Not only should SafepointIRVerifier ignore unreachable blocks (as suggested in https://reviews.llvm.org/D47011) but it also has to ignore dead blocks.
In @test2 (see the new tests):
br i1 true, label %right, label %left
left:
...
right:
...
merge:
%val = phi i8 addrspace(1)* [ ..., %left ], [ ..., %right ]
use %val
both left and right branches are reachable.
If they collide then SafepointIRVerifier reports an error.
Because of the foldable branch condition GVN finds the left branch dead and removes the phi node entry that merges values from right and left. Then the use comes from the right branch. This results in no collision.
So, SafepointIRVerifier ends up in different results depending on either GVN is run or not.
To solve this issue this patch adds Dead Block detection to SafepointIRVerifier which can ignore dead blocks while validating IR. The Dead Block detection algorithm is taken from GVN but modified to not split critical edges. That is needed to keep CFG unchanged by SafepointIRVerifier.
Patch by Yevgeny Rouban.
Reviewed By: anna, apilipenko, DaniilSuchkov
Differential Revision: https://reviews.llvm.org/D47441
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335473 91177308-0d34-0410-b5e6-96231b3b80d8
SafepointIRVerifier crashed while traversing blocks without a DomTreeNode.
This could happen with a custom pipeline or when some optional passes were skipped by OptBisect.
SafepointIRVerifier is fixed to traverse basic blocks that are reachable from entry. Test are added.
Patch Author: Yevgeny Rouban!
Reviewers: anna, reames, dneilson, DaniilSuchkov, skatkov
Reviewed By: reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D47011
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333063 91177308-0d34-0410-b5e6-96231b3b80d8
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.
In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.
Differential Revision: https://reviews.llvm.org/D43624
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@332240 91177308-0d34-0410-b5e6-96231b3b80d8
PHI that has at least one unrelocated input cannot cause any issues by itself,
though its uses should be carefully verified. With this patch PHIs are allowed
to have any inputs but when all inputs are unrelocated the PHI is marked as
unrelocated and if not all inputs are unrelocated then the PHI is marked as
poisoned. Poisoned pointers can be used only in three ways: to derive new
pointers, in PHIs or in comparisons against constants that are exclusively
derived from null.
Patch by Daniil Suchkov!
Differential Revision: https://reviews.llvm.org/D41006
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@321438 91177308-0d34-0410-b5e6-96231b3b80d8
Now two classes are responsible for verification: one of them can track GC
pointers and know whether a pointer is relocated or not and another based on
that information can verify uses of GC pointers.
Patch Author: Daniil Suchkov
Reviewers: mkazantsev, anna, apilipenko
Reviewed By: mkazantsev
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D40885
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@320549 91177308-0d34-0410-b5e6-96231b3b80d8
Introduces usage of AvailableValueSet alias name instead of
DenseSet<const Value *> for better reading.
Patch Author: Daniil Suchkov
Reviewers: mkazantsev, anna, apilipenko
Reviewed By: anna
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D41002
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@320465 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This patch allows to use derived pointers (GEPs/bitcasts) of unrelocated
base pointers. We care only about the uses of these derived pointers.
It is acheived by two changes:
1. When we have enough information to say if the pointer is unrelocated at some
point or not, we walk all BBs to remove from their Contributions all valid defs
of unrelocated pointers (GEP with unrelocated base or bitcast of unrelocated
pointer).
2. When it comes to verification we just ignore instructions that were removed
at stage 1.
Patch by Daniil Suchkov!
Reviewers: anna, reames, apilipenko, mkazantsev
Reviewed By: anna, mkazantsev
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D40289
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319838 91177308-0d34-0410-b5e6-96231b3b80d8
Today the safepoint IR verifier catches some unrelocated uses of base
pointers that are actually valid.
With this change, we narrow down the set of false positives.
Specifically, the verifier knows about compares to null and compares
between 2 unrelocated pointers.
Reviewed by: skatkov
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D35057
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@307392 91177308-0d34-0410-b5e6-96231b3b80d8
Added a new Enum to identify if the base pointer is exclusively null or
exlusively some constant or not exclusively any constant.
Converted the base pointer identification method from recursive to
iterative form.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@307340 91177308-0d34-0410-b5e6-96231b3b80d8
Original Patch and summary by Philip Reames.
RewriteStatepointsForGC tries to rewrite a function in a manner where
the optimizer can't end up using a pointer value after it might have
been relocated by a safepoint. This pass checks the invariant that
RSForGC is supposed to establish and that (if we constructed semantics
correctly) later passes must preserve.
This has been a really useful diagnostic tool when initially developing
the rewriting scheme and has found numerous bugs.
Differential Revision: https://reviews.llvm.org/D15940
Reviewed by: swaroop.sridhar, mjacob
Subscribers: llvm-commits
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@307112 91177308-0d34-0410-b5e6-96231b3b80d8
