All the invalidation issues and bugs in this seem to be fixed, it has
survived a full build of the test suite plus SPEC with asserts and ASan
enabled on the Clang binary used.
Differential Revision: https://reviews.llvm.org/D29815
llvm-svn: 294887
Without any loops, we don't even bother to build the standard analyses
used by loop passes. Without these, we can't run loop analyses or
invalidate them properly. Unfortunately, we did these things in the
wrong order which would allow a loop analysis manager's proxy to be
built but then not have the standard analyses built. When we went to do
the invalidation in the proxy thing would fall apart. In the test case
provided, it would actually crash.
The fix is to carefully check for loops first, and to in fact build the
standard analyses before building the proxy. This allows it to
correctly trigger invalidation for those standard analyses.
An alternative might seem to be to look at whether there are any loops
when doing invalidation, but this doesn't work when during the loop
pipeline run we delete the last loop. I've even included that as a test
case. It is both simpler and more robust to defer building the proxy
until there are definitely the standard set of analyses and indeed
loops.
This bug was uncovered by enabling GlobalsAA in the pipeline.
llvm-svn: 294728
This needs explicit requires of the optimization remark emission before
loop pass pipelines containing LICM as we no longer get it from the
inliner -- Argument Promotion may invalidate it. Technically the inliner
could also have broken this, but it never came up in testing.
Differential Revision: https://reviews.llvm.org/D29595
llvm-svn: 294670
the main pipeline.
This is a very straight forward port. Nothing weird or surprising.
This brings the number of missing passes from the new PM's pipeline down
to three.
llvm-svn: 293249
With this the per-module pass pipeline is *extremely* close to the
legacy PM. The missing pieces are:
- PruneEH (or some equivalent)
- ArgumentPromotion
- LoopLoadElimination
- LoopUnswitch
I'm going to work through those in essentially that order but this seems
like a worthwhile incremental step toward the end state.
One difference in what I have here from the legacy PM is that I've
consolidated some of the per-function passes at the very end of the
pipeline into the main optimization function pipeline. The intervening
passes are *really* uninteresting and so this seems very likely to have
any effect other than minor improvement to locality.
Note that there are still some failures in the test suite, but the
compiler doesn't crash or assert.
Differential Revision: https://reviews.llvm.org/D29114
llvm-svn: 293241
loop-unswitch in the main pipelines for the new PM.
All of these now work, and Clang built using this pipeline can build the
test suite and SPEC without hitting any asserts of ASan failures.
There are still some bugs hiding though -- 7 tests regress with the new
PM. I'm going to be investigating these, but it seems worthwhile to at
least get the pipelines in place so that others can play with them, and
they aren't completely broken.
Differential Revision: https://reviews.llvm.org/D29113
llvm-svn: 293225
a lazy-asserting PoisoningVH.
AssertVH is fundamentally incompatible with cache-invalidation of
analysis results. The invaliadtion happens after the AssertingVH has
already fired. Instead, use a PoisoningVH that will assert if the
dangling handle is ever used rather than merely be assigned or
destroyed.
This patch also removes all of the (numerous) doomed attempts to work
around this fundamental incompatibility. It is a pretty significant
simplification IMO.
The most interesting change is in the Inliner where we still do some
clearing because we don't want to rely on the coarse grained
invalidation strategy of the containing pass manager. However, I prefer
the approach that contains this logic to the cleanup phase of the
Inliner, and I think we could enhance the CGSCC analysis management
layer to make this even better in the future if desired.
The rest is straight cleanup.
I've also added a test for one of the harder cases to work around: when
a *module analysis* contains many AssertingVHes pointing at functions.
Differential Revision: https://reviews.llvm.org/D29006
llvm-svn: 292928
invalidation of deleted functions in GlobalDCE.
This was always testing a bug really triggered in GlobalDCE. Right now
we have analyses with asserting value handles into IR. As long as those
remain, when *deleting* an IR unit, we cannot wait for the normal
invalidation scheme to kick in even though it was designed to work
correctly in the face of these kinds of deletions. Instead, the pass
needs to directly handle invalidating the analysis results pointing at
that IR unit.
I've tought the Inliner about this and this patch teaches GlobalDCE.
This will handle the asserting VH case in the existing test as well as
other issues of the same fundamental variety. I've moved the test into
the GlobalDCE directory and added a comment explaining what is going on.
Note that we cannot simply require LVI here because LVI is too lazy.
llvm-svn: 292773
become unavailable.
The AssumptionCache is now immutable but it still needs to respond to
DomTree invalidation if it ended up caching one.
This lets us remove one of the explicit invalidates of LVI but the
other one continues to avoid hitting a latent bug.
llvm-svn: 292769
new PM's inliner.
The bug happens when we refine an SCC after having computed a proxy for
the FunctionAnalysisManager, and then proceed to compute fresh analyses
for functions in the *new* SCC using the manager provided by the old
SCC's proxy. *And* when we manage to mutate a function in this new SCC
in a way that invalidates those analyses. This can be... challenging to
reproduce.
I've managed to contrive a set of functions that trigger this and added
a test case, but it is a bit brittle. I've directly checked that the
passes run in the expected ways to help avoid the test just becoming
silently irrelevant.
This gets the new PM back to passing the LLVM test suite after the PGO
improvements landed.
llvm-svn: 292757
This adds the last remaining core feature of the loop pass pipeline in
the new PM and removes the last of the really egregious hacks in the
LICM tests.
Sadly, this requires really substantial changes in the unittests in
order to provide and maintain simplified loops. This is particularly
hard because for example LoopSimplify will try to fold undef branches to
an ideal direction and simplify the loop accordingly.
Differential Revision: https://reviews.llvm.org/D28766
llvm-svn: 292709
Use CHECK-NEXT to verify that a test breaks whenever unexpected passes,
analyses, or invalidations show up in default pipelines. The test case
is constructed so that we don't expect to invalidate anything, and needs
to be kept that way.
The test is slightly less strict than we'd like because of differences
in type pretty-printing.
(Right now it does show some invalidations - all of those are intentional
and temporary.)
Differential Revision: https://reviews.llvm.org/D28887
llvm-svn: 292536
Use CHECK-NEXT to verify that a test breaks whenever unexpected passes,
analyses, or invalidations show up in default pipelines. The test case
is constructed so that we don't expect to invalidate anything, and needs
to be kept that way.
(Right now it does show some invalidations - all of those are intentional
and temporary.)
Differential Revision: https://reviews.llvm.org/D28887
llvm-svn: 292530
Davide Italiano