This pull request adds `MachineFunctionProperties` support. If a pass
wants to modify machine function properties, it must derive from
`MachinePassInfoMixin` and define some static methods like in legacy
pass manager. A test pass `RequireAllMachineFunctionPropertiesPass` is
also added here, which could be a example.
These are the last remaining "trivial" changes to passes that use
Instruction pointers for insertion. All of this should be NFC, it's just
changing the spelling of how we identify a position.
In one or two locations, I'm also switching uses of getNextNode etc to
using std::next with iterators. This too should be NFC.
---------
Merged by: Stephen Tozer <stephen.tozer@sony.com>
Some targets have passes with parameters, e.g. ARM, AMDGPU and MIPS.
For example, AMDGPU has a pass `AMDGPUAtomicOptimizerPass`
which need a `ScanOption`, this commit enables the syntax
like `-passes=amdgpu-atomic-optimizer<strategy=dpp>` for backend passes.
UBSAN checks can be too expensive to be used
in release binaries. However not all code affect
performace in the same way. Removing small
number of checks in hot code we can performance
loss, preserving most of the checks.
Many profitable optimizations cannot be performed at -Oz, due to
unrotated loops. While this is worse for size (minimally), many of the
optimizations significantly reduce code size, such as memcpy
optimizations and other patterns found by loop idiom recognition.
Related discussion can be found in issue #50308.
This patch adds an experimental, backend-only flag to allow loop header
duplication, regardless of the optimization level. Downstream consumers
can experiment with this flag, and if it is profitable, we can adjust
the compiler's defaults accordingly, and expose any useful frontend
flags to opt into the new behavior.
The pass itself checks whether to apply the optimization based on the
minsize attribute, so there isn't much functional benefit to preventing
the pass from being added. Gating the pass gets added to the pass
pipeline complicates the interaction with -enable-dfa-jump-thread, as
well.
Reviewers: aeubanks
Reviewed By: aeubanks
Pull Request: https://github.com/llvm/llvm-project/pull/83318
Currently the new PM infra for codegen puts everything into a
MachineFunctionPassManager. The MachineFunctionPassManager owns both
Module passes and MachineFunction passes, and batches adjacent
MachineFunction passes like a typical PassManager.
The current MachineFunctionAnalysisManager also directly references a
module and function analysis manager to get results.
The initial argument was that the codegen pipeline is relatively "flat",
meaning it's mostly machine function passes with a couple of module
passes here and there. However, there are a couple of issues with this
as compared to a more structured nesting more like the optimization
pipeline. For example, it doesn't allow running function passes then
machine function passes on a function and its machine function all at
once. It also currently requires the caller to split out the IR passes
into one pass manager and the MIR passes into another pass manager.
This patch rewrites the new pass manager infra for the codegen pipeline
to be more similar to the nesting in the optimization pipeline.
Basically, a Function contains a MachineFunction. So we can have Module
-> Function -> MachineFunction adaptors. It also rewrites the analysis
managers to have inner/outer proxies like the ones in the optimization
pipeline. The new pass managers/adaptors/analysis managers can be seen
in use in PassManagerTest.cpp.
This allows us to consolidate to just having to add to one
ModulePassManager when using the codegen pipeline.
I haven't added the Function -> MachineFunction adaptor in this patch,
but it should be added when we merge AddIRPass/AddMachinePass so that we
can run IR and MIR passes on a function before proceeding to the next
function.
The MachineFunctionProperties infra for MIR verification is still WIP.
The performance of cold functions shouldn't matter too much, so if we
care about binary sizes, add an option to mark cold functions as
optsize/minsize for binary size, or optnone for compile times [1]. Clang
patch will be in a future patch.
This is intended to replace `shouldOptimizeForSize(Function&, ...)`.
We've seen multiple cases where calls to this expensive function, if not
careful, can blow up compile times. I will clean up users of that
function in a followup patch.
Initial version: https://reviews.llvm.org/D149800
[1]
https://discourse.llvm.org/t/rfc-new-feature-proposal-de-optimizing-cold-functions-using-pgo-info/56388
Add a pass to convert jump tables to switches.
The new pass replaces an indirect call with a switch + direct calls if all the functions in the jump table are smaller than the provided threshold.
The pass is currently disabled by default and can be enabled by -enable-jump-table-to-switch.
Test plan: ninja check-all
This matches the optimization pipeline's PassRegistry.def.
I ran into a bug where CONSTRUCTOR wasn't always being used (in
PassBuilder::registerMachineFunctionAnalyses()).
Make DUMMY_* just accept a pass name, there's no point in having proper
constructors if the generated dummy class has a templated constructor
accepting arbitrary arguments.
Remove unused getPassNameFromLegacyName() as it was using this but for
no purpose.
Remove DUMMY_MACHINE_FUNCTION_ANALYSIS, we can just add those as we port
them.
This for some reason exposed missing mock calls in existing unittests.
The legacy version print machine functions to a string stream, then
output the module and string in `doFinalization`. This patch break
`MIRPrintingPass` into two parts `PrintMIRPreparePass` and
`PrintMIRPass`. `PrintMIRPreparePass` output the original IR in yaml
string, `PrintMIRPass` just print the machine function, so we can avoid
the `doFinalization`.
This pass should be the last machine function pass in pipeline, also
ignore `PI.runAfterPass(*P, MF, PassPA);` to avoid accessing a dangling
reference.
`CodeGenPassBuilder` is not very tightly coupled to CodeGen, it may need
to reference some method in pass builder in future, so move
`CodeGenPassBuilder.h` to Passes.
Currently, the UnifiedLTO pipeline seems to have trouble with several
LTO features, like SplitLTO units, which means we cannot use important
optimizations like Whole Program Devirtualization or security hardening
instrumentation like CFI.
This patch reverts FatLTO to using distinct pipelines for Full LTO and
ThinLTO. It still avoids module cloning, since that was error prone.
- With PGO, indirect call edges are constructed using value profiles, and the profile address is mapped to a function's PGO name. The PGO name is computed using a functions linkage before LTO internalization or global promotion.
- With ThinLTO, local functions [could be
promoted](2663d2cb9c/llvm/lib/Transforms/Utils/FunctionImportUtils.cpp (L288)) to have external linkage; and with
[full](2663d2cb9c/llvm/lib/LTO/LTO.cpp (L1328))
or
[thin](2663d2cb9c/llvm/lib/LTO/LTO.cpp (L448))
LTO, global functions could be internalized. Edge construction should use a function's PGO name before its linkage is updated.
Unfortunately the legacy pass system can't recognize `no-op-module` and
`no-op-function` so it causes test failure in `CodeGenTests`. Add a
workaround in function `PassInfo *getPassInfo(StringRef PassName)`,
`TargetPassConfig.cpp`.
`PassBuilder` would be a better place to parse MIR pipeline. We can
reuse the code to support parsing pass with parameters and targets can
reuse `registerPassBuilderCallbacks` to register the target specific
passes. `PassBuilder` also has ability to check whether a Pass is a
machine pass.
In fact, there are several backends, e.g. AArch64, AMDGPU etc. add
module pass after function pass, this patch removes this constraint.
This patch also adds a simple unit test for `CodeGenPassBuilder`.
The original `StackProtector` is both transform and analysis pass, break
it into two passes now. `getAnalysis<StackProtector>()` could be now
replaced by `FAM.getResult<SSPLayoutAnalysis>(F)` in new pass system.
Port CodeGenPrepare to new pass manager and dependency
BasicBlockSectionsProfileReader
Fixes: #75380
Co-authored-by: Krishna-13-cyber <84722531+Krishna-13-cyber@users.noreply.github.com>
The existing option prints the IR after the pass, but it's not clear
from its name. In this patch I change the option to print the IR before
the pass and change the name to make the behavior clear.
Printing the IR before the pass is slightly simpler than after as I
don't need to worry about printAfterPassInvalidated case. Either before
or after the pass would be ok for the original use case this option was
introduced for.
Revert e0c554ad87d18dcbfcb9b6485d0da800ae1338d1 "Port CodeGenPrepare to new pass manager (and BasicBlockSectionsProfil… (#75380)"
Revert #75380 and #77054 as they were breaking EXPENSIVE_CHECKS buildbots: https://lab.llvm.org/buildbot/#/builders/104
Port CodeGenPrepare to new pass manager and dependency
BasicBlockSectionsProfileReader
Fixes: #64560
Co-authored-by: Krishna-13-cyber <84722531+Krishna-13-cyber@users.noreply.github.com>
