We can actually have dependences between accesses with different
underlying types. Bail in this case.
A test will follow shortly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262267 91177308-0d34-0410-b5e6-96231b3b80d8
merged into a loop that was subsequently unrolled (or otherwise nuked).
In this case it can't merge in the ASTs for any remaining nested loops,
it needs to re-add their instructions dircetly.
The fix is very isolated, but I've pulled the code for merging blocks
into the AST into a single place in the process. The only behavior
change is in the case which would have crashed before.
This fixes a crash reported by Mikael Holmen on the list after r261316
restored much of the loop pass pipelining and allowed us to actually do
this kind of nested transformation sequenc. I've taken that test case
and further reduced it into the somewhat twisty maze of loops in the
included test case. This does in fact trigger the bug even in this
reduced form.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262108 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: Check that we're using SCEV for the same loop we're simulating. Otherwise, we might try to use the iteration number of the current loop in SCEV expressions for inner/outer loops IVs, which is clearly incorrect.
Reviewers: chandlerc, hfinkel
Subscribers: sanjoy, llvm-commits, mzolotukhin
Differential Revision: http://reviews.llvm.org/D17632
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261958 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Since this is an IR pass it's nice to be able to write tests without
llc. This is the counterpart of the llc test under
CodeGen/PowerPC/loop-data-prefetch.ll.
Reviewers: hfinkel
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D17464
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261578 91177308-0d34-0410-b5e6-96231b3b80d8
This flag was part of a migration to a new means of handling vectors-of-points which was described in the llvm-dev thread "FYI: Relocating vector of pointers". The old code path has been off by default for a while without complaints, so time to cleanup.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261569 91177308-0d34-0410-b5e6-96231b3b80d8
This change reverts "246133 [RewriteStatepointsForGC] Reduce the number of new instructions for base pointers" and a follow on bugfix 12575.
As pointed out in pr25846, this code suffers from a memory corruption bug. Since I'm (empirically) not going to get back to this any time soon, simply reverting the problematic change is the right answer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261565 91177308-0d34-0410-b5e6-96231b3b80d8
I missed == and != when I removed implicit conversions between iterators
and pointers in r252380 since they were defined outside ilist_iterator.
Since they depend on getNodePtrUnchecked(), they indirectly rely on UB.
This commit removes all uses of these operators. (I'll delete the
operators themselves in a separate commit so that it can be easily
reverted if necessary.)
There should be NFC here.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261498 91177308-0d34-0410-b5e6-96231b3b80d8
This is inspired by PR24804 -- had this assert been there before,
isolating the root cause for PR24804 would have been far easier.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261481 91177308-0d34-0410-b5e6-96231b3b80d8
routine.
We were getting this wrong in small ways and generally being very
inconsistent about it across loop passes. Instead, let's have a common
place where we do this. One minor downside is that this will require
some analyses like SCEV in more places than they are strictly needed.
However, this seems benign as these analyses are complete no-ops, and
without this consistency we can in many cases end up with the legacy
pass manager scheduling deciding to split up a loop pass pipeline in
order to run the function analysis half-way through. It is very, very
annoying to fix these without just being very pedantic across the board.
The only loop passes I've not updated here are ones that use
AU.setPreservesAll() such as IVUsers (an analysis) and the pass printer.
They seemed less relevant.
With this patch, almost all of the problems in PR24804 around loop pass
pipelines are fixed. The one remaining issue is that we run simplify-cfg
and instcombine in the middle of the loop pass pipeline. We've recently
added some loop variants of these passes that would seem substantially
cleaner to use, but this at least gets us much closer to the previous
state. Notably, the seven loop pass managers is down to three.
I've not updated the loop passes using LoopAccessAnalysis because that
analysis hasn't been fully wired into LoopSimplify/LCSSA, and it isn't
clear that those transforms want to support those forms anyways. They
all run late anyways, so this is harmless. Similarly, LSR is left alone
because it already carefully manages its forms and doesn't need to get
fused into a single loop pass manager with a bunch of other loop passes.
LoopReroll didn't use loop simplified form previously, and I've updated
the test case to match the trivially different output.
Finally, I've also factored all the pass initialization for the passes
that use this technique as well, so that should be done regularly and
reliably.
Thanks to James for the help reviewing and thinking about this stuff,
and Ben for help thinking about it as well!
Differential Revision: http://reviews.llvm.org/D17435
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261316 91177308-0d34-0410-b5e6-96231b3b80d8
LICM starts with an *empty* AST, and then merges in each sub-loop. While the
add code is appropriate for sub-loop 2 and up, it's utterly unnecessary for
sub-loop 1. If the AST starts off empty, we can just clone/move the contents
of the subloop into the containing AST.
Reviewed-by: Philip Reames <listmail@philipreames.com>
Differential Revision: http://reviews.llvm.org/D16753
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260892 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Calls to convergent functions can be duplicated, but only if the
duplicates are not control-flow dependent on any additional values.
Loop rotation doesn't meet the bar.
Reviewers: jingyue
Subscribers: mzolotukhin, llvm-commits, arsenm, joker.eph, resistor, tra, hfinkel, broune
Differential Revision: http://reviews.llvm.org/D17127
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260729 91177308-0d34-0410-b5e6-96231b3b80d8
The attached patch removes all of the block local code for performing X-load forwarding by reusing the code used in the non-local case.
The motivation here is to remove duplication and in the process increase our test coverage of some fairly tricky code. I have some upcoming changes I'll be proposing in this area and wanted to have the code cleaned up a bit first.
Note: The review for this mostly happened in email which didn't make it to phabricator on the 258882 commit thread.
Differential Revision: http://reviews.llvm.org/D16608
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260711 91177308-0d34-0410-b5e6-96231b3b80d8
In short, before r252926 we were comparing an unsigned (StoreSize) against an a
APInt (Stride), which is fine and well. After we were zero extending the Stride
and then converting to an unsigned, which is not the same thing. Obviously,
Stides can also be negative. This commit just restores the original behavior.
AFAICT, it's not possible to write a test case to expose the issue because
the code already has checks to make sure the StoreSize can't overflow an
unsigned (which prevents the Stride from overflowing an unsigned as well).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260706 91177308-0d34-0410-b5e6-96231b3b80d8
It looks like clang has a couple of test cases which caught the fact LVI was not slightly more precise after 260439. When looking at the failures, it struck me as wasteful to be querying nullness of a constant via LVI, so instead of tweaking the clang tests, let's just stop querying constants from this source.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260451 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Unrolling Analyzer is already pretty complicated, and it becomes harder and harder to exercise it with usual IR tests, as with them we can only check the final decision: whether the loop is unrolled or not. This change factors this framework out from LoopUnrollPass to analyses, which allows to use unit tests.
The change itself is supposed to be NFC, except adding a couple of tests.
I plan to add more tests as I add new functionality and find/fix bugs.
Reviewers: chandlerc, hfinkel, sanjoy
Subscribers: zzheng, sanjoy, llvm-commits
Differential Revision: http://reviews.llvm.org/D16623
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260169 91177308-0d34-0410-b5e6-96231b3b80d8
Change a return statement of ComputeValueKnownInPredecessors() to be the same as
the rest return statements of the function. Otherwise, it might return true with
an empty Result when the current basic block has no predecessors and trigger the
first assert of JumpThreading::ProcessThreadableEdges().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260110 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
When alias analysis is uncertain about the aliasing between any two accesses,
it will return MayAlias. This uncertainty from alias analysis restricts LICM
from proceeding further. In cases where alias analysis is uncertain we might
use loop versioning as an alternative.
Loop Versioning will create a version of the loop with aggressive aliasing
assumptions in addition to the original with conservative (default) aliasing
assumptions. The version of the loop making aggressive aliasing assumptions
will have all the memory accesses marked as no-alias. These two versions of
loop will be preceded by a memory runtime check. This runtime check consists
of bound checks for all unique memory accessed in loop, and it ensures the
lack of memory aliasing. The result of the runtime check determines which of
the loop versions is executed: If the runtime check detects any memory
aliasing, then the original loop is executed. Otherwise, the version with
aggressive aliasing assumptions is used.
The pass is off by default and can be enabled with command line option
-enable-loop-versioning-licm.
Reviewers: hfinkel, anemet, chatur01, reames
Subscribers: MatzeB, grosser, joker.eph, sanjoy, javed.absar, sbaranga,
llvm-commits
Differential Revision: http://reviews.llvm.org/D9151
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259986 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Passing the rematerialized values map to insertRematerializationStores by
value looks to be a simple oversight; update it to pass by reference.
Reviewers: reames, sanjoy
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D16911
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259867 91177308-0d34-0410-b5e6-96231b3b80d8
Bail out if we have a PHI on an EHPad that gets a value from a
CatchSwitchInst. Because the CatchSwitchInst cannot be split, there is
no good place to stick any instructions.
This fixes PR26373.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259702 91177308-0d34-0410-b5e6-96231b3b80d8
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
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
- 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
Adam Nemet