30 Commits

Author SHA1 Message Date
Tim Northover
36147adc0b GlobalISel: add combiner to form indexed loads.
Loosely based on DAGCombiner version, but this part is slightly simpler in
GlobalIsel because all address calculation is performed by G_GEP. That makes
the inc/dec distinction moot so there's just pre/post to think about.

No targets can handle it yet so testing is via a special flag that overrides
target hooks.

llvm-svn: 371384
2019-09-09 10:04:23 +00:00
Amara Emerson
fbaf425b79 [GlobalISel][CallLowering] Add support for splitting types according to calling conventions.
On AArch64, s128 types have to be split into s64 GPRs when passed as arguments.
This change adds the generic support in call lowering for dealing with multiple
registers, for incoming and outgoing args.

Support for splitting for return types not yet implemented.

Differential Revision: https://reviews.llvm.org/D66180

llvm-svn: 370822
2019-09-03 21:42:28 +00:00
Daniel Sanders
0c47611131 Apply llvm-prefer-register-over-unsigned from clang-tidy to LLVM
Summary:
This clang-tidy check is looking for unsigned integer variables whose initializer
starts with an implicit cast from llvm::Register and changes the type of the
variable to llvm::Register (dropping the llvm:: where possible).

Partial reverts in:
X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister
X86FixupLEAs.cpp - Some functions return unsigned and arguably should be MCRegister
X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister
HexagonBitSimplify.cpp - Function takes BitTracker::RegisterRef which appears to be unsigned&
MachineVerifier.cpp - Ambiguous operator==() given MCRegister and const Register
PPCFastISel.cpp - No Register::operator-=()
PeepholeOptimizer.cpp - TargetInstrInfo::optimizeLoadInstr() takes an unsigned&
MachineTraceMetrics.cpp - MachineTraceMetrics lacks a suitable constructor

Manual fixups in:
ARMFastISel.cpp - ARMEmitLoad() now takes a Register& instead of unsigned&
HexagonSplitDouble.cpp - Ternary operator was ambiguous between unsigned/Register
HexagonConstExtenders.cpp - Has a local class named Register, used llvm::Register instead of Register.
PPCFastISel.cpp - PPCEmitLoad() now takes a Register& instead of unsigned&

Depends on D65919

Reviewers: arsenm, bogner, craig.topper, RKSimon

Reviewed By: arsenm

Subscribers: RKSimon, craig.topper, lenary, aemerson, wuzish, jholewinski, MatzeB, qcolombet, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, wdng, nhaehnle, sbc100, jgravelle-google, kristof.beyls, hiraditya, aheejin, kbarton, fedor.sergeev, javed.absar, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, tpr, PkmX, jocewei, jsji, Petar.Avramovic, asbirlea, Jim, s.egerton, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65962

llvm-svn: 369041
2019-08-15 19:22:08 +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
Amara Emerson
85e5e28ab4 [AArch64][GlobalISel] Inline tiny memcpy et al at -O0.
FastISel already does this since the initial arm64 port was upstreamed, so
it seems there are no issues with doing this at -O0 for very small memcpys.

Gives a 0.2% geomean code size improvement on CTMark.

Differential Revision: https://reviews.llvm.org/D65758

llvm-svn: 367919
2019-08-05 20:02:52 +00:00
Guillaume Chatelet
65e4b47aad [LLVM][Alignment] Introduce Alignment Type in DataLayout
Summary:
This is patch is part of a serie 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, jfb, jakehehrlich

Subscribers: hiraditya, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65521

Make getFunctionPtrAlign() return MaybeAlign

llvm-svn: 367817
2019-08-05 09:00:43 +00:00
Amara Emerson
13af1ed8e3 [GlobalISel] Support for inlining memcpy, memset and memmove calls.
This introduces a new family of combiner helper routines that re-use the
target specific cost model from SelectionDAG, and generate inline implementations
of the memcpy family of intrinsics.

The combines are only enabled at optimization levels higher than -O0, and give
very substantial performance improvements.

Differential Revision: https://reviews.llvm.org/D65167

llvm-svn: 366951
2019-07-24 22:17:31 +00:00
Amara Emerson
6616e269a6 [AArch64][GlobalISel] Optimize conditional branches followed by unconditional branches
If we have an icmp->brcond->br sequence where the brcond just branches to the
next block jumping over the br, while the br takes the false edge, then we can
modify the conditional branch to jump to the br's target while inverting the
condition of the incoming icmp. This means we can eliminate the br as an
unconditional branch to the fallthrough block.

Differential Revision: https://reviews.llvm.org/D64354

llvm-svn: 365510
2019-07-09 16:05:59 +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
Daniel Sanders
184c8ee920 [globalisel] Fix iterator invalidation in the extload combines
Summary:
Change the way we deal with iterator invalidation in the extload combines as it
was still possible to neglect to visit a use. Even worse, it happened in the
in-tree test cases and the checks weren't good enough to detect it.

We now take a cheap copy of the use list before iterating over it. This
prevents iterator invalidation from occurring and has the nice side effect
of making the existing schedule-for-erase/schedule-for-insert mechanism
moot.

Reviewers: aditya_nandakumar

Reviewed By: aditya_nandakumar

Subscribers: rovka, kristof.beyls, javed.absar, volkan, Petar.Avramovic, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61813

llvm-svn: 363616
2019-06-17 20:56:31 +00:00
Amara Emerson
02a90ea73d [AArch64][GlobalISel] Don't do extending loads combine for non-pow-2 types.
Since non-pow-2 types are going to get split up into multiple loads anyway,
don't do the [SZ]EXTLOAD combine for those and save us trouble later in
legalization.

llvm-svn: 358458
2019-04-15 22:34:08 +00:00
Daniel Sanders
dfa0f556bf [globalisel][combine] Split existing rules into a match and apply step
Summary:
The declarative tablegen definitions split rules into match and apply steps.
Prepare for that by doing the same in the C++ implementations. This aids
some of the migration effort while the tablegen version is incomplete.

Reviewers: bogner, volkan, aditya_nandakumar, paquette, aemerson

Reviewed By: aditya_nandakumar

Subscribers: rovka, kristof.beyls, Petar.Avramovic, jdoerfert, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58150

llvm-svn: 353996
2019-02-14 00:15:28 +00:00
Amara Emerson
bf43004ff1 [AArch64][GlobalISel] Fix the G_EXTLOAD combiner creating non-extending illegal instructions.
This fixes loads like 's1 = load %p (load 1 from %p)' being combined with an
extend into an illegal 's8 = g_extload %p (load 1 from %p)' which doesn't do any
extension, by avoiding touching those < s8 size loads.

This bug was uncovered by a verifier update r351584, which I reverted it to keep
the bots green.

llvm-svn: 352311
2019-01-27 10:56:20 +00:00
Chandler Carruth
2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Daniel Sanders
629db5d8e5 [globalisel][combiner] Make the CombinerChangeObserver a MachineFunction::Delegate
Summary:
This allows us to register it with the MachineFunction delegate and be
notified automatically about erasure and creation of instructions. However,
we still need explicit notification for modifications such as those caused
by setReg() or replaceRegWith().

There is a catch with this though. The notification for creation is
delivered before any operands can be added. While appropriate for
scheduling combiner work. This is unfortunate for debug output since an
opcode by itself doesn't provide sufficient information on what happened.
As a result, the work list remembers the instructions (when debug output is
requested) and emits a more complete dump later.

Another nit is that the MachineFunction::Delegate provides const pointers
which is inconvenient since we want to use it to schedule future
modification. To resolve this GISelWorkList now has an optional pointer to
the MachineFunction which describes the scope of the work it is permitted
to schedule. If a given MachineInstr* is in this function then it is
permitted to schedule work to be performed on the MachineInstr's. An
alternative to this would be to remove the const from the
MachineFunction::Delegate interface, however delegates are not permitted
to modify the MachineInstr's they receive.

In addition to this, the observer has three interface changes.
* erasedInstr() is now erasingInstr() to indicate it is about to be erased
  but still exists at the moment.
* changingInstr() and changedInstr() have been added to report changes
  before and after they are made. This allows us to trace the changes
  in the debug output.
* As a convenience changingAllUsesOfReg() and
  finishedChangingAllUsesOfReg() will report changingInstr() and
  changedInstr() for each use of a given register. This is primarily useful
  for changes caused by MachineRegisterInfo::replaceRegWith()

With this in place, both combine rules have been updated to report their
changes to the observer.

Finally, make some cosmetic changes to the debug output and make Combiner
and CombinerHelp

Reviewers: aditya_nandakumar, bogner, volkan, rtereshin, javed.absar

Reviewed By: aditya_nandakumar

Subscribers: mgorny, rovka, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D52947

llvm-svn: 349167
2018-12-14 17:50:14 +00:00
Daniel Sanders
91dfdd5734 [globalisel] Rename GISelChangeObserver's erasedInstr() to erasingInstr() and related nits. NFC
Summary:
There's little of interest that can be done to an already-erased instruction.
You can't inspect it, write it to a debug log, etc. It ought to be notification
that we're about to erase it. Rename the function to clarify the timing of the
event and reflect current usage.

Also fixed one case where we were trying to print an erased instruction.

Reviewers: aditya_nandakumar

Reviewed By: aditya_nandakumar

Subscribers: rovka, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D55611

llvm-svn: 348976
2018-12-12 21:32:01 +00:00
Aditya Nandakumar
f75d4f329c [GISel]: Provide standard interface to observe changes in GISel passes
https://reviews.llvm.org/D54980

This provides a standard API across GISel passes to observe and notify
passes about changes (insertions/deletions/mutations) to MachineInstrs.
This patch also removes the recordInsertion method in MachineIRBuilder
and instead provides method to setObserver.

Reviewed by: vkeles.

llvm-svn: 348406
2018-12-05 20:14:52 +00:00
Daniel Sanders
a464ffd52c [globalisel][combine] When placing truncates, handle the case when the BB is empty
GlobalISel uses MIR with implicit fallthrough on each basic block. As a result,
getFirstNonPhi() can return end().

llvm-svn: 343829
2018-10-04 23:47:37 +00:00
Daniel Sanders
ab358bfd09 [globalisel][combine] Fix a rare crash when encountering an instruction whose op0 isn't a reg
The simplest instance of this is an intrinsic with no results which will have the
intrinsic ID as operand 0.

Also fix some benign incorrectness when op0 is a reg but isn't a def that was
guarded against by checking for the extension opcodes.

llvm-svn: 343821
2018-10-04 21:44:32 +00:00
Daniel Sanders
a05c7583c9 [globalisel][combine] Improve the truncate placement for the extending-loads combine
This brings the extending loads patch back to the original intent but minus the
PHI bug and with another small improvement to de-dupe truncates that are
inserted into the same block.

The truncates are sunk to their uses unless this would require inserting before a
phi in which case it sinks to the _beginning_ of the predecessor block for that
path (but no earlier than the def).

The reason for choosing the beginning of the predecessor is that it makes de-duping
multiple truncates in the same block simple, and optimized code is going to run a
scheduler at some point which will likely change the position anyway.

llvm-svn: 343804
2018-10-04 18:44:58 +00:00
Daniel Sanders
fb9b99b26e [globalisel][combines] Don't sink G_TRUNC down to use if that use is a G_PHI
This fixes a problem where the register allocator fails to eliminate a PHI
because there's a non-PHI in the middle of the PHI instructions at the start
of a BB.

This G_TRUNC can be better placed but this at least fixes the correctness issue
quickly. I'll follow up with a patch to the verifier to catch this kind of bug
in future.

llvm-svn: 343693
2018-10-03 15:43:39 +00:00
Jonas Toth
602e3a640f [CodeGen] NFC fix pedantic warning from extra semicolon
llvm-svn: 343674
2018-10-03 10:59:19 +00:00
Daniel Sanders
c973ad1878 Re-commit: [globalisel] Add a combiner helpers for extending loads and use them in a pre-legalize combiner for AArch64
Summary: Depends on D45541

Reviewers: ab, aditya_nandakumar, bogner, rtereshin, volkan, rovka, javed.absar, aemerson

Subscribers: aemerson, rengolin, mgorny, javed.absar, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D45543

The previous commit failed portions of the test-suite on GreenDragon due to
duplicate COPY instructions and iterator invalidation. Both issues have now
been fixed. To assist with this, a helper (cloneVirtualRegister) has been added
to MachineRegisterInfo that can be used to get another register that has the same
type and class/bank as an existing one.

llvm-svn: 343654
2018-10-03 02:12:17 +00:00
Daniel Sanders
33f42f97af Revert: r343521 and r343541: [globalisel] Add a combiner helpers for extending loads and use them in a pre-legalize combiner for AArch64
There's a strange assertion on two of the Green Dragon bots that goes away when
this is reverted. The assertion is in RegBankAlloc and if it is this commit then
-verify-machine-instrs should have caught it earlier in the pipeline.

llvm-svn: 343546
2018-10-01 22:32:08 +00:00
Reid Kleckner
7a6966ec27 Fix the Windows build in GlobalISel
Clang-cl was complaining about some sort of constexpr narrowing bug:

C:\src\llvm-project\llvm\lib\CodeGen\GlobalISel\CombinerHelper.cpp(136,31):  error: non-constant-expression cannot be narrowed from type 'llvm::TargetOpcode::(anonymous enum at C:\src\llvm-project\llvm\include\llvm/CodeGen/TargetOpcodes.h:22:1)' to 'unsigned int' in initializer list [-Wc++11-narrowing]
                              unsigned(MI.getOpcode()) == unsigned(TargetOpcode::G_LOAD)
                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
C:\src\llvm-project\llvm\lib\CodeGen\GlobalISel\CombinerHelper.cpp(136,31):  note: insert an explicit cast to silence this issue
                              unsigned(MI.getOpcode()) == unsigned(TargetOpcode::G_LOAD)
                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                              static_cast<unsigned int>(

llvm-svn: 343541
2018-10-01 21:39:39 +00:00
Daniel Sanders
9659bfda5a [globalisel] Add a combiner helpers for extending loads and use them in a pre-legalize combiner for AArch64
Summary: Depends on D45541

Reviewers: ab, aditya_nandakumar, bogner, rtereshin, volkan, rovka, javed.absar, aemerson

Subscribers: aemerson, rengolin, mgorny, javed.absar, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D45543

llvm-svn: 343521
2018-10-01 18:56:47 +00:00
Daniel Sanders
618437459c Revert r331816 and r331820 - [globalisel] Add a combiner helpers for extending loads and use them in a pre-legalize combiner for AArch64
Reverting this to see if the clang-cmake-aarch64-global-isel and
clang-cmake-aarch64-quick bots are failing because of this commit.
We know it wasn't r331819.

llvm-svn: 331846
2018-05-09 05:00:17 +00:00
Daniel Sanders
ec17920da1 [globalisel] Correct r331816 to check the opcode before calling getOperand().
Fix a silly mistake in my pre-commit changes for r331816. It should check what
opcode the insn is before extracting the operands.

NFC at the moment since the caller already checked the opcode.

llvm-svn: 331820
2018-05-08 22:58:35 +00:00
Daniel Sanders
d24dcdd1f7 [globalisel] Add a combiner helpers for extending loads and use them in a pre-legalize combiner for AArch64
Summary: Depends on D45541

Reviewers: ab, aditya_nandakumar, bogner, rtereshin, volkan, rovka, javed.absar, aemerson

Reviewed By: aemerson

Subscribers: aemerson, rengolin, mgorny, javed.absar, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D45543

llvm-svn: 331816
2018-05-08 22:26:39 +00:00
Aditya Nandakumar
81c81b6426 [GISel]: Implement GlobalISel combiner API.
https://reviews.llvm.org/D41373

The various components are

GICombinerHelper contains transformations that are common to all
targets. Targets can pick and choose which transformations (at
function/opcode granularity) each pass uses via configuring a
GICombinerInfo.

GICombiner contains some common code and it does the traversal,
driving of combines, worklist management and iterating until
convergence.

GICombinerInfo is an interface with a virtual method called combine.
The combiner info will allow targets to pick and choose (or
implement their own specific combines). CombineInfos can make
use of available combines in GICombineHelper to configure the
transformations for a particular pass. Currently this approach allows
cherry picking transformations from helpers (at function/opcode
granularity) and also allows early returning on specific
transformations. Targets also get to prioritize whether target specific
combines run before/after the opt-in generic combines. Ideally we would
like this part to be configured by both C++ and Tablegen. The
CombinerInfo also has a field which indicates how to deal with
IllegalOps (ie - should we allow to create them/or legalize them?).

A CombinerPass would configure a CombinerInfo, create the GICombiner
with the Info, and call
GICombiner::combineMachineInstrs(MachineFunction&).
This organization is very similar to the GISelLegalizer.

llvm-svn: 323392
2018-01-25 00:41:58 +00:00