Commit Graph

8877 Commits

Author SHA1 Message Date
Daniel Neilson 5182113f07 [SelectionDAGBuilder] Replace deprecated calls to MemoryIntrinsic::getAlignment() (NFCI)
Summary:
This change is part of step five in the series of changes to remove alignment argument from
memcpy/memmove/memset in favour of alignment attributes. In particular, this changes the
SelectionDAGBuilder to cease using the old getAlignment() API of MemoryIntrinsic in favour of getting
source & dest specific alignments through the new API.

Steps:
Step 1) Remove alignment parameter and create alignment parameter attributes for
memcpy/memmove/memset. ( rL322965, rC322964, rL322963 )
Step 2) Expand the IRBuilder API to allow creation of memcpy/memmove with differing
source and dest alignments. ( rL323597 )
Step 3) Update Clang to use the new IRBuilder API. ( rC323617 )
Step 4) Update Polly to use the new IRBuilder API. ( rL323618 )
Step 5) Update LLVM passes that create memcpy/memmove calls to use the new IRBuilder API,
and those that use use MemIntrinsicInst::[get|set]Alignment() to use [get|set]DestAlignment()
and [get|set]SourceAlignment() instead. ( rL323886, rL323891, rL324148, rL324273, rL324278,
rL324384, rL324395, rL324402, rL324626, rL324642, rL324653, rL324654, rL324773, rL324774,
rL324781, rL324784, rL324955, rL324960, rL325816, rL327398 )
Step 6) Remove the single-alignment IRBuilder API for memcpy/memmove, and the
MemIntrinsicInst::[get|set]Alignment() methods.

Reference
   http://lists.llvm.org/pipermail/llvm-dev/2015-August/089384.html
   http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151109/312083.html

llvm-svn: 327421
2018-03-13 16:31:19 +00:00
Craig Topper 80058e30cc [LegalizeTypes] In SplitVecOp_TruncateHelper, use GetSplitVector on the input instead of creating new extract_subvectors.
llvm-svn: 327355
2018-03-13 01:17:40 +00:00
Bjorn Pettersson a223f815dd [SelectionDAG] Improve handling of dangling debug info
Summary:
1) Make sure to discard dangling debug info if the variable (or
variable fragment) is mapped to something new before we had a
chance to resolve the dangling debug info.

2) When resolving debug info, make sure to bump the associated
SDNodeOrder to ensure that the DBG_VALUE is emitted after the
instruction that defines the value used in the DBG_VALUE.
This will avoid a debug-use before def scenario as seen in
https://bugs.llvm.org/show_bug.cgi?id=36417.

The new test case, test/DebugInfo/X86/sdag-dangling-dbgvalue.ll,
show some other limitations in how dangling debug info is
handled in the SelectionDAG. Since we currently only support
having one dangling dbg.value per Value, we will end up dropping
debug info when there are more than one variable that is described
by the same "dangling value".

Reviewers: aprantl

Reviewed By: aprantl

Subscribers: aprantl, eraman, llvm-commits, JDevlieghere

Tags: #debug-info

Differential Revision: https://reviews.llvm.org/D44369

llvm-svn: 327303
2018-03-12 18:02:39 +00:00
Nirav Dave 042678bd55 Revert: r327172 "Correct load-op-store cycle detection analysis"
r327171 "Improve Dependency analysis when doing multi-node Instruction Selection"
        r328170 "[DAG] Enforce stricter NodeId invariant during Instruction selection"

Reverting patch as NodeId invariant change is causing pathological
increases in compile time on PPC

llvm-svn: 327197
2018-03-10 02:16:15 +00:00
Craig Topper 508a5b2466 [TargetLowering] Remove redundant term in two ifs in SimplifySetCC. NFC
If we get into the right hand side of the OR, we know that isOpaque is true since the left hand size is just a check that it's false.

llvm-svn: 327179
2018-03-09 22:24:12 +00:00
Nirav Dave d668f69ee7 Improve Dependency analysis when doing multi-node Instruction Selection
Relanding after fixing NodeId Invariant.

Cleanup cycle/validity checks in ISel (IsLegalToFold,
HandleMergeInputChains) and X86 (isFusableLoadOpStore). Now do a full
search for cycles / dependencies pruning the search when topological
property of NodeId allows.

As part of this propogate the NodeId-based cutoffs to narrow
hasPreprocessorHelper searches.

Reviewers: craig.topper, bogner

Subscribers: llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D41293

llvm-svn: 327171
2018-03-09 20:57:42 +00:00
Nirav Dave 071699bf82 [DAG] Enforce stricter NodeId invariant during Instruction selection
Instruction Selection makes use of the topological ordering of nodes
by node id (a node's operands have smaller node id than it) when doing
cycle detection.  During selection we may violate this property as a
selection of multiple nodes may induce a use dependence (and thus a
node id restriction) between two unrelated nodes. If a selected node
has an unselected successor this may allow us to miss a cycle in
detection an invalid selection.

This patch fixes this by marking all unselected successors of a
selected node have negated node id.  We avoid pruning on such negative
ids but still can reconstruct the original id for pruning.

In-tree targets have been updated to replace DAG-level replacements
with ISel-level ones which enforce this property.

This preemptively fixes PR36312 before triggering commit r324359 relands

Reviewers: craig.topper, bogner, jyknight

Subscribers: arsenm, nhaehnle, javed.absar, llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D43198

llvm-svn: 327170
2018-03-09 20:57:15 +00:00
Nirav Dave 775f07d121 Make early exit hasPredecessorHelper return true. NFCI.
All uses conservatively assume in early exit case that it will be a
predecessor. Changing default removes checking code in all uses.

llvm-svn: 327169
2018-03-09 20:56:51 +00:00
Peter Collingbourne 2974856ad4 Use branch funnels for virtual calls when retpoline mitigation is enabled.
The retpoline mitigation for variant 2 of CVE-2017-5715 inhibits the
branch predictor, and as a result it can lead to a measurable loss of
performance. We can reduce the performance impact of retpolined virtual
calls by replacing them with a special construct known as a branch
funnel, which is an instruction sequence that implements virtual calls
to a set of known targets using a binary tree of direct branches. This
allows the processor to speculately execute valid implementations of the
virtual function without allowing for speculative execution of of calls
to arbitrary addresses.

This patch extends the whole-program devirtualization pass to replace
certain virtual calls with calls to branch funnels, which are
represented using a new llvm.icall.jumptable intrinsic. It also extends
the LowerTypeTests pass to recognize the new intrinsic, generate code
for the branch funnels (x86_64 only for now) and lay out virtual tables
as required for each branch funnel.

The implementation supports full LTO as well as ThinLTO, and extends the
ThinLTO summary format used for whole-program devirtualization to
support branch funnels.

For more details see RFC:
http://lists.llvm.org/pipermail/llvm-dev/2018-January/120672.html

Differential Revision: https://reviews.llvm.org/D42453

llvm-svn: 327163
2018-03-09 19:11:44 +00:00
Sebastian Pop b4bd0a404f [x86][aarch64] ask the backend whether it has a vector blend instruction
The code to match and produce more x86 vector blends was enabled for all
architectures even though the transform may pessimize the code for other
architectures that do not provide a vector blend instruction.

Added an aarch64 testcase to check that a VZIP instruction is generated instead
of byte movs.

Differential Revision: https://reviews.llvm.org/D44118

llvm-svn: 327132
2018-03-09 14:29:21 +00:00
Sameer AbuAsal 986865c090 Propagate flags to SDValue in SplitVecOp_VECREDUCE
This patch is a fix for PR36642.

 While legalizing long vector types, make sure the smaller types get the
 flags of the wider type.

 bugzilla link: https://bugs.llvm.org/show_bug.cgi?id=36642

Change-Id: I0c2829639f094c862c10a6b51b342d4c2563e1fa
llvm-svn: 327079
2018-03-08 23:41:40 +00:00
Craig Topper 3d2af5038a [TargetLowering] Remove redundant if condition in SimplifySetcc. NFC
We were checking the condition code a second time when we were already in a block with this same condition code check.

llvm-svn: 327069
2018-03-08 21:53:36 +00:00
Simon Pilgrim ca38c762e4 [TargetLowering] Add vector BITCAST support to SimplifyDemandedVectorElts
Notably helps cleanup after legalization of vector types

Differential Revision: https://reviews.llvm.org/D43674

llvm-svn: 326838
2018-03-06 22:32:01 +00:00
Eric Liu 47f42c2167 Fix an unused variable warning introduced by rr326703. NFC
llvm-svn: 326732
2018-03-05 18:36:39 +00:00
Alexander Timofeev 2e5eeceeb7 Pass Divergence Analysis data to Selection DAG to drive divergence
dependent instruction selection.

Differential revision: https://reviews.llvm.org/D35267

llvm-svn: 326703
2018-03-05 15:12:21 +00:00
Craig Topper 4196dd12a2 [DAGCombiner] Add a peekThroughBitcast to MergeStoresOfConstantsOrVecElts to fix a crash if we are storing a bitcast of a constant.
Loading a constant into a k-register in AVX512 requires a bitcast from a scalar constant. In the test case here we have a k-register store that gets split into multiple parts of KNL. MergeConsecutiveStores sees each of these pieces as a consecutive store and looks through the bitcast to find the underly scalar constant. But when we went to create the combined store we didn't look through the same bitcast.

llvm-svn: 326677
2018-03-04 18:51:46 +00:00
Craig Topper dbf75c9c79 [LegalizeVectorTypes] When scalarizing the operand of a unary op like TRUNC, use a SCALAR_TO_VECTOR rather than a single element BUILD_VECTOR to convert back to a vector type.
X86 considers v1i1 a legal type under AVX512 and as such a truncate from a v1iX type to v1i1 can be turned into a scalar truncate plus a conversion to v1i1. We would much prefer a v1i1 SCALAR_TO_VECTOR over a one element BUILD_VECTOR.

During lowering we were detecting the v1i1 BUILD_VECTOR as a splat BUILD_VECTOR like we try to do for v2i1/v4i1/etc. In this case we create (select i1 splat_elt, v1i1 all-ones, v1i1 all-zeroes). That goes through some more legalization and we end up with a CMOV choosing between 0 and 1 in scalar and a scalar_to_vector.

Arguably we could detect the v1i1 BUILD_VECTOR and do this better in X86 target code. But just using a SCALAR_TO_VECTOR in legalization is much easier.

llvm-svn: 326637
2018-03-02 23:27:50 +00:00
Adrian Prantl dfe15f36d5 Add DBG_VALUE support to the linear DAG scheduler
The fast/linear DAG scheduler doesn't lower DBG_VALUEs except for
function entry nodes.

Patch by Joshua Cranmer!

Differential Revision: https://reviews.llvm.org/D43028

llvm-svn: 326631
2018-03-02 22:59:51 +00:00
Craig Topper e7ca6f5456 [DAGCombiner] When combining zero_extend of a truncate, only mask before extending for vectors.
Masking first, prevents the extend from being combine with loads. Its also interfering with some vXi1 extraction code.

Differential Revision: https://reviews.llvm.org/D42679

llvm-svn: 326500
2018-03-01 22:32:25 +00:00
Craig Topper eedfbc4ab7 [SelectionDAG] Support some SimplifySetCC cases for comparing against vector splats of constants.
This supports things like

(setcc ugt X, 0) -> (setcc ne X, 0)

I've restricted to only make changes to vectors before legalize ops because I doubt all targets have accurate condition code legality information for vectors given how little we did before.

Differential Revision: https://reviews.llvm.org/D42948

llvm-svn: 326495
2018-03-01 22:15:39 +00:00
Than McIntosh b3d88a7466 [CodeGen] fix argument attribute in lowering statepoint/patchpoint
Summary:
Use the correct loop index varaible, ArgI, to retrieve attributes.

Reviewers: thanm, sanjoy, rnk

Reviewed By: rnk

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D43832

llvm-svn: 326433
2018-03-01 13:31:57 +00:00
Craig Topper 6df870ca58 [SelectionDAG] Remove code from PromoteIntRes_CONCAT_VECTORS that was added in r320674 to help X86.
AVX512 used to promote v32i1 to v32i8 during legalization when BWI was disabled. So this code was added to improve legalization of v32i1 concat_vectors of v16i1 by extending the v16i1 to v16i8 to avoid scalarization.

X86 has since switched to legalizing v32i1 by splitting to v16i1 instead. This has rendered this code unnecessary and its no longer exercised.

llvm-svn: 326153
2018-02-27 00:07:24 +00:00
Simon Pilgrim 295e8b4e12 [TargetLowering] SimplifyDemandedVectorElts - pass demanded elts through ADD/SUB ops
llvm-svn: 326044
2018-02-24 20:59:14 +00:00
Simon Pilgrim c0dbdb86c3 [TargetLowering] SimplifyDemandedVectorElts - pass demanded elts through TRUNCATE ops
llvm-svn: 326043
2018-02-24 19:28:34 +00:00
Amaury Sechet 893a6b89ff [DAGCOmbine] Ensure that (brcond (setcc ...)) is handled in a canonical manner.
Summary:
There are transformation that change setcc into other constructs, and transform that try to reconstruct a setcc from the brcond condition. Depending on what order these transform are done, the end result differs.

Most of the time, it is preferable to get a setcc as a brcond argument (and this is why brcond try to recreate the setcc in the first place) so we ensure this is done every time by also doing it at the setcc level when the only user is a brcond.

Reviewers: spatel, hfinkel, niravd, craig.topper

Subscribers: nhaehnle, llvm-commits

Differential Revision: https://reviews.llvm.org/D41235

llvm-svn: 325892
2018-02-23 11:50:42 +00:00
Craig Topper a2cc3c055c [TargetLowering] Rename isCondCodeLegal to isCondCodeLegalOrCustom. Add real isCondCodeLegal. Update callers to use one or the other.
isCondCodeLegal internally checked Legal or Custom which is misleading. Though no targets set any cond code action to Custom today.

So I've renamed isCondCodeLegal to isCondCodeLegalOrCustom and added a real isCondCodeLegal that only checks Legal.

I've changed legalization code to use isCondCodeLegalOrCustom and left things reachable via DAG combine as isCondCodeLegal. I've also changed some places that called getCondCodeAction and compared to Legal to just use isCondCodeLegal.

I'm looking at trying to keep SETCC all the way to isel for the AVX512 integer comparisons and I suspect I'll need to make some condition codes Custom to stop DAG combine from changing things post LegalizeOps. Prior to this only Expand stopped DAG combine, but that causes LegalizeOps to try to swap operands or invert rather than calling our Custom handler.

Differential Revision: https://reviews.llvm.org/D43607

llvm-svn: 325829
2018-02-22 20:51:26 +00:00
Sander de Smalen a86f3cfb49 Revert "[DebugInfo][FastISel] Fix dropping dbg.value()"
This patch reverts r325440 and r325438 because it triggers an
assertion in SelectionDAGBuilder.cpp. Also having debug enabled
may unintentionally affect code-gen. The patch is reverted until
we find a better solution.

llvm-svn: 325825
2018-02-22 19:53:59 +00:00
Simon Pilgrim be72fe1fda [SelectionDAG] Move matchUnaryPredicate/matchBinaryPredicate into SelectionDAGNodes.h
This allows us to improve vector constant matching in more DAG code (backends, TargetLowering etc.).

Differential Revision: https://reviews.llvm.org/D43466

llvm-svn: 325815
2018-02-22 18:45:13 +00:00
Craig Topper 1d104b996a [DAGCombiner] Add two calls to isVector before making calls to getVectorElementType/getVectorNumElements to avoid an assert.
We looked through a BITCAST, but the bitcast might be a from a scalar type rather than a vector.

I don't have a test case. I stumbled onto it while prototyping another change that isn't ready yet.

llvm-svn: 325750
2018-02-22 07:05:27 +00:00
Craig Topper 7fbea20b90 [SelectionDAG] Support known true/false SimplifySetCC cases for comparing against vector splats of constants.
This is split off from D42948 and includes just the cases that constant fold to true or false. It also includes some refactoring to keep predicate checks together.

This supports things like

(setcc uge X, 0) -> true

Differential Revision: https://reviews.llvm.org/D43489

llvm-svn: 325627
2018-02-20 21:48:14 +00:00
Craig Topper 35801fa5ce [SelectionDAG] Add LegalTypes flag to getShiftAmountTy. Use it to unify and simplify DAGCombiner and simplifySetCC code and fix a bug.
DAGCombiner and SimplifySetCC both use getPointerTy for shift amounts pre-legalization. DAGCombiner uses a single helper function to hide this. SimplifySetCC does it in multiple places.

This patch adds a defaulted parameter to getShiftAmountTy that can make it return getPointerTy for scalar types. Use this parameter to simplify the SimplifySetCC and DAGCombiner.

Additionally, there were two places in SimplifySetCC that were creating shifts using the target's preferred shift amount pre-legalization. If the target uses a narrow type and the type is illegal, this can cause SimplfiySetCC to create a shift with an amount that can't represent all possible shift values for the type. To fix this we should use pointer type there too.

Alternatively we could make getScalarShiftAmountTy for each target return a safe value for large types as proposed in D43445. And maybe we should still do that, but fixing the SimplifySetCC code keeps other targets from tripping over this in the future.

Fixes PR36250.

Differential Revision: https://reviews.llvm.org/D43449

llvm-svn: 325602
2018-02-20 17:41:05 +00:00
Simon Pilgrim 2f29afb439 [VectorLegalizer] Fix uint64_t typo in ExpandUINT_TO_FLOAT (PR36391)
ExpandUINT_TO_FLOAT can accept vXi32 or vXi64 inputs, so we need to use a uint64_t shift to generate the 2^(BW/2) constant.

No test case unfortunately as no upstream target uses this, but its affecting a downstream target.

llvm-svn: 325578
2018-02-20 13:24:24 +00:00
Simon Pilgrim 70eb508605 [SelectionDAG] ComputeKnownBits - add support for SMIN+SMAX clamp patterns
If we have a clamp pattern, SMIN(SMAX(X, LO),HI) or SMAX(SMIN(X, HI),LO) then we can deduce that the number of signbits (zeros/ones) will be at least the minimum of the LO and HI constants.

ComputeKnownBits equivalent of D43338.

Differential Revision: https://reviews.llvm.org/D43463

llvm-svn: 325521
2018-02-19 18:08:16 +00:00
Simon Pilgrim 6740df386c Fix Wparentheses warning. NFCI
llvm-svn: 325451
2018-02-17 22:45:56 +00:00
Simon Pilgrim 7fae42eb27 [SelectionDAG] ComputeNumSignBits - add support for SMIN+SMAX clamp patterns
If we have a clamp pattern, SMIN(SMAX(X, LO),HI) or SMAX(SMIN(X, HI),LO) then we can deduce that the number of signbits will be at least the minimum of the LO and HI constants.

I haven't bothered with the UMIN/UMAX equivalent as (1) we don't have any current use cases and (2) I wonder if we'd be better off immediately falling back for ComputeKnownBits for UMIN/UMAX which already has optimization patterns useful for unsigned cases.

Differential Revision: https://reviews.llvm.org/D43338

llvm-svn: 325450
2018-02-17 22:19:50 +00:00
Simon Pilgrim 8da142bff1 [SelectionDAG] SimplifyDemandedVectorElts - add support for VECTOR_INSERT_ELT
Differential Revision: https://reviews.llvm.org/D43431

llvm-svn: 325449
2018-02-17 21:49:40 +00:00
Sander de Smalen 47952b0c03 [DebugInfo][FastISel] Fix dropping dbg.value()
Summary:
https://llvm.org/PR36263 shows that when compiling at -O0 a dbg.value()
instruction (that remains from an original dbg.declare()) is dropped
by FastISel. Since FastISel selects instructions by iterating a basic
block backwards, it drops the dbg.value if one of its operands is not
yet instantiated by a previously selected instruction.

Instead of calling 'lookUpRegForValue()' we can call 'getRegForValue()'
instead that will insert a placeholder for the operand to be filled in
when continuing the instruction selection.

Reviewers: aprantl, dblaikie, probinson

Reviewed By: aprantl

Subscribers: llvm-commits, dstenb, JDevlieghere

Differential Revision: https://reviews.llvm.org/D43386

llvm-svn: 325438
2018-02-17 16:42:54 +00:00
Simon Pilgrim d6beac3b76 [DAGCombiner] Remove simplifyShuffleMask - now handled more generally by SimplifyDemandedVectorElts.
llvm-svn: 325429
2018-02-17 12:36:56 +00:00
Chandler Carruth a1d6107b14 [DAG, X86] Revert r324797, r324491, and r324359.
Sadly, r324359 caused at least PR36312. There is a patch out for review
but it seems to be taking a bit and we've already had these crashers in
tree for too long. We're hitting this PR in real code now and are
blocked on shipping new compilers as a consequence so I'm reverting us
back to green.

Sorry for the churn due to the stacked changes that I had to revert. =/

llvm-svn: 325420
2018-02-17 02:26:25 +00:00
Simon Pilgrim 1b81064d1e Fix signed/unsigned comparison warning. NFCI.
llvm-svn: 325363
2018-02-16 17:26:59 +00:00
Simon Pilgrim 5d005a359e Fix signed/unsigned comparison warning. NFCI.
llvm-svn: 325359
2018-02-16 16:52:50 +00:00
Simon Pilgrim ff53a4a234 [SelectionDAG] Enable SimplifyDemandedVectorElts support for simplifying shuffle masks
Based off the DemandedElts mask the and UNDEF elements returned from the SimplifyDemandedVectorElts calls to the shuffle operands, we can attempt to simplify the shuffle mask.

I had to be very conservative here as accepting post-legalized shuffle masks could cause problems for targets that legalize UNDEF mask elements back to inrange values (PowerPC), similarly combining to identity shuffle masks could cause too much UNDEF information to disappear for later combines.

llvm-svn: 325354
2018-02-16 16:22:14 +00:00
Simon Pilgrim 0ffde50f9c [SelectionDAG] Add initial SimplifyDemandedVectorElts support for simplifying VSELECT operands
This just adds a basic pass through - we can add constant selection mask handling in a future patch to fully match InstCombine.

llvm-svn: 325338
2018-02-16 12:21:08 +00:00
Mikhail Maltsev 0a7e107e77 [LegalizeDAG] Fix legalization of SETCC
Summary:
Currently when expanding a SETCC node into a SELECT_CC, LLVM uses
an incorrect type for determining BooleanContent of the result. This
patch fixes the issue.

Fixes PR36079.

Reviewers: rogfer01, javed.absar, efriedma

Reviewed By: efriedma

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D43282

llvm-svn: 325325
2018-02-16 09:35:16 +00:00
Craig Topper dac3c1f5c8 [DAGCombiner] Call ExtendUsesToFormExtLoad in (zext (and (load)))->(and (zextload)) even when the and does not have multiple uses
Same for the sign extend case.

Currently we check for multiple uses on the binop. Then we call ExtendUsesToFormExtLoad to capture SetCCs that use the load. So we only end up finding any setccs when the and has additional uses and the load is used by a setcc. I don't think the and having multiple uses is relevant here. I think we should only be checking for the load having multiple uses.

This changes an NVPTX test because we now find that the load has a second use by a truncate, but ExtendUsesToFormExtLoad only looks at setccs it can extend. All other operations just check isTruncateFree. Maybe we should allow widening of an existing truncate even if its not free?

Differential Revision: https://reviews.llvm.org/D43063

llvm-svn: 325289
2018-02-15 20:20:32 +00:00
Simon Pilgrim 1eb5c455c9 [SelectionDAG] Pull out repeated Op.getOpcode(). NFCI.
llvm-svn: 325253
2018-02-15 15:31:00 +00:00
Simon Pilgrim 80663ee986 [SelectionDAG] Add initial implementation of TargetLowering::SimplifyDemandedVectorElts
This is mainly a move of simplifyShuffleOperands from DAGCombiner::visitVECTOR_SHUFFLE to create a more general purpose TargetLowering::SimplifyDemandedVectorElts implementation.

Further features can be moved/added in future patches.

Differential Revision: https://reviews.llvm.org/D42896

llvm-svn: 325232
2018-02-15 12:14:15 +00:00
Alexander Ivchenko 7e5d525bd5 [SelectionDAG][X86] Fix incorrect offset generated for VMASKMOV
When creating high MachineMemOperand for MSTORE/MLOAD we supply
it with the original PointerInfo, while the pointer itself had been incremented.
The patch adds the proper offset to the PointerInfo.

llvm-svn: 325135
2018-02-14 15:55:24 +00:00
Elena Demikhovsky 945b7e5aa6 Adding a width of the GEP index to the Data Layout.
Making a width of GEP Index, which is used for address calculation, to be one of the pointer properties in the Data Layout.
p[address space]:size:memory_size:alignment:pref_alignment:index_size_in_bits.
The index size parameter is optional, if not specified, it is equal to the pointer size.

Till now, the InstCombiner normalized GEPs and extended the Index operand to the pointer width.
It works fine if you can convert pointer to integer for address calculation and all registered targets do this.
But some ISAs have very restricted instruction set for the pointer calculation. During discussions were desided to retrieve information for GEP index from the Data Layout.
http://lists.llvm.org/pipermail/llvm-dev/2018-January/120416.html

I added an interface to the Data Layout and I changed the InstCombiner and some other passes to take the Index width into account.
This change does not affect any in-tree target. I added tests to cover data layouts with explicitly specified index size.

Differential Revision: https://reviews.llvm.org/D42123

llvm-svn: 325102
2018-02-14 06:58:08 +00:00
Craig Topper 5ecea9fff5 [SelectionDAG] Remove duplicate code from TargetLowering::SimplifySetCC.
This exact code already exists a little further up.

llvm-svn: 325101
2018-02-14 06:51:57 +00:00
Craig Topper f73ff612ca [DAGCombiner] Add one use check to fold (not (and x, y)) -> (or (not x), (not y))
Summary:
If the and has an additional use we shouldn't invert it. That creates an additional instruction.

While there add a one use check to the transform above that looked similar.

Reviewers: spatel, RKSimon

Reviewed By: RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D43225

llvm-svn: 325019
2018-02-13 16:25:27 +00:00
Sanjay Patel 907b58530f [DAG] fix type of undef returned by getNode()
The bug has been lying dormant, but apparently was never exposed, until
after rL324941 because we didn't return the correct result 
for shifts with undef operands.

llvm-svn: 325010
2018-02-13 14:55:07 +00:00
Sanjay Patel 014c000f6a [DAG] make binops with undef operands consistent with IR
This started by noticing that scalar and vector types were producing different results with div ops in PR36305:
https://bugs.llvm.org/show_bug.cgi?id=36305

...but the problem is bigger. I couldn't keep it straight without a table, so I'm attaching that as a PDF to 
the review. The x86 tests in undef-ops.ll correspond to that table.

Green means that instsimplify and the DAG agree on the result for all types.
Red means the DAG was returning undef when IR was not.
Yellow means the DAG was returning a non-undef result when IR returned undef.

This patch assumes that we're currently doing the right thing in IR.

Note: I couldn't find any problems with lowering vector constants as the code comments were warning, 
but those comments were written long ago in rL36413 .

Differential Revision: https://reviews.llvm.org/D43141

llvm-svn: 324941
2018-02-12 21:37:27 +00:00
Oliver Stannard 02f08c9d1f [AArch64] Improve v8.1-A code-gen for atomic load-and
Armv8.1-A added an atomic load-clear instruction (which performs bitwise
and with the complement of it's operand), but not a load-and
instruction. Our current code-generation for atomic load-and always
inserts an MVN instruction to invert its argument, even if it could be
folded into a constant or another instruction.

This adds lowering early in selection DAG to convert a load-and
operation into an xor with -1 and a load-clear, allowing the normal DAG
optimisations to work on it.

To do this, I've had to add a new ISD opcode, ATOMIC_LOAD_CLR. I don't
see any easy way to do this with an AArch64-specific ISD node, because
the code-generation for atomic operations assumes the SDNodes are of
type AtomicSDNode.

I've left the old tablegen patterns in because they are still needed for
global isel.

Differential revision: https://reviews.llvm.org/D42478

llvm-svn: 324908
2018-02-12 17:03:11 +00:00
Sanjay Patel eb8c408e50 [TargetLowering] try to create -1 constant operand for math ops via demanded bits
This reverses instcombine's demanded bits' transform which always tries to clear bits in constants.

As noted in PR35792 and shown in the test diffs:
https://bugs.llvm.org/show_bug.cgi?id=35792
...we can do better in codegen by trying to form -1. The x86 sub test shows a missed opportunity. 

I did investigate changing instcombine's behavior, but it would be more work to change 
canonicalization in IR. Clearing bits / shrinking constants can allow killing instructions, 
so we'd have to figure out how to not regress those cases.

Differential Revision: https://reviews.llvm.org/D42986

llvm-svn: 324839
2018-02-11 14:38:23 +00:00
Simon Pilgrim 0be5567a89 [X86][SSE] Enable SMIN/SMAX/UMIN/UMAX custom lowering for all legal types
This allows us to recognise more saturation patterns and also simplify some MINMAX codegen that was failing to combine CMPGE comparisons to a legal CMPGT.

Differential Revision: https://reviews.llvm.org/D43014

llvm-svn: 324837
2018-02-11 10:52:37 +00:00
Craig Topper 36f913ee80 [SelectionDAG] Remove TargetLowering::getConstTrueVal. Use SelectionDAG::getBoolConstant in the one place it was used.
SelectionDAG::getBoolConstant was recently introduced. At the time I didn't know getConstTrueVal existed, but I think getBoolConstant is better as it will use the source VT to make sure it can properly detect floating point if it is configured differently.

llvm-svn: 324832
2018-02-11 04:58:58 +00:00
Nirav Dave c8c9d4fe35 [DAG] Make early exit hasPredecessorHelper return true. NFCI.
All uses conservatively assume in early exit case that it will be a
predecessor. Changing default removes checking code in all uses.

llvm-svn: 324797
2018-02-10 02:41:22 +00:00
Stefan Maksimovic dc66ae78c6 [SelectionDAG] Provide adequate register class for RegisterSDNode
When adding operands to machine instructions in case of
RegisterSDNodes, generate a COPY node in case the register class
does not match the one in the instruction definition.

Differental Revision: https://reviews.llvm.org/D35561

llvm-svn: 324733
2018-02-09 13:55:25 +00:00
Vedant Kumar 7fd9a58d8c Revert "WIP: [DAGCombiner] Assert that debug info is preserved"
This reverts commit r324648. It was committed accidentally.

llvm-svn: 324650
2018-02-08 20:27:35 +00:00
Vedant Kumar 28323ff5a3 WIP: [DAGCombiner] Assert that debug info is preserved
llvm-svn: 324648
2018-02-08 20:27:09 +00:00
Craig Topper 9b611e436f [SelectionDAG] Add a helper function for creating a boolean constant based on the target's boolean content
Many in SimplifySetCC and FoldSetCC try to create true or false constants. Some of them query getBooleanContents to figure out whether to use all ones or just 1 for true. But many places do not check and just use 1 without ensuring the VT has an i1 scalar type. Note sure if those places only trigger before type legalization so they only see an i1
type?

To cleanup the inconsistency and reduce some duplicated code, this patch adds a getBoolConstant method to SelectionDAG that takes are of querying getBooleanContents and doing the right thing.

Differential Revision: https://reviews.llvm.org/D43037

llvm-svn: 324634
2018-02-08 18:55:14 +00:00
Craig Topper c19aed963e [DAGCombiner] Fix a couple mistakes from r324311 by really passing the original load to ExtendSetCCUses.
We're passing the binary op that uses the load instead of the load.

Noticed by inspection. Not sure how to test this because this just prevents the introduction of an extend that will later be truncated and will probably be combined out.

llvm-svn: 324568
2018-02-08 06:27:18 +00:00
Craig Topper 9b9d527427 [DAGCombiner] Don't create truncate nodes in (aext (zextload x)) -> (zextload x) and similar folds. NFCI
The truncate is being used to replace other users of of the load, but we checked that the load only has one use so there are no other uses to replace.

llvm-svn: 324567
2018-02-08 06:04:18 +00:00
Craig Topper cbfe41ac2f [DAGCombiner] Avoid creating truncate nodes in (zext (and (load)))->(and (zextload)) fold until we know for sure we're going to need it. NFCI
The truncate is only needed if the load has additional users. It used to get passed to extendSetCCUses so was created early, but that's no longer the case.

llvm-svn: 324562
2018-02-08 04:38:04 +00:00
Craig Topper bf4ed42606 [DAGCombiner] Rename variable to be slightly better. NFC
We were calling a load LN0 but it came from N0.getOperand(0) so its really more like LN00 if we follow the name used in other places.

llvm-svn: 324561
2018-02-08 04:38:02 +00:00
Nirav Dave efed656873 [SelectionDAG] More Aggressibly prune nodes in AddChains. NFCI.
Travel all chains paths to first non-tokenfactor node can be
exponential work. Add simple redundency check to avoid this.
Fixes PR36264.

llvm-svn: 324491
2018-02-07 17:12:34 +00:00
Eugene Leviant 25347ea895 [LegalizeDAG] Truncate condition operand of ISD::SELECT
Differential revision: https://reviews.llvm.org/D42737

llvm-svn: 324447
2018-02-07 05:38:29 +00:00
Craig Topper 58ecffd857 [DAGCombiner][AMDGPU][X86] Turn cttz/ctlz into cttz_zero_undef/ctlz_zero_undef if we can prove the input is never zero
X86 currently has a late DAG combine after cttz/ctlz are turned into BSR+BSF+CMOV to detect this and remove the CMOV. But we should be able to do this much earlier and avoid creating the cmov all together.

For the changed AMDGPU test case it appears that previously the i8 cttz was type legalized to i16 which introduced an OR with 256 in order to limit the result to 8 on the widened type. At this point the result is known to never be zero, but nothing checked that. Then operation legalization is told to promote all i16 cttz to i32. This introduces an extend and a truncate and another OR with 65536 to limit the result to 16. With the DAG combiner change we are able to prevent the creation of the second OR since the opcode will have been changed to cttz_zero_undef after the first OR. I the lack of the OR caused the instruction to change to v_ffbl_b32_sdwa

Differential Revision: https://reviews.llvm.org/D42985

llvm-svn: 324427
2018-02-06 23:54:37 +00:00
Andrew Kaylor c41499865b Add SelectionDAGDumper support for strict FP nodes
Patch by Kevin P. Neal

llvm-svn: 324416
2018-02-06 22:28:15 +00:00
Sanjay Patel 87ce2fd82d [TargetLowering] use local variable to reduce duplication; NFCI
llvm-svn: 324401
2018-02-06 21:09:42 +00:00
Sanjay Patel e96a9014ab [TargetLowering] use local variables to reduce duplication; NFCI
llvm-svn: 324397
2018-02-06 20:49:28 +00:00
Nirav Dave 27721e8617 [DAG, X86] Improve Dependency analysis when doing multi-node
Instruction Selection

Cleanup cycle/validity checks in ISel (IsLegalToFold,
HandleMergeInputChains) and X86 (isFusableLoadOpStore). Now do a full
search for cycles / dependencies pruning the search when topological
property of NodeId allows.

As part of this propogate the NodeId-based cutoffs to narrow
hasPreprocessorHelper searches.

Reviewers: craig.topper, bogner

Subscribers: llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D41293

llvm-svn: 324359
2018-02-06 16:14:29 +00:00
Craig Topper ee1f34eb9a [DAGCombiner] Pass the original load to ExtendSetCCUses not the turncate.
Summary:
This method is trying to use the truncate node to find which SETCC operand should be replaced directly with the extended load.

This used to work correctly because all uses of the original load were replaced by the truncate before this function was called. So this was used to effectively bypass the truncate and find the load under it.

All but one of the callers now call this before the truncate has replaced the laod so the setcc doesn't yet use the truncate. To account for this we should pass the original load instead.

I changed the order of that one caller to make this work there too.

I don't have a test case because this is probably hidden by later DAG combines causing the extend and truncate to cancel out. I assume this way is a little more efficient and matches what was originally intended.

Reviewers: RKSimon, spatel, niravd

Reviewed By: niravd

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D42878

llvm-svn: 324311
2018-02-06 03:23:27 +00:00
Krzysztof Parzyszek fee3f419ae [SDAG] Legalize all CondCodes by inverting them and/or swapping operands
Differential Revision: https://reviews.llvm.org/D42788

llvm-svn: 324274
2018-02-05 21:27:16 +00:00
Craig Topper fc5bd023dd [DAGCombiner] When folding fold (sext/zext (and/or/xor (sextload/zextload x), cst)) -> (and/or/xor (sextload/zextload x), (sext/zext cst)) make sure we check the legality of the full extended load.
Summary:
If the load is already an extended load we should be using the memory VT for the legality check, not just the VT of the current extension.

I don't have a test case, just noticed it while investigating some load extension improvements.

Reviewers: RKSimon, spatel, niravd

Reviewed By: niravd

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D42783

llvm-svn: 324181
2018-02-03 23:00:31 +00:00
Simon Pilgrim 4df6499f10 [SelectionDAG] Don't use simple VT in generic shuffle code
Better to assume that any value type may be commuted, not just MVTs.

No test case right now, but discovered while investigating possible shuffle combines.

llvm-svn: 324179
2018-02-03 21:34:42 +00:00
Jonas Paulsson 422dfbf7cc [SelectionDAG] Consider endianness in scalarizeVectorStore().
When handling vectors with non byte-sized elements, reverse the order of the
elements in the built integer if the target is Big-Endian.

SystemZ tests updated.

Review: Eli Friedman, Ulrich Weigand.
https://reviews.llvm.org/D42786

llvm-svn: 324063
2018-02-02 08:48:02 +00:00
Jonas Paulsson ad089fe46e [SelectionDAG] Add an assert in getNode() for EXTRACT_VECTOR_ELT.
When getNode() is called to create an EXTRACT_VECTOR_ELT, assert that
the result VT is at least as wide as the vector element type.

Review: Eli Friedman
llvm-svn: 324061
2018-02-02 08:21:53 +00:00
Craig Topper a5944aade1 [DAGCombiner] When folding (insert_subvector undef, (bitcast (extract_subvector N1, Idx)), Idx) -> (bitcast N1) make sure that N1 has the same total size as the original output
We were only checking the element count, but not the total width. This could cause illegal bitcasts to be created if for example the output was 512-bits, but N1 is 256 bits, and the extraction size was 128-bits.

Fixes PR36199

Differential Revision: https://reviews.llvm.org/D42809

llvm-svn: 324002
2018-02-01 20:48:50 +00:00
Sanjay Patel 657e5d8d41 [DAGCombiner] filter out denorm inputs when calculating sqrt estimate (PR34994)
As shown in the example in PR34994:
https://bugs.llvm.org/show_bug.cgi?id=34994
...we can return a very wrong answer (inf instead of 0.0) for square root when 
using a reciprocal square root estimate instruction.

Here, I've conditionalized the filtering out of denorms based on the function 
having "denormal-fp-math"="ieee" in its attributes. The other options for this 
attribute are 'preserve-sign' and 'positive-zero'.

So we don't generate this extra code by default with just '-ffast-math' (because 
then there's no denormal attribute string at all), but it works if you specify 
'-ffast-math -fdenormal-fp-math=ieee' from clang. 

As noted in the review, there may be other problems in clang that affect the 
results depending on platform (Linux x86 at least), but this should allow 
creating the desired codegen.

Differential Revision: https://reviews.llvm.org/D42323

llvm-svn: 323981
2018-02-01 16:57:18 +00:00
Nirav Dave 18f7f60e17 [SelectionDAG] Fix UpdateChains handling of TokenFactors
Summary:
In Instruction Selection UpdateChains replaces all matched Nodes'
chain references including interior token factors and deletes them.
This may allow nodes which depend on these interior nodes but are not
part of the set of matched nodes to be left with a dangling dependence.
Avoid this by doing the replacement for matched non-TokenFactor nodes.

Fixes PR36164.

Reviewers: jonpa, RKSimon, bogner

Subscribers: llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D42754

llvm-svn: 323977
2018-02-01 16:11:59 +00:00
Dean Michael Berris cdca0730be [XRay][compiler-rt+llvm] Update XRay register stashing semantics
Summary:
This change expands the amount of registers stashed by the entry and
`__xray_CustomEvent` trampolines.

We've found that since the `__xray_CustomEvent` trampoline calls can show up in
situations where the scratch registers are being used, and since we don't
typically want to affect the code-gen around the disabled
`__xray_customevent(...)` intrinsic calls, that we need to save and restore the
state of even the scratch registers in the handling of these custom events.

Reviewers: pcc, pelikan, dblaikie, eizan, kpw, echristo, chandlerc

Reviewed By: echristo

Subscribers: chandlerc, echristo, hiraditya, davide, dblaikie, llvm-commits

Differential Revision: https://reviews.llvm.org/D40894

llvm-svn: 323940
2018-02-01 02:21:54 +00:00
Matt Arsenault df0f25070c DAG: Fix not truncating when promoting bswap/bitreverse
These need to convert back to the original type, like any
other promotion.

llvm-svn: 323932
2018-01-31 23:54:16 +00:00
Nirav Dave c3a1e16db1 [DAG] Prevent NodeId pruning of TokenFactors in Instruction Selection.
Summary:
Instruction Selection preserves relative orders of all nodes save
TokenFactors which we treat specially. As a result Node Ids for
TokenFactors may violate the topological ordering and should not be
considered as valid pruning candidates in predecessor search.

Fixes PR35316.

Reviewers: RKSimon, hfinkel

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D42701

llvm-svn: 323880
2018-01-31 15:23:17 +00:00
Roger Ferrer Ibanez aea4208720 [ARM] Allow the scheduler to clone a node with glue to avoid a copy CPSR ↔ GPR.
In Thumb 1, with the new ADDCARRY / SUBCARRY the scheduler may need to do
copies CPSR ↔ GPR but not all Thumb1 targets implement them.

The schedule can attempt, before attempting a copy, to clone the instructions
but it does not currently do that for nodes with input glue. In this patch we
introduce a target-hook to let the hook decide if a glued machinenode is still
eligible for copying. In this case these are ARM::tADCS and ARM::tSBCS .

As a follow-up of this change we should actually implement the copies for the
Thumb1 targets that do implement them and restrict the hook to the targets that
can't really do such copy as these clones are not ideal.

This change fixes PR35836.

Differential Revision: https://reviews.llvm.org/D42051

llvm-svn: 323857
2018-01-31 09:23:43 +00:00
Simon Dardis daaeaba665 [mips] Fix incorrect sign extension for fpowi libcall
PR36061 showed that during the expansion of ISD::FPOWI, that there
was an incorrect zero extension of the integer argument which for
MIPS64 would then give incorrect results. Address this with the
existing mechanism for correcting sign extensions.

This resolves PR36061.

Thanks to James Cowgill for reporting the issue!

Reviewers: atanasyan, hfinkel

Differential Revision: https://reviews.llvm.org/D42537

llvm-svn: 323781
2018-01-30 16:24:10 +00:00
Dan Gohman 832092ca12 [SelectionDAG]: Ignore "returned" in the presence of an implicit sret.
When a function return value can't be directly lowered, such as
returning an i128 on WebAssembly, as indicated by the CanLowerReturn
target hook, SelectionDAGBuilder can translate it to return the
value through a hidden sret-like argument.

If such a function has an argument with the "returned" attribute,
the attribute can't be automatically lowered, because the function
no longer has a normal return value. For now, just discard the
"returned" attribute.

This fixes PR36128.

llvm-svn: 323715
2018-01-30 00:14:40 +00:00
Craig Topper 62b62356fa [X86] Make foldLogicOfSetCCs work better for vectors pre legal types/operations
Summary:
There's a check in the code to only check getSetCCResultType after LegalOperations or if the type is MVT::i1. But the i1 check is only allowing scalar types through. I think it should check that the scalar type is MVT::i1 so that it will work for vectors.

The changed test already does this combine with AVX512VL where getSetCCResultType returns vXi1. But with avx512f and no VLX getSetCCResultType returns a type matching the width of the input type.

Reviewers: spatel, RKSimon

Reviewed By: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D42619

llvm-svn: 323631
2018-01-29 07:52:55 +00:00
Hiroshi Inoue c8e9245816 [NFC] fix trivial typos in comments and documents
"to to" -> "to"

llvm-svn: 323628
2018-01-29 05:17:03 +00:00
Craig Topper 2c570eaa00 [TargetLowering] Teach TargetLowering::SimplifySetCC to simplify setcc of vXi1 vectors into logic ops.
This transform was already being done for setcc of scalar i1. This extends it to vectors.

llvm-svn: 323585
2018-01-27 09:10:58 +00:00
Craig Topper c80f0ced84 [SelectionDAG] Make DAGTypeLegalizer::PromoteSetCCOperands handle SETEQ/SETNE correctly for vector types.
The code was using getValueSizeInBits and combining with the result of a call to DAG.ComputeNumSignBits. But for vector types getValueSizeInBits returns the width of the full vector while ComputeNumSignBits is going to give a number no larger than the width of a single element. So we should be using getScalarValueSizeInBits to get the element width.

llvm-svn: 323583
2018-01-27 08:41:03 +00:00
Craig Topper 8f324bb1a4 [SelectionDAGISel] Add a debug print before call to Select. Adjust where blank lines are printed during isel process to make things more sensibly grouped.
Previously some targets printed their own message at the start of Select to indicate what they were selecting. For the targets that didn't, it means there was no print of the root node before any custom handling in the target executed. So if the target did something custom and never called SelectNodeCommon, no print would be made. For the targets that did print a message in Select, if they didn't custom handle a node SelectNodeCommon would reprint the root node before walking the isel table.

It seems better to just print the message before the call to Select so all targets behave the same. And then remove the root node printing from SelectNodeCommon and just leave a message that says we're starting the table search.

There were also some oddities in blank line behavior. Usually due to a \n after a call to SelectionDAGNode::dump which already inserted a new line.

llvm-svn: 323551
2018-01-26 19:34:20 +00:00
Nirav Dave 9896238dc9 [DAG] Teach findBaseOffset to interpret indexes of indexed memory operations
Indexed outputs are addition / subtractions and can be interpreted as such.

llvm-svn: 323539
2018-01-26 16:51:27 +00:00
Simon Pilgrim f531cf8964 [DAGCombine] reduceBuildVecToShuffle - ensure EXTRACT_VECTOR_ELT index is in range
From OSS Fuzz Test Case #5688

llvm-svn: 323535
2018-01-26 15:50:20 +00:00
Hiroshi Inoue 0909ca132f [NFC] fix trivial typos in comments and documents
"in in" -> "in", "on on" -> "on" etc.

llvm-svn: 323508
2018-01-26 08:15:29 +00:00
Craig Topper b5c45e0509 [SelectionDAG] Replace a std::vector<SDValue> with a SmallVector.
It likely the number of elements in the type we're legalizing here is reasonably small.

llvm-svn: 323505
2018-01-26 07:15:22 +00:00
Amara Emerson f386e2b081 [GlobalISel] Don't fall back to FastISel.
Apparently checking the pass structure isn't enough to ensure that we don't fall
back to FastISel, as it's set up as part of the SelectionDAGISel.

llvm-svn: 323369
2018-01-24 19:59:29 +00:00
Sven van Haastregt e8404780c3 [DAGCombiner] Bail out if vector size is not a multiple
For the included test case, the DAG transformation
  concat_vectors(scalar, undef) -> scalar_to_vector(sclr)
would attempt to create a v2i32 vector for a v9i8
concat_vector.  Bail out to avoid creating a bitcast with
mismatching sizes later on.

Differential Revision: https://reviews.llvm.org/D42379

llvm-svn: 323312
2018-01-24 09:53:47 +00:00
Jonas Paulsson 7ad28863fb [SelectionDAG] Fix codegen of vector stores with non byte-sized elements.
This was completely broken, but hopefully fixed by this patch.

In cases where it is needed, a vector with non byte-sized elements is stored
by extracting, zero-extending, shift:ing and or:ing the elements into an
integer of the same width as the vector, which is then stored.

Review: Eli Friedman, Ulrich Weigand
https://reviews.llvm.org/D42100#inline-369520
https://bugs.llvm.org/show_bug.cgi?id=35520

llvm-svn: 323042
2018-01-20 16:05:10 +00:00