The code used for propagating equalities (e.g. assume facts) was conservative in two ways - one of which this patch fixes. Specifically, it shifts the code reasoning about whether a use is dominated by the end of the assume block to consider phi uses to exist on the predecessor edge. This matches the dominator tree handling for dominates(Edge, Use), and simply extends it to dominates(BB, Use).
Note that the decision to use the end of the block is itself a conservative choice. The more precise option would be to use the later of the assume and the value, and replace all uses after that. GVN handles that case separately (with the replace operand mechanism) because it used to be expensive to ask dominator questions within blocks. With the new instruction ordering support, we should probably rewrite this code at some point to simplify.
Differential Revision: https://reviews.llvm.org/D98082
Per asbirlea's comment, assert that only instructions, constants
and arguments are passed to this API. Simplify returning true
would not be correct for special Value subclasses like MemoryAccess.
Non-instruction defs like arguments, constants or global values
always dominate all instructions/uses inside the function. This
case currently needs to be treated separately by the caller, see
https://reviews.llvm.org/D89623#inline-832818 for an example.
This patch makes the dominator tree APIs accept a Value instead of
an Instruction and always returns true for the non-Instruction case.
A complication here is that BasicBlocks are also Values. For that
reason we can't support the dominates(Value *, BasicBlock *)
variant, as it would conflict with dominates(BasicBlock *, BasicBlock *),
which has different semantics. For the other two APIs we assert
that the passed value is not a BasicBlock.
Differential Revision: https://reviews.llvm.org/D89632
Extend the `applyUpdates` in DominatorTree to allow a post CFG view,
different from the current CFG.
This patch implements the functionality of updating an already up to
date DT, to the desired PostCFGView.
Combining a set of updates towards an up to date DT and a PostCFGView is
not yet supported.
Differential Revision: https://reviews.llvm.org/D85472
This is the part of the patch that's moving the Updates to a CFGDiff
object. Splitting off from the clean-up work merging the two branches when BUI is null.
Differential Revision: https://reviews.llvm.org/D77341
This replaces the ChildrenGetter inside the DominatorTree with
GraphTraits over a GraphDiff object, an object which encapsulated the
view of the previous CFG.
This also simplifies the extentions in clang which use DominatorTree, as
GraphDiff also filters nullptrs.
Re-land a90374988e after moving CFGDiff.h
to Support.
Differential Revision: https://reviews.llvm.org/D77341
This reverts commit a90374988e and 5da1671bf8.
A new dependency is introduced here from Support to IR which seems like
a layering violation. It also breaks the MLIR build at the moment.
Summary:
This replaces the ChildrenGetter inside the DominatorTree with
GraphTraits over a GraphDiff object, an object which encapsulated the
view of the previous CFG.
This also simplifies the extentions in clang which use DominatorTree, as
GraphDiff also filters nullptrs.
Reviewers: kuhar, dblaikie, NutshellySima
Subscribers: hiraditya, cfe-commits, llvm-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D77341
This file lists every pass in LLVM, and is included by Pass.h, which is
very popular. Every time we add, remove, or rename a pass in LLVM, it
caused lots of recompilation.
I found this fact by looking at this table, which is sorted by the
number of times a file was changed over the last 100,000 git commits
multiplied by the number of object files that depend on it in the
current checkout:
recompiles touches affected_files header
342380 95 3604 llvm/include/llvm/ADT/STLExtras.h
314730 234 1345 llvm/include/llvm/InitializePasses.h
307036 118 2602 llvm/include/llvm/ADT/APInt.h
213049 59 3611 llvm/include/llvm/Support/MathExtras.h
170422 47 3626 llvm/include/llvm/Support/Compiler.h
162225 45 3605 llvm/include/llvm/ADT/Optional.h
158319 63 2513 llvm/include/llvm/ADT/Triple.h
140322 39 3598 llvm/include/llvm/ADT/StringRef.h
137647 59 2333 llvm/include/llvm/Support/Error.h
131619 73 1803 llvm/include/llvm/Support/FileSystem.h
Before this change, touching InitializePasses.h would cause 1345 files
to recompile. After this change, touching it only causes 550 compiles in
an incremental rebuild.
Reviewers: bkramer, asbirlea, bollu, jdoerfert
Differential Revision: https://reviews.llvm.org/D70211
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
by `getTerminator()` calls instead be declared as `Instruction`.
This is the biggest remaining chunk of the usage of `getTerminator()`
that insists on the narrow type and so is an easy batch of updates.
Several files saw more extensive updates where this would cascade to
requiring API updates within the file to use `Instruction` instead of
`TerminatorInst`. All of these were trivial in nature (pervasively using
`Instruction` instead just worked).
llvm-svn: 344502
Summary:
Add the posibility of creating a new DT using a set of Updates.
This will essentially create a DT based on a CFG snapshot/view.
Additional refactoring for either this patch or follow-ups:
- create an utility for building BUI.
- replace BUI with a GraphDiff.
Reviewers: kuhar
Subscribers: sanjoy, jlebar, llvm-commits
Differential Revision: https://reviews.llvm.org/D50671
llvm-svn: 339947
Summary:
Clean-up following D50479.
Make Update and LegalizeUpdate refer to the utilities in Support/CFGUpdate.
Reviewers: kuhar
Subscribers: sanjoy, jlebar, mgrang, llvm-commits
Differential Revision: https://reviews.llvm.org/D50669
llvm-svn: 339694
Summary: After converting all existing passes to use the new DomTreeUpdater interface, there isn't any usage of the original DeferredDominance class. Thus, we can safely remove it from the codebase.
Reviewers: kuhar, brzycki, dmgreen, davide, grosser
Reviewed By: kuhar, brzycki
Subscribers: mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D49747
llvm-svn: 339502
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.
Patch produced by
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done
Differential Revision: https://reviews.llvm.org/D46290
llvm-svn: 331272
See r331124 for how I made a list of files missing the include.
I then ran this Python script:
for f in open('filelist.txt'):
f = f.strip()
fl = open(f).readlines()
found = False
for i in xrange(len(fl)):
p = '#include "llvm/'
if not fl[i].startswith(p):
continue
if fl[i][len(p):] > 'Config':
fl.insert(i, '#include "llvm/Config/llvm-config.h"\n')
found = True
break
if not found:
print 'not found', f
else:
open(f, 'w').write(''.join(fl))
and then looked through everything with `svn diff | diffstat -l | xargs -n 1000 gvim -p`
and tried to fix include ordering and whatnot.
No intended behavior change.
llvm-svn: 331184
Removes verifyDomTree, using assert(verify()) everywhere instead, and
changes verify a little to always run IsSameAsFreshTree first in order
to print good output when we find errors. Also adds verifyAnalysis for
PostDomTrees, which will allow checking of PostDomTrees it the same way
we check DomTrees and MachineDomTrees.
Differential Revision: https://reviews.llvm.org/D41298
llvm-svn: 326315
Summary:
The LazyValueInfo pass caches a copy of the DominatorTree when available.
Whenever there are pending DominatorTree updates within JumpThreading's
DeferredDominance object we cannot use the cached DT for LVI analysis.
This commit adds the new methods enableDT() and disableDT() to LVI.
JumpThreading also sets the appropriate usage model before calling LVI
analysis methods.
Fixes https://bugs.llvm.org/show_bug.cgi?id=36133
Reviewers: sebpop, dberlin, kuhar
Reviewed by: sebpop, kuhar
Subscribers: uabelho, llvm-commits, aprantl, hiraditya, a.elovikov
Differential Revision: https://reviews.llvm.org/D42717
llvm-svn: 325356
Summary:
Currently, there are 2 ways to verify a DomTree:
* `DT.verify()` -- runs full tree verification and checks all the properties and gives a reason why the tree is incorrect. This is run by when EXPENSIVE_CHECKS are enabled or when `-verify-dom-info` flag is set.
* `DT.verifyDominatorTree()` -- constructs a fresh tree and compares it against the old one. This does not check any other tree properties (DFS number, levels), nor ensures that the construction algorithm is correct. Used by some passes inside assertions.
This patch introduces DomTree verification levels, that try to close the gape between the two ways of checking trees by introducing 3 verification levels:
- Full -- checks all properties, but can be slow (O(N^3)). Used when manually requested (e.g. `assert(DT.verify())`) or when `-verify-dom-info` is set.
- Basic -- checks all properties except the sibling property, and compares the current tree with a freshly constructed one instead. This should catch almost all errors, but does not guarantee that the construction algorithm is correct. Used when EXPENSIVE checks are enabled.
- Fast -- checks only basic properties (reachablility, dfs numbers, levels, roots), and compares with a fresh tree. This is meant to replace the legacy `DT.verifyDominatorTree()` and in my tests doesn't cause any noticeable performance impact even in the most pessimistic examples.
When used to verify dom tree wrapper pass analysis on sqlite3, the 3 new levels make `opt -O3` take the following amount of time on my machine:
- no verification: 8.3s
- `DT.verify(VerificationLevel::Fast)`: 10.1s
- `DT.verify(VerificationLevel::Basic)`: 44.8s
- `DT.verify(VerificationLevel::Full)`: 1m 46.2s
(and the previous `DT.verifyDominatorTree()` is within the noise of the Fast level)
This patch makes `DT.verifyDominatorTree()` pick between the 3 verification levels depending on EXPENSIVE_CHECKS and `-verify-dom-info`.
Reviewers: dberlin, brzycki, davide, grosser, dmgreen
Reviewed By: dberlin, brzycki
Subscribers: MatzeB, llvm-commits
Differential Revision: https://reviews.llvm.org/D42337
llvm-svn: 323298
Summary:
See D37528 for a previous (non-deferred) version of this
patch and its description.
Preserves dominance in a deferred manner using a new class
DeferredDominance. This reduces the performance impact of
updating the DominatorTree at every edge insertion and
deletion. A user may call DDT->flush() within JumpThreading
for an up-to-date DT. This patch currently has one flush()
at the end of runImpl() to ensure DT is preserved across
the pass.
LVI is also preserved to help subsequent passes such as
CorrelatedValuePropagation. LVI is simpler to maintain and
is done immediately (not deferred). The code to perform the
preversation was minimally altered and simply marked as
preserved for the PassManager to be informed.
This extends the analysis available to JumpThreading for
future enhancements such as threading across loop headers.
Reviewers: dberlin, kuhar, sebpop
Reviewed By: kuhar, sebpop
Subscribers: mgorny, dmgreen, kuba, rnk, rsmith, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D40146
llvm-svn: 322401
Summary:
See D37528 for a previous (non-deferred) version of this
patch and its description.
Preserves dominance in a deferred manner using a new class
DeferredDominance. This reduces the performance impact of
updating the DominatorTree at every edge insertion and
deletion. A user may call DDT->flush() within JumpThreading
for an up-to-date DT. This patch currently has one flush()
at the end of runImpl() to ensure DT is preserved across
the pass.
LVI is also preserved to help subsequent passes such as
CorrelatedValuePropagation. LVI is simpler to maintain and
is done immediately (not deferred). The code to perfom the
preversation was minimally altered and was simply marked
as preserved for the PassManager to be informed.
This extends the analysis available to JumpThreading for
future enhancements. One example is loop boundary threading.
Reviewers: dberlin, kuhar, sebpop
Reviewed By: kuhar, sebpop
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D40146
llvm-svn: 321825
Summary:
See D37528 for a previous (non-deferred) version of this
patch and its description.
Preserves dominance in a deferred manner using a new class
DeferredDominance. This reduces the performance impact of
updating the DominatorTree at every edge insertion and
deletion. A user may call DDT->flush() within JumpThreading
for an up-to-date DT. This patch currently has one flush()
at the end of runImpl() to ensure DT is preserved across
the pass.
LVI is also preserved to help subsequent passes such as
CorrelatedValuePropagation. LVI is simpler to maintain and
is done immediately (not deferred). The code to perfom the
preversation was minimally altered and was simply marked
as preserved for the PassManager to be informed.
This extends the analysis available to JumpThreading for
future enhancements. One example is loop boundary threading.
Reviewers: dberlin, kuhar, sebpop
Reviewed By: kuhar, sebpop
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D40146
llvm-svn: 320612
These command line options are not intended for public use, and often
don't even make sense in the context of a particular tool anyway. About
90% of them are already hidden, but when people add new options they
forget to hide them, so if you were to make a brand new tool today, link
against one of LLVM's libraries, and run tool -help you would get a
bunch of junk that doesn't make sense for the tool you're writing.
This patch hides these options. The real solution is to not have
libraries defining command line options, but that's a much larger effort
and not something I'm prepared to take on.
Differential Revision: https://reviews.llvm.org/D40674
llvm-svn: 319505
Summary:
This patch introduces a way of informing the (Post)DominatorTree about multiple CFG updates that happened since the last tree update. This makes performing tree updates much easier, as it internally takes care of applying the updates in lockstep with the (virtual) updates to the CFG, which is done by reverse-applying future CFG updates.
The batch updater is able to remove redundant updates that cancel each other out. In the future, it should be also possible to reorder updates to reduce the amount of work needed to perform the updates.
Reviewers: dberlin, sanjoy, grosser, davide, brzycki
Reviewed By: brzycki
Subscribers: mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D36167
llvm-svn: 311015
Summary:
This patch moves root-finding logic from DominatorTreeBase to GenericDomTreeConstruction.h.
It makes the behavior simpler and more consistent by always adding a virtual root to PostDominatorTrees.
Reviewers: dberlin, davide, grosser, sanjoy
Reviewed By: dberlin
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D35597
llvm-svn: 309146
Summary:
This patch implements incremental edge deletions.
It also makes DominatorTreeBase store a pointer to the parent function. The parent function is needed to perform full rebuilts during some deletions, but it is also used to verify that inserted and deleted edges come from the same function.
Reviewers: dberlin, davide, grosser, sanjoy, brzycki
Reviewed By: dberlin
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D35342
llvm-svn: 308062
Summary:
This patch introduces incremental edge insertions based on the Depth Based Search algorithm.
Insertions should work for both dominators and postdominators.
Reviewers: dberlin, grosser, davide, sanjoy, brzycki
Reviewed By: dberlin
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D35341
llvm-svn: 308054
Summary:
DominatorTreeBase used to have IsPostDominators (bool) member to indicate if the tree is a dominator or a postdominator tree. This made it possible to switch between the two 'modes' at runtime, but it isn't used in practice anywhere.
This patch makes IsPostDominator a template argument. This way, it is easier to switch between different algorithms at compile-time based on this argument and design external utilities around it. It also makes it impossible to incidentally assign a postdominator tree to a dominator tree (and vice versa), and to further simplify template code in GenericDominatorTreeConstruction.
Reviewers: dberlin, sanjoy, davide, grosser
Reviewed By: dberlin
Subscribers: mzolotukhin, llvm-commits
Differential Revision: https://reviews.llvm.org/D35315
llvm-svn: 308040
Summary: DominatorTreeBase and related classes used overcomplicated template machinery. This patch simplifies them and gets rid of DominatorTreeBaseTraits and DominatorTreeBaseByTraits, which weren't actually used outside the DomTree construction.
Reviewers: dberlin, sanjoy, davide, grosser
Reviewed By: dberlin, davide, grosser
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D35285
llvm-svn: 307953
Summary:
Some transforms assume that DT.verifyDomInfo() is not expensive and call it even when ENABLE_EXPENSIVE_CHECKS is not set.
This patch disables expensive Dominator Tree verification (reachability, parent property, sibling property) to fix
[[ https://bugs.llvm.org/show_bug.cgi?id=33656 | PR33656 ]].
Note that this is only a temporary fix.
Reviewers: dberlin, chapuni, kparzysz, grosser
Reviewed By: dberlin
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34894
llvm-svn: 306839
Summary:
This patch adds an additional level of verification - it checks parent and sibling properties of a tree. By definition, every tree with these two properties is a dominator tree.
It is possible to run those check by running llvm with `-verify-dom-info=1`.
Bootstrapping clang and building the llvm test suite with this option enabled doesn't yield any errors.
Reviewers: dberlin, sanjoy, chandlerc
Reviewed By: dberlin
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34482
llvm-svn: 306711
This removes a quadratic behavior in assert-enabled builds.
GVN propagates the equivalence from a condition into the blocks guarded by the
condition. E.g. for 'if (a == 7) { ... }', 'a' will be replaced in the block
with 7. It does this by replacing all the uses of 'a' that are dominated by
the true edge.
For a switch with N cases and U uses of the value, this will mean N * U calls
to 'dominates'. Asserting isSingleEdge in 'dominates' make this N^2 * U
because this function checks for the uniqueness of the edge. I.e. traverses
each edge between the SwitchInst's block and the cases.
The change removes the assert and makes 'dominates' works correctly in the
presence of non-unique edges.
This brings build time down by an order of magnitude for an input that has
~10k cases in a switch statement.
Differential Revision: https://reviews.llvm.org/D33584
llvm-svn: 304721
If dominator tree has no roots, the pass that calculates it is
likely to be skipped. It occures, for instance, in the case of
entities with linkage available_externally. Do not run tree
verification in such case.
Differential Revision: https://reviews.llvm.org/D28767
llvm-svn: 293033
Verifications of dominator tree and loop info are expensive operations
so they are disabled by default. They can be enabled by command line
options -verify-dom-info and -verify-loop-info. These options however
enable checks only in files Dominators.cpp and LoopInfo.cpp. If some
transformation changes dominaror tree and/or loop info, it would be
convenient to place similar checks to the files implementing the
transformation.
This change makes corresponding flags global, so they can be used in
any file to optionally turn verification on.
llvm-svn: 292889
a function's CFG when that CFG is unchanged.
This allows transformation passes to simply claim they preserve the CFG
and analysis passes to check for the CFG being preserved to remove the
fanout of all analyses being listed in all passes.
I've gone through and removed or cleaned up as many of the comments
reminding us to do this as I could.
Differential Revision: https://reviews.llvm.org/D28627
llvm-svn: 292054
analyses to have a common type which is enforced rather than using
a char object and a `void *` type when used as an identifier.
This has a number of advantages. First, it at least helps some of the
confusion raised in Justin Lebar's code review of why `void *` was being
used everywhere by having a stronger type that connects to documentation
about this.
However, perhaps more importantly, it addresses a serious issue where
the alignment of these pointer-like identifiers was unknown. This made
it hard to use them in pointer-like data structures. We were already
dodging this in dangerous ways to create the "all analyses" entry. In
a subsequent patch I attempted to use these with TinyPtrVector and
things fell apart in a very bad way.
And it isn't just a compile time or type system issue. Worse than that,
the actual alignment of these pointer-like opaque identifiers wasn't
guaranteed to be a useful alignment as they were just characters.
This change introduces a type to use as the "key" object whose address
forms the opaque identifier. This both forces the objects to have proper
alignment, and provides type checking that we get it right everywhere.
It also makes the types somewhat less mysterious than `void *`.
We could go one step further and introduce a truly opaque pointer-like
type to return from the `ID()` static function rather than returning
`AnalysisKey *`, but that didn't seem to be a clear win so this is just
the initial change to get to a reliably typed and aligned object serving
is a key for all the analyses.
Thanks to Richard Smith and Justin Lebar for helping pick plausible
names and avoid making this refactoring many times. =] And thanks to
Sean for the super fast review!
While here, I've tried to move away from the "PassID" nomenclature
entirely as it wasn't really helping and is overloaded with old pass
manager constructs. Now we have IDs for analyses, and key objects whose
address can be used as IDs. Where possible and clear I've shortened this
to just "ID". In a few places I kept "AnalysisID" to make it clear what
was being identified.
Differential Revision: https://reviews.llvm.org/D27031
llvm-svn: 287783
Summary:
Looking at the implementation, GenericDomTree has more specific
requirements on NodeRef, e.g. NodeRefObject->getParent() should compile,
and NodeRef should be a pointer. We can remove the pointer requirement,
but it seems to have little gain, given the limited use cases.
Also changed GraphTraits<Inverse<Inverse<T>> to be more accurate.
Reviewers: dblaikie, chandlerc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D23593
llvm-svn: 278961
Besides a general consistently benefit, the extra layer of indirection
allows the mechanical part of https://reviews.llvm.org/D23256 that
requires touching every transformation and analysis to be factored out
cleanly.
Thanks to David for the suggestion.
llvm-svn: 278077
pass manager passes' `run` methods.
This removes a bunch of SFINAE goop from the pass manager and just
requires pass authors to accept `AnalysisManager<IRUnitT> &` as a dead
argument. This is a small price to pay for the simplicity of the system
as a whole, despite the noise that changing it causes at this stage.
This will also helpfull allow us to make the signature of the run
methods much more flexible for different kinds af passes to support
things like intelligently updating the pass's progression over IR units.
While this touches many, many, files, the changes are really boring.
Mostly made with the help of my trusty perl one liners.
Thanks to Sean and Hal for bouncing ideas for this with me in IRC.
llvm-svn: 272978
Summary:
Historically, we had a switch in the Makefiles for turning on "expensive
checks". This has never been ported to the cmake build, but the
(dead-ish) code is still around.
This will also make it easier to turn it on in buildbots.
Reviewers: chandlerc
Subscribers: jyknight, mzolotukhin, RKSimon, gberry, llvm-commits
Differential Revision: http://reviews.llvm.org/D19723
llvm-svn: 268050
Removed some unused headers, replaced some headers with forward class declarations.
Found using simple scripts like this one:
clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap'
Patch by Eugene Kosov <claprix@yandex.ru>
Differential Revision: http://reviews.llvm.org/D19219
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266595
Philip Reames