In a CGSCC pass manager, we may visit the same function multiple times
due to SCC mutations. In the inliner pipeline, this results in running
the function simplification pipeline on a function multiple times even
if it hasn't been changed since the last function simplification
pipeline run.
We use a newly introduced analysis to keep track of whether or not a
function has changed since the last time the function simplification
pipeline has run on it. If we see this analysis available for a function
in a CGSCCToFunctionPassAdaptor, we skip running the function passes on
the function. The analysis is queried at the end of the function passes
so that it's available after the first time the function simplification
pipeline runs on a function. This is a per-adaptor option so it doesn't
apply to every adaptor.
The goal of this is to improve compile times. However, currently we
can't turn this on by default at least for the higher optimization
levels since the function simplification pipeline is not robust enough
to be idempotent in many cases, resulting in performance regressions if
we stop running the function simplification pipeline on a function
multiple times. We may be able to turn this on for -O1 in the near
future, but turning this on for higher optimization levels would require
more investment in the function simplification pipeline.
Heavily inspired by D98103.
Example compile time improvements with flag turned on:
https://llvm-compile-time-tracker.com/compare.php?from=998dc4a5d3491d2ae8cbe742d2e13bc1b0cacc5f&to=5c27c913687d3d5559ef3ab42b5a3d513531d61c&stat=instructions
Reviewed By: asbirlea, nikic
Differential Revision: https://reviews.llvm.org/D113947
Previously, any change in any function in an SCC would cause all
analyses for all functions in the SCC to be invalidated. With this
change, we now manually invalidate analyses for functions we modify,
then let the pass manager know that all function analyses should be
preserved since we've already handled function analysis invalidation.
So far this only touches the inliner, argpromotion, function-attrs, and
updateCGAndAnalysisManager(), since they are the most used.
This is part of an effort to investigate running the function
simplification pipeline less on functions we visit multiple times in the
inliner pipeline.
However, this causes major memory regressions especially on larger IR.
To counteract this, turn on the option to eagerly invalidate function
analyses. This invalidates analyses on functions immediately after
they're processed in a module or scc to function adaptor for specific
parts of the pipeline.
Within an SCC, if a pass only modifies one function, other functions in
the SCC do not have their analyses invalidated, so in later function
passes in the SCC pass manager the analyses may still be cached. It is
only after the function passes that the eager invalidation takes effect.
For the default pipelines this makes sense because the inliner pipeline
runs the function simplification pipeline after all other SCC passes
(except CoroSplit which doesn't request any analyses).
Overall this has mostly positive effects on compile time and positive effects on memory usage.
https://llvm-compile-time-tracker.com/compare.php?from=7f627596977624730f9298a1b69883af1555765e&to=39e824e0d3ca8a517502f13032dfa67304841c90&stat=instructionshttps://llvm-compile-time-tracker.com/compare.php?from=7f627596977624730f9298a1b69883af1555765e&to=39e824e0d3ca8a517502f13032dfa67304841c90&stat=max-rss
D113196 shows that we slightly regressed compile times in exchange for
some memory improvements when turning on eager invalidation. D100917
shows that we slightly improved compile times in exchange for major
memory regressions in some cases when invalidating less in SCC passes.
Turning these on at the same time keeps the memory improvements while
keeping compile times neutral/slightly positive.
Reviewed By: asbirlea, nikic
Differential Revision: https://reviews.llvm.org/D113304
To be more consistent with other pass struct names.
There are still more passes that don't end with "Pass", but these are the important ones.
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D112935
Having a NoOpLoopNestPass can ensure that only outermost loop is invoked
for a LoopNestPass with a lit test.
There are some existing passes that are implemented as LoopNestPass, but
they are still using LOOP_PASS macro.
It would be easier to identify LoopNestPasses with a LOOPNEST_PASS
macro.
Differential Revision: https://reviews.llvm.org/D113185
We almost always want to use the default AA pipeline. It's very easy for
users of PassBuilder to forget to customize the AAManager to use the
default AA pipeline (for example, the NewPM C API forgets to do this).
If somebody wants a custom AA pipeline, similar to what is being done
now with the default AA pipeline registration, they can
FAM.registerPass([&] { return std::move(MyAA); });
before calling
PB.registerFunctionAnalyses(FAM);
For example, LTOBackend.cpp and NewPMDriver.cpp do this.
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D113210
Function specialisation was running at all optimisation levels (if enabled on
the command line, it is not on by default). That was an oversight and not
something we want to do. Function specialisation duplicates functions when it
triggers, so the backend is processing more functions/instructions resulting in
compile-time increases, which seems more appropriate with -O3 and inline with
GCC. Please note that since function specialisation is not enabled by default,
this didn't require updating any pass manager tests.
Differential Revision: https://reviews.llvm.org/D112129
* Move `);` outside the #ENDIF. Syntax highlighters that highlight missed
closing parens, but are not aware of the C Preprocessor saw the original
code as having missed parens.
Summary:
Add new options -print-changed=[dot-cfg | dot-cfg-quiet] which create
a website of DOT files showing colourized changes as the IR is changed
by passes in the new pass manager pipeline.
A new change reporter is introduced that creates a website of changes made
by passes in the opt pipeline that change the IR. The hidden option
-dot-cfg-dir=<dir> specifies a directory (defaulting to "./") into which the
website will be created.
A file passes.html is created that contains a list of all the passes that
act on the IR. Those that do not change the IR are listed as omitted
because of no change, ignored or filtered out (using -filter-print-func
and -filter-passes) or not listed in quiet mode. Those that
do change the IR are listed as a link to a DOT file which contains a
CFG depiction of the IR (ala -dot-cfg) except that the instructions,
basic blocks and links that are only in the IR before the pass (ie, removed)
and those that are only in the IR after the pass (ie, added) are shown in
red and green, respectively, while the aspects of the CFG that do not change
are shown in black. Additional hidden options
-dot-cfg-before-color=<dot named color>,
-dot-cfg-after-color=<dot named color> and
-dot-cfg-common-color=<dot named color> are defined that allow the
customization of the colors used in colorizing the CFG.
-change-printer-dot-path=<path to dot exe> is also added.
Author: Jamie Schmeiser <schmeise@ca.ibm.com>
Reviewed By: aeubanks (Arthur Eubanks)
Differential Revision: https://reviews.llvm.org/D87202
Summary:
Break out non-functional changes to the print-changed classes that are needed
for reuse with the DotCfg change printer in https://reviews.llvm.org/D87202.
Various changes to the change printers to facilitate reuse with the
upcoming DotCfg change printer. This includes changing several of
the classes and their support classes to being templates. Also,
some template parameter names were simplified to avoid confusion
with planned identifiers in the DotCfg change printer to come. A
virtual function in the class for comparing functions was changed
to a lambda. The virtual function same was replaced with calls to
operator==. The only intentional functional change was to add the exe name
as the first parameter to llvm::sys::ExecuteAndWait
Author: Jamie Schmeiser <schmeise@ca.ibm.com>
Reviewed By: aeubanks (Arthur Eubanks)
Differential Revision: https://reviews.llvm.org/D110737
This patch adds a pass option to only run transforms that scalarize
vector operations and do not create new vector instructions.
When running VectorCombine early in the pipeline introducing new vector
operations can have negative effects, like blocking loop or SLP
vectorization. To avoid regressions, restrict the early VectorCombine
run (when using -enable-matrix) to only perform scalarization and not
introduce new vector operations.
This is done as option to the pass directly, which is then set when
adding the pass to the pipeline. This is done for the new pass manager
only.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D111800
PseudoProbeUpdatePass is used to distribute sample counts among dulplicated probes. It doesn't make sense for it to run without a sample profile. The pass takes 1% of the build time.
Reviewed By: wenlei
Differential Revision: https://reviews.llvm.org/D111847
Using uselistorders is fairly niche, it shouldn't be on by default and mostly just clutters the output.
Reviewed By: jamieschmeiser
Differential Revision: https://reviews.llvm.org/D111282
Summary:
The IR is saved in its print form before each pass is started and a
signal handler is registered. If the compilation crashes, the signal
handler will print the saved IR to dbgs(). This option
can be modified using -print-module-scope to get the IR for the complete
module. Filtering options can be used to improve performance by limiting
which passes (or functions) save the IR. Note that this option only works
with the new pass manager.
Author: Jamie Schmeiser <schmeise@ca.ibm.com>
Reviewed By: aeubanks (Arthur Eubanks) yrouban (Yevgeny Rouban)
Differential Revision: https://reviews.llvm.org/D86657
This is analogous to D86156 (which preserves "lossy" BFI in loop
passes). Lossy means that the analysis preserved may not be up to date
with regards to new blocks that are added in loop passes, but BPI will
not contain stale pointers to basic blocks that are deleted by the loop
passes.
This is achieved through BasicBlockCallbackVH in BPI, which calls
eraseBlock that updates the data structures in BPI whenever a basic
block is deleted.
This patch does not have any changes in the upstream pipeline, since
none of the loop passes in the pipeline use BPI currently.
However, since BPI wasn't previously preserved in loop passes, the loop
predication pass was invoking BPI *on the entire
function* every time it ran in an LPM. This caused massive compile time
in our downstream LPM invocation which contained loop predication.
See updated test with an invocation of a loop-pipeline containing loop
predication and -debug-pass turned ON.
Reviewed-By: asbirlea, modimo
Differential Revision: https://reviews.llvm.org/D110438
IR with matrix intrinsics is likely to also contain large vector
operations, which can benefit from early simplifications.
This is the last step in a series of changes to improve code-gen for
code using matrix subscript operators with the C/C++ matrix extension in
CLang, like
using matrix_t = double __attribute__((matrix_type(15, 15)));
void foo(unsigned i, matrix_t &A, matrix_t &B) {
for (unsigned j = 0; j < 4; ++j)
for (unsigned k = 0; k < i; k++)
B[k][j] -= A[k][j] * B[i][j];
}
https://clang.godbolt.org/z/6dKxK1Ed7
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D102496
In default pipelines the ModuleInlinerWrapperPass is adding the
InlinerPass to the pipeline twice, once due to MandatoryFirst (passing
true in the ctor) and then a second time with false as argument.
To make it possible to bisect and reduce opt test cases for this
part of the pipeline we need to be able to choose between the two
different variants of the InlinerPass when running opt. This patch is
changing 'inline' to a CGSCC_PASS_WITH_PARAMS in the PassRegistry,
making it possible run opt with both -passes=cgscc(inline) and
-passes=cgscc(inline<only-mandatory>).
Reviewed By: aeubanks, mtrofin
Differential Revision: https://reviews.llvm.org/D109877
Change the asan-module pass into a MODULE_PASS_WITH_PARAMS in the
pass registry, and add a single parameter called 'kernel' that
can be set instead of having a special pass name 'kasan-module'
to trigger that special pass config.
Main reason is to make sure that we have a unique mapping from
ClassName to PassName in the new passmanager framework, making it
possible to correctly identify the passes when dealing with options
such as -print-after and -print-pipeline-passes.
This is a follow-up to D105006 and D105007.
Split ThreadSanitizerPass into ThreadSanitizerPass (as a function
pass) and ModuleThreadSanitizerPass (as a module pass).
Main reason is to make sure that we have a unique mapping from
ClassName to PassName in the new passmanager framework, making it
possible to correctly identify the passes when dealing with options
such as -print-after and -print-pipeline-passes.
This is a follow-up to D105006 and D105007.
Split MemorySanitizerPass into MemorySanitizerPass (as a function
pass) and ModuleMemorySanitizerPass (as a module pass).
Main reason is to make sure that we have a unique mapping from
ClassName to PassName in the new passmanager framework, making it
possible to correctly identify the passes when dealing with options
such as -print-after and -print-pipeline-passes.
This is a follow-up to D105006 and D105007.
PassBuilder.cpp is the slowest file to compile in LLVM.
When trying to test changes to pipelines, it takes a long time to recompile.
This doesn't actually speedup building PassBuilder.cpp itself since most
of the time is spent in other large/duplicated functions caused by
PassRegistry.def.
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D109798
Pseudo probe instrumentation was missing from O0 build. It is needed in cases where some source files are built in O0 while the others are built in optimize mode.
Reviewed By: wenlei, wlei, wmi
Differential Revision: https://reviews.llvm.org/D109531
Added opt option -print-pipeline-passes to print a -passes compatible
string describing the built pass pipeline.
As an example:
$ opt -enable-new-pm=1 -adce -licm -simplifycfg -o /dev/null /dev/null -print-pipeline-passes
verify,function(adce),function(loop-mssa(licm)),function(simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-sink-common-insts>),verify,BitcodeWriterPass
At the moment this is best-effort only and there are some known
limitations:
- Not all passes accepting parameters will print their parameters
(currently only implemented for simplifycfg).
- Some ClassName to pass-name mappings are not unique.
- Some ClassName to pass-name mappings are missing (e.g.
BitcodeWriterPass).
Differential Revision: https://reviews.llvm.org/D108298
Added opt option -print-pipeline-passes to print a -passes compatible
string describing the built pass pipeline.
As an example:
$ opt -enable-new-pm=1 -adce -licm -simplifycfg -o /dev/null /dev/null -print-pipeline-passes
verify,function(adce),function(loop-mssa(licm)),function(simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-sink-common-insts>),verify,BitcodeWriterPass
At the moment this is best-effort only and there are some known
limitations:
- Not all passes accepting parameters will print their parameters
(currently only implemented for simplifycfg).
- Some ClassName to pass-name mappings are not unique.
- Some ClassName to pass-name mappings are missing (e.g.
BitcodeWriterPass).
A couple of passes that are parameterized in new-PM used different
pass names (in cmd line interface) while using the same pass class
name. This patch updates the PassRegistry to model pass parameters
more properly using PASS_WITH_PARAMS.
Reason for the change is to ensure that we have a 1-1 mapping
between class name and pass name (when disregarding the params).
With a 1-1 mapping it is more obvious which pass name to use in
options such as -debug-only, -print-after etc.
The opt -passes syntax is changed for the following passes:
early-cse-memssa => early-cse<memssa>
post-inline-ee-instrument => ee-instrument<post-inline>
loop-extract-single => loop-extract<single>
lower-matrix-intrinsics-minimal => lower-matrix-intrinsics<minimal>
This patch is not updating pass names in docs/Passes.rst. Not quite
sure what the status is for that document (e.g. when it comes to
listing pass paramters). It is only loop-extract-single that is
mentioned in Passes.rst today, out of the passes mentioned above.
Differential Revision: https://reviews.llvm.org/D108362
Refactored implementation of AddressSanitizerPass and
HWAddressSanitizerPass to use pass options similar to passes like
MemorySanitizerPass. This makes sure that there is a single mapping
from class name to pass name (needed by D108298), and options like
-debug-only and -print-after makes a bit more sense when (despite
that it is the unparameterized pass name that should be used in those
options).
A result of the above is that some pass names are removed in favor
of the parameterized versions:
- "khwasan" is now "hwasan<kernel;recover>"
- "kasan" is now "asan<kernel>"
- "kmsan" is now "msan<kernel>"
Differential Revision: https://reviews.llvm.org/D105007
Currently specifying -licm or -passes=licm will implicitly create
-passes=loop(licm). This does not match the intended default (used
by the legacy PM and by the default pipeline) of using the
MemorySSA-based LICM implementation. As I plan to drop the non-MSSA
implementation, this will stop working entirely...
This special-cases licm to create a loop-mssa manager instead. At
this point it's still possible to use -passes='loop(licm)' to opt
into the AST-based implementation.
Differential Revision: https://reviews.llvm.org/D108155
This option has been enabled by default for quite a while now.
The practical impact of removing the option is that MSSA use
cannot be disabled in default pipelines (both LPM and NPM) and
in manual LPM invocations. NPM can still choose to enable/disable
MSSA using loop vs loop-mssa.
The next step will be to require MSSA for LICM and drop the
AST-based implementation entirely.
Differential Revision: https://reviews.llvm.org/D108075
Two standalone LoopRotate passes scheduled using
createFunctionToLoopPassAdaptor() currently enable MemorySSA.
However, while LoopRotate can preserve MemorySSA, it does not use
it, so requiring MemorySSA is unnecessary.
This change doesn't have a practical compile-time impact by itself,
because subsequent passes still request MemorySSA.
Differential Revision: https://reviews.llvm.org/D108073
Summary:
The assertion that both functions were not missing was incorrect and would
fail when one of the functions was missing. Fixed it and moved the
assertion earlier to check the input parameters to better capture
first-failure. Added lit test.
Author: Jamie Schmeiser <schmeise@ca.ibm.com>
Reviewed By: aeubanks (Arthur Eubanks)
Differential Revision: https://reviews.llvm.org/D107989
Pulled out the OptimizationLevel class from PassBuilder in order to be able to access it from within the PassManager and avoid include conflicts.
Reviewed By: mtrofin
Differential Revision: https://reviews.llvm.org/D107025
The current JumpThreading pass does not jump thread loops since it can
result in irreducible control flow that harms other optimizations. This
prevents switch statements inside a loop from being optimized to use
unconditional branches.
This code pattern occurs in the core_state_transition function of
Coremark. The state machine can be implemented manually with goto
statements resulting in a large runtime improvement, and this transform
makes the switch implementation match the goto version in performance.
This patch specifically targets switch statements inside a loop that
have the opportunity to be threaded. Once it identifies an opportunity,
it creates new paths that branch directly to the correct code block.
For example, the left CFG could be transformed to the right CFG:
```
sw.bb sw.bb
/ | \ / | \
case1 case2 case3 case1 case2 case3
\ | / / | \
latch.bb latch.2 latch.3 latch.1
br sw.bb / | \
sw.bb.2 sw.bb.3 sw.bb.1
br case2 br case3 br case1
```
Co-author: Justin Kreiner @jkreiner
Co-author: Ehsan Amiri @amehsan
Reviewed By: SjoerdMeijer
Differential Revision: https://reviews.llvm.org/D99205
Sometimes a transformation can change the name of some IR (e.g. an SCC
with functions added/removed). This can be confusing when debug logging
doesn't match the post-transformation name. The specific example I came
across was that --print-after-all said the inliner was working on an SCC
that only contained one function, but calls in multiple functions were
getting inlined. After all inlining, the current SCC only contained one
function.
Piggyback off of the existing logic to handle invalidated IR +
--print-module-scope. Simply always store the IR description and use
that.
Reviewed By: jamieschmeiser
Differential Revision: https://reviews.llvm.org/D106290
This patch adds a new pass called LNICM which is a LoopNest version of LICM and a test case to show how LNICM works.
Basically, LNICM only hoists invariants out of loop nest (not a loop) to keep/make perfect loop nest. This enables later optimizations that require perfect loop nest.
Reviewed By: Whitney
Differential Revision: https://reviews.llvm.org/D104180
This patch make coroutine passes run by default in LLVM pipeline. Now
the clang and opt could handle IR inputs containing coroutine intrinsics
without special options.
It should be fine. On the one hand, the coroutine passes seems to be stable
since there are already many projects using coroutine feature.
On the other hand, the coroutine passes should do nothing for IR who doesn't
contain coroutine intrinsic.
Test Plan: check-llvm
Reviewed by: lxfind, aeubanks
Differential Revision: https://reviews.llvm.org/D105877
To help with debugging non-trivial unswitching issues.
Don't care about the legacy pass, nobody is using it.
If a pass's string params are empty (e.g. "simple-loop-unswitch"), don't
default to the empty constructor for the pass params. We should still
let the parser take care of it in case the parser has its own defaults.
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D105933
It is confusing to have two ways of specifying the same pass
('simple-loop-unswitch' and 'unswitch'). This patch replaces
'unswitch' by 'simple-loop-unswitch' to get a unique identifier.
Using 'simple-loop-unswitch' instead of 'unswitch' also has the
advantage of matching how the pass is named in DEBUG_TYPE etc. So
this makes it a bit more consistent how we refer to the pass in
options such as -passes, -print-after and -debug-only.
Reviewed By: aeubanks
Differential Revision: https://reviews.llvm.org/D105628
There was an alias between 'simplifycfg' and 'simplify-cfg' in the
PassRegistry. That was the original reason for this patch, which
effectively removes the alias.
This patch also replaces all occurrances of 'simplify-cfg'
by 'simplifycfg'. Reason for choosing that form for the name is
that it matches the DEBUG_TYPE for the pass, and the legacy PM name
and also how it is spelled out in other passes such as
'loop-simplifycfg', and in other options such as
'simplifycfg-merge-cond-stores'.
I for some reason the name should be changed to 'simplify-cfg' in
the future, then I think such a renaming should be more widely done
and not only impacting the PassRegistry.
Reviewed By: aeubanks
Differential Revision: https://reviews.llvm.org/D105627
To support options like -print-before=<pass> and -print-after=<pass>
the PassBuilder will register PassInstrumentation callbacks as well
as a mapping between internal pass class names and the pass names
used in those options (and other cmd line interfaces). But for
some reason all the passes that takes options where missing in those
maps, so for example "-print-after=loop-vectorize" didn't work.
This patch will add the missing entries by also taking care of
function and loop passes with params when setting up the class to
pass name maps.
One might notice that even with this patch it might be tricky to
know what pass name to use in options such as -print-after. This
because there only is a single mapping from class name to pass name,
while the PassRegistry currently is a bit messy as it sometimes
reuses the same class for different pass names (without using the
"pass with params" scheme, or the pass-name<variant> syntax).
It gets extra messy in some situations. For example the
MemorySanitizerPass can run like this (with debug and print-after)
opt -passes='kmsan' -print-after=msan-module -debug-only=msan
The 'kmsan' alias for 'msan<kernel>' is just confusing as one might
think that 'kmsan' is a separate pass (but the DEBUG_TYPE is still
just 'msan'). And since the module pass version of the pass adds
a mapping from 'MemorySanitizerPass' to 'msan-module' one need to
use 'msan-module' in the print-before and print-after options.
Reviewed By: ychen
Differential Revision: https://reviews.llvm.org/D105006
AddDiscriminatorsPass is in Legacy PM's O0 pipeline. This patch did the same
for NPM O0 pipeline.
Reviewed By: aeubanks, MaskRay
Differential Revision: https://reviews.llvm.org/D105650
Relevant discussion can be found at: https://lists.llvm.org/pipermail/llvm-dev/2021-January/148197.html
In the existing design, An SCC that contains a coroutine will go through the folloing passes:
Inliner -> CoroSplitPass (fake) -> FunctionSimplificationPipeline -> Inliner -> CoroSplitPass (real) -> FunctionSimplificationPipeline
The first CoroSplitPass doesn't do anything other than putting the SCC back to the queue so that the entire pipeline can repeat.
As you can see, we run Inliner twice on the SCC consecutively without doing any real split, which is unnecessary and likely unintended.
What we really wanted is this:
Inliner -> FunctionSimplificationPipeline -> CoroSplitPass -> FunctionSimplificationPipeline
(note that we don't really need to run Inliner again on the ramp function after split).
Hence the way we do it here is to move CoroSplitPass to the end of the CGSCC pipeline, make it once for real, insert the newly generated SCCs (the clones) back to the pipeline so that they can be optimized, and also add a function simplification pipeline after CoroSplit to optimize the post-split ramp function.
This approach also conforms to how the new pass manager works instead of relying on an adhoc post split cleanup, making it ready for full switch to new pass manager eventually.
By looking at some of the changes to the tests, we can already observe that this changes allows for more optimizations applied to coroutines.
Reviewed By: aeubanks, ChuanqiXu
Differential Revision: https://reviews.llvm.org/D95807
Dynamically loaded plugins for the new pass manager are initialised by
calling llvmGetPassPluginInfo. This is defined as a weak symbol so that
it is continually redefined by each plugin that is loaded. When loading
a plugin from a shared library, the intention is that
llvmGetPassPluginInfo will be resolved to the definition in the most
recent plugin. However, using a global search for this resolution can
fail in situations where multiple plugins are loaded.
Currently:
* If a plugin does not define llvmGetPassPluginInfo, then it will be
silently resolved to the previous plugin's definition.
* If loading the same plugin twice with another in between, e.g. plugin
A/plugin B/plugin A, then the second load of plugin A will resolve to
llvmGetPassPluginInfo in plugin B.
* The previous case can also occur when a dynamic library defines both
NPM and legacy plugins; the legacy plugins are loaded first and then
with `-fplugin=A -fpass-plugin=B -fpass-plugin=A`: A will be loaded as
a legacy plugin and define llvmGetPassPluginInfo; B will be loaded
and redefine it; and finally when A is loaded as an NPM plugin it will
be resolved to the definition from B.
Instead of searching globally, restrict the symbol lookup to the library
that is currently being loaded.
Differential Revision: https://reviews.llvm.org/D104916
CoroElide pass works only when a post-split coroutine is inlined into another post-split coroutine.
In O0, there is no inlining after CoroSplit, and hence no CoroElide can happen.
It's useless to put CoroElide pass in the O0 pipeline and it will never be triggered (unless I miss anything).
Differential Revision: https://reviews.llvm.org/D105066
Now that the OpenMPOpt module pass include important optimizations for removing
globalization from offloading regions it should be run at a lower optimization
level.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D105056
Addition of this pass has been botched.
There is no particular reason why it had to be sold as an inseparable part
of new-pm transition. It was added when old-pm was still the default,
and very *very* few users were actually tracking new-pm,
so it's effects weren't measured.
Which means, some of the turnoil of the new-pm transition
are actually likely regressions due to this pass.
Likewise, there has been a number of post-commit feedback
(post new-pm switch), namely
* https://reviews.llvm.org/D37467#2787157 (regresses HW-loops)
* https://reviews.llvm.org/D37467#2787259 (should not be in middle-end, should run after LSR, not before)
* https://reviews.llvm.org/D95789 (an attempt to fix bad loop backedge metadata)
and in the half year past, the pass authors (google) still haven't found time to respond to any of that.
Hereby it is proposed to backout the pass from the pipeline,
until someone who cares about it can address the issues reported,
and properly start the process of adding a new pass into the pipeline,
with proper performance evaluation.
Furthermore, neither google nor facebook reports any perf changes
from this change, so i'm dropping the pass completely.
It can always be re-reverted should/if anyone want to pick it up again.
Reviewed By: aeubanks
Differential Revision: https://reviews.llvm.org/D104099
This commit mostly just replaces bad uses of `NDEBUG` with uses of
`LLVM_ENABLE_ABI_BREAKING_CHANGES` - the safe way to include ABI
breaking changes (normally extra struct elements in headers).
Differential Revision: https://reviews.llvm.org/D104216
This adds a function specialization pass to LLVM. Constant parameters
like function pointers and constant globals are propagated to the callee by
specializing the function.
This is a first version with a number of limitations:
- The pass is off by default, so needs to be enabled on the command line,
- It does not handle specialization of recursive functions,
- It does not yet handle constants and constant ranges,
- Only 1 argument per function is specialised,
- The cost-model could be further looked into, and perhaps related,
- We are not yet caching analysis results.
This is based on earlier work by Matthew Simpson (D36432) and Vinay Madhusudan.
More recently this was also discussed on the list, see:
https://lists.llvm.org/pipermail/llvm-dev/2021-March/149380.html.
The motivation for this work is that function specialisation often comes up as
a reason for performance differences of generated code between LLVM and GCC,
which has this enabled by default from optimisation level -O3 and up. And while
this certainly helps a few cpu benchmark cases, this also triggers in real
world codes and is thus a generally useful transformation to have in LLVM.
Function specialisation has great potential to increase compile-times and
code-size. The summary from some investigations with this patch is:
- Compile-time increases for short compile jobs is high relatively, but the
increase in absolute numbers still low.
- For longer compile-jobs, the extra compile time is around 1%, and very much
in line with GCC.
- It is difficult to blame one thing for compile-time increases: it looks like
everywhere a little bit more time is spent processing more functions and
instructions.
- But the function specialisation pass itself is not very expensive; it doesn't
show up very high in the profile of the optimisation passes.
The goal of this work is to reach parity with GCC which means that eventually
we would like to get this enabled by default. But first we would like to address
some of the limitations before that.
Differential Revision: https://reviews.llvm.org/D93838
This patch changes LoopUnrollAndJamPass from FunctionPass to LoopNest pass.
The next patch will utilize LoopNest to effectively handle loop nests.
Also, a crash problem on legacy pass manager is fixed.
Reviewed By: Whitney
Differential Revision: https://reviews.llvm.org/D99149
This pass transforms loops that contain a conditional branch with induction
variable. For example, it transforms left code to right code:
newbound = min(n, c)
while (iv < n) { while(iv < newbound) {
A A
if (iv < c) B
B C
C }
} if (iv != n) {
while (iv < n) {
A
C
}
}
Differential Revision: https://reviews.llvm.org/D102234
This is split off from D102002, and I think it is clear that
the difference in behavior was not intended. Options were
added to SimplifyCFG over time, but different chunks of
the pass pipelines were not kept in sync.
This patch changes LoopFlattenPass from FunctionPass to LoopNestPass.
Utilize LoopNest and let function 'Flatten' generate information from it.
Reviewed By: Whitney
Differential Revision: https://reviews.llvm.org/D102904
This patch changes LoopFlattenPass from FunctionPass to LoopNestPass.
Utilize LoopNest and let function 'Flatten' generate information from it.
Reviewed By: Whitney
Differential Revision: https://reviews.llvm.org/D102904
This patch changes LoopFlattenPass from FunctionPass to LoopNestPass.
Utilize LoopNest and let function 'Flatten' generate information from it.
Reviewed By: Whitney
Differential Revision: https://reviews.llvm.org/D102904
This patch changes LoopUnrollAndJamPass from FunctionPass to LoopNest pass.
The next patch will utilize LoopNest to effectively handle loop nests.
Reviewed By: Whitney
Differential Revision: https://reviews.llvm.org/D99149
Summary:
Make the file name and descriptors static so that they are reused by
print-changed=diff. This avoids errors about being unable to create
temporary files when doing the later comparisons in a large compile.
Author: Jamie Schmeiser <schmeise@ca.ibm.com>
Reviewed By: aeubanks (Arthur Eubanks)
Differential Revision: https://reviews.llvm.org/D100116
This patch changes LoopUnrollAndJamPass from FunctionPass to LoopNest pass.
The next patch will utilize LoopNest to effectively handle loop nests.
Reviewed By: Whitney
Differential Revision: https://reviews.llvm.org/D99149
This patch changes LoopUnrollAndJamPass from FunctionPass to LoopNest pass.
The next patch will utilize LoopNest to effectively handle loop nests.
Reviewed By: Whitney
Differential Revision: https://reviews.llvm.org/D99149
To bring D99599's implementation in line with the existing
PrintPassInstrumentation, and to fix a FIXME, add more customizability
to PrintPassInstrumentation.
Introduce three new options. The first takes over the existing
"-debug-pass-manager-verbose" cl::opt.
The second and third option are specific to -fdebug-pass-structure. They
allow indentation, and also don't print analysis queries.
To avoid more golden file tests than necessary, prune down the
-fdebug-pass-structure tests.
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D102196
This patch contains the bare minimum to run the new Pass Manager from the LLVM-C APIs. It does not feature PGOOptions, PassPlugins or Debugify in its current state. Bugzilla: PR48499
Reviewed By: aeubanks
Differential Revision: https://reviews.llvm.org/D102136
This patch contains the bare minimum to run the new Pass Manager from the LLVM-C APIs. It does not feature PGOOptions, PassPlugins or Debugify in its current state. Bugzilla: PR48499
Reviewed By: aeubanks
Differential Revision: https://reviews.llvm.org/D102136
This patch adjusts the LTO pipeline in the new PM to run GlobalsAA
before LICM to match the legacy PM.
This fixes a regression where the new PM failed to vectorize loops that
require hoisting/sinking by LICM depending on GlobalsAA info.
Reviewed By: aeubanks
Differential Revision: https://reviews.llvm.org/D102345
Split off from D102345 to commit this separately from other changes in
the patch. This aligns the behavior of the new PM with the legacy PM
for LTO, with respect to running LICM.
Together with the remaining changes in D102345, this fixes new PM
regressions where we fail to vectorize loops that are vectorized with
the legacy PM.
This is better no-functional-change-intended than the 1st attempt.
As noted in D102002, there were at least 2 diffs that went
unchecked in pass manager regressions tests: different pass
parameters (SimplifyCFG) and an extension point/callback.
Those should be lifted from the original code blocks correctly
now.
This reverts commit fefcb1f878.
It was supposed to be NFC, but as noted in the post-commit
comments in D102002, that was not true: SimplifyCFG uses
different parameters and there's a difference in an
extension point / callback.
Printing pass manager invocations is fairly verbose and not super
useful.
This allows us to remove DebugLogging from pass managers and PassBuilder
since all logging (aside from analysis managers) goes through
instrumentation now.
This has the downside of never being able to print the top level pass
manager via instrumentation, but that seems like a minor downside.
Reviewed By: ychen
Differential Revision: https://reviews.llvm.org/D101797
We're trying to move DebugLogging into instrumentation, rather than
being part of PassManagers/AnalysisManagers.
Reviewed By: ychen
Differential Revision: https://reviews.llvm.org/D102093
The CGSCC pass manager interplay with the FunctionAnalysisManagerCGSCCProxy is 'special' in the sense that the former will rerun the latter if there are changes to a SCC structure; that being said, some of the functions in the SCC may be unchanged. In that case, the function simplification pipeline will be re-run, which impacts compile time[1].
This patch allows the function simplification pipeline be skipped if it was already run and the function was not modified since.
The behavior is currently disabled by default. This is because, currently, the rerunning of the function simplification pipeline on an unchanged function may still result in changes. The patch simplifies investigating and fixing those cases where repeated function pass runs do actually positively impact code quality, while offering an easy workaround for those impacted negatively by compile time regressions, and not impacting mainline scenarios.
[1] A [[ http://llvm-compile-time-tracker.com/compare.php?from=eb37d3546cd0c6e67798496634c45e501f7806f1&to=ac722d1190dc7bbdd17e977ef7ec95e69eefc91e&stat=instructions | compile time tracker ]] run with the option enabled.
Differential Revision: https://reviews.llvm.org/D98103
GlobalsAA is only created at the beginning of the inliner pipeline. If
an AAManager is cached from previous passes, it won't get rebuilt to
include the newly created GlobalsAA.
Reviewed By: mtrofin
Differential Revision: https://reviews.llvm.org/D101379
Relative look table converter pass caused an issue when full lto
is enabled (reported in https://reviews.llvm.org/D94355).
This patch disables that pass from full lto pre-link phase optimization
pipeline until the issue is fixed.
Differential Revision: https://reviews.llvm.org/D101664
Hoisting and sinking instructions out of conditional blocks enables
additional vectorization by:
1. Executing memory accesses unconditionally.
2. Reducing the number of instructions that need predication.
After disabling early hoisting / sinking, we miss out on a few
vectorization opportunities. One of those is causing a ~10% performance
regression in one of the Geekbench benchmarks on AArch64.
This patch tires to recover the regression by running hoisting/sinking
as part of a SimplifyCFG run after LoopRotate and before LoopVectorize.
Note that in the legacy pass-manager, we run LoopRotate just before
vectorization again and there's no SimplifyCFG run in between, so the
sinking/hoisting may impact the later run on LoopRotate. But the impact
should be limited and the benefit of hosting/sinking at this stage
should outweigh the risk of not rotating.
Compile-time impact looks slightly positive for most cases.
http://llvm-compile-time-tracker.com/compare.php?from=2ea7fb7b1c045a7d60fcccf3df3ebb26aa3699e5&to=e58b4a763c691da651f25996aad619cb3d946faf&stat=instructions
NewPM-O3: geomean -0.19%
NewPM-ReleaseThinLTO: geoman -0.54%
NewPM-ReleaseLTO-g: geomean -0.03%
With a few benchmarks seeing a notable increase, but also some
improvements.
Alternative to D101290.
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D101468
Kazu Hirata