Summary:
End goal is to update MemorySSA in all loop passes. LoopUnswitch clones all blocks in a loop. SimpleLoopUnswitch clones some blocks. LoopRotate clones some instructions.
Some of these loop passes also make CFG changes.
This is an API based on what I found needed in LoopUnswitch, SimpleLoopUnswitch, LoopRotate, LoopInstSimplify, LoopSimplifyCFG.
Adding dependent patches using this API for context.
Reviewers: george.burgess.iv, dberlin
Subscribers: sanjoy, jlebar, Prazek, llvm-commits
Differential Revision: https://reviews.llvm.org/D45299
llvm-svn: 341855
verify*() methods are intended to have no side-effects (unless we detect
broken MSSA, in which case they assert()), and all of the other verify
methods are wrapped by `#ifndef NDEBUG`.
llvm-svn: 340793
We're currently getting this behavior implicitly, since we determine if
a Def's optimization is valid based on the ID of its defining access.
This is incorrect, though I wouldn't be surprised if this was masked in
part by that we're using a WeakVH to track what Defs are optimized to.
(Not to mention that we don't move Defs super often, AFAICT). I'll
submit a patch to fix this shortly.
This also includes a minor refactor to reduce duplication a bit.
No test is included, since like said, this already happens to be our
behavior. I'll add a test for this with my fix to the other bug
mentioned above.
llvm-svn: 340461
We're calling these functions quite a bit from outside of MemorySSA.cpp
now. Given that they're relatively simple one-liners, I think the style
preference is to have them inline.
llvm-svn: 340430
Summary: Expose VerifyMemorySSA as a debug option. If set, passes will call the MSSA->verifyMemorySSA() after calling into the updater's APIs when MemorySSA should be valid.
Reviewers: george.burgess.iv
Subscribers: sanjoy, jlebar, Prazek, llvm-commits
Differential Revision: https://reviews.llvm.org/D50749
llvm-svn: 339795
MemorySSA currently creates MemoryAccesses for lifetime intrinsics, and
sometimes treats them as clobbers. This may/may not be the best way
forward, but while we're doing it, we should consider
MayAlias/PartialAlias to be clobbers.
The ideal fix here is probably to remove all of this reasoning about
lifetimes from MemorySSA + put it into the passes that need to care. But
that's a wayyy broader fix that needs some consensus, and we have
miscompiles + a release branch today, and this should solve the
miscompiles just as well.
differential revision is D43269. Landing without an explicit LGTM (and
without using the special please-autoclose-this syntax) so we can still
use that revision as a place to decide what the right fix here is.
llvm-svn: 339411
Summary:
The move APIs added in this patch will be used to update MemorySSA when CFG changes merge or split blocks, by moving memory accesses accordingly in MemorySSA's internal data structures.
[Split from D45299 for easier review]
Reviewers: george.burgess.iv
Subscribers: sanjoy, jlebar, Prazek, llvm-commits
Differential Revision: https://reviews.llvm.org/D48897
llvm-svn: 336860
Summary:
MemoryPhis now have APIs analogous to BB Phis to remove an incoming value/block.
The MemorySSAUpdater uses the above APIs when updating MemorySSA given a set of dead blocks about to be deleted.
Reviewers: george.burgess.iv
Subscribers: sanjoy, jlebar, Prazek, llvm-commits
Differential Revision: https://reviews.llvm.org/D48396
llvm-svn: 336015
It's easy for domination numbers to get out-of-date, and this is no more
costly than any of the other verifiers we already have, so it seems nice
to have.
A stage3 build with this Works On My Machine, so this hasn't caught any
bugs... yet. :)
llvm-svn: 335444
Summary: Make the MemorySSA verify also check that all Phi incoming blocks are block predecessors.
Reviewers: george.burgess.iv
Subscribers: sanjoy, jlebar, Prazek, llvm-commits
Differential Revision: https://reviews.llvm.org/D48333
llvm-svn: 335174
In particular, when asked to print a MemoryAccess, we'll now print where
defs are optimized to, and we'll print optimized access types.
This patch also introduces an operator<< to make printing AliasResults
easier.
Patch by Juneyoung Lee!
Differential Revision: https://reviews.llvm.org/D47860
llvm-svn: 334760
Style guide says `else`s after returns are iffy, and I agree. I also
don't know what broke the comments here and in CFLAA, but *shrug*.
llvm-svn: 333332
Summary:
After r332167 we started to sort the IDF blocks inside IDF calculation, so
there is no need to re-sort them on the user site. The test changes are due to
a slightly different order we're using now (originally we used DFSInNumber and
now the blocks are sorted by a pair (LevelFromRoot, DFSInNumber)).
Reviewers: dberlin, mgrang
Subscribers: Prazek, hiraditya, george.burgess.iv, llvm-commits
Differential Revision: https://reviews.llvm.org/D46899
llvm-svn: 332385
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.
In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.
Differential Revision: https://reviews.llvm.org/D43624
llvm-svn: 332240
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
The caching walker used to hold its own caches, which made its `reset()`
function meaningful. Since caching has been moved out of it, there's no
reason to continue to have these cache-related methods.
Similarly, the EXPENSIVE_CHECKS block that's getting removed used to
rerun the query with caching disabled. Since that's how we always do
queries now, it's redundant.
llvm-svn: 329638
Summary:
r327219 added wrappers to std::sort which randomly shuffle the container before sorting.
This will help in uncovering non-determinism caused due to undefined sorting
order of objects having the same key.
To make use of that infrastructure we need to invoke llvm::sort instead of std::sort.
Note: This patch is one of a series of patches to replace *all* std::sort to llvm::sort.
Refer D44363 for a list of all the required patches.
Reviewers: sanjoy, dexonsmith, hfinkel, RKSimon
Reviewed By: dexonsmith
Subscribers: david2050, llvm-commits
Differential Revision: https://reviews.llvm.org/D44944
llvm-svn: 328925
Eli pointed out that variadic functions are totally a thing, so this
assert is incorrect.
No test-case is provided, since the only way this assert fires is if a
specific DenseMap falls back to doing `isEqual` checks, and that seems
fairly brittle (and requires a pyramid of growing
`call void (i8, ...) @varargs(i8 0)`).
llvm-svn: 328755
We use a `DenseMap<MemoryLocOrCall, MemlocStackInfo>` to keep track of
prior work when optimizing uses in MemorySSA. Because we weren't
accounting for callsite arguments in either the hash code or equality
tests for `MemoryLocOrCall`s, we optimized uses too aggressively in
some rare cases.
Fix by Daniel Berlin.
Should fix PR36883.
llvm-svn: 328748
Summary:
Building MemorySSA gathers alias information for Defs/Uses.
Store and expose this information when optimizing uses (when building MemorySSA),
and when optimizing defs or updating uses (getClobberingMemoryAccess).
Current patch does not propagate alias information through MemoryPhis.
Reviewers: gbiv, dberlin
Subscribers: Prazek, sanjoy, llvm-commits
Differential Revision: https://reviews.llvm.org/D38569
llvm-svn: 327035
It appears that there were many cases where we were directly (through
templates) calling the dtor of MemoryAccess, which is conceptually an
abstract class.
This hasn't been a problem, since the data members of all of the
subclasses of MemoryAccess have been POD. I'm planning on changing that.
:)
llvm-svn: 326175
Summary:
Make MemorySSA allow reordering of two loads that may alias, when one is volatile.
This makes MemorySSA less conservative and behaving the same as the AliasSetTracker.
For more context, see D16875.
LLVM language reference: "The optimizers must not change the number of volatile operations or change their order of execution relative to other volatile operations. The optimizers may change the order of volatile operations relative to non-volatile operations. This is not Java’s “volatile” and has no cross-thread synchronization behavior."
Reviewers: george.burgess.iv, dberlin
Subscribers: sanjoy, reames, hfinkel, llvm-commits, Prazek
Differential Revision: https://reviews.llvm.org/D41525
llvm-svn: 321382
Summary:
The aim is to make ModRefInfo checks and changes more intuitive
and less error prone using inline methods that abstract the bit operations.
Ideally ModRefInfo would become an enum class, but that change will require
a wider set of changes into FunctionModRefBehavior.
Reviewers: sanjoy, george.burgess.iv, dberlin, hfinkel
Subscribers: nlopes, llvm-commits
Differential Revision: https://reviews.llvm.org/D40749
llvm-svn: 319821
Summary:
Add LLVM_FORCE_ENABLE_DUMP cmake option, and use it along with
LLVM_ENABLE_ASSERTIONS to set LLVM_ENABLE_DUMP.
Remove NDEBUG and only use LLVM_ENABLE_DUMP to enable dump methods.
Move definition of LLVM_ENABLE_DUMP from config.h to llvm-config.h so
it'll be picked up by public headers.
Differential Revision: https://reviews.llvm.org/D38406
llvm-svn: 315590
Summary:
Adding part of the changes in D30369 (needed to make progress):
Current patch updates AliasAnalysis and MemoryLocation, but does _not_ clean up MemorySSA.
Original summary from D30369, by dberlin:
Currently, we have instructions which affect memory but have no memory
location. If you call, for example, MemoryLocation::get on a fence,
it asserts. This means things specifically have to avoid that. It
also means we end up with a copy of each API, one taking a memory
location, one not.
This starts to fix that.
We add MemoryLocation::getOrNone as a new call, and reimplement the
old asserting version in terms of it.
We make MemoryLocation optional in the (Instruction, MemoryLocation)
version of getModRefInfo, and kill the old one argument version in
favor of passing None (it had one caller). Now both can handle fences
because you can just use MemoryLocation::getOrNone on an instruction
and it will return a correct answer.
We use all this to clean up part of MemorySSA that had to handle this difference.
Note that literally every actual getModRefInfo interface we have could be made private and replaced with:
getModRefInfo(Instruction, Optional<MemoryLocation>)
and
getModRefInfo(Instruction, Optional<MemoryLocation>, Instruction, Optional<MemoryLocation>)
and delegating to the right ones, if we wanted to.
I have not attempted to do this yet.
Reviewers: dberlin, davide, dblaikie
Subscribers: sanjoy, hfinkel, chandlerc, llvm-commits
Differential Revision: https://reviews.llvm.org/D35441
llvm-svn: 309641
Summary:
Implements PR889
Removing the virtual table pointer from Value saves 1% of RSS when doing
LTO of llc on Linux. The impact on time was positive, but too noisy to
conclusively say that performance improved. Here is a link to the
spreadsheet with the original data:
https://docs.google.com/spreadsheets/d/1F4FHir0qYnV0MEp2sYYp_BuvnJgWlWPhWOwZ6LbW7W4/edit?usp=sharing
This change makes it invalid to directly delete a Value, User, or
Instruction pointer. Instead, such code can be rewritten to a null check
and a call Value::deleteValue(). Value objects tend to have their
lifetimes managed through iplist, so for the most part, this isn't a big
deal. However, there are some places where LLVM deletes values, and
those places had to be migrated to deleteValue. I have also created
llvm::unique_value, which has a custom deleter, so it can be used in
place of std::unique_ptr<Value>.
I had to add the "DerivedUser" Deleter escape hatch for MemorySSA, which
derives from User outside of lib/IR. Code in IR cannot include MemorySSA
headers or call the MemoryAccess object destructors without introducing
a circular dependency, so we need some level of indirection.
Unfortunately, no class derived from User may have any virtual methods,
because adding a virtual method would break User::getHungOffOperands(),
which assumes that it can find the use list immediately prior to the
User object. I've added a static_assert to the appropriate OperandTraits
templates to help people avoid this trap.
Reviewers: chandlerc, mehdi_amini, pete, dberlin, george.burgess.iv
Reviewed By: chandlerc
Subscribers: krytarowski, eraman, george.burgess.iv, mzolotukhin, Prazek, nlewycky, hans, inglorion, pcc, tejohnson, dberlin, llvm-commits
Differential Revision: https://reviews.llvm.org/D31261
llvm-svn: 303362
Analysis, it has Analysis passes, and once NewGVN is made an Analysis,
this removes the cross dependency from Analysis to Transform/Utils.
NFC.
llvm-svn: 299980
Vitaly Buka