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| author | Serguei Katkov <serguei.katkov@azul.com> | 2017-08-09 05:17:02 +0000 |
|---|---|---|
| committer | Serguei Katkov <serguei.katkov@azul.com> | 2017-08-09 05:17:02 +0000 |
| commit | 6ea2e81cf64b4362a22e8a64a61d3c29709b0d9b (patch) | |
| tree | c54413b9a81288da6902b51a0f51ad79517d1fce /llvm/lib/CodeGen/ImplicitNullChecks.cpp | |
| parent | 2a77b266b5f9eed7c81c02e28f273814cee27d74 (diff) | |
| download | bcm5719-llvm-6ea2e81cf64b4362a22e8a64a61d3c29709b0d9b.tar.gz bcm5719-llvm-6ea2e81cf64b4362a22e8a64a61d3c29709b0d9b.zip | |
[ImplicitNullCheck] Fix the bug when dependent instruction accesses memory
It is possible that dependent instruction may access memory.
In this case we must reject optimization because the memory change will
be visible in null handler basic block. So we will execute an instruction which
we must not execute if check fails.
Reviewers: sanjoy, reames
Reviewed By: sanjoy
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D36392
llvm-svn: 310443
Diffstat (limited to 'llvm/lib/CodeGen/ImplicitNullChecks.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/ImplicitNullChecks.cpp | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/llvm/lib/CodeGen/ImplicitNullChecks.cpp b/llvm/lib/CodeGen/ImplicitNullChecks.cpp index e308f49ec4e..e3dcffe6bae 100644 --- a/llvm/lib/CodeGen/ImplicitNullChecks.cpp +++ b/llvm/lib/CodeGen/ImplicitNullChecks.cpp @@ -390,8 +390,10 @@ bool ImplicitNullChecks::canHoistInst(MachineInstr *FaultingMI, // We don't want to reason about speculating loads. Note -- at this point // we should have already filtered out all of the other non-speculatable // things, like calls and stores. + // We also do not want to hoist stores because it might change the memory + // while the FaultingMI may result in faulting. assert(canHandle(DependenceMI) && "Should never have reached here!"); - if (DependenceMI->mayLoad()) + if (DependenceMI->mayLoadOrStore()) return false; for (auto &DependenceMO : DependenceMI->operands()) { |
