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
Arthur Eubanks