Following discussions in #110443, and the following earlier discussions
in https://lists.llvm.org/pipermail/llvm-dev/2017-October/117907.html,
https://reviews.llvm.org/D38482, https://reviews.llvm.org/D38489, this
PR attempts to overhaul the `TargetMachine` and `LLVMTargetMachine`
interface classes. More specifically:
1. Makes `TargetMachine` the only class implemented under
`TargetMachine.h` in the `Target` library.
2. `TargetMachine` contains target-specific interface functions that
relate to IR/CodeGen/MC constructs, whereas before (at least on paper)
it was supposed to have only IR/MC constructs. Any Target that doesn't
want to use the independent code generator simply does not implement
them, and returns either `false` or `nullptr`.
3. Renames `LLVMTargetMachine` to `CodeGenCommonTMImpl`. This renaming
aims to make the purpose of `LLVMTargetMachine` clearer. Its interface
was moved under the CodeGen library, to further emphasis its usage in
Targets that use CodeGen directly.
4. Makes `TargetMachine` the only interface used across LLVM and its
projects. With these changes, `CodeGenCommonTMImpl` is simply a set of
shared function implementations of `TargetMachine`, and CodeGen users
don't need to static cast to `LLVMTargetMachine` every time they need a
CodeGen-specific feature of the `TargetMachine`.
5. More importantly, does not change any requirements regarding library
linking.
cc @arsenm @aeubanks
reserveRegisterTuples is slow because it uses MCRegAliasIterator and
hence ends up reserving the same aliased registers many times. This
patch changes getReservedRegs not to use it for reserving SGPRs, VGPRs
and AGPRs. Instead it iterates through base register classes, which
should come closer to reserving each register once only.
Overall this speeds up the time to run check-llvm-codegen-amdgpu in my
Release build from 18.4 seconds to 16.9 seconds (all timings +/- 0.2).
This patch replaces uses of StringRef::{starts,ends}with with
StringRef::{starts,ends}_with for consistency with
std::{string,string_view}::{starts,ends}_with in C++20.
I'm planning to deprecate and eventually remove
StringRef::{starts,ends}with.
As alluded to in #20571, it would be nice if we could mutate operand
lists of MachineInstr's more safely. Add an insert method that together
with removeOperand allows for easier splicing of operands.
Splitting this patch off early to get feedback; I need to either:
- mutate an INLINEASM{_BR} MachinInstr's MachineOperands from being
registers (physical or virtual) to memory
(MachineOperandType::MO_FrameIndex). These are not 1:1 operand
replacements, but N:M operand replacements. i.e. we need to
update 2 MachineOperands into the middle of the operand list to 5 (at
least for x86_64).
- copy, modify, write a new MachineInstr which has its relevant operands
replaced.
Either approaches are hazarded by existing references to either the
operands being moved, or the instruction being removed+replaced. For my
purposes in regalloc, either seem to work for me, so hopefully reviewers
can help me determine which approach is preferable. The second would
involve no new methods on MachineInstr.
One question I had while looking at this was: "why does MachineInstr
have BOTH a NumOperands member AND a MCInstrDesc member that itself has
a NumOperands member? How many operands can a MachineInstr have? Do I
need to update BOTH (keeping them in sync)?" FWICT, only "variadic"
MachineInstrs have MCInstrDesc with NumOperands (of the MCInstrDesc) set
to zero. If the MCInstrDesc's NumOperands is non-zero, then the
NumOperands
on the MachineInstr itself cannot exceed this value (IIUC) else an
assert will
be triggered.
For most non-psuedo instructions (or at least non-varidic instructions),
insert is less likely to be useful.
To run the newly added unittest:
$ pushd llvm/build; ninja CodeGenTests; popd
$ ./llvm/build/unittests/CodeGen/CodeGenTests \
--gtest_filter=MachineInstrTest.SpliceOperands
This is meant to mirror `MCInst::insert`.
This shrinks MCInstrDesc (and hence the whole TargetInsts table) because
we can store a 16-bit offset value to access the operands info, instead
of a pointer. This also reduces the number of relocs that need to be
applied when LLVM is compiled as position-independent code.
Differential Revision: https://reviews.llvm.org/D142219
This shrinks MCInstrDesc (and hence the whole TargetInsts table) because
we can store a 16-bit offset value to access the implicit operands,
instead of a pointer. This also reduces the number of relocs that need
to be applied when LLVM is compiled as position-independent code.
Differential Revision: https://reviews.llvm.org/D142218
Combine the implicit uses and defs lists into a single list of uses
followed by defs. Instead of 0-terminating the list, store the number
of uses and defs. This avoids having to scan the whole list to find the
length and removes one pointer from MCInstrDesc (although it does not
get any smaller due to alignment issues).
Remove the old accessor methods getImplicitUses, getNumImplicitUses,
getImplicitDefs and getNumImplicitDefs as all clients are using the new
implicit_uses and implicit_defs.
Differential Revision: https://reviews.llvm.org/D142216
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated. The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.
This is part of an effort to migrate from llvm::Optional to
std::optional:
https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
This was done as a test for D137302 and it makes sense to push these changes
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D137493
In many places DebugLoc and PCSections metadata are just copied along to
propagate them through MachineInstrs. Simplify doing so by bundling them
up in a MIMetadata class that replaces the DebugLoc argument to most
BuildMI() variants.
The DebugLoc-only constructors allow implicit construction, so that
existing usage of `BuildMI(.., DL, ..)` works as before, and the rest of
the codebase using BuildMI() does not require changes.
NFC.
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D130883
Provide MachineInstr::setPCSection(), to propagate relevant metadata
through the backend. Use ExtraInfo to store the metadata.
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D130876
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
Based on the reasoning of D53903, register operands of DBG_VALUE are
invariably treated as RegState::Debug operands. This change enforces
this invariant as part of MachineInstr::addOperand so that all passes
emit this flag consistently.
RegState::Debug is inconsistently set on DBG_VALUE registers throughout
LLVM. This runs the risk of a filtering iterator like
MachineRegisterInfo::reg_nodbg_iterator to process these operands
erroneously when not parsed from MIR sources.
This issue was observed in the development of the llvm-mos fork which
adds a backend that relies on physical register operands much more than
existing targets. Physical RegUnit 0 has the same numeric encoding as
$noreg (indicating an undef for DBG_VALUE). Allowing debug operands into
the machine scheduler correlates $noreg with RegUnit 0 (i.e. a collision
of register numbers with different zero semantics). Eventually, this
causes an assert where DBG_VALUE instructions are prohibited from
participating in live register ranges.
Reviewed By: MatzeB, StephenTozer
Differential Revision: https://reviews.llvm.org/D110105
This makes it possible for targets to define their own MCObjectFileInfo.
This MCObjectFileInfo is then used to determine things like section alignment.
This is a follow up to D101462 and prepares for the RISCV backend defining the
text section alignment depending on the enabled extensions.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D101921
This untangles the MCContext and the MCObjectFileInfo. There is a circular
dependency between MCContext and MCObjectFileInfo. Currently this dependency
also exists during construction: You can't contruct a MOFI without a MCContext
without constructing the MCContext with a dummy version of that MOFI first.
This removes this dependency during construction. In a perfect world,
MCObjectFileInfo wouldn't depend on MCContext at all, but only be stored in the
MCContext, like other MC information. This is future work.
This also shifts/adds more information to the MCContext making it more
available to the different targets. Namely:
- TargetTriple
- ObjectFileType
- SubtargetInfo
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D101462
Revert "Delete llvm::is_trivially_copyable and CMake variable HAVE_STD_IS_TRIVIALLY_COPYABLE"
This reverts commit 4d4bd40b578d77b8c5bc349ded405fb58c333c78.
This reverts commit 557b00e0afb2dc1776f50948094ca8cc62d97be4.
Summary:
Preserve call site info for duplicated instructions. We copy over the
call site info in CloneMachineInstrBundle to avoid repeated calls to
copyCallSiteInfo in CloneMachineInstr.
(Alternatively, we could copy call site info higher up the stack, e.g.
into TargetInstrInfo::duplicate, or even into individual backend passes.
However, I don't see how that would be safer or more general than the
current approach.)
Reviewers: aprantl, djtodoro, dstenb
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77685
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: jyknight, sdardis, nemanjai, hiraditya, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, jfb, PkmX, jocewei, Jim, lenary, s.egerton, pzheng, sameer.abuasal, apazos, luismarques, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77059
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
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
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
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
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
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
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
As noted in https://bugs.llvm.org/show_bug.cgi?id=36651, the specialization for
isPodLike<std::pair<...>> did not match the expectation of
std::is_trivially_copyable which makes the memcpy optimization invalid.
This patch renames the llvm::isPodLike trait into llvm::is_trivially_copyable.
Unfortunately std::is_trivially_copyable is not portable across compiler / STL
versions. So a portable version is provided too.
Note that the following specialization were invalid:
std::pair<T0, T1>
llvm::Optional<T>
Tests have been added to assert that former specialization are respected by the
standard usage of llvm::is_trivially_copyable, and that when a decent version
of std::is_trivially_copyable is available, llvm::is_trivially_copyable is
compared to std::is_trivially_copyable.
As of this patch, llvm::Optional is no longer considered trivially copyable,
even if T is. This is to be fixed in a later patch, as it has impact on a
long-running bug (see r347004)
Note that GCC warns about this UB, but this got silented by https://reviews.llvm.org/D50296.
Differential Revision: https://reviews.llvm.org/D54472
llvm-svn: 351701
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 will hold flags specific to subprograms. In the future
we could potentially free up scarce bits in DIFlags by moving
subprogram-specific flags from there to the new flags word.
This patch does not change IR/bitcode formats, that will be
done in a follow-up.
Differential Revision: https://reviews.llvm.org/D54597
llvm-svn: 347239
Discussed here:
http://lists.llvm.org/pipermail/llvm-dev/2018-January/120320.html
In preparation for adding support for named vregs we are changing the sigil for
physical registers in MIR to '$' from '%'. This will prevent name clashes of
named physical register with named vregs.
llvm-svn: 323922
