Summary:
LoopVersioning is a transform utility that transform passes can use to
run-time disambiguate may-aliasing accesses. I'd like to also expose as
pass to allow it to be unit-tested.
I am planning to add support for non-aliasing annotation in
LoopVersioning and I'd like to be able to write tests directly using
this pass.
(After that feature is done, the pass could also be used to look for
optimization opportunities that are hidden behind incomplete alias
information at compile time.)
The pass drives LoopVersioning in its default way which is to fully
disambiguate may-aliasing accesses no matter how many checks are
required.
Reviewers: hfinkel, ashutosh.nema, sbaranga
Subscribers: zzheng, mssimpso, llvm-commits, sanjoy
Differential Revision: http://reviews.llvm.org/D16612
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259610 91177308-0d34-0410-b5e6-96231b3b80d8
This miscompile came about because we tried to use a transform which was
only appropriate for xor operators when addition was present.
This fixes PR26407.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259375 91177308-0d34-0410-b5e6-96231b3b80d8
In the future, we will vectorize recurrences other than reductions. This patch
renames a few variables and updates their associated comments to enable them to
be reused for non-reduction PHI nodes.
This change was requested in the review for D16197.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259364 91177308-0d34-0410-b5e6-96231b3b80d8
The previous patch caused PR26364. The fix is to ensure that we don't enter a
cycle when iterating over use-def chains.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259357 91177308-0d34-0410-b5e6-96231b3b80d8
These sets perform linear searching in small mode so it is never a good
idea to use SmallSize/N bigger than 32.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259283 91177308-0d34-0410-b5e6-96231b3b80d8
Loop transformations can sometimes fail because the loop, while in
valid rotated LCSSA form, is not in a canonical CFG form. This is
an extremely simple pass that just merges obviously redundant
blocks, which can be used to fix some known failure cases. In the
future, it may be enhanced with more cases (and have code shared with
SimplifyCFG).
This allows us to run LoopSimplifyCFG -> LoopRotate -> LoopUnroll,
so that SimplifyCFG cleans up the loop before Rotate tries to run.
Not currently used in the pass manager, since this pass doesn't do
anything unless you can hook it up in an LPM with other loop passes.
It'll be added once Chandler cleans up things to allow this.
Tested in a custom pipeline out of tree to confirm it works in
practice (in addition to the included trivial test).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259256 91177308-0d34-0410-b5e6-96231b3b80d8
We would infinite loop because we created a shufflevector that was wider than
needed and then failed to combine that with the insertelement. When subsequently
visiting the extractelement from that shuffle, we see that it's unnecessary,
delete it, and trigger another visit to the insertelement.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259236 91177308-0d34-0410-b5e6-96231b3b80d8
- Locally declare struct, and call it BaseDerivedPair
- Use a lambda to compare, instead of a singleton with uninitialized
fields
- Add a constructor to BaseDerivedPair and use SmallVector::emplace_back
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259208 91177308-0d34-0410-b5e6-96231b3b80d8
Just adding an assert which makes invariants between AnalyzeLoadsFromClobberingLoads and GetLoadValueForLoad slightly more clear.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259145 91177308-0d34-0410-b5e6-96231b3b80d8
The full diff for the test directory may be hard to read because of the
filename clash; so here's all that happened as far as the tests are
concerned:
```
cd test/Transforms/RewriteStatepointsForGC
git rm *ll
git mv deopt-bundles/* ./
rmdir deopt-bundles
find . -name '*.ll' | xargs gsed -i 's/-rs4gc-use-deopt-bundles //g'
```
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259129 91177308-0d34-0410-b5e6-96231b3b80d8
These changes are aimed at bringing PlaceSafepoints up to code with the
LLVM coding guidelines:
- Fix variable naming
- Use DenseSet instead of std::set
- Remove dead code
- Minor local code simplifications
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259112 91177308-0d34-0410-b5e6-96231b3b80d8
This change permanently clamps -spp-no-statepoints to true (the code
deletion will come later). Tests that specifically tested
PlaceSafepoint's ability to wrap calls in gc.statepoint have been moved
to RS4GC's test suite.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259096 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
If the instruction we're hoisting out of a loop into its preheader is
guaranteed to have executed in the loop, then the metadata associated
with the instruction (e.g. !range or !dereferenceable) is valid in the
preheader. This is because once we're in the preheader, we know we're
eventually going to reach the location the metadata was valid at.
This change makes LICM smarter around this, and helps it recognize cases
like these:
```
do {
int a = *ptr; !range !0
...
} while (i++ < N);
```
to
```
int a = *ptr; !range !0
do {
...
} while (i++ < N);
```
Earlier we'd drop the `!range` metadata after hoisting the load from
`ptr`.
Reviewers: igor-laevsky
Subscribers: mcrosier, llvm-commits
Differential Revision: http://reviews.llvm.org/D16669
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259053 91177308-0d34-0410-b5e6-96231b3b80d8
This is a fix for:
https://llvm.org/bugs/show_bug.cgi?id=26308
With the switch to using the TTI cost model in:
http://reviews.llvm.org/rL228826
...it became possible to hit a zero-cost cycle of instructions (gep -> phi -> gep...),
so we need a cap for the recursion in DominatesMergePoint().
A recursion depth parameter was already added for a different reason in:
http://reviews.llvm.org/rL255660
...so we can just set a limit for it.
I pulled "10" out of the air and made it an independent parameter that we can play with.
It might be higher than it needs to be given the currently low default value of
PHINodeFoldingThreshold (2). That's the starting cost value that we enter the recursion
with, and most instructions have cost set to TCC_Basic (1), so I don't think we're going
to speculate more than 2 instructions with the current parameters.
As noted in the review and the TODO comment, we can do better than just limiting recursion
depth.
Differential Revision: http://reviews.llvm.org/D16637
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258971 91177308-0d34-0410-b5e6-96231b3b80d8
ObjC ARC Optimizer.
The main implication of this is:
1. Ensuring that we treat it conservatively in terms of optimization.
2. We put the ASM marker on it so that the runtime can recognize
objc_unsafeClaimAutoreleasedReturnValue from releaseRV.
<rdar://problem/21567064>
Patch by Michael Gottesman!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258970 91177308-0d34-0410-b5e6-96231b3b80d8
