- `CollectorMetadataAnalysis` provides `GCStrategyMap`.
- `GCFunctionAnalysis` provides `GCFunctionInfo`.
`GCStrategyMap` owns `GCStrategy` pointers and this
pass is used by `AsmPrinter` to iterate all GC strategies.
Most passes that require `GCModuleInfo` actually require the
`GCFunctionInfo`,
so add `GCFunctionAnalysis` for convenience.
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.
- Use `BlockFrequencyInfoWrapperPass` in legacy pass so member
`std::unique_ptr<BranchProbabilityInfo> BPI` could be removed.
- Member `DominatorTree *DT = nullptr` is unused, remove it.
https://github.com/llvm/llvm-project/issues/70703 pointed out that
cloning LLVM modules could lead to miscompiles when using FatLTO.
This is due to an existing issue when cloning modules with labels (see
#55991 and #47769). Since this can lead to miscompilation, we can avoid
cloning the LLVM modules, which was desirable anyway.
This patch modifies the EmbedBitcodePass to no longer clone the module
or run an input pipeline over it. Further, it make FatLTO always perform
UnifiedLTO, so we can still defer the Thin/Full LTO decision to
link-time. Lastly, it removes dead/obsolete code related to now defunct
options that do not work with the EmbedBitcodePass implementation any
longer.
This reverts commit a4d5fd4d2ee9470e55345a9540f6b6fb6faf66e1.
The above commit breaks greendragon lldb bots:
Link to failing builds:
https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/63300/https://green.lab.llvm.org/green/view/LLDB/job/as-lldb-cmake/10345/
I found this PR to be the offending one after using git bisect with the
cmake invocation:
cmake -G Ninja ../llvm -DCMAKE_BUILD_TYPE=Release
-DCMAKE_EXPORT_COMPILE_COMMANDS=ON
'-DLLVM_TARGETS_TO_BUILD=X86;ARM;AArch64'
-DLLVM_ENABLE_ASSERTIONS:BOOL=TRUE
-DLLVM_ENABLE_MODULES=On
-DLLVM_ENABLE_PROJECTS='clang;lld;lldb;cross-project-tests'
-DLLVM_VERSION_PATCH=99
'-DLLVM_ENABLE_RUNTIMES=libcxx;libcxxabi;compiler-rt'
and running
ninja lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/CodeGenPassBuilder.cpp.o
Just copy the `runOnFunction` method from `SafeStackLegacyPass` and
remove the workaround for computing analysis lazily, the analysis result
in new pass manager is computed lazily by default.
See RFC for details:
https://discourse.llvm.org/t/rfc-for-moving-swift-s-merge-function-pass-to-llvm/73778
We will need to refactor extension to FunctionComparator/FunctionHash to
StructuralHash. This patch adds a new pass which is ported from Swift,
and will need to discuss on how to migrate Swift’s pass over after we
land this in llvm.
Create this PR to get some early review on the patch.
---------
Co-authored-by: Manman Ren <mren@meta.com>
This patch adds the LLVM changes needed for enabling HIP parallel algorithm offload on AMDGPU targets. What we do here is add two passes, one mandatory and one optional:
1. HipStdParAcceleratorCodeSelectionPass is mandatory, depends on CallGraphAnalysis, and implements the following transform:
- Traverse the call-graph, and check for functions that are roots for accelerator execution (at the moment, these are GPU kernels exclusively, and would originate in the accelerator specific algorithm library the toolchain uses as an implementation detail);
- Starting from a root, do a BFS to find all functions that are reachable (called directly or indirectly via a call- chain) and record them;
- After having done the above for all roots in the Module, we have the computed the set of reachable functions, which is the union of roots and functions reachable from roots;
- All functions that are not in the reachable set are removed; for the special case where the reachable set is empty we completely clear the module;
2. HipStdParAllocationInterpositionPass is optional, is meant as a fallback with restricted functionality for cases where on-demand paging is unavailable on a platform, and implements the following transform:
- Iterate all functions in a Module;
- If a function's name is in a predefined set of allocation / deallocation that the runtime implementation is allowed and expected to interpose, replace all its uses with the equivalent accelerator aware function, iff the latter is available;
- If the accelerator aware equivalent is unavailable we warn, but compilation will go ahead, which means that it is possible to get issues around the accelerator trying to access inaccessible memory at run time;
- We rely on direct name matching as opposed to using the new alloc-kind family of attributes and / or the LibCall analysis pass because some of the legacy functions that need replacing would not carry the former or be identified by the latter.
Reviewed by: JonChesterfield, yaxunl
Differential Revision: https://reviews.llvm.org/D155856
This patch adds the LLVM changes needed for enabling HIP parallel algorithm offload on AMDGPU targets. What we do here is add two passes, one mandatory and one optional:
1. HipStdParAcceleratorCodeSelectionPass is mandatory, depends on CallGraphAnalysis, and implements the following transform:
- Traverse the call-graph, and check for functions that are roots for accelerator execution (at the moment, these are GPU kernels exclusively, and would originate in the accelerator specific algorithm library the toolchain uses as an implementation detail);
- Starting from a root, do a BFS to find all functions that are reachable (called directly or indirectly via a call- chain) and record them;
- After having done the above for all roots in the Module, we have the computed the set of reachable functions, which is the union of roots and functions reachable from roots;
- All functions that are not in the reachable set are removed; for the special case where the reachable set is empty we completely clear the module;
2. HipStdParAllocationInterpositionPass is optional, is meant as a fallback with restricted functionality for cases where on-demand paging is unavailable on a platform, and implements the following transform:
- Iterate all functions in a Module;
- If a function's name is in a predefined set of allocation / deallocation that the runtime implementation is allowed and expected to interpose, replace all its uses with the equivalent accelerator aware function, iff the latter is available;
- If the accelerator aware equivalent is unavailable we warn, but compilation will go ahead, which means that it is possible to get issues around the accelerator trying to access inaccessible memory at run time;
- We rely on direct name matching as opposed to using the new alloc-kind family of attributes and / or the LibCall analysis pass because some of the legacy functions that need replacing would not carry the former or be identified by the latter.
Reviewed by: JonChesterfield, yaxunl
Differential Revision: https://reviews.llvm.org/D155856
This patch adds the LLVM changes needed for enabling HIP parallel algorithm offload on AMDGPU targets. What we do here is add two passes, one mandatory and one optional:
1. HipStdParAcceleratorCodeSelectionPass is mandatory, depends on CallGraphAnalysis, and implements the following transform:
- Traverse the call-graph, and check for functions that are roots for accelerator execution (at the moment, these are GPU kernels exclusively, and would originate in the accelerator specific algorithm library the toolchain uses as an implementation detail);
- Starting from a root, do a BFS to find all functions that are reachable (called directly or indirectly via a call- chain) and record them;
- After having done the above for all roots in the Module, we have the computed the set of reachable functions, which is the union of roots and functions reachable from roots;
- All functions that are not in the reachable set are removed; for the special case where the reachable set is empty we completely clear the module;
2. HipStdParAllocationInterpositionPass is optional, is meant as a fallback with restricted functionality for cases where on-demand paging is unavailable on a platform, and implements the following transform:
- Iterate all functions in a Module;
- If a function's name is in a predefined set of allocation / deallocation that the runtime implementation is allowed and expected to interpose, replace all its uses with the equivalent accelerator aware function, iff the latter is available;
- If the accelerator aware equivalent is unavailable we warn, but compilation will go ahead, which means that it is possible to get issues around the accelerator trying to access inaccessible memory at run time;
- We rely on direct name matching as opposed to using the new alloc-kind family of attributes and / or the LibCall analysis pass because some of the legacy functions that need replacing would not carry the former or be identified by the latter.
Reviewed by: JonChesterfield, yaxunl
Differential Revision: https://reviews.llvm.org/D155856
This pass aims to infer alignment for instructions as a separate pass,
to reduce redundant work done by InstCombine running multiple times. It
runs late in the pipeline, just before the back-end passes where this
information is most useful.
Differential Revision: https://reviews.llvm.org/D158529
This pass will upgrade DXIL-style llvm constructs (which are mostly
metadata) into the representations we use in LLVM for the same concepts.
For now we just strip the valver metadata, which we don't need. Later
changes will make this pass more useful, and then we should be able to
wire it into clang and possibly the DirectX backend's AsmParser.
This patch adds in a StructuralHash printer pass that prints out the
hexadeicmal representation of the hash of a module and all of the
functions within it.
Reviewed By: aeubanks
Differential Revision: https://reviews.llvm.org/D158317
Summary:
Argument attributes like NoAlias and ReadOnly could affect memoryssa and thus earlyCSE in the function simplification pipeline.
https://reviews.llvm.org/D145210 adjusted PostOrderFunctionAttrs placement and caused the argument attributes not referred for the use
in the pipeline. This work (initiated by @nikic) unconditionally performs argument attribute inference in the first function-attrs pass.
Reviewers:
aeubanks and nikic
Differential Revision:
https://reviews.llvm.org/D156397
InstCombine is a worklist-driven algorithm, which works roughly
as follows:
* All instructions are initially pushed to the worklist.
The initial order is in RPO program order.
* All newly inserted instructions get added to the worklist.
* When an instruction is folded, its users get added back to the
worklist.
* When the use-count of an instruction decreases, it gets added
back to the worklist.
* And a few of other heuristics on when we should revisit
instructions.
On top of the worklist algorithm, InstCombine layers an additional
fix-point iteration: If any fold was performed in the previous
iteration, then InstCombine will re-populate the worklist from
scratch and fold the entire function again. This continues until
a fix-point is reached.
In the vast majority of cases, InstCombine will reach a fix-point
within a single iteration: However, a second iteration is performed
to verify that this is indeed the fixpoint. We can see this in the
statistics for llvm-test-suite:
"instcombine.NumOneIteration": 411380,
"instcombine.NumTwoIterations": 117921,
"instcombine.NumThreeIterations": 236,
"instcombine.NumFourOrMoreIterations": 2,
The way to read these numbers is that in 411380 cases, InstCombine
performs no folds. In 117921 cases it performs a fold and reaches
the fix-point within one iteration (the second iteration verifies
the fixpoint). In the remaining 238 cases, more than one iteration
is needed to reach the fixpoint.
In other words, only in 0.04% of cases are additional iterations
needed to reach a fixpoint. Conversely, in 22.3% of cases InstCombine
performs a completely useless extra iteration to verify the fix point.
This patch removes the fixpoint iteration from InstCombine, and always
only perform a single iteration. This results in a major compile-time
improvement of around 4% at negligible codegen impact.
This explicitly does accept that we will not reach a fixpoint in all
cases. However, this is mitigated by two factors: First, the data
suggests that this happens very rarely in practice. Second,
InstCombine runs many times during the optimization pipeline
(8 times even without LTO), so there are many chances to recover
such cases.
In order to prevent accidental optimization regressions in the
future, this implements a verify-fixpoint option, which is enabled
by default when instcombine is specified in -passes and disabled
when InstCombinePass() is constructed from C++. This means that
test cases need to explicitly use the no-verify-fixpoint option
if they fail to reach a fixed point (for a well understand reason
we cannot / do not want to avoid).
Differential Revision: https://reviews.llvm.org/D154579
This restores commit b4a82b62258c5f650a1cccf5b179933e6bae4867, reverted
in 3ab7ef28eebf9019eb3d3c4efd7ebfd160106bb1 because it was thought to
cause a bot failure, which ended up being unrelated to this patch set.
Differential Revision: https://reviews.llvm.org/D154856
Previously the MemProf profile was expected to be in the same profile
file as a normal PGO profile, passed via the usual -fprofile-use=
option, and was matched in the same pass. To simplify profile
preparation, since the raw MemProf profile requires the binary for
symbolization and may be simpler to index separately from the raw PGO
profile, and also to enable providing a MemProf profile for a SamplePGO
build, separate out the MemProf feedback option and matching pass.
This patch adds the -fmemory-profile-use=${file} option, and the
provided file is passed down to LLVM and ultimately used in a new
MemProfUsePass which performs the matching of just the memory profile
contents of that file.
Note that a single profile file containing both normal PGO and MemProf
profile data is still supported, and the relevant profile data is
matched by the appropriate matching pass(es) based on which option(s)
the profile is provided with (the same profile file can be supplied to
both feedback options).
Differential Revision: https://reviews.llvm.org/D154856
Here's a high level summary of the changes in this patch. For more
information on rational, see the RFC.
(https://discourse.llvm.org/t/rfc-a-unified-lto-bitcode-frontend/61774).
- Add config parameter to LTO backend, specifying which LTO mode is
desired when using unified LTO.
- Add unified LTO flag to the summary index for efficiency. Unified
LTO modules can be detected without parsing the module.
- Make sure that the ModuleID is generated by incorporating more types
of symbols.
Differential Revision: https://reviews.llvm.org/D123803
Fat LTO objects contain both LTO compatible IR, as well as generated
object code. This allows users to defer the choice of whether to use LTO
or not to link-time. This is a feature available in GCC for some time,
and makes the existing -ffat-lto-objects flag functional in the same
way as GCC's.
Within LLVM, we add a new EmbedBitcodePass that serializes the module to
the object file, and expose a new pass pipeline for compiling fat
objects. The new pipeline initially clones the module and runs the
selected (Thin)LTOPrelink pipeline, after which it will serialize the
module into a `.llvm.lto` section of an ELF file. When compiling for
(Thin)LTO, this normally the point at which the compiler would emit a
object file containing the bitcode and metadata.
After that point we compile the original module using the
PerModuleDefaultPipeline used for non-LTO compilation. We generate
standard object files at the end of this pipeline, which contain machine
code and the new `.llvm.lto` section containing bitcode.
Since the two pipelines operate on different copies of the module, we
can be sure that the bitcode in the `.llvm.lto` section and object code
in `.text` are congruent with the existing output produced by the
default and LTO pipelines.
Original RFC: https://discourse.llvm.org/t/rfc-ffat-lto-objects-support/63977
Earlier versions of this patch were missing REQUIRES lines for llc
related tests in Transforms/EmbedBitcode. Those tests are now under
CodeGen/X86, which should avoid running the check on unsupported
platforms.
The EmbedbBitcodePass also returned PreservedAnalyses::all when adding a
metadata section, which failed expensive checks, since it modified the
module. This is now corrected.
Reviewed By: tejohnson, MaskRay, nikic
Differential Revision: https://reviews.llvm.org/D146776
D63932 added a module flag to indicate that we are executing the regular
LTO post merge pipeline, so that GlobalDCE could perform more aggressive
optimization for Dead Virtual Function Elimination. This caused issues
trying to reuse bitcode that had already been through the LTO pipeline
(see context in D139816).
Instead support this by passing down a parameter flag to the
GlobalDCEPass constructor, which is the more usual way for indicating
this information.
Most test changes are to remove incidental uses of this flag. Of the 2
real uses, llvm/test/LTO/ARM/lto-linking-metadata.ll is now obsolete and
removed in this patch, and the virtual-functions-visibility-post-lto.ll
test is updated to use the regular LTO default pipeline where this
parameter is set to true.
Differential Revision: https://reviews.llvm.org/D153655
Fat LTO objects contain both LTO compatible IR, as well as generated
object code. This allows users to defer the choice of whether to use LTO
or not to link-time. This is a feature available in GCC for some time,
and makes the existing -ffat-lto-objects flag functional in the same
way as GCC's.
Within LLVM, we add a new EmbedBitcodePass that serializes the module to
the object file, and expose a new pass pipeline for compiling fat
objects. The new pipeline initially clones the module and runs the
selected (Thin)LTOPrelink pipeline, after which it will serialize the
module into a `.llvm.lto` section of an ELF file. When compiling for
(Thin)LTO, this normally the point at which the compiler would emit a
object file containing the bitcode and metadata.
After that point we compile the original module using the
PerModuleDefaultPipeline used for non-LTO compilation. We generate
standard object files at the end of this pipeline, which contain machine
code and the new `.llvm.lto` section containing bitcode.
Since the two pipelines operate on different copies of the module, we
can be sure that the bitcode in the `.llvm.lto` section and object code
in `.text` are congruent with the existing output produced by the
default and LTO pipelines.
Original RFC: https://discourse.llvm.org/t/rfc-ffat-lto-objects-support/63977
Earlier versions of this patch were missing REQUIRES lines for llc
related tests in Transforms/EmbedBitcode. Those tests are now under
CodeGen/X86, which should avoid running the check on unsupported
platforms.
Reviewed By: tejohnson, MaskRay, nikic
Differential Revision: https://reviews.llvm.org/D146776
There seems to be a problem on arm buildbots. Reverting until I can
investigate. https://lab.llvm.org/buildbot#builders/245/builds/10184
This reverts commit a67208e1c697649ce432e6497f56a93675273dd8
and dependent commit e54a3112cee5ae0a9117359ecbea878e1388f51e.
Fat LTO objects contain both LTO compatible IR, as well as generated
object code. This allows users to defer the choice of whether to use LTO
or not to link-time. This is a feature available in GCC for some time,
and makes the existing -ffat-lto-objects flag functional in the same
way as GCC's.
Within LLVM, we add a new EmbedBitcodePass that serializes the module to
the object file, and expose a new pass pipeline for compiling fat
objects. The new pipeline initially clones the module and runs the
selected (Thin)LTOPrelink pipeline, after which it will serialize the
module into a `.llvm.lto` section of an ELF file. When compiling for
(Thin)LTO, this normally the point at which the compiler would emit a
object file containing the bitcode and metadata.
After that point we compile the original module using the
PerModuleDefaultPipeline used for non-LTO compilation. We generate
standard object files at the end of this pipeline, which contain machine
code and the new `.llvm.lto` section containing bitcode.
Since the two pipelines operate on different copies of the module, we
can be sure that the bitcode in the `.llvm.lto` section and object code
in `.text` are congruent with the existing output produced by the
default and LTO pipelines.
Original RFC: https://discourse.llvm.org/t/rfc-ffat-lto-objects-support/63977
Reviewed By: tejohnson, MaskRay, nikic
Differential Revision: https://reviews.llvm.org/D146776
There is a gap between running opt -Oz and running opt -passes="OZ_PASSES" where OZ_PASSES is taken from running opt -Oz -print-pipeline-passes.
One of the reasons causing this is that -Oz uses non-default setting for LoopRotate but LoopRotate does not expose its settings when printing the pipeline.
This commit fixes this by exposing LoopRotates parameters.
Reviewed By: aeubanks
Differential Revision: https://reviews.llvm.org/D153437
