-11-04 14:20:31 -06:00
Kerry McLaughlin
f2412d372d [SVE][CodeGen] Lower scalable integer vector reductions
This patch uses the existing LowerFixedLengthReductionToSVE function to also lower
scalable vector reductions. A separate function has been added to lower VECREDUCE_AND
& VECREDUCE_OR operations with predicate types using ptest.

Lowering scalable floating-point reductions will be addressed in a follow up patch,
for now these will hit the assertion added to expandVecReduce() in TargetLowering.

Reviewed By: paulwalker-arm

Differential Revision: https://reviews.llvm.org/D89382
2020-11-04 11:38:49 +00:00
Simon Pilgrim
825e517e34 [DAG] computeKnownBits - Replace ISD::MUL handling with the common KnownBits::computeForMul implementation 2020-11-04 11:32:08 +00:00
Simon Pilgrim
e9b88c754a [DAG] computeKnownBits - Move ISD::SRA handling into KnownBits::ashr
As discussed on D90527, we should be trying to move shift handling functionality into KnownBits to avoid code duplication in SelectionDAG/GlobalISel/ValueTracking.
2020-11-03 18:09:33 +00:00
Simon Pilgrim
cb798f040a [DAG] computeKnownBits - Move (most) ISD::SRL handling into KnownBits::lshr
As discussed on D90527, we should be be trying to move shift handling functionality into KnownBits to avoid code duplication in SelectionDAG/GlobalISel/ValueTracking.

The refactor to use the KnownBits fixed/min/max constant helpers allows us to hit a couple of cases that we were missing before.

We still need the getValidMinimumShiftAmountConstant case as KnownBits doesn't handle per-element vector cases.
2020-11-03 17:30:36 +00:00
Simon Pilgrim
cab21d4fa8 [DAG] computeKnownBits - Move (most) ISD::SHL handling into KnownBits::shl
As discussed on D90527, we should be be trying to move shift handling functionality into KnownBits to avoid code duplication in SelectionDAG/GlobalISel/ValueTracking.

The refactor to use the KnownBits fixed/min/max constant helpers allows us to hit a couple of cases that we were missing before.

We still need the getValidMinimumShiftAmountConstant case as KnownBits doesn't handle per-element vector cases.
2020-11-03 14:22:28 +00:00
Cameron McInally
dda1e74b58 [Legalize] Add legalizations for VECREDUCE_SEQ_FADD
Add Legalization support for VECREDUCE_SEQ_FADD, so that we don't need to depend on ExpandReductionsPass.

Differential Revision: https://reviews.llvm.org/D90247
2020-10-30 16:02:55 -05:00
Nikita Popov
6c2ad4cf87 [SDAG] Extract helper to determine neutral element (NFC)
Make the existing VECREDUCE based code more generic, but expressing
it in terms of the neutral value of the base opcode instead.
2020-10-29 22:05:06 +01:00
Nikita Popov
91bf172088 [SDAG] Extract helper to get vecreduce base opcode (NFC) 2020-10-29 20:22:22 +01:00
Simon Pilgrim
ce356e1546 [DAG] Add BuildVectorSDNode::getRepeatedSequence helper to recognise multi-element splat patterns
Replace the X86 specific isSplatZeroExtended helper with a generic BuildVectorSDNode method.

I've just used this to simplify the X86ISD::BROADCASTM lowering so far (and remove isSplatZeroExtended), but we should be able to use this in more places to lower to complex broadcast patterns.

Differential Revision: https://reviews.llvm.org/D87930
2020-10-24 12:23:09 +01:00
Simon Pilgrim
88523f6f4b [DAG] getNode(ISD::EXTRACT_SUBVECTOR) Drop unnecessary N2C null check - we assert that this isn't null and have already used the pointer. NFCI.
Fixes cppcheck + null dereference warning.
2020-10-21 11:53:44 +01:00
David Sherwood
5b17b323a6 [SVE][CodeGen] Replace use of TypeSize comparison operator in CreateStackTemporary
We were previously relying upon the TypeSize comparison operators to
obtain the maximum size of two types, however use of such operators is
being deprecated in favour of making the caller aware that it could
be dealing with scalable vector types. I have changed the code to assert
that the two types have the same scalable property and thus we can
simply take the maximum of the known minimum sizes instead.

Differential Revision: https://reviews.llvm.org/D88563
2020-10-21 08:31:36 +01:00
Krzysztof Parzyszek
61eaa2e14a [SDAG] Remember to set UndefElts in isSplatValue for SPLAT_VECTOR 2020-10-10 19:42:24 -05:00
David Sherwood
fa0293081d [SVE][CodeGen] Fix TypeSize/ElementCount related warnings in sve-split-store.ll
I have fixed up a number of warnings resulting from TypeSize -> uint64_t
casts and calling getVectorNumElements() on scalable vector types. I
think most of the changes are fairly trivial except for those in
DAGTypeLegalizer::SplitVecRes_MSTORE I've tried to ensure we create
the MachineMemoryOperands in a sensible way for scalable vectors.

I have added a CHECK line to the following test:

 CodeGen/AArch64/sve-split-store.ll

that ensures no new warnings are added.

Differential Revision: https://reviews.llvm.org/D86928
2020-10-05 19:27:00 +01:00
Sanjay Patel
2ccbf3dbd5 [SDAG] fold x * 0.0 at node creation time
In the motivating case from https://llvm.org/PR47517
we create a node that does not get constant folded
before getNegatedExpression is attempted from some
other node, and we crash.

By moving the fold into SelectionDAG::simplifyFPBinop(),
we get the constant fold sooner and avoid the problem.
2020-10-04 11:31:57 -04:00
Kerry McLaughlin
fcf70e1e3b [SVE][CodeGen] Lower scalable fp_extend & fp_round operations
This patch adds FP_EXTEND_MERGE_PASSTHRU & FP_ROUND_MERGE_PASSTHRU
ISD nodes, used to lower scalable vector fp_extend/fp_round operations.
fp_round has an additional argument, the 'trunc' flag, which is an integer of zero or one.

This also fixes a warning introduced by the new tests added to sve-split-fcvt.ll,
resulting from an implicit TypeSize -> uint64_t cast in SplitVecOp_FP_ROUND.

Reviewed By: sdesmalen, paulwalker-arm

Differential Revision: https://reviews.llvm.org/D88321
2020-10-01 12:17:37 +01:00
Krzysztof Parzyszek
db04bec5f1 [SDAG] Do not convert undef to 0 when folding CONCAT/BUILD_VECTOR
Differential Revision: https://reviews.llvm.org/D88273
2020-09-29 09:12:26 -05:00
Jay Foad
d6b04f3937 [SDag] Refactor and simplify divergence calculation and checking. NFC. 2020-09-29 14:05:07 +01:00
Qiu Chaofan
c0f8e4c06c [SelectionDAG] Add guard to automatically insert flags
This is like FastMathFlagGuard in IR. Since we use SDAG instance to get
values, it's with SelectionDAG. By creating a FlagInserter in current
scope, all values created by getNode will get the flags if no Flags
argument provided.

In this patch, I applied it to floating point operations folding part in
DAG combiner, and removed Flags passing to getNode to show its effect.
Other places in DAG combiner and other helper methods similar to getNode
also need this. They can be done in follow-up patches.

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D87361
2020-09-26 13:57:52 +08:00
David Sherwood
e077367a28 [SVE] Make EVT::getScalarSizeInBits and others consistent with Type::getScalarSizeInBits
An existing function Type::getScalarSizeInBits returns a uint64_t
instead of a TypeSize class because the caller is requesting a
scalar size, which cannot be scalable. This patch makes other
similar functions requesting a scalar size consistent with that,
thereby eliminating more than 1000 implicit TypeSize -> uint64_t
casts.

Differential revision: https://reviews.llvm.org/D87889
2020-09-23 09:20:08 +01:00
Simon Pilgrim
d967aaa8fa [DAG] BuildVectorSDNode::getSplatValue - pull out repeated getNumOperands() calls. NFCI. 2020-09-18 16:10:23 +01:00
Craig Topper
c193a689b4 [SelectionDAG] Use Align/MaybeAlign in calls to getLoad/getStore/getExtLoad/getTruncStore.
The versions that take 'unsigned' will be removed in the future.

I tried to use getOriginalAlign instead of getAlign in some
places. getAlign factors in the minimum alignment implied by
the offset in the pointer info. Since we're also passing the
pointer info we can use the original alignment.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D87592
2020-09-14 13:54:50 -07:00