Commit Graph

306 Commits

Author SHA1 Message Date
Matt Arsenault 2e77362626 GlobalISel: Fix lower bswap for vectors
This would hit an assertion from trying to use the wrong bitwidth for
the constants.
2020-03-16 13:59:08 -04:00
Matt Arsenault 19a0350187 GlobalISel: Fix round lowering
I used the implementation for floor instead of round. It also turns
out the OpenCL builtin library wasn't using the round builtin, but
implemented the expanded form.
2020-03-16 11:37:30 -04:00
Dominik Montada 8ff2dcb18b [GlobalISel] add additional lowering support for G_INSERT
Summary: Add lowering support for inserting pointers or scalars into scalars, vectors or pointers

Reviewers: arsenm, dsanders

Reviewed By: arsenm

Subscribers: jvesely, wdng, nhaehnle, rovka, hiraditya, volkan, kerbowa, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D75994
2020-03-16 16:27:17 +01:00
Dominik Montada 6b96623dcb [GlobalISel] fix crash in narrowScalarExtract if DstRegs only has one register
Summary: When narrowing a scalar G_EXTRACT where the destination lines up perfectly with a single result of the emitted G_UNMERGE_VALUES a COPY should be emitted instead of unconditionally trying to emit a G_MERGE_VALUES.

Reviewers: arsenm, dsanders

Reviewed By: arsenm

Subscribers: wdng, rovka, hiraditya, volkan, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D75743
2020-03-12 09:14:35 +01:00
Matt Arsenault b17a81f8b2 GlobalISel: Add missing add/sub with carries to MachineIRBuilder 2020-03-10 22:39:55 -04:00
Dominik Montada feb20a1594 [GlobalISel] add missing libcalls and 128-bit support for floating points
Add libcall support for G_FMINNUM, G_FMAXNUM, G_FSQRT, G_FRINT, G_FNEARBYINT.
Add 128-bit libcall support for all simple libcalls.

Reviewers: arsenm, Petar.Avramovic, dsanders, petarj, paquette

Subscribers: wdng, rovka, hiraditya, volkan, llvm-commits

Differential Revision: https://reviews.llvm.org/D75516
2020-03-06 09:06:13 +01:00
Jeremy Morse 6af859dcca [DebugInfo] Re-implement LexicalScopes dominance method, add unit tests
Way back in D24994, the combination of LexicalScopes::dominates and
LiveDebugValues was identified as having worst-case quadratic complexity,
but it wasn't triggered by any code path at the time. I've since run into a
scenario where this occurs, in a very large basic block where large numbers
of inlined DBG_VALUEs are present.

The quadratic-ness comes from LiveDebugValues::join calling "dominates" on
every variable location, and LexicalScopes::dominates potentially touching
every instruction in a block to test for the presence of a scope. We have,
however, already computed the presence of scopes in blocks, in the
"InstrRanges" of each scope. This patch switches the dominates method to
examine whether a block is present in a scope's InsnRanges, avoiding
walking through the whole block.

At the same time, fix getMachineBasicBlocks to account for the fact that
InsnRanges can cover multiple blocks, and add some unit tests, as Lexical
Scopes didn't have any.

Differential revision: https://reviews.llvm.org/D73725
2020-02-28 11:41:28 +00:00
Quentin Colombet 5bf0023b0d [GISel][KnownBits] Update a comment regarding the effect of cache on PHIs
Unlike what I claimed in my previous commit. The caching is
actually not NFC on PHIs.

When we put a big enough max depth, we end up simulating loops.
The cache is effectively cutting the simulation short and we
get less information as a result.
E.g.,
```
v0 = G_CONSTANT i8 0xC0
jump
v1 = G_PHI i8 v0, v2
v2 = G_LSHR i8 v1, 1
```

Let say we want the known bits of v1.
- With cache:
Set v1 cache to we know nothing
v1 is v0 & v2
v0 gives us 0xC0
v2 gives us known bits of v1 >> 1
v1 is in the cache
=> v1 is 0, thus v2 is 0x80
Finally v1 is v0 & v2 => 0x80

- Without cache and enough depth to do two iteration of the loop:
v1 is v0 & v2
v0 gives us 0xC0
v2 gives us known bits of v1 >> 1
v1 is v0 & v2
v0 is 0xC0
v2 is v1 >> 1
Reach the max depth for v1...
unwinding
v1 is know nothing
v2 is 0x80
v0 is 0xC0
v1 is 0x80
v2 is 0xC0
v0 is 0xC0
v1 is 0xC0

Thus now v1 is 0xC0 instead of 0x80.

I've added a unittest demonstrating that.

NFC
2020-02-25 15:56:15 -08:00
Quentin Colombet e4a9225f5d [GISel][KnownBits] Give up on PHI analysis as soon as we don't know anything
When analyzing PHIs, we gather the known bits for every operand and
merge them together to get the known bits of the result of the PHI.
It is not unusual that merging the information leads to know nothing
on the result (e.g., phi a: i8 3, b: i8 unknown, ..., after looking at the
second argument we know we will know nothing on the result), thus, as
soon as we reach that state, stop analyzing the following operand (i.e.,
on the previous example, we won't process anything after looking at `b`).

This improves compile time in particular with PHIs with a large number
of operands.

NFC.
2020-02-20 11:34:01 -08:00
Matt Arsenault 323db5d666 GlobalISel: Add matcher for G_LSHR 2020-02-17 09:20:13 -05:00
Matt Arsenault 6135f5eda4 GlobalISel: Fix narrowing of G_CTLZ/G_CTTZ
The result type is separate from the source type.
2020-02-09 18:11:43 -05:00
Petar Avramovic 7df5fc9e03 [GlobalISel] Add buildMerge with SrcOp initializer list
Allows more flexible use of buildMerge in places where
use operands are available as SrcOp since it does not
require explicit conversion to Register.
Simplify code with new buildMerge.

Differential Revision: https://reviews.llvm.org/D74223
2020-02-07 18:43:45 +01:00
Matt Arsenault 8de2dad9e0 GlobalISel: Fix lowering of G_CTLZ/G_CTTZ
The type passed to lower was invalid, so I'm not sure how this was
even working before. The source and destination type also do not have
to match, so make sure to use the right ones.
2020-02-07 06:54:12 -08:00
Konstantin Schwarz 76986bdc46 [GlobalISel] Legalize more G_FP(EXT|TRUNC) libcalls.
This adds a new helper function for retrieving the
floating point type corresponding to the specified
bit-width.
2020-02-06 11:41:34 -08:00
Matt Arsenault 9087ef0765 GlobalISel: Allow CSE of G_IMPLICIT_DEF
The legalizer produces a lot of these, and they make reading legalized
MIR annoying. For some reason, this does seem to sometimes introduce
copies of implicit def, which is dumb.
2020-02-05 17:47:21 -05:00
Matt Arsenault 24ab761a60 LLT: Add changeNumElements
This is the element analog of changeElementType/changeElementSize
2020-01-29 07:32:07 -08:00
Quentin Colombet 5d87b5d202 [GISelKnownBits] Add support for PHIs
Teach the GISelKnowBits analysis how to deal with PHI operations.
PHIs are essentially COPYs happening on edges, so we can just reuse
the code for COPY.

This is NFC COPY-wise has we leave Depth untouched when calling
computeKnownBitsImpl for COPYs, like it was before this patch.
Increasing Depth is however required for PHIs as they may loop back to
themselves and we would end up in an infinite loop if we were not
increasing Depth.

Differential Revision: https://reviews.llvm.org/D73317
2020-01-24 16:43:52 -08:00
Matt Arsenault c77bbea9a6 GlobalISel: Add MIPatternMatch for G_ICMP/G_FCMP 2020-01-23 13:30:47 -08:00
Jay Foad b482e1bfe2 [CodeGen] Make use of MachineInstrBuilder::getReg
Reviewers: arsenm

Subscribers: wdng, hiraditya, Petar.Avramovic, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73262
2020-01-23 13:38:13 +00:00
Daniel Sanders de3d0ee023 Revert "Revert "[MIR] Target specific MIR formating and parsing""
There was an unguarded dereference of MF in a function that permitted
nullptr. Fixed

This reverts commit 71d64f72f9.
2020-01-08 20:03:29 -08:00
Nico Weber 71d64f72f9 Revert "[MIR] Target specific MIR formating and parsing"
This reverts commit 3ef05d85be.
It broke check-llvm on many bots, see comments on D69836.
2020-01-08 22:50:49 -05:00
Peng Guo 3ef05d85be [MIR] Target specific MIR formating and parsing
Summary:
Added MIRFormatter for target specific MIR formating and parsing with
immediate and custom pseudo source values. Target machine can subclass
MIRFormatter and implement custom logic for printing and parsing
immediate and custom pseudo source values for better readability.

* Target specific immediate mnemonic need to start with "." follows by
  identifier string. When MIR parser sees immediate it will call target
  specific parsing function.

* Custom pseudo source value need to start with custom follows by
  double-quoted string. MIR parser will pass the quoted string to target
  specific PSV parsing function.

* MIRFormatter have 2 helper functions to facilitate LLVM value printing
  and parsing for custom PSV if they refers LLVM values.

Patch by Peng Guo

Reviewers: dsanders, arsenm

Reviewed By: dsanders

Subscribers: wdng, jvesely, nhaehnle, hiraditya, jfb, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69836
2020-01-08 18:48:02 -08:00
Daniel Sanders 5ab6fa7b70 Revert "[MIR] Target specific MIR formating and parsing"
Forgot to credit Peng in the commit message.

This reverts commit be841f89d0.
2020-01-08 18:48:02 -08:00
Peng Guo be841f89d0 [MIR] Target specific MIR formating and parsing
Summary:
Added MIRFormatter for target specific MIR formating and parsing with
immediate and custom pseudo source values. Target machine can subclass
MIRFormatter and implement custom logic for printing and parsing
immediate and custom pseudo source values for better readability.

* Target specific immediate mnemonic need to start with "." follows by
  identifier string. When MIR parser sees immediate it will call target
  specific parsing function.

* Custom pseudo source value need to start with custom follows by
  double-quoted string. MIR parser will pass the quoted string to target
  specific PSV parsing function.

* MIRFormatter have 2 helper functions to facilitate LLVM value printing
  and parsing for custom PSV if they refers LLVM values.

Reviewers: dsanders, arsenm

Reviewed By: dsanders

Subscribers: wdng, jvesely, nhaehnle, hiraditya, jfb, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69836
2020-01-08 18:34:21 -08:00
Matt Arsenault 0b093f0212 GlobalISel: Start adding computeNumSignBits to GISelKnownBits 2020-01-06 17:21:51 -05:00
Simon Pilgrim d76202d3e3 Fix Wpedantic 'extra semicolon' warning. NFC. 2019-12-21 17:32:00 +00:00
Roman Tereshin 8731799fc6 [Legalizer] Making artifact combining order-independent
Legalization algorithm is complicated by two facts:
1) While regular instructions should be possible to legalize in
   an isolated, per-instruction, context-free manner, legalization
   artifacts can only be eliminated in pairs, which could be deeply, and
   ultimately arbitrary nested: { [ () ] }, where which paranthesis kind
   depicts an artifact kind, like extend, unmerge, etc. Such structure
   can only be fully eliminated by simple local combines if they are
   attempted in a particular order (inside out), or alternatively by
   repeated scans each eliminating only one innermost pair, resulting in
   O(n^2) complexity.
2) Some artifacts might in fact be regular instructions that could (and
   sometimes should) be legalized by the target-specific rules. Which
   means failure to eliminate all artifacts on the first iteration is
   not a failure, they need to be tried as instructions, which may
   produce more artifacts, including the ones that are in fact regular
   instructions, resulting in a non-constant number of iterations
   required to finish the process.

I trust the recently introduced termination condition (no new artifacts
were created during as-a-regular-instruction-retrial of artifacts not
eliminated on the previous iteration) to be efficient in providing
termination, but only performing the legalization in full if and only if
at each step such chains of artifacts are successfully eliminated in
full as well.

Which is currently not guaranteed, as the artifact combines are applied
only once and in an arbitrary order that has to do with the order of
creation or insertion of artifacts into their worklist, which is a no
particular order.

In this patch I make a small change to the artifact combiner, making it
to re-insert into the worklist immediate (modulo a look-through copies)
artifact users of each vreg that changes its definition due to an
artifact combine.

Here the first scan through the artifacts worklist, while not
being done in any guaranteed order, only needs to find the innermost
pair(s) of artifacts that could be immediately combined out. After that
the process follows def-use chains, making them shorter at each step, thus
combining everything that can be combined in O(n) time.

Reviewers: volkan, aditya_nandakumar, qcolombet, paquette, aemerson, dsanders

Reviewed By: aditya_nandakumar, paquette

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71448
2019-12-13 15:45:18 -08:00
Roman Tereshin 18bf9670aa [Legalizer] Refactoring out legalizeMachineFunction
and introducing new unittests/CodeGen/GlobalISel/LegalizerTest.cpp
relying on it to unit test the entire legalizer algorithm (including the
top-level main loop).

See also https://reviews.llvm.org/D71448
2019-12-13 15:45:18 -08:00
Hiroshi Yamauchi 52e377497d [PGO][PGSO] DAG.shouldOptForSize part.
Summary:
(Split of off D67120)

SelectionDAG::shouldOptForSize changes for profile guided size optimization.

Reviewers: davidxl

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70095
2019-11-21 14:16:00 -08:00
Graham Hunter 3f08ad611a [SVE][CodeGen] Scalable vector MVT size queries
* Implements scalable size queries for MVTs, split out from D53137.

* Contains a fix for FindMemType to avoid using scalable vector type
  to contain non-scalable types.

* Explicit casts for several places where implicit integer sign
  changes or promotion from 32 to 64 bits caused problems.

* CodeGenDAGPatterns will treat scalable and non-scalable vector types
  as different.

Reviewers: greened, cameron.mcinally, sdesmalen, rovka

Reviewed By: rovka

Differential Revision: https://reviews.llvm.org/D66871
2019-11-18 12:30:59 +00:00
Heejin Ahn 3306fe10fa [unittests] Add InitializePasses.h includes
Summary:
After D70211, Pass.h does not include InitializePasses.h anymore, so
these files need to include InitializePasses.h directly.

Reviewers: rnk

Subscribers: MatzeB, mehdi_amini, zzheng, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70217
2019-11-13 19:42:58 -08:00
Amy Huang fdd0815eac Fix initialization-order-fiasco error in "Add a heap alloc site marker field to the ExtraInfo in MachineInstrs" 2019-10-31 10:52:53 -07:00
Amy Huang 742043047c Recommit "Add a heap alloc site marker field to the ExtraInfo in MachineInstrs"
Summary:
Fixes some things from original commit at https://reviews.llvm.org/D69136. The main
change is that the heap alloc marker is always stored as ExtraInfo in the machine
instruction instead of in the PointerSumType because it cannot hold more than
4 pointer types.

Add instruction marker to MachineInstr ExtraInfo. This does almost the
same thing as Pre/PostInstrSymbols, except that it doesn't create a label until
printing instructions. This allows for labels to be put around instructions that
are deleted/duplicated somewhere.
Use this marker to track heap alloc site call instructions.

Reviewers: rnk

Subscribers: MatzeB, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69536
2019-10-28 16:59:32 -07:00
Amy Huang 64c1f6602a Revert "Add an instruction marker field to the ExtraInfo in MachineInstrs."
Reverting commit b85b4e5a6f due to some
buildbot failures/ out of memory errors.
2019-10-25 12:41:34 -07:00
Amy Huang b85b4e5a6f Add an instruction marker field to the ExtraInfo in MachineInstrs.
Summary:
Add instruction marker to MachineInstr ExtraInfo. This does almost the
same thing as Pre/PostInstrSymbols, except that it doesn't create a label until
printing instructions. This allows for labels to be put around instructions that
are deleted/duplicated somewhere.

Also undo the workaround in r375137.

Reviewers: rnk

Subscribers: MatzeB, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69136
2019-10-25 09:21:10 -07:00
Vladimir Vereschaka 92c96c7bc0 Reverted r375254 as it has broken some build bots for a long time.
llvm-svn: 375375
2019-10-20 20:39:33 +00:00
Roman Lebedev 9a055dc191 [Codegen] Link MIRParser into CodeGenTests to fix MachineSizeOptsTest building
llvm-svn: 375261
2019-10-18 17:18:21 +00:00
Hiroshi Yamauchi 7e1637451d [PGO][PGSO] SizeOpts changes.
Summary:
(Split of off D67120)

SizeOpts/MachineSizeOpts changes for profile guided size optimization.

Reviewers: davidxl

Subscribers: mgorny, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69070

llvm-svn: 375254
2019-10-18 16:46:01 +00:00
Guillaume Chatelet 882c43d703 [Alignment][NFC] Use Align for TargetFrameLowering/Subtarget
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet

Subscribers: jholewinski, arsenm, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, sbc100, jgravelle-google, hiraditya, aheejin, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, Jim, lenary, s.egerton, pzheng, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68993

llvm-svn: 375084
2019-10-17 07:49:39 +00:00
Quentin Colombet 49036dd3ae [GISel][UnitTest] Fix a bunch of tests that were not doing anything
After r368065, all the tests using GISelMITest must call setUp() before
doing anything, otherwise the TargetMachine is not going to be set up.
A few tests added after that commit were not doing that and ended up
testing effectively nothing.

Fix the setup of all the tests and fix the failing tests.

llvm-svn: 374595
2019-10-11 20:58:26 +00:00
Quentin Colombet 7720f11498 [MachineIRBuilder] Fix an assertion failure with buildMerge
Teach buildMerge how to deal with scalar to vector kind of requests.

Prior to this patch, buildMerge would issue either a G_MERGE_VALUES
when all the vregs are scalars or a G_CONCAT_VECTORS when the destination
vreg is a vector.
G_CONCAT_VECTORS was actually not the proper instruction when the source
vregs were scalars and the compiler would assert that the sources must
be vectors. Instead we want is to issue a G_BUILD_VECTOR when we are
in this situation.

This patch fixes that.

llvm-svn: 374588
2019-10-11 20:22:47 +00:00
Marcello Maggioni 0112123eea [GISel] Allow getConstantVRegVal() to return G_FCONSTANT values.
In GISel we have both G_CONSTANT and G_FCONSTANT, but because
in GISel we don't really have a concept of Float vs Int value
the only difference between the two is where the data originates
from.

What both G_CONSTANT and G_FCONSTANT return is just a bag of bits
with the constant representation in it.

By making getConstantVRegVal() return G_FCONSTANTs bit representation
as well we allow ConstantFold and other things to operate with
G_FCONSTANT.

Adding tests that show ConstantFolding to work on mixed G_CONSTANT
and G_FCONSTANT sources.

Differential Revision: https://reviews.llvm.org/D68739

llvm-svn: 374458
2019-10-10 21:46:26 +00:00
Marcello Maggioni ff38448148 [GISel] Refactor and split PatternMatchTest. NFC
Split the ConstantFold part into a separate file and
make it use the fixture GISelMITest.

llvm-svn: 374245
2019-10-09 22:10:10 +00:00
Graham Hunter b302561b76 [SVE][IR] Scalable Vector size queries and IR instruction support
* Adds a TypeSize struct to represent the known minimum size of a type
  along with a flag to indicate that the runtime size is a integer multiple
  of that size
* Converts existing size query functions from Type.h and DataLayout.h to
  return a TypeSize result
* Adds convenience methods (including a transparent conversion operator
  to uint64_t) so that most existing code 'just works' as if the return
  values were still scalars.
* Uses the new size queries along with ElementCount to ensure that all
  supported instructions used with scalable vectors can be constructed
  in IR.

Reviewers: hfinkel, lattner, rkruppe, greened, rovka, rengolin, sdesmalen

Reviewed By: rovka, sdesmalen

Differential Revision: https://reviews.llvm.org/D53137

llvm-svn: 374042
2019-10-08 12:53:54 +00:00
Thomas Preud'homme 02ada9bd2b [FileCheck] Remove implementation types from API
Summary:
Remove use of FileCheckPatternContext and FileCheckString concrete types
from FileCheck API to allow moving it and the other implementation only
only declarations into a private header file.

Reviewers: jhenderson, chandlerc, jdenny, probinson, grimar, arichardson, rnk

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68186

llvm-svn: 373211
2019-09-30 14:12:03 +00:00
Matt Arsenault cf10372119 GlobalISel: Add G_FMAD instruction
llvm-svn: 371254
2019-09-06 20:49:10 +00:00
Daniel Sanders f803237926 [globalisel][knownbits] Account for missing type constraints
Now that we look through copies, it's possible to visit registers that
have a register class constraint but not a type constraint. Avoid looking
through copies when this occurs as the SrcReg won't be able to determine
it's bit width or any known bits.

Along the same lines, if the initial query is on a register that doesn't
have a type constraint then the result is a default-constructed KnownBits,
that is, a 1-bit fully-unknown value.

llvm-svn: 371116
2019-09-05 20:26:02 +00:00
Daniel Sanders e55c4f33ec [globalisel][knownbits] Correct a typo that prevented a test working as intended
llvm-svn: 371115
2019-09-05 20:25:52 +00:00
Daniel Sanders b276a9a51e [globalisel] Support trivial COPY in GISelKnownBits
Summary: Allow GISelKnownBits to look through the trivial case of TargetOpcode::COPY

Reviewers: aditya_nandakumar

Subscribers: rovka, hiraditya, volkan, Petar.Avramovic, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67131

llvm-svn: 370955
2019-09-04 18:59:43 +00:00
Matt Arsenault b2b9a23758 GlobalISel: Add maskedValueIsZero and signBitIsZero to known bits
I dropped the DemandedElts since it seems to be missing from some of
the new interfaces, but not others.

llvm-svn: 370389
2019-08-29 17:24:36 +00:00
Jonas Devlieghere 0eaee545ee [llvm] Migrate llvm::make_unique to std::make_unique
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.

llvm-svn: 369013
2019-08-15 15:54:37 +00:00
Aditya Nandakumar 70fdfed45f [GlobalISel]: Add KnownBits for G_XOR
https://reviews.llvm.org/D66119

llvm-svn: 368648
2019-08-13 04:32:33 +00:00
Aditya Nandakumar 55371e697c [GISel]: Fix a bug in KnownBits where we should have been using SizeInBits
https://reviews.llvm.org/D66039

We were using getIndexSize instead of getIndexSizeInBits().
Added test case for G_PTRTOINT and G_INTTOPTR.

llvm-svn: 368618
2019-08-12 21:28:12 +00:00
Daniel Sanders 0a317df59f Remove leftover MF->dump()'s from r368487 that break release builds
llvm-svn: 368489
2019-08-09 21:33:31 +00:00
Daniel Sanders e9a57c2b23 [globalisel] Add G_SEXT_INREG
Summary:
Targets often have instructions that can sign-extend certain cases faster
than the equivalent shift-left/arithmetic-shift-right. Such cases can be
identified by matching a shift-left/shift-right pair but there are some
issues with this in the context of combines. For example, suppose you can
sign-extend 8-bit up to 32-bit with a target extend instruction.
  %1:_(s32) = G_SHL %0:_(s32), i32 24 # (I've inlined the G_CONSTANT for brevity)
  %2:_(s32) = G_ASHR %1:_(s32), i32 24
  %3:_(s32) = G_ASHR %2:_(s32), i32 1
would reasonably combine to:
  %1:_(s32) = G_SHL %0:_(s32), i32 24
  %2:_(s32) = G_ASHR %1:_(s32), i32 25
which no longer matches the special case. If your shifts and extend are
equal cost, this would break even as a pair of shifts but if your shift is
more expensive than the extend then it's cheaper as:
  %2:_(s32) = G_SEXT_INREG %0:_(s32), i32 8
  %3:_(s32) = G_ASHR %2:_(s32), i32 1
It's possible to match the shift-pair in ISel and emit an extend and ashr.
However, this is far from the only way to break this shift pair and make
it hard to match the extends. Another example is that with the right
known-zeros, this:
  %1:_(s32) = G_SHL %0:_(s32), i32 24
  %2:_(s32) = G_ASHR %1:_(s32), i32 24
  %3:_(s32) = G_MUL %2:_(s32), i32 2
can become:
  %1:_(s32) = G_SHL %0:_(s32), i32 24
  %2:_(s32) = G_ASHR %1:_(s32), i32 23

All upstream targets have been configured to lower it to the current
G_SHL,G_ASHR pair but will likely want to make it legal in some cases to
handle their faster cases.

To follow-up: Provide a way to legalize based on the constant. At the
moment, I'm thinking that the best way to achieve this is to provide the
MI in LegalityQuery but that opens the door to breaking core principles
of the legalizer (legality is not context sensitive). That said, it's
worth noting that looking at other instructions and acting on that
information doesn't violate this principle in itself. It's only a
violation if, at the end of legalization, a pass that checks legality
without being able to see the context would say an instruction might not be
legal. That's a fairly subtle distinction so to give a concrete example,
saying %2 in:
  %1 = G_CONSTANT 16
  %2 = G_SEXT_INREG %0, %1
is legal is in violation of that principle if the legality of %2 depends
on %1 being constant and/or being 16. However, legalizing to either:
  %2 = G_SEXT_INREG %0, 16
or:
  %1 = G_CONSTANT 16
  %2:_(s32) = G_SHL %0, %1
  %3:_(s32) = G_ASHR %2, %1
depending on whether %1 is constant and 16 does not violate that principle
since both outputs are genuinely legal.

Reviewers: bogner, aditya_nandakumar, volkan, aemerson, paquette, arsenm

Subscribers: sdardis, jvesely, wdng, nhaehnle, rovka, kristof.beyls, javed.absar, hiraditya, jrtc27, atanasyan, Petar.Avramovic, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61289

llvm-svn: 368487
2019-08-09 21:11:20 +00:00
Aditya Nandakumar c8ac029d0a [GISel]: Add GISelKnownBits analysis
https://reviews.llvm.org/D65698

This adds a KnownBits analysis pass for GISel. This was done as a
pass (compared to static functions) so that we can add other features
such as caching queries(within a pass and across passes) in the future.
This patch only adds the basic pass boiler plate, and implements a lazy
non caching knownbits implementation (ported from SelectionDAG). I've
also hooked up the AArch64PreLegalizerCombiner pass to use this - there
should be no compile time regression as the analysis is lazy.

llvm-svn: 368065
2019-08-06 17:18:29 +00:00
Graham Hunter 208d63ea90 [MVT][SVE] Map between scalable vector IR Type and VTs
Adds a two way mapping between the scalable vector IR type and
corresponding SelectionDAG ValueTypes.

Reviewers: craig.topper, jeroen.dobbelaere, fhahn, rengolin, greened, rovka

Reviewed By: greened

Differential Revision: https://reviews.llvm.org/D47770

llvm-svn: 367832
2019-08-05 11:18:19 +00:00
Matt Arsenault 5faa533e47 GlobalISel: Fix widenScalar for G_MERGE_VALUES to pointer
AMDGPU testcase isn't broken now, but will be in a future patch
without this.

llvm-svn: 367591
2019-08-01 18:13:16 +00:00
Matt Arsenault 9cf980d4a7 GlobalISel: Add G_ATOMICRMW_{FADD|FSUB}
llvm-svn: 367369
2019-07-30 23:56:30 +00:00
Michael Liao 9ad917c2da Minor styling fix. NFC.
llvm-svn: 366456
2019-07-18 16:14:22 +00:00
Matt Arsenault 0966dd0d69 GlobalISel: Handle widenScalar of arbitrary G_MERGE_VALUES sources
Extract the sources to the GCD of the original size and target size,
padding with implicit_def as necessary.

Also fix the case where the requested source type is wider than the
original result type. This was ignoring the type, and just using the
destination. Do the operation in the requested type and truncate back.

llvm-svn: 366367
2019-07-17 20:22:44 +00:00
Matt Arsenault 914a59cad8 GlobalISel: Handle more cases for widenScalar of G_MERGE_VALUES
Use an anyext to the requested type for the leftover operand to
produce a slightly wider type, and then truncate the final merge.

I have another implementation almost ready which handles arbitrary
widens, but I think it produces worse code in this example (which I
think is 90% due to not folding redundant copies or folding out
implicit_def users), so I wanted to add this as a baseline first.

llvm-svn: 366366
2019-07-17 20:22:38 +00:00
Michael Liao 9cf71d10f8 [unittest] Add the missing bogus machine register info initialization.
llvm-svn: 365529
2019-07-09 18:22:48 +00:00
Michael Liao 329c032040 [unittest] Add bogus register info.
Reviewers: dstenb

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64421

llvm-svn: 365516
2019-07-09 17:19:01 +00:00
Matt Arsenault bd791b57f8 GlobalISel: widenScalar for G_BUILD_VECTOR
llvm-svn: 365320
2019-07-08 13:48:06 +00:00
Michael Liao 8d6ea2d48c [CodeGen] Enhance `MachineInstrSpan` to allow the end of MBB to be used.
Summary:
- Explicitly specify the parent MBB to allow the end iterator to be
  used.

Reviewers: aprantl, MatzeB, craig.topper, qcolombet

Subscribers: arsenm, jvesely, nhaehnle, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64261

llvm-svn: 365240
2019-07-05 20:23:59 +00:00
Matt Arsenault 6f74f55750 GlobalISel: Implement lower for min/max
llvm-svn: 364816
2019-07-01 17:18:03 +00:00
Matt Arsenault faeaedf8e9 GlobalISel: Remove unsigned variant of SrcOp
Force using Register.

One downside is the generated register enums require explicit
conversion.

llvm-svn: 364194
2019-06-24 16:16:12 +00:00
Matt Arsenault e3a676e9ad CodeGen: Introduce a class for registers
Avoids using a plain unsigned for registers throughoug codegen.
Doesn't attempt to change every register use, just something a little
more than the set needed to build after changing the return type of
MachineOperand::getReg().

llvm-svn: 364191
2019-06-24 15:50:29 +00:00
Matt Arsenault 5a321b899e GlobalISel: Use the original flags when lowering fneg to fsub
This was ignoring the flag on fneg, and using the source instruction's
flags. Also fixes tests missing from r358702.

Note the expansion itself isn't correct without nnan, but that should
be fixed separately.

llvm-svn: 363637
2019-06-17 23:48:43 +00:00
Aditya Nandakumar 5c7fcbdc4b [GISel]: Fix pattern matcher for m_OneUse
https://reviews.llvm.org/D63302

llvm-svn: 363424
2019-06-14 17:19:37 +00:00
Craig Topper 78c794a70b [X86] Fix several places that weren't passing what they though they were to MachineInstr::print
Over a year ago, MachineInstr gained a fourth boolean parameter that occurs
before the TII pointer. When this happened, several places started accidentally
passing TII into this boolean parameter instead of the TII parameter.

llvm-svn: 362312
2019-06-02 01:36:48 +00:00
Eli Friedman d8e8722791 [CodeGen] Fix hashing for MO_ExternalSymbol MachineOperands.
We were hashing the string pointer, not the string, so two instructions
could be identical (isIdenticalTo), but have different hash codes.

This showed up as a very rare, non-deterministic assertion failure
rehashing a DenseMap constructed by MachineOutliner.  So there's no
"real" testcase, just a unittest which checks that the hash function
behaves correctly.

I'm a little scared fixing this is going to cause a regression in
outlining or MachineCSE, but hopefully we won't run into any issues.

Differential Revision: https://reviews.llvm.org/D61975

llvm-svn: 362281
2019-06-01 00:08:54 +00:00
Matt Arsenault f3cedf4823 GlobalISel: Define integer min/max instructions
Doesn't attempt to emit them for anything yet, but some legalizations
I want to port use them.

llvm-svn: 361061
2019-05-17 18:36:31 +00:00
Matt Arsenault e1a2a28d6b GlobalISel: Add fp<->int casts to MachineIRBuilder
llvm-svn: 361019
2019-05-17 11:49:39 +00:00
Matt Arsenault 7f8ea15ffa GlobalISel: Add MIRBuilder wrappers for bitcount instructions
Various expansions use these.

llvm-svn: 361018
2019-05-17 11:49:35 +00:00
Matt Arsenault 2120748f77 GlobalISel: Add buildFMA to MachineIRBuilder
llvm-svn: 360888
2019-05-16 13:04:20 +00:00
Matt Arsenault d72f25e5b0 GlobalISel: Add buildXor/buildNot
llvm-svn: 360880
2019-05-16 12:23:04 +00:00
Matt Arsenault 27ac8408f6 GlobalISel: Add DstOp version of buildIntrinsic
llvm-svn: 360879
2019-05-16 12:22:56 +00:00
Matt Arsenault 11be78bc7a GlobalISel: Add buildFConstant for APFloat
llvm-svn: 360853
2019-05-16 04:09:06 +00:00
Matt Arsenault 940a9ff0f3 GlobalISel: Add some FP instructions to MachineIRBuilder
This makes FP legalization code more convenient.

llvm-svn: 360852
2019-05-16 04:08:55 +00:00
Bjorn Pettersson 60569363a5 [SelectionDAG] Use KnownBits::computeForAddSub/computeForAddCarry
Summary:
Use KnownBits::computeForAddSub/computeForAddCarry
in SelectionDAG::computeKnownBits when doing value
tracking for addition/subtraction.

This should improve the precision of the known bits,
as we only used to make a simple estimate of known
zeroes. The KnownBits support functions are also
able to deduce bits that are known to be one in the
result.

Reviewers: spatel, RKSimon, nikic, lebedev.ri

Reviewed By: nikic

Subscribers: nikic, javed.absar, lebedev.ri, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60460

llvm-svn: 358372
2019-04-15 07:19:11 +00:00
Amara Emerson d189680baa [GlobalISel] Introduce a CSEConfigBase class to allow targets to define their own CSE configs.
Because CodeGen can't depend on GlobalISel, we need a way to encapsulate the CSE
configs that can be passed between TargetPassConfig and the targets' custom
pass configs. This CSEConfigBase allows targets to create custom CSE configs
which is then used by the GISel passes for the CSEMIRBuilder.

This support will be used in a follow up commit to allow constant-only CSE for
-O0 compiles in D60580.

llvm-svn: 358368
2019-04-15 04:53:46 +00:00
Matt Arsenault 106429b4e4 GlobalISel: Add another overload of buildUnmerge
It's annoying to have to create an array of the result type,
particularly when you don't care about the size of the value.

llvm-svn: 357763
2019-04-05 14:03:07 +00:00
Craig Topper 2982b846e9 [Subtarget] Merge ProcSched and ProcDesc arrays in MCSubtargetInfo into a single array.
These arrays are both keyed by CPU name and go into the same tablegenerated file. Merge them so we only need to store keys once.

This also removes a weird space saving quirk where we used the ProcDesc.size() to create to build an ArrayRef for ProcSched.

Differential Revision: https://reviews.llvm.org/D58939

llvm-svn: 355431
2019-03-05 18:54:38 +00:00
Matt Arsenault d3093c2f1f GlobalISel: Implement fewerElementsVector for phi
llvm-svn: 355048
2019-02-28 00:16:32 +00:00
Daniel Sanders 6ac16e91f6 Try again to fix memory leak in r354692
The previous one didn't fix everything.

llvm-svn: 354719
2019-02-23 03:25:37 +00:00
Daniel Sanders f250cf8b41 Fix memory leak in r354692
llvm-svn: 354712
2019-02-23 01:13:35 +00:00
Daniel Sanders 07cda257f8 Restore ability for C++ API users to Enable IPRA.
Summary:
Prior to r310876 one of our out-of-tree targets was enabling IPRA by modifying
the TargetOptions::EnableIPRA. This no longer works on current trunk since the
useIPRA() hook overrides any values that are set in advance. This patch adjusts
the behaviour of the hook so that API users and useIPRA() can both enable it
but useIPRA() cannot disable it if the API user already enabled it.

Reviewers: arsenm

Reviewed By: arsenm

Subscribers: wdng, mgorny, llvm-commits

Differential Revision: https://reviews.llvm.org/D38043

llvm-svn: 354692
2019-02-22 20:59:07 +00:00
Matt Arsenault 26b7e859ef GlobalISel: Implement moreElementsVector for bit ops
llvm-svn: 354345
2019-02-19 16:30:19 +00:00
Matt Arsenault debaf4bd31 GlobalISel: Fix double count of offset for irregular vector breakdowns
Fixes cases with odd vectors that break into multiple requested size
pieces.

llvm-svn: 354280
2019-02-18 17:01:09 +00:00
Matt Arsenault 530d05e94a GlobalISel: Add alignment to LegalityQuery MMOs
This allows targets to specify the minimum alignment required for the
load/store.

llvm-svn: 354071
2019-02-14 22:41:09 +00:00
Chandler Carruth 3b387a7e3c Update files that were mistakenly added with the old file header.
llvm-svn: 353664
2019-02-11 08:07:32 +00:00
Matt Arsenault 91be65be65 GlobalISel: Try to make legalize rules more useful for vectors
Mostly keep the existing functions on scalars, but add versions which
also operate based on the vector element size.

llvm-svn: 353430
2019-02-07 17:25:51 +00:00
Matt Arsenault 3d6a49b0b9 GlobalISel: Fix not calling observer when legalizing bitcount ops
This was hiding bugs from never legalizing the source type.

llvm-svn: 353102
2019-02-04 22:26:33 +00:00
Matt Arsenault 22309c8701 GlobalISel: Fix CheckMachineFunction passing if ReadCheckFile files
This could be tested, but the FileCheck library spams the error
message to the console.

llvm-svn: 353081
2019-02-04 19:53:22 +00:00
Matt Arsenault f3a46d0ae9 GlobalISel: Allow constructing SrcOp/DstOp from MachineOperand
llvm-svn: 353080
2019-02-04 19:53:19 +00:00
Matt Arsenault 8121ec26c0 GlobalISel: Fix CSE handling of buildConstant
This fixes two problems with CSE done in buildConstant. First, this
would hit an assert when used with a vector result type. Solve this by
allowing CSE on the vector elements, but not on the result vector for
now.

Second, this was also performing the CSE based on the input
ConstantInt pointer. The underlying buildConstant could potentially
convert the constant depending on the result type, giving in a
different ConstantInt*. Stop allowing the APInt and ConstantInt forms
from automatically casting to the result type to avoid any similar
problems in the future.

llvm-svn: 353077
2019-02-04 19:15:50 +00:00
Matt Arsenault b3e86709dc GlobalISel: Improve gtest usage
Don't unnecessarily use ASSERT_*, and print the MachineFunction
on failure.

llvm-svn: 353072
2019-02-04 18:58:27 +00:00
Matt Arsenault 0723828675 GlobalISel: Fix moreElementsToNextPow2
This was completely broken. The condition was inverted, and changed
the element type for vectors of pointers.

Fixes bug 40592.

llvm-svn: 353069
2019-02-04 18:42:24 +00:00