dependency. NFC
Use findSingleDependency in place of FindDependencies and stop passing a
set of Instructions around. Modify FindDependencies to return a boolean
flag which indicates whether the dependencies it has found are all
valid.
Since doInitialization() in the legacy pass modifies the module, the NPM
pass is a Module pass.
Reviewed By: ahatanak, ychen
Differential Revision: https://reviews.llvm.org/D86178
a tail call
This reapplies the patch in https://reviews.llvm.org/rG1f5b471b8bf4,
which was reverted because it was causing crashes.
https://bugs.chromium.org/p/chromium/issues/detail?id=1061289#c2
Check that HasSafePathToCall is true before checking the call is a tail
call.
Original commit message:
Previosly ARC optimizer removed the autoreleaseRV/retainRV pair in the
following code, which caused the object returned by @something to be
placed in the autorelease pool because the call to @something isn't a
tail call:
```
%call = call i8* @something(...)
%2 = call i8* @objc_retainAutoreleasedReturnValue(i8* %call)
%3 = call i8* @objc_autoreleaseReturnValue(i8* %2)
ret i8* %3
```
Fix the bug by checking whether @something is a tail call.
rdar://problem/59275894
a tail call
Previosly ARC optimizer removed the autoreleaseRV/retainRV pair in the
following code, which caused the object returned by @something to be
placed in the autorelease pool because the call to @something isn't a
tail call:
```
%call = call i8* @something(...)
%2 = call i8* @objc_retainAutoreleasedReturnValue(i8* %call)
%3 = call i8* @objc_autoreleaseReturnValue(i8* %2)
ret i8* %3
```
Fix the bug by checking whether @something is a tail call.
rdar://problem/59275894
body
We started seeing cases where ARC optimizer would move retain calls into
loop bodies, causing imbalance in the number of retain and release
calls, after changes were made to delete inert ARC calls since the inert
calls that used to block code motion are gone.
Fix the bug by setting the CFG hazard flag when visiting a loop header.
rdar://problem/56908836
This improves on the following patch, which removed ARC runtime calls
taking inert global variables:
https://reviews.llvm.org/D62433
rdar://problem/59137105
Pair up inlined AutoreleaseRV calls with their matching RetainRV or
ClaimRV.
- RetainRV cancels out AutoreleaseRV. Delete both instructions.
- ClaimRV is a peephole for RetainRV+Release. Delete AutoreleaseRV and
replace ClaimRV with Release.
This avoids problems where more aggressive inlining triggers memory
regressions.
This patch is happy to skip over non-callable instructions and non-ARC
intrinsics looking for the pair. It is likely sound to also skip over
opaque function calls, but that's harder to reason about, and it's not
relevant to the goal here: if there's an opaque function call splitting
up a pair, it's very unlikely that a handshake would have happened
dynamically without inlining.
Note that this patch also subsumes the previous logic that looked
backwards from ReleaseRV.
https://reviews.llvm.org/D70370
rdar://problem/46509586
Split out a helper function for the individual call optimizations and
skip useless calls to it (where the instruction is not an ARC
intrinsic). Besides reducing indentation (and possibly speeding up
compile time in some small way), an upcoming patch will add additional
calls and expand out the `switch`.
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
When eliminating a pair of
`llvm.objc.autoreleaseReturnValue`
followed by
`llvm.objc.retainAutoreleasedReturnValue`
we need to make sure that the instructions in between are safe to
ignore.
Other than bitcasts and useless GEPs, it's also safe to ignore lifetime
markers for both static allocas (lifetime.start/lifetime.end) and dynamic
allocas (stacksave/stackrestore).
These get added by the inliner as part of the return sequence and can
prevent the transformation from happening in practice.
Differential Revision: https://reviews.llvm.org/D69833
with 'objc_arc_inert'
Those calls are no-ops, so they can be safely deleted.
rdar://problem/49839633
Differential Revision: https://reviews.llvm.org/D62433
llvm-svn: 363468
it keeps track of becomes too large
ARC optimizer does a top-down and a bottom-up traversal of the whole
function to pair up retain and release instructions and remove them.
This can be expensive if the number of instructions in the function and
pointer states it tracks are large since it has to look at each pointer
state and determine whether the instruction being visited can
potentially use the pointer.
This patch adds a command line option that sets a limit to the number of
pointers it tracks.
rdar://problem/49477063
Differential Revision: https://reviews.llvm.org/D61100
llvm-svn: 359226
are annotated with notail.
r356705 annotated calls to objc_retainAutoreleasedReturnValue with
notail on x86-64. This commit teaches ARC optimizer to check the notail
marker on the call before turning it into a tail call.
rdar://problem/38675807
llvm-svn: 356707
This cleans up all CallInst creation in LLVM to explicitly pass a
function type rather than deriving it from the pointer's element-type.
Differential Revision: https://reviews.llvm.org/D57170
llvm-svn: 352909
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
OptimizeAutoreleaseRVCall skips optimizing llvm.objc.autoreleaseReturnValue if it
sees a user which is llvm.objc.retainAutoreleasedReturnValue, and if they have
equivalent arguments (either identical or equivalent PHIs). It then assumes that
ObjCARCOpt::OptimizeRetainRVCall will optimize the pair instead.
Trouble is, ObjCARCOpt::OptimizeRetainRVCall doesn't know about equivalent PHIs
so optimizes in a different way and we are left with an unoptimized llvm.objc.autoreleaseReturnValue.
This teaches ObjCARCOpt::OptimizeRetainRVCall to also understand PHI equivalence.
rdar://problem/47005143
Reviewed By: ahatanak
Differential Revision: https://reviews.llvm.org/D56235
llvm-svn: 350284
Summary:
- Add wasm personality function
- Re-categorize the existing `isFuncletEHPersonality()` function into
two different functions: `isFuncletEHPersonality()` and
`isScopedEHPersonality(). This becomes necessary as wasm EH uses scoped
EH instructions (catchswitch, catchpad/ret, and cleanuppad/ret) but not
outlined funclets.
- Changed some callsites of `isFuncletEHPersonality()` to
`isScopedEHPersonality()` if they are related to scoped EH IR-level
stuff.
Reviewers: majnemer, dschuff, rnk
Subscribers: jfb, sbc100, jgravelle-google, eraman, JDevlieghere, sunfish, llvm-commits
Differential Revision: https://reviews.llvm.org/D45559
llvm-svn: 332667
A catchswitch must be the only non-phi instruction in its basic block;
attempting to move a retain or release into a catchswitch basic block
will result in invalid IR. Explicitly mark a CFG hazard in this case to
prevent the code motion.
Differential Revision: https://reviews.llvm.org/D46482
llvm-svn: 332430
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
In the case that the CallInst that is being moved has an associated
operand bundle which is a funclet, the move will construct an invalid
instruction. The new site will have a different token and needs to be
reassociated with the new instruction.
Unfortunately, there is no way to alter the bundle after the
construction of the instruction. Replace the call instruction cloning
with a custom helper to clone the instruction and reassociate the
funclet token.
llvm-svn: 327336
to @objc_autorelease if its operand is a PHI and the PHI has an
equivalent value that is used by a return instruction.
For example, ARC optimizer shouldn't replace the call in the following
example, as doing so breaks the AutoreleaseRV/RetainRV optimization:
%v1 = bitcast i32* %v0 to i8*
br label %bb3
bb2:
%v3 = bitcast i32* %v2 to i8*
br label %bb3
bb3:
%p = phi i8* [ %v1, %bb1 ], [ %v3, %bb2 ]
%retval = phi i32* [ %v0, %bb1 ], [ %v2, %bb2 ] ; equivalent to %p
%v4 = tail call i8* @objc_autoreleaseReturnValue(i8* %p)
ret i32* %retval
Also, make sure ObjCARCContract replaces @objc_autoreleaseReturnValue's
operand uses with its value so that the call gets tail-called.
rdar://problem/15894705
llvm-svn: 323009
above PHI instructions.
ARC optimizer has an optimization that moves a call to an ObjC runtime
function above a phi instruction when the phi has a null operand and is
an argument passed to the function call. This optimization should not
kick in when the runtime function is an objc_release that releases an
object with precise lifetime semantics.
rdar://problem/34959669
llvm-svn: 315914
The BasicBlock passed to FindPredecessorRetainWithSafePath should be the
parent block of Autorelease. This fixes a crash that occurs in
FindDependencies when StartInst is not in StartBB.
rdar://problem/33866381
llvm-svn: 312266
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.
I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.
This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.
Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).
llvm-svn: 304787
instruction.
This avoids dereferencing null in the debug logging if the instruction
was not in fact a return instruction. This potential bug was found by
PVS-Studio.
This actually fixes the last of the "dereferenced a pointer before
checking it for null" reports in the recent PVS-Studio run. However,
there are quite a few reports of this nature that I did not do anything
to fix because they are pretty glaring false positives. They usually
took the form of quite clear correlated checks or a check made in
a separate function. I've even added asserts anywhere this correlation
wasn't pretty obvious and fundamental to the code.
llvm-svn: 285988
Stop looking at users of UndefValue and ConstantPointerNull in the
objective C ARC optimizers. The other users aren't actually
interesting, since they're not pointing at a particular object. I
imagine these calls could be optimized through -instcombine... maybe
they already are?
These early returns will be required at some point in the future, with a
WIP patch that asserts when someone accesses a use-list on ConstantData.
llvm-svn: 282338
When support for objc_unsafeClaimAutoreleasedReturnValue has been added to the
ARC optimizer in r258970, one case was missed which would lead the optimizer
to execute an llvm_unreachable. In this case, just handle ClaimRV in the same
way we handle RetainRV.
llvm-svn: 261134
with the new pass manager, and no longer relying on analysis groups.
This builds essentially a ground-up new AA infrastructure stack for
LLVM. The core ideas are the same that are used throughout the new pass
manager: type erased polymorphism and direct composition. The design is
as follows:
- FunctionAAResults is a type-erasing alias analysis results aggregation
interface to walk a single query across a range of results from
different alias analyses. Currently this is function-specific as we
always assume that aliasing queries are *within* a function.
- AAResultBase is a CRTP utility providing stub implementations of
various parts of the alias analysis result concept, notably in several
cases in terms of other more general parts of the interface. This can
be used to implement only a narrow part of the interface rather than
the entire interface. This isn't really ideal, this logic should be
hoisted into FunctionAAResults as currently it will cause
a significant amount of redundant work, but it faithfully models the
behavior of the prior infrastructure.
- All the alias analysis passes are ported to be wrapper passes for the
legacy PM and new-style analysis passes for the new PM with a shared
result object. In some cases (most notably CFL), this is an extremely
naive approach that we should revisit when we can specialize for the
new pass manager.
- BasicAA has been restructured to reflect that it is much more
fundamentally a function analysis because it uses dominator trees and
loop info that need to be constructed for each function.
All of the references to getting alias analysis results have been
updated to use the new aggregation interface. All the preservation and
other pass management code has been updated accordingly.
The way the FunctionAAResultsWrapperPass works is to detect the
available alias analyses when run, and add them to the results object.
This means that we should be able to continue to respect when various
passes are added to the pipeline, for example adding CFL or adding TBAA
passes should just cause their results to be available and to get folded
into this. The exception to this rule is BasicAA which really needs to
be a function pass due to using dominator trees and loop info. As
a consequence, the FunctionAAResultsWrapperPass directly depends on
BasicAA and always includes it in the aggregation.
This has significant implications for preserving analyses. Generally,
most passes shouldn't bother preserving FunctionAAResultsWrapperPass
because rebuilding the results just updates the set of known AA passes.
The exception to this rule are LoopPass instances which need to preserve
all the function analyses that the loop pass manager will end up
needing. This means preserving both BasicAAWrapperPass and the
aggregating FunctionAAResultsWrapperPass.
Now, when preserving an alias analysis, you do so by directly preserving
that analysis. This is only necessary for non-immutable-pass-provided
alias analyses though, and there are only three of interest: BasicAA,
GlobalsAA (formerly GlobalsModRef), and SCEVAA. Usually BasicAA is
preserved when needed because it (like DominatorTree and LoopInfo) is
marked as a CFG-only pass. I've expanded GlobalsAA into the preserved
set everywhere we previously were preserving all of AliasAnalysis, and
I've added SCEVAA in the intersection of that with where we preserve
SCEV itself.
One significant challenge to all of this is that the CGSCC passes were
actually using the alias analysis implementations by taking advantage of
a pretty amazing set of loop holes in the old pass manager's analysis
management code which allowed analysis groups to slide through in many
cases. Moving away from analysis groups makes this problem much more
obvious. To fix it, I've leveraged the flexibility the design of the new
PM components provides to just directly construct the relevant alias
analyses for the relevant functions in the IPO passes that need them.
This is a bit hacky, but should go away with the new pass manager, and
is already in many ways cleaner than the prior state.
Another significant challenge is that various facilities of the old
alias analysis infrastructure just don't fit any more. The most
significant of these is the alias analysis 'counter' pass. That pass
relied on the ability to snoop on AA queries at different points in the
analysis group chain. Instead, I'm planning to build printing
functionality directly into the aggregation layer. I've not included
that in this patch merely to keep it smaller.
Note that all of this needs a nearly complete rewrite of the AA
documentation. I'm planning to do that, but I'd like to make sure the
new design settles, and to flesh out a bit more of what it looks like in
the new pass manager first.
Differential Revision: http://reviews.llvm.org/D12080
llvm-svn: 247167
Kazu Hirata