Commit Graph

11615 Commits

Author SHA1 Message Date
Fraser Cormack f924a3d474 [SelectionDAG] Support scalable-vector splats in yet more cases
This patch extends support for (scalable-vector) splats in the
DAGCombiner via the `ISD::matchBinaryPredicate` function, which enable a
variety of simple combines of constants.

Users of this function may now have to distinguish between
`BUILD_VECTOR` and `SPLAT_VECTOR` vector operands. The way of dealing
with this in-tree follows the approach added for
`ISD::matchUnaryPredicate` implemented in D94501.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D106575
2021-07-26 10:15:08 +01:00
Simon Pilgrim c261a06b7a [DAG] Add initial SelectionDAG::isGuaranteedNotToBeUndefOrPoison framework (PR51129)
I've setup the basic framework for the isGuaranteedNotToBeUndefOrPoison call and updated DAGCombiner::visitFREEZE to use it, further Opcodes can be handled when we have test coverage.

I'm not aware of any vector test freeze coverage so the DemandedElts (and the Depth) args are not being used yet - but they are in place.

SelectionDAG::isGuaranteedNotToBePoison wrappers have also been added.

Differential Revision: https://reviews.llvm.org/D106668
2021-07-24 11:36:35 +01:00
David Truby 1528a4d400 [llvm][sve] Lowering for VLS truncating stores
This adds custom lowering for truncating stores when operating on
fixed length vectors in SVE. It also includes a DAG combine to
fold extends followed by truncating stores into non-truncating
stores in order to prevent this pattern appearing once truncating
stores are supported.

Currently truncating stores are not used in certain cases where
the size of the vector is larger than the target vector width.

Differential Revision: https://reviews.llvm.org/D104471
2021-07-23 14:04:55 +01:00
Paulo Matos 46667a1003 [WebAssembly] Implementation of global.get/set for reftypes in LLVM IR
Reland of 31859f896.

This change implements new DAG notes GLOBAL_GET/GLOBAL_SET, and
lowering methods for load and stores of reference types from IR
globals. Once the lowering creates the new nodes, tablegen pattern
matches those and converts them to Wasm global.get/set.

Reviewed By: tlively

Differential Revision: https://reviews.llvm.org/D104797
2021-07-22 22:07:24 +02:00
Roman Lebedev af8fa36bf0
[NFCI][TLI] prepare[US]REMEqFold(): don't add nonsensical 'exact' flag to rotates created
As pointed out by Craig Topper.
2021-07-22 23:02:58 +03:00
Eli Friedman 0ca46a1757 [SelectionDAG] Fix the representation of ISD::STEP_VECTOR.
The existing rule about the operand type is strange.  Instead, just say
the operand is a TargetConstant with the right width.  (Legalization
ignores TargetConstants, so it doesn't matter if that width is legal.)

Highlights:

1. I had to substantially rewrite the AArch64 isel patterns to expect a
TargetConstant.  Nothing too exotic, but maybe a little hairy. Maybe
worth considering a target-specific node with some dagcombines instead
of this complicated nest of isel patterns.
2. Our behavior on RV32 for vectors of i64 has changed slightly. In
particular, we correctly preserve the width of the arithmetic through
legalization.  This changes the DAG a bit. Maybe room for
improvement here.
3. I explicitly defined the behavior around overflow. This is necessary
to make the DAGCombine transforms legal, and I don't think it causes any
practical issues.

Differential Revision: https://reviews.llvm.org/D105673
2021-07-21 10:58:40 -07:00
Guillaume Chatelet d6da02d952 [llvm] Add enum iteration to Sequence
This patch allows iterating typed enum via the ADT/Sequence utility.

It also changes the original design to better separate concerns:
 - `StrongInt` only deals with safe `intmax_t` operations,
 - `SafeIntIterator` presents the iterator and reverse iterator
 interface but only deals with safe `StrongInt` internally.
 - `iota_range` only deals with `SafeIntIterator` internally.

 This design ensures that operations are always valid. In particular,
 "Out of bounds" assertions fire when:
  - the `value_type` is not representable as an `intmax_t`
  - iterator operations make internal computation underflow/overflow
  - the internal representation cannot be converted back to `value_type`

Differential Revision: https://reviews.llvm.org/D106279
2021-07-21 12:48:53 +00:00
Amy Huang fd972bb9fd Revert "[llvm][sve] Lowering for VLS truncating stores" because it
causes a seg fault (see https://reviews.llvm.org/D104471).

This reverts commit c305557acd.
2021-07-19 11:03:33 -07:00
Craig Topper 50302feb1d [SelectionDAG][RISCV] Use isSExtCheaperThanZExt to control whether sext or zext is used for constant folding any_extend.
RISCV would prefer a sign extended constant since that works better
with our constant materialization. We have an existing TLI hook we
use to control sign extension of setcc operands in type legalization.
That hook happens to do the right check we need here, but might be
straying from its original purpose. With only RISCV defining this
hook in tree, I wasn't sure if it was worth adding another hook
with identical behavior.

This is an alternative to D105785 where I tried to handle this in
the RISCV backend by not creating ANY_EXTENDs in some places.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D105918
2021-07-19 09:25:28 -07:00
Roman Lebedev 5b51bd1878
[TLI] prepareSREMEqFold(): use correct VT for the final VSELECT (PR51133)
We were using the wrong VT for this final VSELECT,
it should be in the final comparison VT,
not the source value's VT.

Fixes https://bugs.llvm.org/show_bug.cgi?id=51133
2021-07-19 16:44:00 +03:00
Eli Friedman 6601be4419 [X86] Remove incorrect use of known bits in shuffle simplification.
This reverts commit 2a419a0b99.

The result of a shufflevector must not propagate poison from any element
other than the one noted in the shuffle mask.

The regressions outside of fptoui-may-overflow.ll can probably be
recovered some other way; for example, using isGuaranteedNotToBePoison.

See discussion on https://reviews.llvm.org/D106053 for more background.

Differential Revision: https://reviews.llvm.org/D106222
2021-07-18 18:13:11 -07:00
Simon Pilgrim fd7a54c709 [DAG] DAGCombiner::foldSelectOfBinops - propagate the common flags to the merged binop
As discussed on D106058 - we were failing to keep the common flags. This matches the behaviour in InstCombinerImpl::foldSelectOpOp.
2021-07-18 18:38:59 +01:00
Simon Pilgrim 5643be96bc [DAG] Enable foldSelectOfBinops on select(setcc(),binop(),binop()) calls 2021-07-18 18:38:59 +01:00
Simon Pilgrim 1a6a8443c2 [DAG] Move select(cc, binop(), binop()) folds into DAGCombiner::foldSelectOfBinops. NFCI.
I'm going to extend the functionality started in D106058 so move the folds into their own method to reduce the amount of code in DAGCombiner::visitSELECT
2021-07-18 14:54:41 +01:00
Simon Pilgrim 95995673d1 [DAG] SelectionDAG::MaskedElementsAreZero - assert we're calling with a vector. NFCI.
Add an assertion that we've calling MaskedElementsAreZero with a vector op and that the DemandedElts arg is a matching width.

Makes the error a lot easier to grok when something else accidentally gets used.
2021-07-16 17:43:35 +01:00
Jeremy Morse 231bf52119 [InstrRef][FastISel] Support emitting DBG_INSTR_REF from fast-isel
If you attach __attribute__((optnone)) to a function when using
optimisations, that function will use fast-isel instead of the usual
SelectionDAG method. This is a problem for instruction referencing,
because it means DBG_VALUEs of virtual registers will be created,
triggering some safety assertions in LiveDebugVariables. Those assertions
exist to detect exactly this scenario, where an unexpected piece of code is
generating virtual register references in instruction referencing mode.

Fix this by transforming the DBG_VALUEs created by fast-isel into
half-formed DBG_INSTR_REFs, after which they get patched up in
finalizeDebugInstrRefs. The test modified adds a fast-isel mode to the
instruction referencing isel test.

Differential Revision: https://reviews.llvm.org/D105694
2021-07-16 13:56:15 +01:00
Simon Pilgrim 0aece73aba [DAG] Fold select(cond,binop(x,y),binop(x,z)) -> binop(x,select(cond,y,z))
Similar to the folds performed in InstCombinerImpl::foldSelectOpOp, this attempts to push a select further up to help merge a pair of binops.

I'm primarily interested in select(cond,add(x,y),add(x,z)) folds to help expose pointer math (see https://bugs.llvm.org/show_bug.cgi?id=51069 etc.) but I've tried to use the more generic isBinOp().

Differential Revision: https://reviews.llvm.org/D106058
2021-07-15 16:08:30 +01:00
Eli Friedman 1e30bf8621 [SelectionDAG] Add an overload of getStepVector that assumes step 1.
This is mostly a minor convenience, but the pattern seems frequent
enough to be worthwhile (and we'll probably add more uses in the
future).

Differential Revision: https://reviews.llvm.org/D105850
2021-07-14 11:37:01 -07:00
Guillaume Chatelet 2c47b8847e Revert "[llvm] Add enum iteration to Sequence"
This reverts commit a006af5d6e.
2021-07-13 16:44:42 +00:00
Guillaume Chatelet a006af5d6e [llvm] Add enum iteration to Sequence
This patch allows iterating typed enum via the ADT/Sequence utility.

Differential Revision: https://reviews.llvm.org/D103900
2021-07-13 16:22:19 +00:00
Qiu Chaofan 954a15d639 [SelectionDAG] Check use before combining into USUBSAT
Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D105789
2021-07-13 14:50:26 +08:00
Arthur Eubanks 7987c46273 [OpaquePtr][ISel] Use ArgListEntry::IndirectType more 2021-07-12 21:14:35 -07:00
Eli Friedman ec1cdee6aa [SelectionDAG][RISCV] Support @llvm.vscale.i64() on 32-bit targets.
Not really useful on its own, but D105673 depends on it.

Differential Revision: https://reviews.llvm.org/D105840
2021-07-12 14:53:42 -07:00
Bradley Smith 112c09039b [SelectionDAG] Simplify PromoteIntRes_INSERT_SUBVECTOR to only handle result
Let other parts of legalization handle the rest of the node, this allows
re-use of existing optimizations elsewhere.

Differential Revision: https://reviews.llvm.org/D105624
2021-07-12 15:20:44 +00:00
David Truby c305557acd [llvm][sve] Lowering for VLS truncating stores
This adds custom lowering for truncating stores when operating on
fixed length vectors in SVE. It also includes a DAG combine to
fold extends followed by truncating stores into non-truncating
stores in order to prevent this pattern appearing once truncating
stores are supported.

Currently truncating stores are not used in certain cases where
the size of the vector is larger than the target vector width.

Differential Revision: https://reviews.llvm.org/D104471
2021-07-12 11:14:17 +01:00
Jeremy Morse 63cc251eb9 [DebugInfo][InstrRef][4/4] Support DBG_INSTR_REF through all backend passes
This is a cleanup patch -- we're now able to support all flavours of
variable location in instruction referencing mode. This patch updates
various tests for debug instructions to be broader: numerous code paths
try to ignore debug isntructions, and they now have to ignore the
additional DBG_PHI and DBG_INSTR_REFs that we can generate.

A small amount of rework happens for LiveDebugVariables: as we don't need
to track live intervals through regalloc any more, we can get away with
unlinking debug instructions before regalloc, then re-inserting them after.
Note that this isn't (yet) true of DBG_VALUE_LISTs, they still have to go
through live interval tracking.

In SelectionDAG, add a helper lambda that emits half-formed DBG_INSTR_REFs
for arguments in instr-ref mode, DBG_VALUE otherwise. This is one of the
final locations where DBG_VALUEs are emitted for vreg arguments.

X86InstrInfo now un-sets the debug instr number on SUB instructions that
get mutated into CMP instructions. As the instruction no longer computes a
subtraction, we can't use it for variable locations.

Differential Revision: https://reviews.llvm.org/D88898
2021-07-08 16:42:24 +01:00
Arthur Eubanks aad41e2299 [OpaquePtr] Use ArgListEntry::IndirectType for lowering ABI attributes
Consolidate PreallocatedType and ByValType into IndirectType, and use that for inalloca.
2021-07-07 14:58:38 -07:00
Dylan Fleming 8ae9ab43dd [SVE] Fixed cast<FixedVectorType> on scalable vector in SelectionDAGBuilder::getUniformBase
Reviewed By: sdesmalen

Differential Revision: https://reviews.llvm.org/D105350
2021-07-07 10:48:17 +01:00
David Green 4ce26deac2 [DAG] Reassociate Add with Or
We already have reassociation code for Adds and Ors separately in DAG
combiner, this adds it for the combination of the two where Ors act like
Adds. It reassociates (add (or (x, c), y) -> (add (add (x, y), c)) where
we know that the Ors operands have no common bits set, and the Or has
one use.

Differential Revision: https://reviews.llvm.org/D104765
2021-07-07 10:21:07 +01:00
Jeremy Morse 2b2ffb7bdc [DebugInfo][InstrRef][3/4] Produce DBG_INSTR_REFs for all variable locations
This patch emits DBG_INSTR_REFs for two remaining flavours of variable
locations that weren't supported: copies, and inter-block VRegs. There are
still some locations that must be represented by DBG_VALUE such as
constants, but they're mostly independent of optimisations.

For variable locations that refer to values defined in different blocks,
vregs are allocated before isel begins, but the defining instruction
might not exist until late in isel. To get around this, emit
DBG_INSTR_REFs in a "half done" state, where the first operand refers to a
VReg. Then at the end of isel, patch these back up to refer to
instructions, using the finalizeDebugInstrRefs method.

Copies are something that I complained about the original RFC, and I
really don't want to have to put instruction numbers on copies. They don't
define a value: they move them. To address this isel, salvageCopySSA
interprets:
 * COPYs,
 * SUBREG_TO_REG,
 * Anything that isCopyInstr thinks is a copy.
And follows chains of copies back to the defining instruction that they
read from. This relies on any physical registers that COPYs read being
defined in the same block, or being entry-block arguments. For the former
we can put an instruction number on the defining instruction; for the
latter we can drop a DBG_PHI that reads the incoming value.

Differential Revision: https://reviews.llvm.org/D88896
2021-07-06 18:31:38 +01:00
David Stuttard 83cb9632a1 [DAGCombiner] Add support for mulhi const folding in DAGCombiner
Differential Revision: https://reviews.llvm.org/D103323

Change-Id: I4ffaaa32301795ba8a339567a68e77fe0862b869
2021-07-05 12:01:26 +01:00
Paul Walker 287d39dd5a [NFC] Fix a few whitespace issues and typos. 2021-07-04 11:49:58 +01:00
Simon Pilgrim 80dd591610 [SelectionDAG] Replace APInt.lshr().trunc() with APInt.extractBits() where possible. NFC.
This also allows us to use KnownBits::extractBits in one case.
2021-07-03 16:33:00 +01:00
Simon Pilgrim e2e44c3da9 [SelectionDAG] Use KnownBits::insertBits instead of separate APInt::insertBits calls. NFC. 2021-07-03 16:32:59 +01:00
Craig Topper af331e8284 [SelectionDAG] Rename memory VT argument for getMaskedGather/getMaskedScatter from VT to MemVT.
Use getMemoryVT() in MGATHER/MSCATTER DAG combines instead of
using the passthru or store value VT for this argument.
2021-07-02 17:37:40 -07:00
Roman Lebedev c2c0d3ea89
Revert "[WebAssembly] Implementation of global.get/set for reftypes in LLVM IR"
This reverts commit 4facbf213c.

```
********************
FAIL: LLVM :: CodeGen/WebAssembly/funcref-call.ll (44466 of 44468)
******************** TEST 'LLVM :: CodeGen/WebAssembly/funcref-call.ll' FAILED ********************
Script:
--
: 'RUN: at line 1';   /builddirs/llvm-project/build-Clang12/bin/llc < /repositories/llvm-project/llvm/test/CodeGen/WebAssembly/funcref-call.ll --mtriple=wasm32-unknown-unknown -asm-verbose=false -mattr=+reference-types | /builddirs/llvm-project/build-Clang12/bin/FileCheck /repositories/llvm-project/llvm/test/CodeGen/WebAssembly/funcref-call.ll
--
Exit Code: 2

Command Output (stderr):
--
llc: /repositories/llvm-project/llvm/include/llvm/Support/LowLevelTypeImpl.h:44: static llvm::LLT llvm::LLT::scalar(unsigned int): Assertion `SizeInBits > 0 && "invalid scalar size"' failed.

```
2021-07-02 11:49:51 +03:00
Paulo Matos 4facbf213c [WebAssembly] Implementation of global.get/set for reftypes in LLVM IR
Reland of 31859f896.

This change implements new DAG notes GLOBAL_GET/GLOBAL_SET, and
lowering methods for load and stores of reference types from IR
globals. Once the lowering creates the new nodes, tablegen pattern
matches those and converts them to Wasm global.get/set.

Differential Revision: https://reviews.llvm.org/D104797
2021-07-02 09:46:28 +02:00
Craig Topper 066524ea54 [ScalarizeMaskedMemIntrin][SelectionDAGBuilder] Use the element type to calculate alignment for gather/scatter when alignment operand is 0.
Previously we used the vector type, but we're loading/storing
invididual elements so I think only element alignment should matter.

Noticed while looking at the code for something else so I don't
have a test case.

Differential Revision: https://reviews.llvm.org/D105220
2021-07-01 19:08:47 -07:00
Bradley Smith 2668727929 [SelectionDAG] Implement PromoteIntRes_INSERT_SUBVECTOR
Inserting into a smaller-than-legal scalable vector would result in an
internal compiler error. For example, inserting a <vscale x 4 x i8> into
a <vscale x 8 x i8> (both illegal vector types for SVE) would cause a
crash.

This crash was happening because there was no code to promote (legalise)
the result of an INSERT_SUBVECTOR node.

This patch implements PromoteIntRes_INSERT_SUBVECTOR, which legalises
the ISD node. This is currently done by going through memory. This is
necessary because of the requirement that the SubVec parameter of the
INSERT_SUBVECTOR node must be smaller than the Vec parameter, which
means that INSERT_SUBVECTOR cannot always have a legal result/operand
types.

Co-Authored-by: Joe Ellis <joe.ellis@arm.com>

Differential Revision: https://reviews.llvm.org/D102766
2021-07-01 17:05:53 +01:00
Bradley Smith 01b846674d [AArch64][SVE] Add support for fixed length MSCATTER/MGATHER
Since gather lowering can now lower to nodes that may need expansion via
the vector legalizer, do MGATHER lowering via vector legalizer.

Additionally, as part of adding passthru support for fixed typed
gathers, fix passthru support for scalable types.

Depends on D104910

Differential Revision: https://reviews.llvm.org/D104217
2021-07-01 12:13:59 +01:00
Bradley Smith 002911503f [TargetLowering][AArch64][SVE] Take into account accessed type when clamping address
When clamping the index for a memory access to a stacked vector we must
take into account the entire type being accessed, not just assume that
we are accessing only a single element.

Differential Revision: https://reviews.llvm.org/D105016
2021-06-30 13:30:18 +01:00
Craig Topper 9132299836 [LegalizeTypes][VE] Don't Expand BITREVERSE/BSWAP during type legalization promotion if they will be promoted for NVT in op legalization.
We were trying to expand these if they were going to be expanded
in op legalization so that we generated the minimum number of
operations. We failed to take into account that NVT could be
promoted to another legal type in op legalization.

Hoping this fixes the issue on the VE target reported as a follow
up to D96681. The check line changes were taken from before
1e46b6f401 so this patch does
appear to improve some cases that had previously regressed.
2021-06-29 11:00:11 -07:00
Melanie Blower 931e95687d [llvm][clang][fpenv] Create new intrinsic llvm.arith.fence to control FP optimization at expression level
This intrinsic blocks floating point transformations by the optimizer.

Author: Pengfei

Reviewed By: LuoYuanke, Andy Kaylor, Craig Topper, kpn

Differential Revision: https://reviews.llvm.org/D99675
2021-06-28 12:26:52 -04:00
David Green 2887f14639 [ISel] Port AArch64 SABD and UABD to DAGCombine
This ports the AArch64 SABD and USBD over to DAG Combine, where they can be
used by more backends (notably MVE in a follow-up patch). The matching code
has changed very little, just to handle legal operations and types
differently. It selects from (ABS (SUB (EXTEND a), (EXTEND b))), producing
a ubds/abdu which is zexted to the original type.

Differential Revision: https://reviews.llvm.org/D91937
2021-06-26 19:34:16 +01:00
David Green b8c8bb0769 [DAG] Fold neg(splat(neg(x)) -> splat(x)
This add as a fold of sub(0, splat(sub(0, x))) -> splat(x). This can
come up in the lowering of right shifts under AArch64, where we generate
a shift left of a negated number.

Differential Revision: https://reviews.llvm.org/D103755
2021-06-25 19:53:29 +01:00
Martin Storsjö 42f74e8249 [llvm] Rename StringRef _lower() method calls to _insensitive()
This is a mechanical change. This actually also renames the
similarly named methods in the SmallString class, however these
methods don't seem to be used outside of the llvm subproject, so
this doesn't break building of the rest of the monorepo.
2021-06-25 00:22:01 +03:00
Craig Topper 03f9e04bc3 [TargetLowering][ARM] Don't alter opaque constants in TargetLowering::ShrinkDemandedConstant.
We don't constant fold based on demanded bits elsewhere in
SimplifyDemandedBits, so I don't think we should shrink them either.

The affected ARM test changes because a constant become non-opaque
and eventually enabled some constant folding. This no longer happens.
I checked and InstCombine is able to simplify this test. I'm not sure exactly
what it was trying to test.

Reviewed By: lebedev.ri, dmgreen

Differential Revision: https://reviews.llvm.org/D104832
2021-06-24 10:09:36 -07:00
Stephen Tozer c72705678c Partial Reapply "[DebugInfo] Use variadic debug values to salvage BinOps and GEP instrs with non-const operands"
This is a partial reapply of the original commit and the followup commit
that were previously reverted; this reapply also includes a small fix
for a potential source of non-determinism, but also has a small change
to turn off variadic debug value salvaging, to ensure that any future
revert/reapply steps to disable and renable this feature do not risk
causing conflicts.

Differential Revision: https://reviews.llvm.org/D91722

This reverts commit 386b66b2fc.
2021-06-24 09:46:38 +01:00
Jinsong Ji c125af82a5 [DAGCombine] Check reassoc flags in aggressive fsub fusion
The is from discussion in https://reviews.llvm.org/D104247#inline-993387

The contract and reassoc flags shouldn't imply each other .

All the aggressive fsub fusion reassociate operations,
we should guard them with reassoc flag check.

Reviewed By: mcberg2017

Differential Revision: https://reviews.llvm.org/D104723
2021-06-23 13:59:40 +00:00
Jinsong Ji 3996311ee1 [DAGCombine] reassoc flag shouldn't enable contract
According to IR LangRef, the FMF flag:

contract
Allow floating-point contraction (e.g. fusing a multiply followed by an
addition into a fused multiply-and-add).

reassoc
Allow reassociation transformations for floating-point instructions.
This may dramatically change results in floating-point.

My understanding is that these two flags shouldn't imply each other,
as we might have a SDNode that can be reassociated with others, but
not contractble.

eg: We may want following fmul/fad/fsub to freely reassoc, but don't
want fma being generated here.

   %F = fmul reassoc double %A, %B         ; <double> [#uses=1]
   %G = fmul reassoc double %C, %D         ; <double> [#uses=1]
   %H = fadd reassoc double %F, %G         ; <double> [#uses=1]
   %I = fsub reassoc double %H, %E         ; <double> [#uses=1]

Before https://reviews.llvm.org/D45710, `reassoc` flag actually
did not imply isContratable either.

The current implementation also only check the flag in fadd node,
ignoring fmul node, this patch update that as well.

Reviewed By: spatel, qiucf

Differential Revision: https://reviews.llvm.org/D104247
2021-06-21 21:15:43 +00:00
Simon Pilgrim 7353beda4a [DAG] SelectionDAG::computeKnownBits - use APInt::insertBits to merge subvector knownbits. NFCI.
As noticed on D104472 we can use APInt::insertBits which will avoid a lot of temporary APInt creations
2021-06-18 14:59:01 +01:00
Bjorn Pettersson 4c7f820b2b Update @llvm.powi to handle different int sizes for the exponent
This can be seen as a follow up to commit 0ee439b705,
that changed the second argument of __powidf2, __powisf2 and
__powitf2 in compiler-rt from si_int to int. That was to align with
how those runtimes are defined in libgcc.
One thing that seem to have been missing in that patch was to make
sure that the rest of LLVM also handle that the argument now depends
on the size of int (not using the si_int machine mode for 32-bit).
When using __builtin_powi for a target with 16-bit int clang crashed.
And when emitting libcalls to those rtlib functions, typically when
lowering @llvm.powi), the backend would always prepare the exponent
argument as an i32 which caused miscompiles when the rtlib was
compiled with 16-bit int.

The solution used here is to use an overloaded type for the second
argument in @llvm.powi. This way clang can use the "correct" type
when lowering __builtin_powi, and then later when emitting the libcall
it is assumed that the type used in @llvm.powi matches the rtlib
function.

One thing that needed some extra attention was that when vectorizing
calls several passes did not support that several arguments could
be overloaded in the intrinsics. This patch allows overload of a
scalar operand by adding hasVectorInstrinsicOverloadedScalarOpd, with
an entry for powi.

Differential Revision: https://reviews.llvm.org/D99439
2021-06-17 09:38:28 +02:00
David Spickett e4ecd83fe9 [llvm][AArch64] Handle arrays of struct properly (from IR)
This only applies to FastIsel. GlobalIsel seems to sidestep
the issue.

This fixes https://bugs.llvm.org/show_bug.cgi?id=46996

One of the things we do in llvm is decide if a type needs
consecutive registers. Previously, we just checked if it
was an array or not.
(plus an SVE specific check that is not changing here)

This causes some confusion when you arbitrary IR like:
```
%T1 = type { double, i1 };
define [ 1 x %T1 ] @foo() {
entry:
  ret [ 1 x %T1 ] zeroinitializer
}
```

We see it is an array so we call CC_AArch64_Custom_Block
which bails out when it sees the i1, a type we don't want
to put into a block.

This leaves the location of the double in some kind of
intermediate state and leads to odd codegen. Which then crashes
the backend because it doesn't know how to implement
what it's been asked for.

You get this:
```
  renamable $d0 = FMOVD0
  $w0 = COPY killed renamable $d0
```

Rather than this:
```
  $d0 = FMOVD0
  $w0 = COPY $wzr
```

The backend knows how to copy 64 bit to 64 bit registers,
but not 64 to 32. It can certainly be taught how but the real
issue seems to be us even trying to assign a register block
in the first place.

This change makes the logic of
AArch64TargetLowering::functionArgumentNeedsConsecutiveRegisters
a bit more in depth. If we find an array, also check that all the
nested aggregates in that array have a single member type.

Then CC_AArch64_Custom_Block's assumption of a type that looks
like [ N x type ] will be valid and we get the expected codegen.

New tests have been added to exercise these situations. Note that
some of the output is not ABI compliant. The aim of this change is
to simply handle these situations and not to make our processing
of arbitrary IR ABI compliant.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D104123
2021-06-16 13:56:01 +00:00
Dylan Fleming dab05335a6 [SVE] Fix PromoteIntRes_TRUNCATE not to call getVectorNumElements
Reviewed By: sdesmalen

Differential Revision: https://reviews.llvm.org/D104115
2021-06-16 13:09:43 +01:00
Roman Lebedev 585e65d330
[TLI] SimplifyDemandedVectorElts(): handle SCALAR_TO_VECTOR(EXTRACT_VECTOR_ELT(?, 0))
Iff we have `SCALAR_TO_VECTOR` (and we demand it's only defined 0'th element),
and said scalar was produced by `EXTRACT_VECTOR_ELT` from the 0'th element
of some vector, then we can just continue traversal into said source vector.

This comes up in X86 vector uniform shift lowering.

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D104250
2021-06-14 23:52:53 +03:00
Saleem Abdulrasool 5b5833b9e0 SelectionDAG: repair the Windows build
6e5628354e regressed the Windows build as
the return type no longer matched in both branches for the return value
type deduction.  This uses a bit more compiler magic to deal with that.
2021-06-14 08:25:36 -07:00
Roman Lebedev 0f94c3c80d
[NFC][DAGCombine] Extract getFirstIndexOf() lambda back into a function
Not all supported compilers like such lambdas, at least one buildbot is unhappy.
2021-06-14 16:25:59 +03:00
Roman Lebedev 6e5628354e
[DAGCombine] reduceBuildVecToShuffle(): sort input vectors by decreasing size
The sorting, obviously, must be stable, else we will have random assembly fluctuations.

Apparently there was no test coverage that would benefit from that,
so i've added one test.

The sorting consists of two parts - just sort the input vectors,
and recompute the shuffle mask -> input vector mapping.
I don't believe we need to do anything else.

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D104187
2021-06-14 16:18:37 +03:00
Jeroen Dobbelaere bb8ce25e88 Intrinsic::getName: require a Module argument
Ensure that we provide a `Module` when checking if a rename of an intrinsic is necessary.

This fixes the issue that was detected by https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=32288
(as mentioned by @fhahn), after committing D91250.

Note that the `LLVMIntrinsicCopyOverloadedName` is being deprecated in favor of `LLVMIntrinsicCopyOverloadedName2`.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D99173
2021-06-14 14:52:29 +02:00
Carl Ritson cfbb92441f [SDAG] Fix pow2 assumption when splitting vectors
When reducing vector builds to shuffles it possible that
the DAG combiner may try to extract invalid subvectors.

This happens as the existing code assumes vectors will be power
of 2 sizes, which is already untrue, but becomes more noticable
with v6 and v7 types.
Specifically the existing code assumes that half PowerOf2Ceil of
a given vector index will fit twice into a given vector.

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D103880
2021-06-11 08:58:16 +09:00
David Spickett 64de8763aa Revert "Implementation of global.get/set for reftypes in LLVM IR"
This reverts commit 31859f896c.

Causing SVE and RISCV-V test failures on bots.
2021-06-10 10:11:17 +00:00
Paulo Matos 31859f896c Implementation of global.get/set for reftypes in LLVM IR
This change implements new DAG notes GLOBAL_GET/GLOBAL_SET, and
lowering methods for load and stores of reference types from IR
globals. Once the lowering creates the new nodes, tablegen pattern
matches those and converts them to Wasm global.get/set.

Reviewed By: tlively

Differential Revision: https://reviews.llvm.org/D95425
2021-06-10 10:07:45 +02:00
Sanjay Patel dd763ac791 [SDAG] fix miscompile from merging stores of different sizes
As shown in:
https://llvm.org/PR50623
...and the similar tests here, we were not accounting for
store merging of different sizes that do not cover the
entire range of the wide value to be stored.

This is the easy fix: just make sure that all of the
original stores are the same size, so when we calculate
the wide width, it's a simple N * M check.

This still allows all of the motivating optimizations from:
D86420 / 54a5dd485c
D87112 / 7a06b166b1

We could enhance this code to track individual bytes and
allow merging multiple sizes.
2021-06-09 09:51:39 -04:00
Simon Pilgrim 114e712c34 InstrEmitter.cpp - don't dereference a dyn_cast<>.
dyn_cast<> can return nullptr which we would then dereference - use cast<> which will assert that the type is correct.
2021-06-08 17:59:04 +01:00
Simon Pilgrim 61a2d6bfe4 [DAG] foldShuffleOfConcatUndefs - ensure shuffles of upper (undef) subvector elements is undef (PR50609)
shuffle(concat(x,undef),concat(y,undef)) -> concat(shuffle(x,y),shuffle(x,y))

If the original shuffle references any of the upper (undef) subvector elements, ensure the split shuffle masks uses undef instead of an out-of-bounds value.

Fixes PR50609
2021-06-08 15:49:41 +01:00
Hans Wennborg 386b66b2fc Revert "3rd Reapply "[DebugInfo] Use variadic debug values to salvage BinOps and GEP instrs with non-const operands""
> This reapplies c0f3dfb9, which was reverted following the discovery of
> crashes on linux kernel and chromium builds - these issues have since
> been fixed, allowing this patch to re-land.

This reverts commit 36ec97f76a.

The change caused non-determinism in the compiler, see comments on the code
review at https://reviews.llvm.org/D91722.

Reverting to unbreak people's builds until that can be addressed.

This also reverts the follow-up "[DebugInfo] Limit the number of values
that may be referenced by a dbg.value" in
a0bd6105d8.
2021-06-08 14:54:08 +02:00
David Green b889c6ee99 [DAG] Allow isNullOrNullSplat to see truncated zeroes
This sets the AllowTruncation flag on isConstOrConstSplat in
isNullOrNullSplat, allowing it to see truncated constant zeroes on
architectures such as AArch64, where only a i32.i64 are legal. As a
truncation of 0 is always 0, this should always be valid, allowing some
extra folding to happen including some of the cases from D103755.

Differential Revision: https://reviews.llvm.org/D103756
2021-06-08 10:18:58 +01:00
Arthur Eubanks 47211fa889 Revert "[TargetLowering] Only inspect attributes in the arguments for ArgListEntry"
Needs to be discussed more.

This reverts commit 255a5c1baa6020c009934b4fa342f9f6dbbcc46
This reverts commit df2056ff3730316f376f29d9986c9913b95ceb1
This reverts commit faff79b7ca144e505da6bc74aa2b2f7cffbbf23
This reverts commit d2a9020785c6e02afebc876aa2778fa64c5cafd
2021-06-07 16:07:44 -07:00
Guillaume Chatelet 1da2c7d25c [NFC] Fix semantic discrepancy for MVT::LAST_VALUETYPE
Differential Revision: https://reviews.llvm.org/D103251
2021-06-07 10:04:16 +00:00
Fraser Cormack aec9cbbeb8 [SelectionDAG] Extend FoldConstantVectorArithmetic to SPLAT_VECTOR
This patch extends the SelectionDAG's ability to constant-fold vector
arithmetic to include support for SPLAT_VECTOR. This is not only for
scalable-vector types but also for fixed-length vector types, which
helps Hexagon in a couple of cases.

The original RISC-V test case was in fact an infinite DAGCombine loop.
The pattern `and (truncate v1), (truncate v2)` can be combined to
`truncate (and v1, v2)` but the truncate can similarly be combined back
to `truncate (and v1, v2)` (but, crucially, only when one of `v1` or
`v2` is a constant vector).

It wasn't exposed in on fixed-length types because a TRUNCATE of a
constant BUILD_VECTOR was folded into the BUILD_VECTOR itself, whereas
this did not happen for the equivalent (scalable-vector) SPLAT_VECTOR.

Reviewed By: RKSimon, craig.topper

Differential Revision: https://reviews.llvm.org/D103246
2021-06-04 09:53:15 +01:00
Arthur Eubanks 9255a5c1ba [TargetLowering] Only inspect attributes in the arguments for ArgListEntry
Parameter attributes are considered part of the function [1], and like
mismatched calling conventions [2], we can't have the verifier check for
mismatched parameter attributes.

Issues can be diagnosed with D103412.

[1] https://llvm.org/docs/LangRef.html#parameter-attributes
[2] https://llvm.org/docs/FAQ.html#why-does-instcombine-simplifycfg-turn-a-call-to-a-function-with-a-mismatched-calling-convention-into-unreachable-why-not-make-the-verifier-reject-it

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D101806
2021-06-03 15:52:01 -07:00
Fraser Cormack 1de1887f5f [CodeGen] Fix a scalable-vector crash in VSELECT legalization
The `DAGTypeLegalizer::WidenVSELECTMask` function is not (yet) ready for
scalable vector types, and has numerous places in which it tries to grab
either the fixed size or number of elements of its types.

I believe that it should be possible to update this method to properly
account for scalable-vector types, but we don't have test cases for
that; RISC-V bails out early on as it has legal i1 vector masks. As
such, this patch just prevents it from crashing.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D103536
2021-06-03 10:24:55 +01:00
Sanjay Patel 0718ac706d [SDAG] allow cast folding for vector sext-of-setcc with signed compare
This extends 434c8e013a and ede3982792 to handle signed
predicates by sign-extending the setcc operands.

This is not shown directly in https://llvm.org/PR50055 ,
but the pattern is visible by changing the unsigned convert
to signed in the source code.
2021-06-02 15:05:02 -04:00
Sanjay Patel ede3982792 [SDAG] allow more cast folding for vector sext-of-setcc
This is a follow-up to D103280 that eases the use restrictions,
so we can handle the motivating case from:
https://llvm.org/PR50055

The loop code is adapted from similar use checks in
ExtendUsesToFormExtLoad() and SliceUpLoad(). I did not see an
easier way to filter out non-chain uses of load values.

Differential Revision: https://reviews.llvm.org/D103462
2021-06-02 13:14:49 -04:00
Bjorn Pettersson 536e02a23c [CodeGen] Refactor libcall lookups for RTLIB::POWI_*
Use RuntimeLibcalls to get a common way to pick correct RTLIB::POWI_*
libcall for a given value type.

This includes a small refactoring of ExpandFPLibCall and
ExpandArgFPLibCall in SelectionDAGLegalize to share a bit of code,
plus adding an ExpandFPLibCall version that can be called directly
when expanding FPOWI/STRICT_FPOWI to ensure that we actually use
the same RTLIB::Libcall when expanding the libcall as we used when
checking the legality of such a call by doing a getLibcallName check.

Differential Revision: https://reviews.llvm.org/D103050
2021-06-02 11:40:34 +02:00
Bjorn Pettersson d1273d39d3 [LegalizeTypes] Avoid promotion of exponent in FPOWI
The FPOWI DAG node is normally lowered to a libcall to one of the
RTLIB::POWI* runtime functions and the exponent should normally
have a type matching sizeof(int) when making the call. Thus,
type promotion of the exponent could lead to an FPOWI with a type
for the second operand that would be incorrect when doing the
libcall (a situation which would be hard to detect post-legalization
if we allow such FPOWI nodes).

This patch is changing DAGTypeLegalizer::PromoteIntOp_FPOWI to
do the rewrite into a libcall directly instead of promoting the
operand. This way we can check that the exponent is smaller than
sizeof(int) and we can let TargetLowering handle promotion as
part of making the libcall. It could be noticed here that makeLibCall
has some knowledge about targets such as 64-bit RISCV, for which the
libcall argument should be extended to a type larger than sizeof(int).

Differential Revision: https://reviews.llvm.org/D102950
2021-06-02 11:40:34 +02:00
Sanjay Patel 1b14f3951a [SDAG] add helper function for sext-of-setcc folds; NFC
Try to make this easier to read as noted in D103280
2021-06-01 08:07:17 -04:00
Sanjay Patel 63fe4cb082 [SDAG] add check to sext-of-setcc fold to bypass changing a legal op
I accidentaly pushed a draft of D103280 that was discussed
during the review, but it was not supposed to be the final
version.

Rather than revert and recommit, I'm updating the existing
code. This way we have a record of the codegen diff that
would result if we decide to remove this predicate in the
future.
2021-05-31 08:58:11 -04:00
Sanjay Patel 434c8e013a [SDAG] try harder to fold casts into vector compare
sext (vsetcc X, Y) --> vsetcc (zext X), (zext Y) --
(when the zexts are free and a bunch of other conditions)

We have a couple of similar folds to this already for vector selects,
but this pattern slips through because it is only a setcc.

The tests are based on the motivating case from:
https://llvm.org/PR50055
...but we need extra logic to get that example, so I've left that as
a TODO for now.

Differential Revision: https://reviews.llvm.org/D103280
2021-05-31 07:14:01 -04:00
Florian Hahn 126f90b252
[DAGCombine] Poison-prove scalarizeExtractedVectorLoad.
extractelement is poison if the index is out-of-bounds, so just
scalarizing the load may introduce an out-of-bounds load, which is UB.

To avoid introducing new UB, we can mask the index so it only contains
valid indices.

Fixes PR50382.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D103077
2021-05-30 11:40:55 +01:00
Arthur Eubanks 71cca4f728 Revert "[TargetLowering] Only inspect attributes in the arguments for ArgListEntry"
This reverts commit 1c7f32334d.

Some code still needs to properly set parameter ABI attributes, see
D101806.
2021-05-29 23:08:15 -07:00
Arthur Eubanks 3a6f12f915 Revert "[NFC] Use ArgListEntry indirect types more in ISel lowering"
This reverts commit bc7d15c61d.

Dependent change is to be reverted.
2021-05-29 22:40:33 -07:00
Eli Friedman 0b3b0a727a [AArch64][RISCV] Make sure isel correctly honors failure orderings.
If a cmpxchg specifies acquire or seq_cst on failure, make sure we
generate code consistent with that ordering even if the success ordering
is not acquire/seq_cst.

At one point, it was ambiguous whether this sort of construct was valid,
but the C++ standad and LLVM now accept arbitrary combinations of
success/failure orderings.

This doesn't address the corresponding issue in AtomicExpand. (This was
reported as https://bugs.llvm.org/show_bug.cgi?id=33332 .)

Fixes https://bugs.llvm.org/show_bug.cgi?id=50512.

Differential Revision: https://reviews.llvm.org/D103284
2021-05-28 12:47:40 -07:00
Craig Topper 2830d924b0 [VP] Make getMaskParamPos/getVectorLengthParamPos return unsigned. Lowercase function names.
Parameter positions seem like they should be unsigned.

While there, make function names lowercase per coding standards.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D103224
2021-05-28 11:28:47 -07:00
Craig Topper d24d2447cd [SelectionDAG] Fix typo in assert. NFC 2021-05-28 10:37:11 -07:00
Tim Northover 9ff2eb1ea5 SwiftTailCC: teach verifier musttail rules applicable to this CC.
SwiftTailCC has a different set of requirements than the C calling convention
for a tail call. The exact argument sequence doesn't have to match, but fewer
ABI-affecting attributes are allowed.

Also make sure the musttail diagnostic triggers if a musttail call isn't
actually a tail call.
2021-05-28 11:12:00 +01:00
Fraser Cormack 5a80dc4988 [VP][SelectionDAG] Add a target-configurable EVL operand type
This patch adds a way for the target to configure the type it uses for
the explicit vector length operands of VP SDNodes. The type must be a
legal integer type (there is still no target-independent legalization of
this operand) and must currently be at least as big as i32, the type
used by the IR intrinsics. An implicit zero-extension takes place on
targets which choose a larger type. All VP nodes should be created with
this type used for the EVL operand.

This allows 64-bit RISC-V to avoid custom legalization of all VP nodes,
keeping them in their target-independent form for that bit longer.

Reviewed By: simoll

Differential Revision: https://reviews.llvm.org/D103027
2021-05-27 15:27:36 +01:00
Fraser Cormack b7101e218c [DAGCombine][RISCV] Don't try to trunc-store combined vector stores
DAGCombine's `mergeStoresOfConstantsOrVecElts` optimization is told
whether it's to use vector types and also whether it's to issue a
truncating store. However, the truncating store code path assumes a
scalar integer `ConstantSDNode`, and when using vector types it creates
either a `BUILD_VECTOR` or `CONCAT_VECTORS` to store: neither of which
is a constant.

The `riscv64` target is able to expose a crash here because it switches
on both code paths at the same time. The `f32` is stored as `i32` which
must be promoted to `i64`, necessitating a truncating store.
It also decides later that it prefers a vector store of `v2f32`.

While vector truncating stores are legal, this combine is not able to
emit them. We also don't have a test case. This patch adds an assert to
catch this case more gracefully, and updates one of the caller functions
to the function to turn off the use of truncating stores when preferring
vectors.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D103173
2021-05-27 14:16:32 +01:00
Fraser Cormack 772b58a641 [SelectionDAG][RISCV] Don't unroll 0/1-type bool VSELECTs
This patch extends the cases in which the legalizer is able to express
VSELECT in terms of XOR/AND/OR. When dealing with a VSELECT between
boolean vector types, the mask itself is an all-ones or all-ones value
of the operand type, so a 0/1 boolean type behaves identically to a 0/-1
type.

This greatly helps RISC-V which relies on expansion for these nodes. It
also allows scalable-vector bool VSELECTs to use the default expansion,
where before it would crash in SelectionDAG::UnrollVectorOp.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D103147
2021-05-27 10:08:57 +01:00
Jonas Paulsson d058262b14 [SystemZ] Support i128 inline asm operands.
Support virtual, physical and tied i128 register operands in inline assembly.

i128 is on SystemZ not really supported and is not a legal type and generally
such a value will be split into two i64 parts. There are however some
instructions that require a pair of two GPR64 registers contained in the GR128
bit reg class, which is untyped.

For inline assmebly operands, it proved to be very cumbersome to first follow
the general behavior of splitting an i128 operand into two parts and then
later rebuild the INLINEASM MI to have one GR128 register. Instead, some
minor common code changes were made to SelectionDAGBUilder to only create one
GR128 register part to begin with. In particular:

- getNumRegisters() now has an optional parameter "RegisterVT" which is
  passed by AddInlineAsmOperands() and GetRegistersForValue().

- The bitcasting in GetRegistersForValue is not performed if RegVT is
  Untyped.

- The RC for a tied use in AddInlineAsmOperands() is now computed either from
  the tied def (virtual register), or by getMinimalPhysRegClass() (physical
  register).

- InstrEmitter.cpp:EmitCopyFromReg() has been fixed so that the register
  class (DstRC) can also be computed for an illegal type.

In the SystemZ backend getNumRegisters(), splitValueIntoRegisterParts() and
joinRegisterPartsIntoValue() have been implemented to handle i128 operands.

Differential Revision: https://reviews.llvm.org/D100788

Review: Ulrich Weigand
2021-05-26 10:08:32 -05:00
Michael Liao c9dd29925f [SelectionDAG] Propagate scoped AA metadata when lowering mem intrinsics.
- When memory intrinsics, such as memcpy, the attached scoped AA
  metadata is not passed down to the backend. As a result, the backend
  cannot schedule relevant memory operations around them following that
  hint. In this patch, SelectionDAG is enhanced to propagate that
  metadata (scoped AA only) when they are lowered into loads and stores.

Differential Revision: https://reviews.llvm.org/D102215
2021-05-25 14:42:26 -04:00
LemonBoy fd5cc41818 [SelectionDAG] Fix argument copy elision with irregular types
D29668 enabled to avoid a useless copy of the argument value into an alloca if the caller places it in memory (as it often happens on x86) by directly forwarding the pointer to it. This optimization is illegal if the type contains padding bytes: if a truncating store into the alloca is replaced the upper bits are filled with garbage and produce code misbehaving at runtime.

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D102153
2021-05-22 09:43:37 +02:00
Stephen Tozer 36ec97f76a 3rd Reapply "[DebugInfo] Use variadic debug values to salvage BinOps and GEP instrs with non-const operands"
This reapplies c0f3dfb9, which was reverted following the discovery of
crashes on linux kernel and chromium builds - these issues have since
been fixed, allowing this patch to re-land.

This reverts commit 4397b7095d.
2021-05-21 11:06:20 +01:00
Jessica Clarke e10958c807 [SelectionDAG][Mips][PowerPC][RISCV][WebAssembly] Teach computeKnownBits/ComputeNumSignBits about atomics
Unlike normal loads these don't have an extension field, but we know
from TargetLowering whether these are sign-extending or zero-extending,
and so can optimise away unnecessary extensions.

This was noticed on RISC-V, where sign extensions in the calling
convention would result in unnecessary explicit extension instructions,
but this also fixes some Mips inefficiencies. PowerPC sees churn in the
tests as all the zero extensions are only for promoting 32-bit to
64-bit, but these zero extensions are still not optimised away as they
should be, likely due to i32 being a legal type.

This also simplifies the WebAssembly code somewhat, which currently
works around the lack of target-independent combines with some ugly
patterns that break once they're optimised away.

Re-landed with correct handling in ComputeNumSignBits for Tmp == VTBits,
where zero-extending atomics were incorrectly returning 0 rather than
the (slightly confusing) required return value of 1.

Re-landed again after D102819 fixed PowerPC to correctly zero-extend all
of its atomics as it claimed to do, since the combination of that bug
and this optimisation caused buildbot regressions.

Reviewed By: RKSimon, atanasyan

Differential Revision: https://reviews.llvm.org/D101342
2021-05-20 20:34:23 +01:00
Fraser Cormack 26bd2250c1 [RISCV] Ensure shuffle splat operands are type-legal
The use of `SelectionDAG::getSplatValue` isn't guaranteed to return a
type-legal splat value as it may implicitly extract a vector element
from another shuffle. It is not permitted to introduce an illegal type
when lowering shuffles.

This patch addresses the crash by adding a boolean flag to
`getSplatValue`, defaulting to false, which when set will ensure a
type-legal return value. If it is unable to do that it will fail to
return a splat value.

I've been through the existing uses of `getSplatValue` in other targets
and was unable to find a need or test cases showing a need to update
their uses. In some cases, the call is made during `LegalizeVectorOps`
which may still produce illegal scalar types. In other situations, the
illegally-typed splat value may be quickly patched up to a legal type
(such as any-extending the returned `extract_vector_elt` up to a legal
type) before `LegalizeDAG` notices.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D102687
2021-05-20 18:00:03 +01:00
Stephen Tozer cf725dde9c [DebugInfo] Handle DIArgList in FastISel or GlobalIsel
Currently, variadic dbg.values (i.e. those using a DIArgList as part of
their location) are not handled properly by FastISel or GlobalISel, and
will produce invalid DBG_VALUE instructions if they encounter them. This
patch fixes this issue by emitting undef DBG_VALUE instructions for
variadic dbg.values, so that no incorrect instruction is produced and
any prior variable location is terminated.

This is simply a quick-fix to prevent errors; a correct implementation
should come later for these ISel pipelines to ensure that we do not drop
debug information unnecessarily.

Differential Revision: https://reviews.llvm.org/D102500
2021-05-20 17:37:28 +01:00
David Sherwood a21bff0673 [CodeGen] Add support for widening the result of EXTRACT_SUBVECTOR
When trying to return a type such as <vscale x 1 x i32> from a
function we crash in DAGTypeLegalizer::WidenVecRes_EXTRACT_SUBVECTOR
when attempting to get the fixed number of elements in the vector.

For the simple case we are dealing with, i.e. extracting
<vscale x 1 x i32> from index 0 of input vector <vscale x 4 x i32>
we can simply rely upon existing code that just returns the input.

Differential Revision: https://reviews.llvm.org/D102605
2021-05-20 12:27:08 +01:00
David Sherwood d07d5c1b06 [CodeGen] Add support for widening INSERT_SUBVECTOR operands
When attempting to return something like a <vscale x 1 x i32>
type from a function we end up trying to widen the vector by
inserting a <vscale x 1 x i32> subvector into an undefined
<vscale x 4 x i32> vector. However, during legalisation we
then attempt to widen the INSERT_SUBVECTOR operands and hit
an error in WidenVectorOperand.

This patch adds a new WidenVecOp_INSERT_SUBVECTOR function
that currently only supports inserting subvectors into undefined
vectors.

Differential Revision: https://reviews.llvm.org/D102501
2021-05-20 10:37:03 +01:00
Sanjay Patel 6025663578 [SDAG] propagate FMF from target-specific IR intrinsics
This is a step towards relying more on node-level FMF rather than function-wide
or target settings.
I think it was just an oversight that we didn't get this path in D87361
or follow-on patches.

The lack of FMF propagation is blocking D90901 from converting tests to IR-level FMF.

We can't do much more than this currently because we also fail to propagate flags
from x86-specific node to generic FMA node. That would be another patch, so the
test just verifies that we can transfer from IR to initial SDAG node.

Differential Revision: https://reviews.llvm.org/D102725
2021-05-19 07:50:50 -04:00
Arthur Eubanks bc7d15c61d [NFC] Use ArgListEntry indirect types more in ISel lowering
For opaque pointers, we're trying to avoid uses of
PointerType::getElementType().

A couple of ISel places use PointerType::getElementType(). Some of these
are easy to fix by using ArgListEntry's indirect types.

The inalloca type wasn't stored there, as opposed to preallocated and
byval which have their indirect types available, so add it and use it.

This is a reland after an MSan fix in D102667.

Differential Revision: https://reviews.llvm.org/D101713
2021-05-18 14:30:22 -07:00
Arthur Eubanks 1c7f32334d [TargetLowering] Only inspect attributes in the arguments for ArgListEntry
Parameter attributes are considered part of the function [1], and like
mismatched calling conventions [2], we can't have the verifier check for
mismatched parameter attributes.

This is a reland after fixing MSan issues in D102667.

[1] https://llvm.org/docs/LangRef.html#parameter-attributes
[2] https://llvm.org/docs/FAQ.html#why-does-instcombine-simplifycfg-turn-a-call-to-a-function-with-a-mismatched-calling-convention-into-unreachable-why-not-make-the-verifier-reject-it

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D101806
2021-05-18 14:30:22 -07:00
Ten Tzen 797ad70152 [Windows SEH]: HARDWARE EXCEPTION HANDLING (MSVC -EHa) - Part 1
This patch is the Part-1 (FE Clang) implementation of HW Exception handling.

This new feature adds the support of Hardware Exception for Microsoft Windows
SEH (Structured Exception Handling).
This is the first step of this project; only X86_64 target is enabled in this patch.

Compiler options:
For clang-cl.exe, the option is -EHa, the same as MSVC.
For clang.exe, the extra option is -fasync-exceptions,
plus -triple x86_64-windows -fexceptions and -fcxx-exceptions as usual.

NOTE:: Without the -EHa or -fasync-exceptions, this patch is a NO-DIFF change.

The rules for C code:
For C-code, one way (MSVC approach) to achieve SEH -EHa semantic is to follow
three rules:
* First, no exception can move in or out of _try region., i.e., no "potential
  faulty instruction can be moved across _try boundary.
* Second, the order of exceptions for instructions 'directly' under a _try
  must be preserved (not applied to those in callees).
* Finally, global states (local/global/heap variables) that can be read
  outside of _try region must be updated in memory (not just in register)
  before the subsequent exception occurs.

The impact to C++ code:
Although SEH is a feature for C code, -EHa does have a profound effect on C++
side. When a C++ function (in the same compilation unit with option -EHa ) is
called by a SEH C function, a hardware exception occurs in C++ code can also
be handled properly by an upstream SEH _try-handler or a C++ catch(...).
As such, when that happens in the middle of an object's life scope, the dtor
must be invoked the same way as C++ Synchronous Exception during unwinding
process.

Design:
A natural way to achieve the rules above in LLVM today is to allow an EH edge
added on memory/computation instruction (previous iload/istore idea) so that
exception path is modeled in Flow graph preciously. However, tracking every
single memory instruction and potential faulty instruction can create many
Invokes, complicate flow graph and possibly result in negative performance
impact for downstream optimization and code generation. Making all
optimizations be aware of the new semantic is also substantial.

This design does not intend to model exception path at instruction level.
Instead, the proposed design tracks and reports EH state at BLOCK-level to
reduce the complexity of flow graph and minimize the performance-impact on CPP
code under -EHa option.

One key element of this design is the ability to compute State number at
block-level. Our algorithm is based on the following rationales:

A _try scope is always a SEME (Single Entry Multiple Exits) region as jumping
into a _try is not allowed. The single entry must start with a seh_try_begin()
invoke with a correct State number that is the initial state of the SEME.
Through control-flow, state number is propagated into all blocks. Side exits
marked by seh_try_end() will unwind to parent state based on existing
SEHUnwindMap[].
Note side exits can ONLY jump into parent scopes (lower state number).
Thus, when a block succeeds various states from its predecessors, the lowest
State triumphs others.  If some exits flow to unreachable, propagation on those
paths terminate, not affecting remaining blocks.
For CPP code, object lifetime region is usually a SEME as SEH _try.
However there is one rare exception: jumping into a lifetime that has Dtor but
has no Ctor is warned, but allowed:

Warning: jump bypasses variable with a non-trivial destructor

In that case, the region is actually a MEME (multiple entry multiple exits).
Our solution is to inject a eha_scope_begin() invoke in the side entry block to
ensure a correct State.

Implementation:
Part-1: Clang implementation described below.

Two intrinsic are created to track CPP object scopes; eha_scope_begin() and eha_scope_end().
_scope_begin() is immediately added after ctor() is called and EHStack is pushed.
So it must be an invoke, not a call. With that it's also guaranteed an
EH-cleanup-pad is created regardless whether there exists a call in this scope.
_scope_end is added before dtor(). These two intrinsics make the computation of
Block-State possible in downstream code gen pass, even in the presence of
ctor/dtor inlining.

Two intrinsic, seh_try_begin() and seh_try_end(), are added for C-code to mark
_try boundary and to prevent from exceptions being moved across _try boundary.
All memory instructions inside a _try are considered as 'volatile' to assure
2nd and 3rd rules for C-code above. This is a little sub-optimized. But it's
acceptable as the amount of code directly under _try is very small.

Part-2 (will be in Part-2 patch): LLVM implementation described below.

For both C++ & C-code, the state of each block is computed at the same place in
BE (WinEHPreparing pass) where all other EH tables/maps are calculated.
In addition to _scope_begin & _scope_end, the computation of block state also
rely on the existing State tracking code (UnwindMap and InvokeStateMap).

For both C++ & C-code, the state of each block with potential trap instruction
is marked and reported in DAG Instruction Selection pass, the same place where
the state for -EHsc (synchronous exceptions) is done.
If the first instruction in a reported block scope can trap, a Nop is injected
before this instruction. This nop is needed to accommodate LLVM Windows EH
implementation, in which the address in IPToState table is offset by +1.
(note the purpose of that is to ensure the return address of a call is in the
same scope as the call address.

The handler for catch(...) for -EHa must handle HW exception. So it is
'adjective' flag is reset (it cannot be IsStdDotDot (0x40) that only catches
C++ exceptions).
Suppress push/popTerminate() scope (from noexcept/noTHrow) so that HW
exceptions can be passed through.

Original llvm-dev [RFC] discussions can be found in these two threads below:
https://lists.llvm.org/pipermail/llvm-dev/2020-March/140541.html
https://lists.llvm.org/pipermail/llvm-dev/2020-April/141338.html

Differential Revision: https://reviews.llvm.org/D80344/new/
2021-05-17 22:42:17 -07:00
Serguei Katkov 57c660f374 [Statepoint Lowering] Cleanup: remove unused option statepoint-always-spill-base. 2021-05-18 12:15:15 +07:00
Simon Pilgrim c29522d648 [TargetLowering] prepareUREMEqFold/prepareSREMEqFold - account for non legal shift types
Ensure we tell getShiftAmountTy that we're working with pre-legalized types to prevent cases where the (legalized) shift type can no longer handle the (non-legalized) type width.

Fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=34366
2021-05-17 11:03:27 +01:00
Fraser Cormack 85e31eddf2 [DAGCombiner] Relax an assertion to an early return
The select-of-constants transform was asserting that its constant vector
inputs did not implicitly truncate their input without that as an
explicit precondition to the function. This patch relaxes that assertion
into an early return to skip the optimization.

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D102393
2021-05-17 09:15:55 +01:00
Arthur Eubanks 341902672c Revert "[TargetLowering] Only inspect attributes in the arguments for ArgListEntry"
This reverts commit 16748bd2fb.

Causes https://crbug.com/1209013
2021-05-16 22:02:10 -07:00
Arthur Eubanks 7647cb14dc Revert "[NFC] Use ArgListEntry indirect types more in ISel lowering"
This reverts commit 85af8a8c1b.
2021-05-16 22:00:54 -07:00
Pan, Tao 976a3e5f61 [SelectionDAG] Make fast and linearize visible by clang -pre-RA-sched
ScheduleDAGFast.cpp is compiled to object file, but the ScheduleDAGFast
object file isn't linked into clang executable file as no symbol is
referred by outside. Add calling to createXxx of ScheduleDAGFast.cpp,
then the ScheduleDAGFast object file will be linked into clang
executable file. The static RegisterScheduler will register scheduler
fast and linearize at clang boot time.

Reviewed By: pengfei

Differential Revision: https://reviews.llvm.org/D101601
2021-05-17 11:25:15 +08:00
Nikita Popov fb9ed1979a [IR] Add BasicBlock::isEntryBlock() (NFC)
This is a recurring and somewhat awkward pattern. Add a helper
method for it.
2021-05-15 12:41:58 +02:00
Sanjay Patel 9dfd7f9b67 [SDAG] reduce code duplication for extend_vec_inreg combines; NFC
These are identical so far, and I was looking at adding a fold
for a pattern with scalar_to_vector which would also nd up duplicated.
2021-05-14 08:29:57 -04:00
Tim Northover ea0eec69f1 IR+AArch64: add a "swiftasync" argument attribute.
This extends any frame record created in the function to include that
parameter, passed in X22.

The new record looks like [X22, FP, LR] in memory, and FP is stored with 0b0001
in bits 63:60 (CodeGen assumes they are 0b0000 in normal operation). The effect
of this is that tools walking the stack should expect to see one of three
values there:

  * 0b0000 => a normal, non-extended record with just [FP, LR]
  * 0b0001 => the extended record [X22, FP, LR]
  * 0b1111 => kernel space, and a non-extended record.

All other values are currently reserved.

If compiling for arm64e this context pointer is address-discriminated with the
discriminator 0xc31a and the DB (process-specific) key.

There is also an "i8** @llvm.swift.async.context.addr()" intrinsic providing
front-ends access to this slot (and forcing its creation initialized to nullptr
if necessary).
2021-05-14 11:43:58 +01:00
cynecx 8ec9fd4839 Support unwinding from inline assembly
I've taken the following steps to add unwinding support from inline assembly:

1) Add a new `unwind` "attribute" (like `sideeffect`) to the asm syntax:

```
invoke void asm sideeffect unwind "call thrower", "~{dirflag},~{fpsr},~{flags}"()
    to label %exit unwind label %uexit
```

2.) Add Bitcode writing/reading support + LLVM-IR parsing.

3.) Emit EHLabels around inline assembly lowering (SelectionDAGBuilder + GlobalISel) when `InlineAsm::canThrow` is enabled.

4.) Tweak InstCombineCalls/InlineFunction pass to not mark inline assembly "calls" as nounwind.

5.) Add clang support by introducing a new clobber: "unwind", which lower to the `canThrow` being enabled.

6.) Don't allow unwinding callbr.

Reviewed By: Amanieu

Differential Revision: https://reviews.llvm.org/D95745
2021-05-13 19:13:03 +01:00
Max Kazantsev d8b37de8a4 [GC][NFC] Move GCStrategy from CodeGen to IR
We want it to be available in analyzes so that we could use the
CodeGen notion in middle-end passes (for example, to check if
a GC may free some particular pointer).

This is a preparatory patch that simply moves the files around.

Note: if this causes some build issues, this patch must just be reverted.

Differential Revision: https://reviews.llvm.org/D100557
Reviewed By: reames
2021-05-13 12:31:59 +07:00
Fraser Cormack c5ec00e62b [TargetLowering] Improve legalization of scalable vector types
This patch extends the vector type-conversion and legalization capabilities of
scalable vector types.

Firstly, `vscale x 1` types now behave more like the corresponding `vscale x
2+` types. This enables the integer promotion legalization of extended scalable
types, such as the promotion of `<vscale x 1 x i5>` to `<vscale x 1 x i8>`.

These `vscale x 1` types are also now better handled by
`getVectorTypeBreakdown`, where what looks like older handling for 1-element
fixed-length vector types was spuriously updated to include scalable types.

Widening of scalable types is now better supported, by using `INSERT_SUBVECTOR`
to insert the smaller scalable vector "value" type into the wider scalable
vector "part" type. This allows AArch64 to pass and return `vscale x 1` types
by value by widening.

There are still cases where we are unable to legalize `vscale x 1` types, such
as where expansion would require splitting the vector in two.

Reviewed By: sdesmalen

Differential Revision: https://reviews.llvm.org/D102073
2021-05-12 16:33:07 +01:00
Stefan Pintilie 8d37411e48 Revert "[SelectionDAG][Mips][PowerPC][RISCV][WebAssembly] Teach computeKnownBits/ComputeNumSignBits about atomics"
This reverts commit 6c80361b84.
Breaks PowerPC Big Endian buildbots.
2021-05-12 09:46:18 -05:00
Hendrik Greving 762ac725bf [DAGCombiner] Fix DAG combine store elimination, different address space.
Fixes a bug in the DAG combiner that eliminates the stores because it missed
to inspect the address space of the pointers.

%v = load %ptr_as1
// no chain side effect
store %v, %ptr_as2

As well as

store %v, %ptr_as1
store %v, %ptr_as2

Fixes a test for above in X86.

Differential Revision: https://reviews.llvm.org/D102096
2021-05-12 07:14:22 -07:00
Arthur Eubanks 85af8a8c1b [NFC] Use ArgListEntry indirect types more in ISel lowering
For opaque pointers, we're trying to avoid uses of
PointerType::getElementType().

A couple of ISel places use PointerType::getElementType(). Some of these
are easy to fix by using ArgListEntry's indirect types.

The inalloca type wasn't stored there, as opposed to preallocated and
byval which have their indirect types available, so add it and use it.

Differential Revision: https://reviews.llvm.org/D101713
2021-05-10 13:05:15 -07:00
Arthur Eubanks 16748bd2fb [TargetLowering] Only inspect attributes in the arguments for ArgListEntry
Parameter attributes are considered part of the function [1], and like
mismatched calling conventions [2], we can't have the verifier check for
mismatched parameter attributes.

[1] https://llvm.org/docs/LangRef.html#parameter-attributes
[2] https://llvm.org/docs/FAQ.html#why-does-instcombine-simplifycfg-turn-a-call-to-a-function-with-a-mismatched-calling-convention-into-unreachable-why-not-make-the-verifier-reject-it

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D101806
2021-05-10 12:35:11 -07:00
Bradley Smith 635164b95a [AArch64][SVE] Improve SVE codegen for fixed length BITCAST
Expanding a fixed length operation involves wrapping the operation in an
insert/extract subvector pair, as such, when this is done to bitcast we
end up with an extract_subvector of a bitcast. DAGCombine tries to
convert this into a bitcast of an extract_subvector which restores the
initial fixed length bitcast, causing an infinite loop of legalization.

As part of this patch, we must make sure the above DAGCombine does not
trigger after legalization if the created bitcast would not be legal.

Differential Revision: https://reviews.llvm.org/D101990
2021-05-10 14:43:53 +01:00
Fraser Cormack 6db0cedd23 [LegalizeVectorOps][RISCV] Add scalable-vector SELECT expansion
This patch extends VectorLegalizer::ExpandSELECT to permit expansion
also for scalable vector types. The only real change is conditionally
checking for BUILD_VECTOR or SPLAT_VECTOR legality depending on the
vector type.

We can use this to fix "cannot select" errors for scalable vector
selects on the RISCV target. Note that in future patches RISCV will
possibly custom-lower vector SELECTs to VSELECTs for branchless codegen.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D102063
2021-05-10 08:22:35 +01:00
Simon Pilgrim dd21c6b843 [DAG] Ensure all SD classes consistently return a const reference with getDebugLoc(). NFCI.
Avoids a lot of unnecessary tracking increments/decrements of the underlying TrackingMDNodeRef.
2021-05-07 14:48:23 +01:00
Stephen Tozer ce0c1f3ced [DebugInfo] Fix crash when emitting an invalidated SDDbgValue
This patch fixes a crash in the compiler that occurs when certain
invalidated SDDbgValues are emitted. The cause of this was that we would
attempt to check the liveness of the debug value's operands, which
triggers an assert if any of those operands are invalid. This patch
changes this check such that it only occurs if the SDDbgValue is valid;
if not, the check is irrelevant anyway, so can be safely ignored.

Differential Revision: https://reviews.llvm.org/D101540
2021-05-07 13:13:56 +01:00
Simon Pilgrim 280aa3415e [DAG] Add a generic expansion for SHIFT_PARTS opcodes using funnel shifts
Based off a discussion on D89281 - where the AARCH64 implementations were being replaced to use funnel shifts.

Any target that has efficient funnel shift lowering can handle the shift parts expansion using the same expansion, avoiding a lot of duplication.

I've generalized the X86 implementation and moved it to TargetLowering - so far I've found that AARCH64 and AMDGPU benefit, but many other targets (ARM, PowerPC + RISCV in particular) could easily use this with a few minor improvements to their funnel shift lowering (or the folding of their target ops that funnel shifts lower to).

NOTE: I'm trying to avoid adding full SHIFT_PARTS legalizer handling as I think it might actually be possible to remove these opcodes in the medium-term and use funnel shift / libcall expansion directly.

Differential Revision: https://reviews.llvm.org/D101987
2021-05-07 13:12:30 +01:00
Jessica Clarke 6c80361b84 [SelectionDAG][Mips][PowerPC][RISCV][WebAssembly] Teach computeKnownBits/ComputeNumSignBits about atomics
Unlike normal loads these don't have an extension field, but we know
from TargetLowering whether these are sign-extending or zero-extending,
and so can optimise away unnecessary extensions.

This was noticed on RISC-V, where sign extensions in the calling
convention would result in unnecessary explicit extension instructions,
but this also fixes some Mips inefficiencies. PowerPC sees churn in the
tests as all the zero extensions are only for promoting 32-bit to
64-bit, but these zero extensions are still not optimised away as they
should be, likely due to i32 being a legal type.

This also simplifies the WebAssembly code somewhat, which currently
works around the lack of target-independent combines with some ugly
patterns that break once they're optimised away.

Re-landed with correct handling in ComputeNumSignBits for Tmp == VTBits,
where zero-extending atomics were incorrectly returning 0 rather than
the (slightly confusing) required return value of 1.

Reviewed By: RKSimon, atanasyan

Differential Revision: https://reviews.llvm.org/D101342
2021-05-06 04:01:20 +01:00
Jessica Clarke 897d7bceb9 Revert "[SelectionDAG][Mips][PowerPC][RISCV][WebAssembly] Teach computeKnownBits/ComputeNumSignBits about atomics"
This seems to have broken sanitizers, giving lots of

  Assertion `NumBits <= MAX_INT_BITS && "bitwidth too large"' failed.

failures across multiple targets (currently X86 and PowerPC). Reverting
until I have a chance to reproduce and debug.

This reverts commit 6e876f9ded.
2021-05-05 17:02:05 +01:00
Jessica Clarke 6e876f9ded [SelectionDAG][Mips][PowerPC][RISCV][WebAssembly] Teach computeKnownBits/ComputeNumSignBits about atomics
Unlike normal loads these don't have an extension field, but we know
from TargetLowering whether these are sign-extending or zero-extending,
and so can optimise away unnecessary extensions.

This was noticed on RISC-V, where sign extensions in the calling
convention would result in unnecessary explicit extension instructions,
but this also fixes some Mips inefficiencies. PowerPC sees churn in the
tests as all the zero extensions are only for promoting 32-bit to
64-bit, but these zero extensions are still not optimised away as they
should be, likely due to i32 being a legal type.

This also simplifies the WebAssembly code somewhat, which currently
works around the lack of target-independent combines with some ugly
patterns that break once they're optimised away.

Reviewed By: RKSimon, atanasyan

Differential Revision: https://reviews.llvm.org/D101342
2021-05-05 16:34:45 +01:00
Christudasan Devadasan 80c79035ef DAG: Cleanup assertion in EmitFuncArgumentDbgValue
Removing an assertion introduced with D68945. The
patch was later reverted with 6531a78ac4, but failed
to remove this assertion. It causes a problem while
trying to split a 64-bit argument into sub registers.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D101594
2021-05-04 21:48:58 +05:30
Tomas Matheson 9d86095ff8 Revert "[CodeGen][ARM] Implement atomicrmw as pseudo operations at -O0"
This reverts commit 753185031d.
2021-05-03 21:48:20 +01:00
Tomas Matheson 753185031d [CodeGen][ARM] Implement atomicrmw as pseudo operations at -O0
atomicrmw instructions are expanded by AtomicExpandPass before register allocation
into cmpxchg loops. Register allocation can insert spills between the exclusive loads
and stores, which invalidates the exclusive monitor and can lead to infinite loops.

To avoid this, reimplement atomicrmw operations as pseudo-instructions and expand them
after register allocation.

Floating point legalisation:
f16 ATOMIC_LOAD_FADD(*f16, f16) is legalised to
f32 ATOMIC_LOAD_FADD(*i16, f32) and then eventually
f32 ATOMIC_LOAD_FADD_16(*i16, f32)

Differential Revision: https://reviews.llvm.org/D101164

Originally submitted as 3338290c18.
Reverted in c7df6b1223.
2021-05-03 20:25:15 +01:00
Craig Topper 6430430958 [TableGen] Use sign rotated VBR for OPC_EmitInteger.
This allows for a much more efficient encoding for small negative
numbers by storing the sign bit first and negating the rest of
the bits. This was already being used for OPC_CheckInteger.

For every in tree target this affects, the table got smaller.
R600GenDAGISel.inc saw the largest reduction of 7K.

I did have to add a new opcode for StringIntegers used for
register class ids and subregister indices since we don't have the
integer value to encode. The enum name is emitted directly into
the table. Previously assumed the enum would expand to a positive
7-bit number. We might be able to just shift that right by 1 and
assume it is a positive 6 bit number, but that will need more
investigation.
2021-05-02 12:40:44 -07:00
Nathan Chancellor 4397b7095d
Revert "Re-reapply "[DebugInfo] Use variadic debug values to salvage BinOps and GEP instrs with non-const operands""
This reverts commit 791930d740, as per
https://llvm.org/docs/DeveloperPolicy.html#patch-reversion-policy.

I observed breakage with the Linux kernel, as reported at
https://reviews.llvm.org/D91722#2724321

Fixes exist at
https://reviews.llvm.org/D101523
https://reviews.llvm.org/D101540

but they have not landed so to unbreak the tree for the weekend, revert
this commit.

Commit b11e4c9907 ("Revert "[DebugInfo] Drop DBG_VALUE_LISTs with an
excessive number of debug operands"") only reverted one follow-up fix,
not the original patch that broke the kernel.

e
2021-04-30 20:23:21 -07:00
Tomas Matheson c7df6b1223 Revert "[CodeGen][ARM] Implement atomicrmw as pseudo operations at -O0"
This reverts commit 3338290c18.

Broke expensive checks on debian.
2021-04-30 16:53:14 +01:00
Tomas Matheson 3338290c18 [CodeGen][ARM] Implement atomicrmw as pseudo operations at -O0
atomicrmw instructions are expanded by AtomicExpandPass before register allocation
into cmpxchg loops. Register allocation can insert spills between the exclusive loads
and stores, which invalidates the exclusive monitor and can lead to infinite loops.

To avoid this, reimplement atomicrmw operations as pseudo-instructions and expand them
after register allocation.

Floating point legalisation:
f16 ATOMIC_LOAD_FADD(*f16, f16) is legalised to
f32 ATOMIC_LOAD_FADD(*i16, f32) and then eventually
f32 ATOMIC_LOAD_FADD_16(*i16, f32)

Differential Revision: https://reviews.llvm.org/D101164
2021-04-30 16:40:33 +01:00
Craig Topper 0c330afdfa [RISCV] Enable SPLAT_VECTOR for fixed vXi64 types on RV32.
This replaces D98479.

This allows type legalization to form SPLAT_VECTOR_PARTS so we don't
lose the splattedness when the scalar type is split.

I'm handling SPLAT_VECTOR_PARTS for fixed vectors separately so
we can continue using non-VL nodes for scalable vectors.

I limited to RV32+vXi64 because DAGCombiner::visitBUILD_VECTOR likes
to form SPLAT_VECTOR before seeing if it can replace the BUILD_VECTOR
with other operations. Especially interesting is a splat BUILD_VECTOR of
the extract_vector_elt which can become a splat shuffle, but won't if
we form SPLAT_VECTOR first. We either need to reorder visitBUILD_VECTOR
or add visitSPLAT_VECTOR.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D100803
2021-04-29 08:20:09 -07:00
Craig Topper 3067520bf4 [SelectionDAG] Use a VTSDNode to store the saturation width for FP_TO_SINT_SAT/FP_TO_UINT_SAT
Previously we used an i32 constant to store the saturation width, but i32 isn't
legal on RISCV64. This wasn't a big deal to fix, but it is extra work for the
type legalizer.

This patch uses a VTSDNode to store the type similar to SEXT_INREG. This makes
it opaque to the type legalizer.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D101262
2021-04-27 14:38:42 -07:00
Dávid Bolvanský ef2dc7ed9f [Analysis] Attribute alignment should not prevent tail call optimization
Fixes tail folding issue mentioned in D100879.
Reviewed By: dmgreen
Differential Revision: https://reviews.llvm.org/D101230
2021-04-24 19:57:42 +02:00
Stephen Tozer 791930d740 Re-reapply "[DebugInfo] Use variadic debug values to salvage BinOps and GEP instrs with non-const operands"
Previous build failures were caused by an error in bitcode reading and
writing for DIArgList metadata, which has been fixed in e5d844b587.
There were also some unnecessary asserts that were being triggered on
certain builds, which have been removed.

This reverts commit dad5caa59e.
2021-04-23 10:54:01 +01:00
Craig Topper 5185b52988 [RISCV] Fix crash with fptosi.sat/fptoui.sat intrinsics on RV64. Add test cases.
Add PromoteIntOp_FP_TO_XINT_SAT to type legalize the bit width
operand from i32 to i64 for RV64.

Add test cases for the saturating intrinsics for half/float/double
and i32/i64. CodeGen is definitely not optimal. We can probably
make use of the native behavior of fcvt instructions in many cases.

Fixes PR50083
2021-04-22 15:18:15 -07:00
Jun Ma 978eb3f168 [DAGCombiner] Allow operand of step_vector to be negative.
It is proper to relax non-negative limitation of step_vector.
Also this patch adds more combines for step_vector:
(sub X, step_vector(C)) -> (add X,  step_vector(-C))

Differential Revision: https://reviews.llvm.org/D100812
2021-04-22 20:58:03 +08:00
Simon Pilgrim d860bf2d0e [DAG] TargetLowering.cpp - breakup if-else chains where each block returns. NFCI.
Match style guide that requests that if+return blocks are separate.
2021-04-21 11:17:27 +01:00
Fraser Cormack c141bd3cf9 [DAGCombiner] Support all-ones/all-zeros SPLAT_VECTOR in more combines
This patch adds incrementally-better support for SPLAT_VECTOR in a
handful of vector combines by changing a few more
isBuildVectorAllOnes/isBuildVectorAllZeros to the equivalent
isConstantSplatVectorAllOnes/Zeros calls.

Reviewed By: paulwalker-arm

Differential Revision: https://reviews.llvm.org/D100851
2021-04-21 11:05:37 +01:00
Philip Reames 4824d876f0 Revert "Allow invokable sub-classes of IntrinsicInst"
This reverts commit d87b9b81cc.

Post commit review raised concerns, reverting while discussion happens.
2021-04-20 15:38:38 -07:00
Philip Reames d87b9b81cc Allow invokable sub-classes of IntrinsicInst
It used to be that all of our intrinsics were call instructions, but over time, we've added more and more invokable intrinsics. According to the verifier, we're up to 8 right now. As IntrinsicInst is a sub-class of CallInst, this puts us in an awkward spot where the idiomatic means to check for intrinsic has a false negative if the intrinsic is invoked.

This change switches IntrinsicInst from being a sub-class of CallInst to being a subclass of CallBase. This allows invoked intrinsics to be instances of IntrinsicInst, at the cost of requiring a few more casts to CallInst in places where the intrinsic really is known to be a call, not an invoke.

After this lands and has baked for a couple days, planned cleanups:
    Make GCStatepointInst a IntrinsicInst subclass.
    Merge intrinsic handling in InstCombine and use idiomatic visitIntrinsicInst entry point for InstVisitor.
    Do the same in SelectionDAG.
    Do the same in FastISEL.

Differential Revision: https://reviews.llvm.org/D99976
2021-04-20 15:03:49 -07:00
Simon Pilgrim 2a419a0b99 [X86][SSE] combineX86ShuffleChain - check if we're blending with zero into already zero elements
Add a SelectionDAG::MaskedElementsAreZero helper that wraps SelectionDAG::MaskedValueIsZero testing for entirely zero vector elements
2021-04-20 17:09:49 +01:00
Simon Pilgrim e156f2515c [DAG] SelectionDAG.cpp - breakup if-else chains where each block returns. NFCI.
Match style guide that requests that if+return blocks are separate.
2021-04-20 12:37:00 +01:00
Jun Ma 1ef5699d1a [DAGCombiner] Support fold zero scalar vector.
This patch changes ISD::isBuildVectorAllZeros to
ISD::isConstantSplatVectorAllZeros which handles zero sclar vector.

TestPlan: check-llvm

Differential Revision: https://reviews.llvm.org/D100813
2021-04-20 16:28:43 +08:00
Fraser Cormack 457da7f298 [SelectionDAG] Relax constraints on STEP_VECTOR step operand
This patch relaxes the requirement that the STEP_VECTOR step constant
must be of a type at least as large as the vector element type. This
does not permit its use on targets which have legal vector element types
larger than the largest legal scalar type, such as i64 vectors on RV32.

As such, the requirement has been loosened so that the step operand must
be any scalar type so long as the constant immediate is non-negative and
the value fits inside the vector element type.

This limits combining optimizations in certain circumstances but in
practice it's unlikely to be a hindrance.

Reviewed By: paulwalker-arm

Differential Revision: https://reviews.llvm.org/D100660
2021-04-20 08:41:42 +01:00
David Sherwood 83f5fa519e [CodeGen] Improve code generation for clamping of constant indices with scalable vectors
When trying to clamp a constant index into a scalable vector we can
test if the index is less than the minimum number of elements in the
vector. If so, we can simply return the index because we know it is
guaranteed to fit inside the vector.

Differential Revision: https://reviews.llvm.org/D100639
2021-04-19 08:34:17 +01:00
Serge Guelton d6de1e1a71 Normalize interaction with boolean attributes
Such attributes can either be unset, or set to "true" or "false" (as string).
throughout the codebase, this led to inelegant checks ranging from

        if (Fn->getFnAttribute("no-jump-tables").getValueAsString() == "true")

to

        if (Fn->hasAttribute("no-jump-tables") && Fn->getFnAttribute("no-jump-tables").getValueAsString() == "true")

Introduce a getValueAsBool that normalize the check, with the following
behavior:

no attributes or attribute set to "false" => return false
attribute set to "true" => return true

Differential Revision: https://reviews.llvm.org/D99299
2021-04-17 08:17:33 +02:00
Simon Pilgrim 37a4621fb6 [DAG] SelectionDAG::isSplatValue - early out if binop is not splat. NFCI.
Just return false if we fail to match splats - the remainder of the code is for (fixed)vector operations - shuffles/insertions etc.
2021-04-16 18:26:33 +01:00