When multiple loop transformation are defined in a loop's metadata, their order of execution is defined by the order of their respective passes in the pass pipeline. For instance, e.g.
#pragma clang loop unroll_and_jam(enable)
#pragma clang loop distribute(enable)
is the same as
#pragma clang loop distribute(enable)
#pragma clang loop unroll_and_jam(enable)
and will try to loop-distribute before Unroll-And-Jam because the LoopDistribute pass is scheduled after UnrollAndJam pass. UnrollAndJamPass only supports one inner loop, i.e. it will necessarily fail after loop distribution. It is not possible to specify another execution order. Also,t the order of passes in the pipeline is subject to change between versions of LLVM, optimization options and which pass manager is used.
This patch adds 'followup' attributes to various loop transformation passes. These attributes define which attributes the resulting loop of a transformation should have. For instance,
!0 = !{!0, !1, !2}
!1 = !{!"llvm.loop.unroll_and_jam.enable"}
!2 = !{!"llvm.loop.unroll_and_jam.followup_inner", !3}
!3 = !{!"llvm.loop.distribute.enable"}
defines a loop ID (!0) to be unrolled-and-jammed (!1) and then the attribute !3 to be added to the jammed inner loop, which contains the instruction to distribute the inner loop.
Currently, in both pass managers, pass execution is in a fixed order and UnrollAndJamPass will not execute again after LoopDistribute. We hope to fix this in the future by allowing pass managers to run passes until a fixpoint is reached, use Polly to perform these transformations, or add a loop transformation pass which takes the order issue into account.
For mandatory/forced transformations (e.g. by having been declared by #pragma omp simd), the user must be notified when a transformation could not be performed. It is not possible that the responsible pass emits such a warning because the transformation might be 'hidden' in a followup attribute when it is executed, or it is not present in the pipeline at all. For this reason, this patche introduces a WarnMissedTransformations pass, to warn about orphaned transformations.
Since this changes the user-visible diagnostic message when a transformation is applied, two test cases in the clang repository need to be updated.
To ensure that no other transformation is executed before the intended one, the attribute `llvm.loop.disable_nonforced` can be added which should disable transformation heuristics before the intended transformation is applied. E.g. it would be surprising if a loop is distributed before a #pragma unroll_and_jam is applied.
With more supported code transformations (loop fusion, interchange, stripmining, offloading, etc.), transformations can be used as building blocks for more complex transformations (e.g. stripmining+stripmining+interchange -> tiling).
Reviewed By: hfinkel, dmgreen
Differential Revision: https://reviews.llvm.org/D49281
Differential Revision: https://reviews.llvm.org/D55288
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@348944 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r342387 as it's showing significant performance
regressions in a number of benchmarks. Followed up with the
committer and original thread with an example and will get performance
numbers before recommitting.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@343522 91177308-0d34-0410-b5e6-96231b3b80d8
Rebase rL341954 since https://bugs.llvm.org/show_bug.cgi?id=38912
has been fixed by rL342055.
Precommit testing performed:
* Overnight runs of csmith comparing the output between programs
compiled with gvn-hoist enabled/disabled.
* Bootstrap builds of clang with UbSan/ASan configurations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@342387 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts rL341954.
The builder `sanitizer-x86_64-linux-bootstrap-ubsan` has been
failing with timeouts at stage2 clang/ubsan:
[3065/3073] Linking CXX executable bin/lld
command timed out: 1200 seconds without output running python
../sanitizer_buildbot/sanitizers/buildbot_selector.py,
attempting to kill
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@342001 91177308-0d34-0410-b5e6-96231b3b80d8
This version of the patch fixes cleaning up ssa_copy intrinsics, so it does not
crash for instructions in blocks that have been marked unreachable.
This patch updates IPSCCP to use PredicateInfo to propagate
facts to true branches predicated by EQ and to false branches
predicated by NE.
As a follow up, we should be able to extend it to also propagate additional
facts about nonnull.
Reviewers: davide, mssimpso, dberlin, efriedma
Reviewed By: davide, dberlin
Differential Revision: https://reviews.llvm.org/D45330
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@340525 91177308-0d34-0410-b5e6-96231b3b80d8
This is being done in order to make GVN able to better optimize certain inputs.
MemDep doesn't use PhiValues directly, but does need to notifiy it when things
get invalidated.
Differential Revision: https://reviews.llvm.org/D48489
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338384 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r338240 because it was causing OOMs on the UBSan
buildbot when building clang/lib/Sema/SemaChecking.cpp
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338297 91177308-0d34-0410-b5e6-96231b3b80d8
The combination of r338240 and r338242 causes the opt pass pipeline tests to
fail because of how r338242 makes BasicAA be invalidated more often. Adjust the
tests to reflect this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338250 91177308-0d34-0410-b5e6-96231b3b80d8
By using PhiValuesAnalysis we can get all the values reachable from a phi, so
we can be more precise instead of giving up when a phi has phi operands. We
can't make BaseicAA directly use PhiValuesAnalysis though, as the user of
BasicAA may modify the function in ways that PhiValuesAnalysis can't cope with.
For this optional usage to work correctly BasicAAWrapperPass now needs to be not
marked as CFG-only (i.e. it is now invalidated even when CFG is preserved) due
to how the legacy pass manager handles dependent passes being invalidated,
namely the depending pass still has a pointer to the now-dead dependent pass.
Differential Revision: https://reviews.llvm.org/D44564
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338242 91177308-0d34-0410-b5e6-96231b3b80d8
r337828 resolves a PredicateInfo issue with unnamed types.
Original message:
This patch updates IPSCCP to use PredicateInfo to propagate
facts to true branches predicated by EQ and to false branches
predicated by NE.
As a follow up, we should be able to extend it to also propagate additional
facts about nonnull.
Reviewers: davide, mssimpso, dberlin, efriedma
Reviewed By: davide, dberlin
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337904 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
PGOMemOPSize only modifies CFG in a couple of places; thus we can preserve the DominatorTree with little effort.
When optimizing SQLite with -O3, this patch can decrease 3.8% of the numbers of nodes traversed by DFS and 5.7% of the times DominatorTreeBase::recalculation is called.
Reviewers: kuhar, davide, dmgreen
Reviewed By: dmgreen
Subscribers: mzolotukhin, vsk, llvm-commits
Differential Revision: https://reviews.llvm.org/D48914
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336522 91177308-0d34-0410-b5e6-96231b3b80d8
This is the first pass in the main pipeline to use the legacy PM's
ability to run function analyses "on demand". Unfortunately, it turns
out there are bugs in that somewhat-hacky approach. At the very least,
it leaks memory and doesn't support -debug-pass=Structure. Unclear if
there are larger issues or not, but this should get the sanitizer bots
back to green by fixing the memory leaks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335320 91177308-0d34-0410-b5e6-96231b3b80d8
This wasn't obvious for the author to fix because this is the first
pipeline use of the magic utility to get function analyses within
a module pass in the lagecy pass manager. Turns out that has a bug which
prevents dumping the structure of the pipeline and shows up as an
unnamed pass.
I've just left a FIXME for that as it doesn't seem likely worth fixing
and certainly shouldn't hold up getting the bots green.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335314 91177308-0d34-0410-b5e6-96231b3b80d8
r335150 should resolve the issues with the clang-with-thin-lto-ubuntu
and clang-with-lto-ubuntu builders.
Original message:
This patch updates IPSCCP to use PredicateInfo to propagate
facts to true branches predicated by EQ and to false branches
predicated by NE.
As a follow up, we should be able to extend it to also propagate additional
facts about nonnull.
Reviewers: davide, mssimpso, dberlin, efriedma
Reviewed By: davide, dberlin
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335206 91177308-0d34-0410-b5e6-96231b3b80d8
This patch updates IPSCCP to use PredicateInfo to propagate
facts to true branches predicated by EQ and to false branches
predicated by NE.
As a follow up, we should be able to extend it to also propagate additional
facts about nonnull.
Reviewers: davide, mssimpso, dberlin, efriedma
Reviewed By: davide, dberlin
Differential Revision: https://reviews.llvm.org/D45330
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333740 91177308-0d34-0410-b5e6-96231b3b80d8
Reverting this to see if this is causing the failures of the
clang-with-thin-lto-ubuntu bot.
[IPSCCP] Use PredicateInfo to propagate facts from cmp instructions.
This patch updates IPSCCP to use PredicateInfo to propagate
facts to true branches predicated by EQ and to false branches
predicated by NE.
As a follow up, we should be able to extend it to also propagate additional
facts about nonnull.
Reviewers: davide, mssimpso, dberlin, efriedma
Reviewed By: davide, dberlin
Differential Revision: https://reviews.llvm.org/D45330
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333323 91177308-0d34-0410-b5e6-96231b3b80d8
This patch updates IPSCCP to use PredicateInfo to propagate
facts to true branches predicated by EQ and to false branches
predicated by NE.
As a follow up, we should be able to extend it to also propagate additional
facts about nonnull.
Reviewers: davide, mssimpso, dberlin, efriedma
Reviewed By: davide, dberlin
Differential Revision: https://reviews.llvm.org/D45330
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333268 91177308-0d34-0410-b5e6-96231b3b80d8
Michael Kruse