Commit Graph

23 Commits

Author SHA1 Message Date
Stephen Lin
15bfd6d3ad Catch more CHECK that can be converted to CHECK-LABEL in Transforms for easier debugging. No functionality change.
This conversion was done with the following bash script:

  find test/Transforms -name "*.ll" | \
  while read NAME; do
    echo "$NAME"
    if ! grep -q "^; *RUN: *llc" $NAME; then
      TEMP=`mktemp -t temp`
      cp $NAME $TEMP
      sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \
      while read FUNC; do
        sed -i '' "s/;\(.*\)\([A-Za-z0-9_]*\):\( *\)define\([^@]*\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3define\4@$FUNC(/g" $TEMP
      done
      mv $TEMP $NAME
    fi
  done


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186269 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-14 01:50:49 +00:00
Michael Gottesman
0a80c12402 [objc-arc] Teach the ARC optimizer that objc_sync_enter/objc_sync_exit do not modify the ref count of an objc object and additionally are inert for modref purposes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185769 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-07 01:52:55 +00:00
Michael Gottesman
2c2e85536d [objc-arc] Test cleanups.
Mainly adding paranoid checks for the closing brace of a function to
help with FileCheck error readability. Also some other minor changes.

No actual CHECK changes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180668 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-27 05:25:54 +00:00
Michael Gottesman
e8b3c2e48a An objc_retain can serve as a use for a different pointer.
This is the counterpart to commit r160637, except it performs the action
in the bottomup portion of the data flow analysis.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178922 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-05 22:54:32 +00:00
Michael Gottesman
e7ce2b3f75 Properly model precise lifetime when given an incomplete dataflow sequence.
The normal dataflow sequence in the ARC optimizer consists of the following
states:

    Retain -> CanRelease -> Use -> Release

The optimizer before this patch stored the uses that determine the lifetime of
the retainable object pointer when it bottom up hits a retain or when top down
it hits a release. This is correct for an imprecise lifetime scenario since what
we are trying to do is remove retains/releases while making sure that no
``CanRelease'' (which is usually a call) deallocates the given pointer before we
get to the ``Use'' (since that would cause a segfault).

If we are considering the precise lifetime scenario though, this is not
correct. In such a situation, we *DO* care about the previous sequence, but
additionally, we wish to track the uses resulting from the following incomplete
sequences:

  Retain -> CanRelease -> Release   (TopDown)
  Retain <- Use <- Release          (BottomUp)

*NOTE* This patch looks large but the most of it consists of updating
test cases. Additionally this fix exposed an additional bug. I removed
the test case that expressed said bug and will recommit it with the fix
in a little bit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178921 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-05 22:54:28 +00:00
Michael Gottesman
a67a20c95f Remove an optimization where we were changing an objc_autorelease into an objc_autoreleaseReturnValue.
The semantics of ARC implies that a pointer passed into an objc_autorelease
must live until some point (potentially down the stack) where an
autorelease pool is popped. On the other hand, an
objc_autoreleaseReturnValue just signifies that the object must live
until the end of the given function at least.

Thus objc_autorelease is stronger than objc_autoreleaseReturnValue in
terms of the semantics of ARC* implying that performing the given
strength reduction without any knowledge of how this relates to
the autorelease pool pop that is further up the stack violates the
semantics of ARC.

*Even though objc_autoreleaseReturnValue if you know that no RV
optimization will occur is more computationally expensive.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178612 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-03 02:57:24 +00:00
Michael Gottesman
0d92a3c600 [ObjCARC] Strength reduce objc_retainBlock -> objc_retain if the objc_retainBlock is optimizable.
If an objc_retainBlock has the copy_on_escape metadata attached to it
AND if the block pointer argument only escapes down the stack, we are
allowed to strength reduce the objc_retainBlock to to an objc_retain and
thus optimize it.

Current there is logic in the ARC data flow analysis to handle
this case which is complicated and involved making distinctions in
between objc_retainBlock and objc_retain in certain places and
considering them the same in others.

This patch simplifies said code by:

1. Performing the strength reduction in the initial ARC peephole
analysis (ObjCARCOpts::OptimizeIndividualCalls).

2. Changes the ARC dataflow analysis (which runs after the peephole
analysis) to consider all objc_retainBlock calls to not be optimizable
(since if the call was optimizable, we would have strength reduced it
already).

This patch leaves in the infrastructure in the ARC dataflow analysis to
handle this case, which due to 2 will just be dead code. I am doing this
on purpose to separate the removal of the old code from the testing of
the new code.

<rdar://problem/13249661>.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178284 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-28 20:11:19 +00:00
Bill Wendling
351b7a10e2 Use references to attribute groups on the call/invoke instructions.
Listing all of the attributes for the callee of a call/invoke instruction is way
too much and makes the IR unreadable. Use references to attributes instead.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175877 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-22 09:09:42 +00:00
Michael Gottesman
e8c161a924 Fixed a bug where we were tail calling objc_autorelease causing an object to not be placed into an autorelease pool.
The reason that this occurs is that tail calling objc_autorelease eventually
tail calls -[NSObject autorelease] which supports fast autorelease. This can
cause us to violate the semantic gaurantees of __autoreleasing variables that
assignment to an __autoreleasing variables always yields an object that is
placed into the innermost autorelease pool.

The fix included in this patch works by:

1. In the peephole optimization function OptimizeIndividualFunctions, always
remove tail call from objc_autorelease.
2. Whenever we convert to/from an objc_autorelease, set/unset the tail call
keyword as appropriate.

*NOTE* I also handled the case where objc_autorelease is converted in
OptimizeReturns to an autoreleaseRV which still violates the ARC semantics. I
will be removing that in a later patch and I wanted to make sure that the tree
is in a consistent state vis-a-vis ARC always.

Additionally some test cases are provided and all tests that have tail call marked
objc_autorelease keywords have been modified so that tail call has been removed.

*NOTE* One test fails due to a separate bug that I am going to commit soon. Thus
I marked the check line TMP: instead of CHECK: so make check does not fail.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172287 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-12 01:25:15 +00:00
Dan Gohman
230768bd13 Make provenance checking conservative in cases when
pointers-to-strong-pointers may be in play. These can lead to retains and
releases happening in unstructured ways, foiling the optimizer. This fixes
rdar://12150909.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163180 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-04 23:16:20 +00:00
Benjamin Kramer
4e81d40545 Fix broken check lines.
I really need to find a way to automate this, but I can't come up with a regex
that has no false positives while handling tricky cases like custom check
prefixes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162097 91177308-0d34-0410-b5e6-96231b3b80d8
2012-08-17 12:28:26 +00:00
Dan Gohman
c72d3be389 An objc_retain can serve as a may-use for a different pointer.
rdar://11931823.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160637 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-23 19:27:31 +00:00
Dan Gohman
511568dd1f Don't move objc_autorelease calls past autorelease pool boundaries when
optimizing autorelease calls on phi nodes with null operands.
This fixes rdar://11207070.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154642 91177308-0d34-0410-b5e6-96231b3b80d8
2012-04-13 00:59:57 +00:00
Dan Gohman
5992f67e68 When identifying exit nodes for the reverse-CFG reverse-post-order
traversal, consider nodes for which the only successors are backedges
which the traversal is ignoring to be exit nodes. This fixes a problem
where the bottom-up traversal was failing to visit split blocks along
split loop backedges. This fixes rdar://10989035.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152421 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-09 18:50:52 +00:00
Dan Gohman
79522dc569 Implement proper ObjC ARC objc_retainBlock "escape" analysis, so that
the optimizer doesn't eliminate objc_retainBlock calls which are needed
for their side effect of copying blocks onto the heap.
This implements rdar://10361249.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148076 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-13 00:39:07 +00:00
Dan Gohman
f9096e450b It turns out that clang does use pointer-to-function types to
point to ARC-managed pointers sometimes. This fixes rdar://10551239.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146577 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-14 19:10:53 +00:00
Chris Lattner
d2bf432b2b Upgrade syntax of tests using volatile instructions to use 'load volatile' instead of 'volatile load', which is archaic.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145171 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-27 06:54:59 +00:00
Dan Gohman
90b8bcd33a Suppress partial retain+release elimination when there's a
possibility that it will span multiple CFG diamonds/triangles which
could have different controlling predicates.  rdar://10282956


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142222 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-17 18:48:25 +00:00
Bill Wendling
ab98f9d155 Update more tests to the new EH scheme.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138894 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-31 21:04:11 +00:00
Dan Gohman
1b31ea8f93 Constant pointers to objects don't need reference counting.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138242 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-22 17:29:11 +00:00
Dan Gohman
986b865c03 Make a few tests slightly more strict.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138241 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-22 17:27:02 +00:00
Dan Gohman
e6d5e88c12 Track a retain+release nesting level independently of the
known-incremented level, because the two concepts can be used
to prove the saftey of a retain+release removal in different
ways.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138016 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-19 00:26:36 +00:00
John McCall
9fbd318d36 The ARC language-specific optimizer. Credit to Dan Gohman.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133108 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-15 23:37:01 +00:00