Summary:
A new option exec-on-ir-changed is defined that allows one to specify an
exe that is called after each pass in the opt pipeline that changes the IR.
The exec-on-ir-change=exe option saves the IR in a temporary file and calls exe
with the name of the file and the name of the pass that just changed it after
each pass alters the IR. exe is also called with the initial IR. This
can be used, for example, to determine which pass corrupts the IR by having
exe as a script that calls llc and runs a test to see after which pass the
results change. The print-changed filtering options are respected. Note that
this is only supported with the new pass manager.
Author: Jamie Schmeiser <schmeise@ca.ibm.com>
Reviewed By: aeubanks (Arthur Eubanks)
Differential Revision: https://reviews.llvm.org/D110776
Summary:
A new option test-changed is defined that allows one to specify an
exe that is called after each pass in the opt pipeline that changes the IR.
The test-changed=exe option saves the IR in a temporary file and calls exe
with the name of the file and the name of the pass that just changed it after
each pass alters the IR. exe is also called with the initial IR. This
can be used, for example, to determine which pass corrupts the IR by having
exe as a script that calls llc and runs a test to see after which pass the
results change. The print-changed filtering options are respected.
Author: Jamie Schmeiser <schmeise@ca.ibm.com>
Reviewed By: aeubanks (Arthur Eubanks)
Differential Revision: https://reviews.llvm.org/D110776
Summary:
The Colours array is apparently the source of TSAN errors. It is
unnecessary and was there to ease readability of the code. Remove it to
clean up the TSAN errors.
Author: Jamie Schmeiser <schmeise@ca.ibm.com>
Reviewed By: aeubanks (Arthur Eubanks)
Differential Revision: https://reviews.llvm.org/D115175
* 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
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
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
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 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
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
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
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
Being lazy with printing the banner seems hard to reason with, we should print it
unconditionally first (it could also lead to duplicate banners if we
have multiple functions in -filter-print-funcs).
The printIR() functions were doing too many things. I separated out the
call from PrintPassInstrumentation since we were essentially doing two
completely separate things in printIR() from different callers.
There were multiple ways to generate the name of some IR. That's all
been moved to getIRName(). The printing of the IR name was also
inconsistent, now it's always "IR Dump on $foo" where "$foo" is the
name. For a function, it's the function name. For a loop, it's what's
printed by Loop::print(), which is more detailed. For an SCC, it's the
list of functions in parentheses. For a module it's "[module]", to
differentiate between a possible SCC with a function called "module".
To preserve D74814, we have to check if we're going to print anything at
all first. This is unfortunate, but I would consider this a special
case that shouldn't be handled in the core logic.
Reviewed By: jamieschmeiser
Differential Revision: https://reviews.llvm.org/D100231
-filter-print-funcs -print-changed was crashing after the filter func
was removed by a pass with
Assertion failed: After.find("*** IR Dump") == 0 && "Unexpected banner format."
We weren't printing the banner because when we have -filter-print-funcs,
we print each function separately, letting the print function filter out
unwanted functions.
Reviewed By: jamieschmeiser
Differential Revision: https://reviews.llvm.org/D100237
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
Evgeny Mandrikov