RegisterBank Selection for scalable vector G_ADD and G_SUB by creating
new mappings for different types of vector register banks.
Then implement Instruction Selection for the same operations by choosing
the correct RISC-V vector register class.
Add a debug counter that allows forcing an sdag fallback after a certain
number of functions.
The intended use-case is to bisect which function gets miscompiled by
global isel using `-debug-counter=globalisel-count=N` (in cases where
sdag doesn't also miscompile it, of course).
The "falling back" debug line is printed unconditionally, because using
`-debug-only` is usually too spammy for the intended purpose.
G_GLOBAL_VALUE should be lowered into an absolute address if
`-codemodel=small` is used or into a PC-relative if `-codemodel=medium`
is used.
PR #68380 tried to create special instructions to do this, but I don't
see why we need to do that.
This will make it easy for callers to see issues with and fix up calls
to createTargetMachine after a future change to the params of
TargetMachine.
This matches other nearby enums.
For downstream users, this should be a fairly straightforward
replacement,
e.g. s/CodeGenOpt::Aggressive/CodeGenOptLevel::Aggressive
or s/CGFT_/CodeGenFileType::
Use the new matchtable-based combiner backend for all AMDGPU combiners.
This drop-in from the user's perspective; there are no test changes, the new combiner behaves exactly like the old one.
Depends on D153757
NOTE: This would land iff D153757 (RFC) lands too.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D153758
hoisted constants.
The constant hoisting pass tries to hoist large constants into predecessors and also
generates remat instructions in terms of the hoisted constants. These aim to prevent
codegen from rematerializing expensive constants multiple times. So we can re-use
this optimization, we can preserve the no-op bitcasts that are used to anchor
constants to the predecessor blocks.
SelectionDAG achieves this by having the OpaqueConstant node, which is just a
normal constant with an opaque flag set. I've opted to avoid introducing a new
constant generic instruction here. Instead, we have a new G_CONSTANT_FOLD_BARRIER
operation that constitutes a folding barrier.
These are somewhat like the optimization hints, G_ASSERT_ZEXT in that they're
eliminated by the generic instruction selection code.
This change by itself has very minor improvements in -Os CTMark overall. What this
does allow is better optimizations when future combines are added that rely on having
expensive constants remain unfolded.
Differential Revision: https://reviews.llvm.org/D144336
We currently have a bug where the legalizer, when dealing with phi operands,
may create instructions in the phi's incoming blocks at points which are effectively
dead due to a possible exception throw.
Say we have:
throwbb:
EH_LABEL
x0 = %callarg1
BL @may_throw_call
EH_LABEL
B returnbb
bb:
%v = phi i1 %true, throwbb, %false....
When legalizing we may need to widen the i1 %true value, and to do that we need
to create new extension instructions in the incoming block. Our insertion point
currently is the MBB::getFirstTerminator() which puts the IP before the unconditional
branch terminator in throwbb. These extensions may never be executed if the call
throws, and therefore we need to emit them before the call (but not too early, since
our new instruction may need values defined within throwbb as well).
throwbb:
EH_LABEL
x0 = %callarg1
BL @may_throw_call
EH_LABEL
%true = G_CONSTANT i32 1 ; <<<-- ruh'roh, this never executes if may_throw_call() throws!
B returnbb
bb:
%v = phi i32 %true, throwbb, %false....
To fix this, I've added two new instructions. The main idea is that G_INVOKE_REGION_START
is a terminator, which tries to model the fact that in the IR, the original invoke inst
is actually a terminator as well. By using that as the new insertion point, we
make sure to place new instructions on always executing paths.
Unfortunately we still need to make the legalizer use a new insertion point API
that I've added, since the existing `getFirstTerminator()` method does a reverse
walk up the block, and any non-terminator instructions cause it to bail out. To
avoid impacting compile time for all `getFirstTerminator()` uses, I've added a new
method that does a forward walk instead.
Differential Revision: https://reviews.llvm.org/D137905
Use salvageDebugInfo for instructions erased as trivially dead in
GlobalISel.
It would be helpful to implement support of G_PTR_ADD and G_FRAME_INDEX
in salvageDebugInfo in future in order to preserve more variable
location.
Reviewed by: arsenm
Differential Revision: https://reviews.llvm.org/D133986
This wasn't running at -O0, and causing crashes for AMDGPU. AMDGPU
needs this to match the addressing modes of stack access instructions,
which is even more important at -O0 than with optimizations.
It currently costs nothing to run ahead of time, so just always enable
it.
Expanding on D109750.
Since `DBG_VALUE` instructions have final register validity determined in
`LDVImpl::handleDebugValue`, there is no apparent reason to immediately prune
unused register operands as their defs are erased. Consequently, this renders
`MachineInstr::eraseFromParentAndMarkDBGValuesForRemoval` moot; gaining a
substantial performance improvement.
The only necessary changes involve making relevant passes consider invalid
DBG_VALUE vregs uses as valid.
Reviewed By: MatzeB
Differential Revision: https://reviews.llvm.org/D112852
This moves the registry higher in the LLVM library dependency stack.
Every client of the target registry needs to link against MC anyway to
actually use the target, so we might as well move this out of Support.
This allows us to ensure that Support doesn't have includes from MC/*.
Differential Revision: https://reviews.llvm.org/D111454
If these blocks are unreachable, then we can discard all of the instructions.
However, keep the block around because it may have an address taken or the
block may have a stale reference from a PHI somewhere. Instead of finding
those PHIs and fixing them up, just leave the block empty.
Differential Revision: https://reviews.llvm.org/D111201
This reverts commit d95cd81141a4e398e0d3337cb2e6617281d06278.
The selector sometimes leaves unreachable blocks unselected because it uses a
postorder traversal for the block ordering.
With the trap intrinsics now being emitted, these blocks are no longer empty and
the unselected G_INTRINSIC instructions survive past selection. To fix this,
keep track of which blocks are selected and later delete any blocks that weren't
selected.
To do this while supporting the existing functionality in SelectionDAG of using
PGO info, we add the ProfileSummaryInfo and LazyBlockFrequencyInfo analysis
dependencies to the instruction selector pass.
Then, use the predicate to generate constant pool loads for f32 materialization,
if we're targeting optsize/minsize.
Differential Revision: https://reviews.llvm.org/D97732
When replacing the dst reg with the src reg, we need to make sure that we
propagate the dst reg's register class through to the src.
Otherwise, we aren't meeting the requirements for G_ASSERT_ZEXT, and so the
verifier will fail.
Differential Revision: https://reviews.llvm.org/D95708
I think every target will want to remove these in the same way. Rather than
making them all implement the same code, let's just put this in
InstructionSelect.
Differential Revision: https://reviews.llvm.org/D95652
This matches the DAG behavior where this is called after the loop
checking for calls. The AMDGPU implementation depends on knowing if
there are calls in the function or not, so move this later.
Another problem is finalizeLowering is actually called twice; I was
seeing weird inconsistencies since the first call would produce
unexpected results and the second run would correct them in some
contexts. Since this requires disabling the verifier, and it's useful
to serialize the MIR immediately after selection, FinalizeISel should
probably not be a real pass.
Replace with forward declaration and move dependency down to source files that actually need it.
Both TargetLowering.h and TargetMachine.h are 2 of the most expensive headers (top 10) in the ClangBuildAnalyzer report when building llc.
We currently always set the HasCalls on MFI during translation and legalization if
we're handling a call or legalizing to a libcall. However, if that call is later
optimized to a tail call then we don't need the flag. The flag being set to true
causes frame lowering to always save and restore FP/LR, which adds unnecessary code.
This change does the same thing as SelectionDAG and ports over some code that scans
instructions after selection, using TargetInstrInfo to determine if target opcodes
are known calls.
Code size geomean improvements on CTMark:
-O0 : 0.1%
-Os : 0.3%
Differential Revision: https://reviews.llvm.org/D67868
llvm-svn: 372443
AMDGPU uses this for some addressing mode selection patterns. The
analysis run itself doesn't do anything so it seems easier to just
always require this than adding a way to opt in.
llvm-svn: 370388
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
Currently we can't keep any state in the selector object that we get from
subtarget. As a result we have to plumb through all our variables through
multiple functions. This change makes it non-const and adds a virtual init()
method to allow further state to be captured for each target.
AArch64 makes use of this in this patch to cache a call to hasFnAttribute()
which is expensive to call, and is used on each selection of G_BRCOND.
Differential Revision: https://reviews.llvm.org/D65984
llvm-svn: 368652
Summary:
All the GlobalISel passes are initialized when the target calls
initializeGlobalISel(), so we don't need to call the initializers
from the pass constructors.
Reviewers: qcolombet, t.p.northover, paquette, dsanders, aemerson, aditya_nandakumar
Reviewed By: aemerson
Subscribers: rovka, kristof.beyls, hiraditya, volkan, Petar.Avramovic, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63235
llvm-svn: 363642
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
This re-applies r336929 with a fix to accomodate for the Mips target
scheduling multiple SelectionDAG instances into the pass pipeline.
PrologEpilogInserter and StackColoring depend on the StackProtector analysis
being alive from the point it is run until PEI, which requires that they are all
scheduled in the same FunctionPassManager. Inserting a (machine) ModulePass
between StackProtector and PEI results in these passes being in separate
FunctionPassManagers and the StackProtector is not available for PEI.
PEI and StackColoring don't use much information from the StackProtector pass,
so transfering the required information to MachineFrameInfo is cleaner than
keeping the StackProtector pass around. This commit moves the SSP layout
information to MFI instead of keeping it in the pass.
This patch set (D37580, D37581, D37582, D37583, D37584, D37585, D37586, D37587)
is a first draft of the pagerando implementation described in
http://lists.llvm.org/pipermail/llvm-dev/2017-June/113794.html.
Patch by Stephen Crane <sjc@immunant.com>
Differential Revision: https://reviews.llvm.org/D49256
llvm-svn: 336964
PrologEpilogInserter and StackColoring depend on the StackProtector analysis
being alive from the point it is run until PEI, which requires that they are all
scheduled in the same FunctionPassManager. Inserting a (machine) ModulePass
between StackProtector and PEI results in these passes being in separate
FunctionPassManagers and the StackProtector is not available for PEI.
PEI and StackColoring don't use much information from the StackProtector pass,
so transfering the required information to MachineFrameInfo is cleaner than
keeping the StackProtector pass around. This commit moves the SSP layout
information to MFI instead of keeping it in the pass.
This patch set (D37580, D37581, D37582, D37583, D37584, D37585, D37586, D37587)
is a first draft of the pagerando implementation described in
http://lists.llvm.org/pipermail/llvm-dev/2017-June/113794.html.
Patch by Stephen Crane <sjc@immunant.com>
Differential Revision: https://reviews.llvm.org/D49256
llvm-svn: 336929
by replacing DenseMap with IndexedMap for LLTs within MRI, as
benchmarked by cross-compiling sqlite3 amalgamation for AArch64
on x86 machine.
Reviewed By: qcolombet
Differential Revision: https://reviews.llvm.org/D46809
llvm-svn: 333125
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.
In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.
Differential Revision: https://reviews.llvm.org/D43624
llvm-svn: 332240
The main goal of this change is to make it much easier to track which
rules are actually covered by Testgen'erated regression tests.
Reviewers: aemerson, dsanders
Differential Revision: https://reviews.llvm.org/D46095
llvm-svn: 330988
Currently it's impossible to test InstructionSelect pass with MIR which
is considered illegal by the Legalizer in Assert builds. In early stages
of porting an existing backend from SelectionDAG ISel to GlobalISel,
however, we would have very basic CallLowering, Legalizer, and
RegBankSelect implementations, but rather functional Instruction Select
with quite a few patterns selectable due to the semi-automatic porting
process borrowing them from SelectionDAG ISel.
As we are trying to define legality as a property of being selectable by
the instruction selector, it would be nice to be able to easily check
what the selector can do in its current state w/o the legality check
provided by the Legalizer getting in the way.
It also seems beneficial to have a regression testing set up that would
not allow the selector to silently regress in its support of the MIR not
supported yet by the previous passes in the GlobalISel pipeline.
This commit adds -disable-gisel-legality-check command line option to
llc that disables those legality checks in RegBankSelect and
InstructionSelect passes.
It also adds quite a few MIR test cases for AArch64's Instruction
Selector. Every one of them would fail on the legality check at the
moment, but will select just fine if the check is disabled. Every test
MachineFunction is intended to exercise a specific selection rule and
that rule only, encoded in the MachineFunction's name by the rule's
number, ID, and index of its GIM_Try opcode in TableGen'erated
MatchTable (-optimize-match-table=false).
Reviewers: ab, dsanders, qcolombet, rovka
Reviewed By: bogner
Subscribers: kristof.beyls, volkan, aditya_nandakumar, aemerson,
rengolin, t.p.northover, javed.absar, llvm-commits
Differential Revision: https://reviews.llvm.org/D42886
llvm-svn: 326396
FailedISel MachineFunction property is part of the CodeGen pipeline
state as much as every other property, notably, Legalized,
RegBankSelected, and Selected. Let's make that part of the state also
serializable / de-serializable, so if GlobalISel aborts on some of the
functions of a large module, but not the others, it could be easily seen
and the state of the pipeline could be maintained through llc's
invocations with -stop-after / -start-after.
To make MIR printable and generally to not to break it too much too
soon, this patch also defers cleaning up the vreg -> LLT map until
ResetMachineFunctionPass.
To make MIR with FailedISel: true also machine verifiable, machine
verifier is changed so it treats a MIR-module as non-regbankselected and
non-selected if there is FailedISel property set.
Reviewers: qcolombet, ab
Reviewed By: dsanders
Subscribers: javed.absar, rovka, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D42877
llvm-svn: 326343
https://reviews.llvm.org/D42402
A lot of these copies are useless (copies b/w VRegs having the same
regclass) and should be cleaned up.
llvm-svn: 323291
All these headers already depend on CodeGen headers so moving them into
CodeGen fixes the layering (since CodeGen depends on Target, not the
other way around).
llvm-svn: 318490
Summary:
This patch adds a LLVM_ENABLE_GISEL_COV which, like LLVM_ENABLE_DAGISEL_COV,
causes TableGen to instrument the generated table to collect rule coverage
information. However, LLVM_ENABLE_GISEL_COV goes a bit further than
LLVM_ENABLE_DAGISEL_COV. The information is written to files
(${CMAKE_BINARY_DIR}/gisel-coverage-* by default). These files can then be
concatenated into ${LLVM_GISEL_COV_PREFIX}-all after which TableGen will
read this information and use it to emit warnings about untested rules.
This technique could also be used by SelectionDAG and can be further
extended to detect hot rules and give them priority over colder rules.
Usage:
* Enable LLVM_ENABLE_GISEL_COV in CMake
* Build the compiler and run some tests
* cat gisel-coverage-[0-9]* > gisel-coverage-all
* Delete lib/Target/*/*GenGlobalISel.inc*
* Build the compiler
Known issues:
* ${LLVM_GISEL_COV_PREFIX}-all must be generated as a manual
step due to a lack of a portable 'cat' command. It should be the
concatenation of all ${LLVM_GISEL_COV_PREFIX}-[0-9]* files.
* There's no mechanism to discard coverage information when the ruleset
changes
Depends on D39742
Reviewers: ab, qcolombet, t.p.northover, aditya_nandakumar, rovka
Reviewed By: rovka
Subscribers: vsk, arsenm, nhaehnle, mgorny, kristof.beyls, javed.absar, igorb, llvm-commits
Differential Revision: https://reviews.llvm.org/D39747
llvm-svn: 318356
This exposes a method in MachineFrameInfo that calculates
MaxCallFrameSize and calls it after instruction selection in the ARM
target.
This avoids
ARMBaseRegisterInfo::canRealignStack()/ARMFrameLowering::hasReservedCallFrame()
giving different answers in early/late phases of codegen.
The testcase shows a particular nasty example result of that where we
would fail to properly align an alloca.
Differential Revision: https://reviews.llvm.org/D32622
llvm-svn: 302303
1. RegisterClass::getSize() is split into two functions:
- TargetRegisterInfo::getRegSizeInBits(const TargetRegisterClass &RC) const;
- TargetRegisterInfo::getSpillSize(const TargetRegisterClass &RC) const;
2. RegisterClass::getAlignment() is replaced by:
- TargetRegisterInfo::getSpillAlignment(const TargetRegisterClass &RC) const;
This will allow making those values depend on subtarget features in the
future.
Differential Revision: https://reviews.llvm.org/D31783
llvm-svn: 301221
Quentin points out that r298358 would cause us to emit different code
with debug info. That's a big no-no; also erase the instructions that
only live thanks to DBG_VALUE users.
Adrian explained how this is an existing problem and an OK thing to do:
clang has allocas for all variables so shouldn't be affected at -O0, but
swift uses a bit of inlineasm to explicitly keep values live for the
purpose of debug info quality. I'm not sure there is a better scheme.
llvm-svn: 298460
Folding instructions when selecting can cause them to become dead.
Don't select these dead instructions (if they don't have other side
effects, and don't define physical registers).
Preserve existing tests by adding COPYs.
In some tests, the G_CONSTANT vregs never get constrained to a class:
the only use of the vreg was folded into another instruction, so the
G_CONSTANT, now dead, never gets selected.
llvm-svn: 298224
