The reason for the NewPM redesign is described in the commit
cba3e783389a: [NewPM] Disable PreservedCFGChecker ...
The checker introduces an internal custom CFG analysis that tracks
current up-to date CFG snapshot. The analysis is invalidated along
any other CFG related analysis (the key is CFGAnalyses). If the CFG
analysis is not invalidated at a functional pass exit then the checker
asserts that the CFG snapshot taken from this analysis is equals to
a snapshot of the current CFG.
Along the way:
- the function CFG::printDiff() is simplified by removing function
name calculation. The name is printed by the caller;
- fixed CFG invalidated condition (see CFG::invalidate());
- StandardInstrumentations::registerCallbacks() gets additional
optional parameter of type FunctionAnalysisManager*, which is
needed by the checker to get the custom CFG analysis;
- several PM related tests updated to explicitly set
-verify-cfg-preserved=1 as they need.
This patch is safe to land as the CFGChecker is left switched off
(the options -verify-cfg-preserved is false by default). It will be
switched on by a separate patch to minimize possible reverts.
Reviewed By: skatkov, kuhar
Differential Revision: https://reviews.llvm.org/D91327
Summary:
The colour characters currently added to the output of -print-changed=diff
and -print-changed=diff-quiet cause difficulties when capturing the output
and examining it in an editor. Change the function to not have the colour
characters and add 2 new choices (-print-changed=cdiff and
-print-changed=cdiff-quiet) to retain the existing functionality of adding
the colour characters.
Author: Jamie Schmeiser <schmeise@ca.ibm.com>
Reviewed By: aeubanks (Arthur Eubanks) yrouban (Yevgeny Rouban)
Differential Revision: https://reviews.llvm.org/D97398
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. 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
Summary:
Introduce base classes that hold a textual represent of the IR
based on basic blocks and a base class for comparing this
representation. A new change printer is introduced that uses these
classes to save and compare representations of the IR before and after
each pass. It only reports when changes are made by a pass (similar to
-print-changed) except that the changes are shown in a patch-like format
with those lines that are removed shown in red prefixed with '-' and those
added shown in green with '+'. This functionality was introduced in my
tutorial at the 2020 virtual developer's meeting.
Author: Jamie Schmeiser <schmeise@ca.ibm.com>
Reviewed By: aeubanks (Arthur Eubanks)
Differential Revision: https://reviews.llvm.org/D91890
Sample re-annotation is required in LTO time to achieve a reasonable post-inline profile quality. However, we have seen that such LTO-time re-annotation degrades profile quality. This is mainly caused by preLTO code duplication that is done by passes such as loop unrolling, jump threading, indirect call promotion etc, where samples corresponding to a source location are aggregated multiple times due to the duplicates. In this change we are introducing a concept of distribution factor for pseudo probes so that samples can be distributed for duplicated probes scaled by a factor. We hope that optimizations duplicating code well-maintain the branch frequency information (BFI) based on which probe distribution factors are calculated. Distribution factors are updated at the end of preLTO pipeline to reflect an estimated portion of the real execution count.
This change also introduces a pseudo probe verifier that can be run after each IR passes to detect duplicated pseudo probes.
A saturated distribution factor stands for 1.0. A pesudo probe will carry a factor with the value ranged from 0.0 to 1.0. A 64-bit integral distribution factor field that represents [0.0, 1.0] is associated to each block probe. Unfortunately this cannot be done for callsite probes due to the size limitation of a 32-bit Dwarf discriminator. A 7-bit distribution factor is used instead.
Changes are also needed to the sample profile inliner to deal with prorated callsite counts. Call sites duplicated by PreLTO passes, when later on inlined in LTO time, should have the callees’s probe prorated based on the Prelink-computed distribution factors. The distribution factors should also be taken into account when computing hotness for inline candidates. Also, Indirect call promotion results in multiple callisites. The original samples should be distributed across them. This is fixed by adjusting the callisites' distribution factors.
Reviewed By: wmi
Differential Revision: https://reviews.llvm.org/D93264
Summary:
Introduce a new mode of operation for -print-changed that only reports
after a pass changes the IR with all of the other messages suppressed (ie,
no initial IR and no messages about ignored, filtered or non-modifying
passes).
The option processing for -print-changed is changed to take an optional
string indicating options for print-changed. Initially, the only option
supported is quiet (as described above). This new quiet mode is specified
with -print-changed=quiet while -print-changed will continue to function
in the same way. It is intended that there will be more options in the
future.
Author: Jamie Schmeiser <schmeise@ca.ibm.com>
Reviewed By: aeubanks (Arthur Eubanks)
Differential Revision: https://reviews.llvm.org/D92589
Currently there is an issue where the legacy pass manager uses a different OptBisect counter than the new pass manager.
This fix makes the npm OptBisectInstrumentation use the global OptBisect.
Reviewed By: aeubanks
Differential Revision: https://reviews.llvm.org/D92897
This changes --print-before/after to be a list of strings rather than
legacy passes. (this also has the effect of not showing the entire list
of passes in --help-hidden after --print-before/after, which IMO is
great for making it less verbose).
Currently PrintIRInstrumentation passes the class name rather than pass
name to llvm::shouldPrintBeforePass(), meaning
llvm::shouldPrintBeforePass() never functions as intended in the NPM.
There is no easy way of converting class names to pass names outside of
within an instance of PassBuilder.
This adds a map of pass class names to their short names in
PassRegistry.def within PassInstrumentationCallbacks. It is populated
inside the constructor of PassBuilder, which takes a
PassInstrumentationCallbacks.
Add a pointer to PassInstrumentationCallbacks inside
PrintIRInstrumentation and use the newly created map.
This is a bit hacky, but I can't think of a better way since the short
id to class name only exists within PassRegistry.def. This also doesn't
handle passes not in PassRegistry.def but rather added via
PassBuilder::registerPipelineParsingCallback().
llvm/test/CodeGen/Generic/print-after.ll doesn't seem very useful now
with this change.
Reviewed By: ychen, jamieschmeiser
Differential Revision: https://reviews.llvm.org/D87216
Summary:
[NFC intended] Refactor the code for printChanged for reuse and to facilitate
subsequent reporters of changes to the IR in the new pass manager.
Create abstract template base classes for common functionality and give
classes more appropriate names. The base classes handle all of the
determination of when a function or pass is "interesting" and should be
reported or filtered out. They have pure virtual functions which are called
when a change by a pass has been recognized so the derived class need only
provide the overrides to present the information about the changing IR.
There are at least 2 more change reporters to come (which were presented
in my tutorial at the 2020 llvm developer's meeting) that derive from
these classes.
Respond to review comments: move function out of line, remove inline keyword,
remove unneeded qualifiers, simplify comparison.
Author: Jamie Schmeiser <schmeise@ca.ibm.com>
Reviewed By: aeubanks (Arthur Eubanks), madhur13490 (Madhur Amilkanthwar)
Differential Revision: https://reviews.llvm.org/D87000
The design of the PreservedCFG Checker (landed with the commit
28012e00d8) has a fundamental flaw which makes it incorrect.
The checker is based on the PreservedAnalyses result returned
by functional passes: if CFGAnalyses is in the returned
PreservedAnalyses set, then the checker asserts that the CFG
snapshot saved before the pass is equal to the CFG snapshot
taken after the the pass. The problem is in passes that change
CFG and invalidate CFGAnalyses on their own. Such passes do not
return CFGanalyses in the returned PreservedAnalyses. So the
checker mistakenly expects CFG unchanged. As an example see the
class TestSimplifyCFGInvalidatingAnalysisPass in the new tests.
It is interesting that the bug was not found in LLVM. That is
because the CFG checker ran only if CFGAnalyses was checked
incorrectly:
if (!PassPA.allAnalysesInSetPreserved<CFGAnalyses>())
return;
but must be checked as follows:
auto PAC = PA.getChecker<PreservedCFGCheckerAnalysis>();
if (!(PAC.preserved() ||
PAC.preservedSet<AllAnalysesOn<Function>>() ||
PAC.preservedSet<CFGAnalyses>())
return;
A fully redesigned checker will be sent as a separate follow-up
patch.
Reviewed By: Serguei Katkov, Jakub Kuderski
Differential Revision: https://reviews.llvm.org/D91324
Summary:
Add an option -print-before-changed that modifies the print-changed
behaviour so that it prints the IR before a pass that changed it in
addition to printing the IR after the pass. Note that the option
does nothing in isolation. The filtering options work as expected.
Lit tests are included.
Author: Jamie Schmeiser <schmeise@ca.ibm.com>
Reviewed By: aeubanks (Arthur Eubanks)
Differential Revision: https://reviews.llvm.org/D88757
This instruments a should-run-optional-pass callback using the existing
OptBisect class to decide if new passes should be skipped. Passes that
force isRequired never reach this at all, so they are not included in
"BISECT:" output nor its pass count.
The test case is resurrected from r267022, an early version of D19172
that had new pass manager support (later reverted and redone without).
Reviewed By: aeubanks
Differential Revision: https://reviews.llvm.org/D87951
This allows those instrumentation to log when they decide to skip a
pass. This provides extra helpful info for optnone functions and also
will help with opt-bisect.
Have OptNoneInstrumentation print when it skips due to seeing optnone.
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D90545
This removes "VerifyEachPass" parameters from a lot of functions which is nice.
Don't verify after special passes or VerifierPass.
This introduces verification on loop and cgscc passes, verifying the corresponding function/module.
Reviewed By: ychen
Differential Revision: https://reviews.llvm.org/D88764
This makes the NPM skip not required passes on functions marked optnone.
If this causes a pass that should be required but has not been marked
required to be skipped, add
`static bool isRequired() { return true; }`
to the pass class. AlwaysInlinerPass is an example.
clang/test/CodeGen/O0-no-skipped-passes.c is useful for checking that
no passes are skipped under -O0.
The -enable-npm-optnone option will be removed once this has been stable
for long enough without issues.
Reviewed By: ychen, asbirlea
Differential Revision: https://reviews.llvm.org/D87869
A new hidden option -print-changed is added along with code to support
printing the IR as it passes through the opt pipeline in the new pass
manager. Only those passes that change the IR are reported, with others
only having the banner reported, indicating that they did not change the
IR, were filtered out or ignored. Filtering of output via the
-filter-print-funcs is supported and a new supporting hidden option
-filter-passes is added. The latter takes a comma separated list of pass
names and filters the output to only show those passes in the list that
change the IR. The output can also be modified via the -print-module-scope
function.
The code introduces an abstract template base class that generalizes the
comparison of IRs that takes an IR representation as template parameter.
Derived classes provide overrides that provide an event based API
for generalized reporting of IRs as they are changed in the opt pipeline
through the new pass manager.
The first of several instantiations is provided that prints the IR
in a form similar to that produced by -print-after-all with the above
mentioned filtering capabilities. This version, and the others to
follow will be introduced at the upcoming developer's conference.
Reviewed By: aeubanks (Arthur Eubanks), yrouban (Yevgeny Rouban), ychen (Yuanfang Chen), MaskRay (Fangrui Song)
Differential Revision: https://reviews.llvm.org/D86360
A new hidden option -print-changed is added along with code to support
printing the IR as it passes through the opt pipeline in the new pass
manager. Only those passes that change the IR are reported, with others
only having the banner reported, indicating that they did not change the
IR, were filtered out or ignored. Filtering of output via the
-filter-print-funcs is supported and a new supporting hidden option
-filter-passes is added. The latter takes a comma separated list of pass
names and filters the output to only show those passes in the list that
change the IR. The output can also be modified via the -print-module-scope
function.
The code introduces a template base class that generalizes the comparison
of IRs that takes an IR representation as template parameter. The
constructor takes a series of lambdas that provide an event based API
for generalized reporting of IRs as they are changed in the opt pipeline
through the new pass manager.
The first of several instantiations is provided that prints the IR
in a form similar to that produced by -print-after-all with the above
mentioned filtering capabilities. This version, and the others to
follow will be introduced at the upcoming developer's conference.
Reviewed By: aeubanks (Arthur Eubanks), yrouban (Yevgeny Rouban), ychen (Yuanfang Chen)
Differential Revision: https://reviews.llvm.org/D86360
Check that all passes, which report they preserve CFG,
are really preserving CFG.
A new standard instrumentation is introduced. It can be
switched on/off by the flag verify-cfg-preserved, which
is on by default for debug builds.
Reviewers: kuhar, fedor.sergeev
Differential Revision: https://reviews.llvm.org/D81558
A new hidden option -print-changed is added along with code to support
printing the IR as it passes through the opt pipeline in the new pass
manager. Only those passes that change the IR are reported, with others
only having the banner reported, indicating that they did not change the
IR, were filtered out or ignored. Filtering of output via the
-filter-print-funcs is supported and a new supporting hidden option
-filter-passes is added. The latter takes a comma separated list of pass
names and filters the output to only show those passes in the list that
change the IR. The output can also be modified via the -print-module-scope
function.
The code introduces a template base class that generalizes the comparison
of IRs that takes an IR representation as template parameter. The
constructor takes a series of lambdas that provide an event based API
for generalized reporting of IRs as they are changed in the opt pipeline
through the new pass manager.
The first of several instantiations is provided that prints the IR
in a form similar to that produced by -print-after-all with the above
mentioned filtering capabilities. This version, and the others to
follow will be introduced at the upcoming developer's conference.
See https://hotcrp.llvm.org/usllvm2020/paper/29 for more information.
Reviewed By: yrouban (Yevgeny Rouban)
Differential Revision: https://reviews.llvm.org/D86360
Both AfterPass and AfterPassInvalidated pass instrumentation
callbacks get additional parameter of type PreservedAnalyses.
This patch was created by @fedor.sergeev. I have just slightly
changed it.
Reviewers: fedor.sergeev
Differential Revision: https://reviews.llvm.org/D81555
This is a non-functional-change to generalize the printIR routines so that
the output can be saved and manipulated rather than being directly output
to dbgs(). This is a prerequisite change for many upcoming changes that
allow new ways of examining changes made to the IR in the new pass manager.
Reviewed By: aeubanks (Arthur Eubanks)
Differential Revision: https://reviews.llvm.org/D85999
If OptNoneInstrumentation prints it instead, 'Skipping pass' will print for even required passes.
Reviewed By: ychen
Differential Revision: https://reviews.llvm.org/D85493
Problem:
Right now, our "Running pass" is not accurate when passes are wrapped in adaptor because adaptor is never skipped and a pass could be skipped. The other problem is that "Running pass" for a adaptor is before any "Running pass" of passes/analyses it depends on. (for example, FunctionToLoopPassAdaptor). So the order of printing is not the actual order.
Solution:
Doing things like PassManager::Debuglogging is very intrusive because we need to specify Debuglogging whenever adaptor is created. (Actually, right now we're not specifying Debuglogging for some sub-PassManagers. Check PassBuilder)
This patch move debug logging for pass as a PassInstrument callback. We could be sure that all running passes are logged and in the correct order.
This could also be used to implement hierarchy pass logging in legacy PM. We could also move logging of pass manager to this if we want.
The test fixes looks messy. It includes changes:
- Remove PassInstrumentationAnalysis
- Remove PassAdaptor
- If a PassAdaptor is for a real pass, the pass is added
- Pass reorder (to the correct order), related to PassAdaptor
- Add missing passes (due to Debuglogging not passed down)
Reviewed By: asbirlea, aeubanks
Differential Revision: https://reviews.llvm.org/D84774
OptNoneInstrumentation is part of StandardInstrumentations. It skips
functions (or loops) that are marked optnone.
The feature of skipping optional passes for optnone functions under NPM
is gated on a -enable-npm-optnone flag. Currently it is by default
false. That is because we still need to mark all required passes to be
required. Otherwise optnone functions will start having incorrect
semantics. After that is done in following changes, we can remove the
flag and always enable this.
Reviewed By: ychen
Differential Revision: https://reviews.llvm.org/D83519
Summary:
The IR printing always prints out all functions in a module with the new pass manager, even with -filter-print-funcs specified. This is being fixed in this change. However, there are two exceptions, i.e, with user-specified wildcast switch -filter-print-funcs=* or -print-module-scope, under which IR of all functions should be printed.
Test Plan:
make check-clang
make check-llvm
Reviewers: wenlei
Reviewed By: wenlei
Subscribers: wenlei, hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D74814
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.
This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.
This doesn't actually modify StringRef yet, I'll do that in a follow-up.
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
-print-after IR printing generally can not print the IR unit (Loop or SCC)
which has just been invalidated by the pass. However, when working in -print-module-scope
mode even if Loop was invalidated there is still a valid module that we can print.
Since we can not access invalidated IR unit from AfterPassInvalidated instrumentation
point we can remember the module to be printed *before* pass. This change introduces
BeforePass instrumentation that stores all the information required for module printing
into the stack and then after pass (in AfterPassInvalidated) just print whatever
has been placed on stack.
Reviewed By: philip.pfaffe
Differential Revision: https://reviews.llvm.org/D55278
llvm-svn: 349896
IR-printing AfterPass instrumentation might be called on a loop
that has just been invalidated. We should skip printing it to
avoid spurious asserts.
Reviewed By: chandlerc, philip.pfaffe
Differential Revision: https://reviews.llvm.org/D54740
llvm-svn: 348887
Removing deficiency of initial implementation of -print-before-all/-after-all
- it was effectively skipping IR printing for all the SCC passes.
Now LazyCallGraph:SCC gets its IR printed.
Reviewed By: skatkov
Differential Revision: https://reviews.llvm.org/D53270
llvm-svn: 344505
Enable time-passes functionality through PassInstrumentation callbacks
for passes and analyses.
TimePassesHandler class keeps all the callbacks, the timing data as it
is being collected as well as the stack of currently active timers.
Parts of the fix that might be somewhat unobvious:
- mapping of passes into Timer (TimingData) can not be done per-instance.
PassID name provided into the callback is common for all the pass invocations.
Thus the only way to get a timing with reasonable granularity is to collect
timing data per pass invocation, getting a new timer for each BeforePass.
Hence the key for TimingData uses a pair of <StringRef/unsigned count> to
uniquely identify a pass invocation.
- consequently, this new-pass-manager implementation performs no aggregation
of timing data, reporting timings for each pass invocation separately.
In that it differs from legacy-pass-manager time-passes implementation that
reports timing data aggregated per pass instance.
- pass managers and adaptors are not tracked, similar to how pass managers are
not tracked in legacy time-passes.
- TimerStack tracks timers that are active, each BeforePass pushes the new timer
on stack, each AfterPass pops active timer from stack and stops it.
Reviewers: chandlerc, philip.pfaffe
Differential Revision: https://reviews.llvm.org/D51276
llvm-svn: 343898
Implementing -print-before-all/-print-after-all/-filter-print-func support
through PassInstrumentation callbacks.
- PrintIR routines implement printing callbacks.
- StandardInstrumentations class provides a central place to manage all
the "standard" in-tree pass instrumentations. Currently it registers
PrintIR callbacks.
Reviewers: chandlerc, paquette, philip.pfaffe
Differential Revision: https://reviews.llvm.org/D50923
llvm-svn: 342896
Yevgeny Rouban