Commit Graph

205 Commits

Author SHA1 Message Date
Akira Hatanaka dca5737945 Move ObjCARCUtil.h back to llvm/Analysis
Instead of adding the header to llvm/IR, just duplicate the marker
string in the auto upgrader.
2021-03-08 16:35:24 -08:00
David Blaikie a2a55def35 Move llvm/Analysis/ObjCARCUtil.h to IR to fix layering.
This is included from IR files, and IR doesn't/can't depend on Analysis
(because Analysis depends on IR).

Also fix the implementation - don't use non-member static in headers, as
it leads to ODR violations, inaccurate "unused function" warnings, etc.
And fix the header protection macro name (we don't generally include
"LIB" in the names, so far as I can tell).
2021-03-04 16:14:53 -08:00
Akira Hatanaka 1900503595 [ObjC][ARC] Use operand bundle 'clang.arc.attachedcall' instead of
explicitly emitting retainRV or claimRV calls in the IR

This reapplies ed4718eccb, which was reverted
because it was causing a miscompile. The bug that was causing the miscompile
has been fixed in 75805dce5f.

Original commit message:

Background:

This fixes a longstanding problem where llvm breaks ARC's autorelease
optimization (see the link below) by separating calls from the marker
instructions or retainRV/claimRV calls. The backend changes are in
https://reviews.llvm.org/D92569.

https://clang.llvm.org/docs/AutomaticReferenceCounting.html#arc-runtime-objc-autoreleasereturnvalue

What this patch does to fix the problem:

- The front-end adds operand bundle "clang.arc.attachedcall" to calls,
  which indicates the call is implicitly followed by a marker
  instruction and an implicit retainRV/claimRV call that consumes the
  call result. In addition, it emits a call to
  @llvm.objc.clang.arc.noop.use, which consumes the call result, to
  prevent the middle-end passes from changing the return type of the
  called function. This is currently done only when the target is arm64
  and the optimization level is higher than -O0.

- ARC optimizer temporarily emits retainRV/claimRV calls after the calls
  with the operand bundle in the IR and removes the inserted calls after
  processing the function.

- ARC contract pass emits retainRV/claimRV calls after the call with the
  operand bundle. It doesn't remove the operand bundle on the call since
  the backend needs it to emit the marker instruction. The retainRV and
  claimRV calls are emitted late in the pipeline to prevent optimization
  passes from transforming the IR in a way that makes it harder for the
  ARC middle-end passes to figure out the def-use relationship between
  the call and the retainRV/claimRV calls (which is the cause of
  PR31925).

- The function inliner removes an autoreleaseRV call in the callee if
  nothing in the callee prevents it from being paired up with the
  retainRV/claimRV call in the caller. It then inserts a release call if
  claimRV is attached to the call since autoreleaseRV+claimRV is
  equivalent to a release. If it cannot find an autoreleaseRV call, it
  tries to transfer the operand bundle to a function call in the callee.
  This is important since the ARC optimizer can remove the autoreleaseRV
  returning the callee result, which makes it impossible to pair it up
  with the retainRV/claimRV call in the caller. If that fails, it simply
  emits a retain call in the IR if retainRV is attached to the call and
  does nothing if claimRV is attached to it.

- SCCP refrains from replacing the return value of a call with a
  constant value if the call has the operand bundle. This ensures the
  call always has at least one user (the call to
  @llvm.objc.clang.arc.noop.use).

- This patch also fixes a bug in replaceUsesOfNonProtoConstant where
  multiple operand bundles of the same kind were being added to a call.

Future work:

- Use the operand bundle on x86-64.

- Fix the auto upgrader to convert call+retainRV/claimRV pairs into
  calls with the operand bundles.

rdar://71443534

Differential Revision: https://reviews.llvm.org/D92808
2021-03-04 11:22:30 -08:00
Hans Wennborg 0a5dd06718 Revert "[ObjC][ARC] Use operand bundle 'clang.arc.attachedcall' instead of explicitly emitting retainRV or claimRV calls in the IR"
This caused miscompiles of Chromium tests for iOS due clobbering of live
registers. See discussion on the code review for details.

> Background:
>
> This fixes a longstanding problem where llvm breaks ARC's autorelease
> optimization (see the link below) by separating calls from the marker
> instructions or retainRV/claimRV calls. The backend changes are in
> https://reviews.llvm.org/D92569.
>
> https://clang.llvm.org/docs/AutomaticReferenceCounting.html#arc-runtime-objc-autoreleasereturnvalue
>
> What this patch does to fix the problem:
>
> - The front-end adds operand bundle "clang.arc.attachedcall" to calls,
>   which indicates the call is implicitly followed by a marker
>   instruction and an implicit retainRV/claimRV call that consumes the
>   call result. In addition, it emits a call to
>   @llvm.objc.clang.arc.noop.use, which consumes the call result, to
>   prevent the middle-end passes from changing the return type of the
>   called function. This is currently done only when the target is arm64
>   and the optimization level is higher than -O0.
>
> - ARC optimizer temporarily emits retainRV/claimRV calls after the calls
>   with the operand bundle in the IR and removes the inserted calls after
>   processing the function.
>
> - ARC contract pass emits retainRV/claimRV calls after the call with the
>   operand bundle. It doesn't remove the operand bundle on the call since
>   the backend needs it to emit the marker instruction. The retainRV and
>   claimRV calls are emitted late in the pipeline to prevent optimization
>   passes from transforming the IR in a way that makes it harder for the
>   ARC middle-end passes to figure out the def-use relationship between
>   the call and the retainRV/claimRV calls (which is the cause of
>   PR31925).
>
> - The function inliner removes an autoreleaseRV call in the callee if
>   nothing in the callee prevents it from being paired up with the
>   retainRV/claimRV call in the caller. It then inserts a release call if
>   claimRV is attached to the call since autoreleaseRV+claimRV is
>   equivalent to a release. If it cannot find an autoreleaseRV call, it
>   tries to transfer the operand bundle to a function call in the callee.
>   This is important since the ARC optimizer can remove the autoreleaseRV
>   returning the callee result, which makes it impossible to pair it up
>   with the retainRV/claimRV call in the caller. If that fails, it simply
>   emits a retain call in the IR if retainRV is attached to the call and
>   does nothing if claimRV is attached to it.
>
> - SCCP refrains from replacing the return value of a call with a
>   constant value if the call has the operand bundle. This ensures the
>   call always has at least one user (the call to
>   @llvm.objc.clang.arc.noop.use).
>
> - This patch also fixes a bug in replaceUsesOfNonProtoConstant where
>   multiple operand bundles of the same kind were being added to a call.
>
> Future work:
>
> - Use the operand bundle on x86-64.
>
> - Fix the auto upgrader to convert call+retainRV/claimRV pairs into
>   calls with the operand bundles.
>
> rdar://71443534
>
> Differential Revision: https://reviews.llvm.org/D92808

This reverts commit ed4718eccb.
2021-03-03 15:51:40 +01:00
Akira Hatanaka 32dc79c5ef [ObjC][ARC] Do not perform code motion on precise release calls
This fixes a bug where an object can get deallocated before reaching the
end of its full formal lifetime.

rdar://72110887
rdar://74123176
2021-02-15 17:39:37 -08:00
Akira Hatanaka ed4718eccb [ObjC][ARC] Use operand bundle 'clang.arc.attachedcall' instead of
explicitly emitting retainRV or claimRV calls in the IR

Background:

This fixes a longstanding problem where llvm breaks ARC's autorelease
optimization (see the link below) by separating calls from the marker
instructions or retainRV/claimRV calls. The backend changes are in
https://reviews.llvm.org/D92569.

https://clang.llvm.org/docs/AutomaticReferenceCounting.html#arc-runtime-objc-autoreleasereturnvalue

What this patch does to fix the problem:

- The front-end adds operand bundle "clang.arc.attachedcall" to calls,
  which indicates the call is implicitly followed by a marker
  instruction and an implicit retainRV/claimRV call that consumes the
  call result. In addition, it emits a call to
  @llvm.objc.clang.arc.noop.use, which consumes the call result, to
  prevent the middle-end passes from changing the return type of the
  called function. This is currently done only when the target is arm64
  and the optimization level is higher than -O0.

- ARC optimizer temporarily emits retainRV/claimRV calls after the calls
  with the operand bundle in the IR and removes the inserted calls after
  processing the function.

- ARC contract pass emits retainRV/claimRV calls after the call with the
  operand bundle. It doesn't remove the operand bundle on the call since
  the backend needs it to emit the marker instruction. The retainRV and
  claimRV calls are emitted late in the pipeline to prevent optimization
  passes from transforming the IR in a way that makes it harder for the
  ARC middle-end passes to figure out the def-use relationship between
  the call and the retainRV/claimRV calls (which is the cause of
  PR31925).

- The function inliner removes an autoreleaseRV call in the callee if
  nothing in the callee prevents it from being paired up with the
  retainRV/claimRV call in the caller. It then inserts a release call if
  claimRV is attached to the call since autoreleaseRV+claimRV is
  equivalent to a release. If it cannot find an autoreleaseRV call, it
  tries to transfer the operand bundle to a function call in the callee.
  This is important since the ARC optimizer can remove the autoreleaseRV
  returning the callee result, which makes it impossible to pair it up
  with the retainRV/claimRV call in the caller. If that fails, it simply
  emits a retain call in the IR if retainRV is attached to the call and
  does nothing if claimRV is attached to it.

- SCCP refrains from replacing the return value of a call with a
  constant value if the call has the operand bundle. This ensures the
  call always has at least one user (the call to
  @llvm.objc.clang.arc.noop.use).

- This patch also fixes a bug in replaceUsesOfNonProtoConstant where
  multiple operand bundles of the same kind were being added to a call.

Future work:

- Use the operand bundle on x86-64.

- Fix the auto upgrader to convert call+retainRV/claimRV pairs into
  calls with the operand bundles.

rdar://71443534

Differential Revision: https://reviews.llvm.org/D92808
2021-02-12 09:51:57 -08:00
Nico Weber de1966e542 Revert "[ObjC][ARC] Use operand bundle 'clang.arc.rv' instead of explicitly"
This reverts commit 4a64d8fe39.
Makes clang crash when buildling trivial iOS programs, see comment
after https://reviews.llvm.org/D92808#2551401
2021-02-09 11:06:32 -05:00
Akira Hatanaka 4a64d8fe39 [ObjC][ARC] Use operand bundle 'clang.arc.rv' instead of explicitly
emitting retainRV or claimRV calls in the IR

This reapplies 3fe3946d9a without the
changes made to lib/IR/AutoUpgrade.cpp, which was violating layering.

Original commit message:

Background:

This patch makes changes to the front-end and middle-end that are
needed to fix a longstanding problem where llvm breaks ARC's autorelease
optimization (see the link below) by separating calls from the marker
instructions or retainRV/claimRV calls. The backend changes are in
https://reviews.llvm.org/D92569.

https://clang.llvm.org/docs/AutomaticReferenceCounting.html#arc-runtime-objc-autoreleasereturnvalue

What this patch does to fix the problem:

- The front-end adds operand bundle "clang.arc.rv" to calls, which
  indicates the call is implicitly followed by a marker instruction and
  an implicit retainRV/claimRV call that consumes the call result. In
  addition, it emits a call to @llvm.objc.clang.arc.noop.use, which
  consumes the call result, to prevent the middle-end passes from changing
  the return type of the called function. This is currently done only when
  the target is arm64 and the optimization level is higher than -O0.

- ARC optimizer temporarily emits retainRV/claimRV calls after the calls
  with the operand bundle in the IR and removes the inserted calls after
  processing the function.

- ARC contract pass emits retainRV/claimRV calls after the call with the
  operand bundle. It doesn't remove the operand bundle on the call since
  the backend needs it to emit the marker instruction. The retainRV and
  claimRV calls are emitted late in the pipeline to prevent optimization
  passes from transforming the IR in a way that makes it harder for the
  ARC middle-end passes to figure out the def-use relationship between
  the call and the retainRV/claimRV calls (which is the cause of
  PR31925).

- The function inliner removes an autoreleaseRV call in the callee if
  nothing in the callee prevents it from being paired up with the
  retainRV/claimRV call in the caller. It then inserts a release call if
  the call is annotated with claimRV since autoreleaseRV+claimRV is
  equivalent to a release. If it cannot find an autoreleaseRV call, it
  tries to transfer the operand bundle to a function call in the callee.
  This is important since ARC optimizer can remove the autoreleaseRV
  returning the callee result, which makes it impossible to pair it up
  with the retainRV/claimRV call in the caller. If that fails, it simply
  emits a retain call in the IR if the implicit call is a call to
  retainRV and does nothing if it's a call to claimRV.

Future work:

- Use the operand bundle on x86-64.

- Fix the auto upgrader to convert call+retainRV/claimRV pairs into
  calls annotated with the operand bundles.

rdar://71443534

Differential Revision: https://reviews.llvm.org/D92808
2021-02-05 06:09:42 -08:00
Akira Hatanaka 2fbbb18c1d Revert "[ObjC][ARC] Use operand bundle 'clang.arc.rv' instead of explicitly"
This reverts commit 3fe3946d9a.

The commit violates layering by including a header from Analysis in
lib/IR/AutoUpgrade.cpp.
2021-02-05 06:00:05 -08:00
Akira Hatanaka 3fe3946d9a [ObjC][ARC] Use operand bundle 'clang.arc.rv' instead of explicitly
emitting retainRV or claimRV calls in the IR

Background:

This patch makes changes to the front-end and middle-end that are
needed to fix a longstanding problem where llvm breaks ARC's autorelease
optimization (see the link below) by separating calls from the marker
instructions or retainRV/claimRV calls. The backend changes are in
https://reviews.llvm.org/D92569.

https://clang.llvm.org/docs/AutomaticReferenceCounting.html#arc-runtime-objc-autoreleasereturnvalue

What this patch does to fix the problem:

- The front-end adds operand bundle "clang.arc.rv" to calls, which
  indicates the call is implicitly followed by a marker instruction and
  an implicit retainRV/claimRV call that consumes the call result. In
  addition, it emits a call to @llvm.objc.clang.arc.noop.use, which
  consumes the call result, to prevent the middle-end passes from changing
  the return type of the called function. This is currently done only when
  the target is arm64 and the optimization level is higher than -O0.

- ARC optimizer temporarily emits retainRV/claimRV calls after the calls
  with the operand bundle in the IR and removes the inserted calls after
  processing the function.

- ARC contract pass emits retainRV/claimRV calls after the call with the
  operand bundle. It doesn't remove the operand bundle on the call since
  the backend needs it to emit the marker instruction. The retainRV and
  claimRV calls are emitted late in the pipeline to prevent optimization
  passes from transforming the IR in a way that makes it harder for the
  ARC middle-end passes to figure out the def-use relationship between
  the call and the retainRV/claimRV calls (which is the cause of
  PR31925).

- The function inliner removes an autoreleaseRV call in the callee if
  nothing in the callee prevents it from being paired up with the
  retainRV/claimRV call in the caller. It then inserts a release call if
  the call is annotated with claimRV since autoreleaseRV+claimRV is
  equivalent to a release. If it cannot find an autoreleaseRV call, it
  tries to transfer the operand bundle to a function call in the callee.
  This is important since ARC optimizer can remove the autoreleaseRV
  returning the callee result, which makes it impossible to pair it up
  with the retainRV/claimRV call in the caller. If that fails, it simply
  emits a retain call in the IR if the implicit call is a call to
  retainRV and does nothing if it's a call to claimRV.

Future work:

- Use the operand bundle on x86-64.

- Fix the auto upgrader to convert call+retainRV/claimRV pairs into
  calls annotated with the operand bundles.

rdar://71443534

Differential Revision: https://reviews.llvm.org/D92808
2021-02-05 05:55:18 -08:00
Richard Smith 925ae8c790 Revert "[ObjC][ARC] Annotate calls with attributes instead of emitting retainRV"
This reverts commit 53176c1680, which
introduceed a layering violation. LLVM's IR library can't include
headers from Analysis.
2021-01-25 13:53:38 -08:00
Akira Hatanaka 53176c1680 [ObjC][ARC] Annotate calls with attributes instead of emitting retainRV
or claimRV calls in the IR

Background:

This patch makes changes to the front-end and middle-end that are
needed to fix a longstanding problem where llvm breaks ARC's autorelease
optimization (see the link below) by separating calls from the marker
instructions or retainRV/claimRV calls. The backend changes are in
https://reviews.llvm.org/D92569.

https://clang.llvm.org/docs/AutomaticReferenceCounting.html#arc-runtime-objc-autoreleasereturnvalue

What this patch does to fix the problem:

- The front-end annotates calls with attribute "clang.arc.rv"="retain"
  or "clang.arc.rv"="claim", which indicates the call is implicitly
  followed by a marker instruction and a retainRV/claimRV call that
  consumes the call result. This is currently done only when the target
  is arm64 and the optimization level is higher than -O0.

- ARC optimizer temporarily emits retainRV/claimRV calls after the
  annotated calls in the IR and removes the inserted calls after
  processing the function.

- ARC contract pass emits retainRV/claimRV calls after the annotated
  calls. It doesn't remove the attribute on the call since the backend
  needs it to emit the marker instruction. The retainRV/claimRV calls
  are emitted late in the pipeline to prevent optimization passes from
  transforming the IR in a way that makes it harder for the ARC
  middle-end passes to figure out the def-use relationship between the
  call and the retainRV/claimRV calls (which is the cause of PR31925).

- The function inliner removes the autoreleaseRV call in the callee that
  returns the result if nothing in the callee prevents it from being
  paired up with the calls annotated with "clang.arc.rv"="retain/claim"
  in the caller. If the call is annotated with "claim", a release call
  is inserted since autoreleaseRV+claimRV is equivalent to a release. If
  it cannot find an autoreleaseRV call, it tries to transfer the
  attributes to a function call in the callee. This is important since
  ARC optimizer can remove the autoreleaseRV call returning the callee
  result, which makes it impossible to pair it up with the retainRV or
  claimRV call in the caller. If that fails, it simply emits a retain
  call in the IR if the call is annotated with "retain" and does nothing
  if it's annotated with "claim".

- This patch teaches dead argument elimination pass not to change the
  return type of a function if any of the calls to the function are
  annotated with attribute "clang.arc.rv". This is necessary since the
  pass can incorrectly determine nothing in the IR uses the function
  return, which can happen since the front-end no longer explicitly
  emits retainRV/claimRV calls in the IR, and change its return type to
  'void'.

Future work:

- Use the attribute on x86-64.

- Fix the auto upgrader to convert call+retainRV/claimRV pairs into
  calls annotated with the attributes.

rdar://71443534

Differential Revision: https://reviews.llvm.org/D92808
2021-01-25 11:57:08 -08:00
Arthur Eubanks 756dd70766 [NewPM] Run ObjC ARC passes
Match the legacy PM in running various ObjC ARC passes.

This requires making some module passes into function passes. These were
initially ported as module passes since they add function declarations
(e.g. https://reviews.llvm.org/D86178), but that's still up for debate
and other passes do so.

Reviewed By: ahatanak

Differential Revision: https://reviews.llvm.org/D93743
2021-01-08 15:47:11 -08:00
Kazu Hirata 43c0e4f665 [Transforms] Use llvm::is_contained (NFC) 2020-11-18 20:42:22 -08:00
Akira Hatanaka 2ed3a76745 [ObjC][ARC] Add and use a function which finds and returns the single
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.
2020-11-13 14:02:58 -08:00
Akira Hatanaka 00d0974e62 Move variable declarations to functions in which they are used. NFC 2020-11-13 14:02:58 -08:00
Akira Hatanaka 09266e4af0 [ObjC][ARC] Clear the lists of basic blocks and instructions before
continuing the loop

This fixes a bug introduced in c6f1713c46.
2020-11-12 22:20:02 -08:00
Akira Hatanaka 5e85d00ed6 Move variable declarations to functions in which they are used. NFC 2020-11-11 10:58:43 -08:00
Arthur Eubanks cfde93e5d6 [ObjCARCOpt] Port objc-arc to NPM
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
2020-08-28 12:59:33 -07:00
serge-sans-paille 80f1ec7008 Correctly report modified status for ObjCARCOpt
Differential Revision: https://reviews.llvm.org/D81234
2020-06-05 15:56:57 +02:00
Mircea Trofin b8960b5d81 [llvm][NFC][CallSite] Remove remaining {Immutable}CallSite uses
Reviewers: dblaikie, craig.topper

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D78789
2020-04-23 22:19:39 -07:00
Akira Hatanaka c6f1713c46 [ObjC][ARC] Don't remove autoreleaseRV/retainRV pairs if the call isn't
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
2020-03-13 13:52:14 -07:00
Nico Weber 86eb2c3991 Revert "[ObjC][ARC] Don't remove autoreleaseRV/retainRV pairs if the call isn't"
This reverts commit 1f5b471b8b.
Causes asserts when building code with arc. See
https://bugs.chromium.org/p/chromium/issues/detail?id=1061289#c2
for a full repro. Will post a creduced repro once creduce is done
running.
2020-03-13 10:16:02 -04:00
ahatanak 1f5b471b8b [ObjC][ARC] Don't remove autoreleaseRV/retainRV pairs if the call isn't
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
2020-03-09 13:21:38 -07:00
Akira Hatanaka 430512ed7d [ObjC][ARC] Don't move a retain call living outside a loop into the loop
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
2020-02-25 13:00:10 -08:00
Akira Hatanaka 4dcc029edb [ObjC][ARC] Keep track of phis that have been discovered to avoid an
infinite loop

This fixes a bug introduced in 6770fbb314.

rdar://problem/59137105
2020-02-07 20:33:11 -08:00
Akira Hatanaka 6770fbb314 [ObjC][ARC] Delete ARC runtime calls that take inert phi values
This improves on the following patch, which removed ARC runtime calls
taking inert global variables:

https://reviews.llvm.org/D62433

rdar://problem/59137105
2020-02-07 16:31:36 -08:00
Duncan P. N. Exon Smith 3279724905 llvm/ObjCARC: Eliminate inlined AutoreleaseRV calls
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
2019-11-19 12:02:01 -08:00
Duncan P. N. Exon Smith 783cb86b61 llvm/ObjCARC: Split OptimizeIndividualCallImpl out of OptimizeIndividualCalls, NFC
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`.
2019-11-17 21:54:27 -08:00
Duncan P. N. Exon Smith a937a588dd llvm/ObjCARC: Use continue to reduce some nesting, NFC 2019-11-17 18:22:35 -08:00
Reid Kleckner 4c1a1d3cf9 Add missing includes needed to prune LLVMContext.h include, NFC
These are a pre-requisite to removing #include "llvm/Support/Options.h"
from LLVMContext.h: https://reviews.llvm.org/D70280
2019-11-14 15:23:15 -08:00
Reid Kleckner 05da2fe521 Sink all InitializePasses.h includes
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
2019-11-13 16:34:37 -08:00
Francis Visoiu Mistrih 47d1029788 [ObjC][ARC] Ignore lifetime markers between *ReturnValue calls
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
2019-11-05 06:39:22 -08:00
Akira Hatanaka a704a8f28c [ObjC][ARC] Delete ObjC runtime calls on global variables annotated
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
2019-06-14 22:06:32 +00:00
Akira Hatanaka 8edf8f317b [ObjC][ARC] Let ARC optimizer bail out if the number of pointer states
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
2019-04-25 19:42:55 +00:00
Akira Hatanaka b576c77a9e Don't add a tail keyword to calls to ObjC runtime functions if the calls
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
2019-03-21 20:16:09 +00:00
James Y Knight 291f791ef1 [opaque pointer types] Pass function type for CallBase::setCalledFunction.
Differential Revision: https://reviews.llvm.org/D57174

llvm-svn: 352914
2019-02-01 20:44:54 +00:00
James Y Knight 7976eb5838 [opaque pointer types] Pass function types to CallInst creation.
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
2019-02-01 20:43:25 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
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
2019-01-19 08:50:56 +00:00
Pete Cooper 697281df42 Teach ObjCARC optimizer about equivalent PHIs when eliminating autoreleaseRV/retainRV pairs
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
2019-01-03 01:38:08 +00:00
Chandler Carruth c1e3ee29a4 [TI removal] Switch ObjCARC code to directly use the nice range-based
successors API or directly build the iterators out of the terminator
instruction and avoid requiring a TerminatorInst variable.

llvm-svn: 344715
2018-10-18 00:38:34 +00:00
Heejin Ahn b4be38fcdd [WebAssembly] Add Wasm personality and isScopedEHPersonality()
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
2018-05-17 20:52:03 +00:00
Shoaib Meenai 074728a2a9 [ObjCARC] Prevent code motion into a catchswitch
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
2018-05-16 04:52:18 +00:00
Nicola Zaghen d34e60ca85 Rename DEBUG macro to LLVM_DEBUG.
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
2018-05-14 12:53:11 +00:00
Adrian Prantl 5f8f34e459 Remove \brief commands from doxygen comments.
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
2018-05-01 15:54:18 +00:00
Shoaib Meenai 106df7dd20 [ObjCARC] Take BlockColors by const reference. NFC
llvm-svn: 330489
2018-04-20 22:14:45 +00:00
Saleem Abdulrasool f159a389df ObjCARC: address review comments from majnemer
I forgot to incorporate these comments into the original revision.  This
is just code cleanup addressing the feedback, NFC.

llvm-svn: 327351
2018-03-12 23:48:20 +00:00
Saleem Abdulrasool 8b342680bf ObjCARC: teach the cloner about funclets
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
2018-03-12 21:46:09 +00:00
Akira Hatanaka 73ceb50d85 [ObjCARC] Do not turn a call to @objc_autoreleaseReturnValue into a call
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
2018-01-19 23:51:13 +00:00
Eugene Zelenko 57bd5a0274 [Transforms] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 316724
2017-10-27 01:09:08 +00:00