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| author | Jessica Paquette <jpaquette@apple.com> | 2018-09-20 21:53:25 +0000 |
|---|---|---|
| committer | Jessica Paquette <jpaquette@apple.com> | 2018-09-20 21:53:25 +0000 |
| commit | b320ca264216cb09d70927792f6f3d04bca7f58b (patch) | |
| tree | 5e2e1cd4f1ebc2eb0e9fe95712b37937f278689d /llvm/lib/CodeGen/MachineOutliner.cpp | |
| parent | a07166995667a86af8856d052671d3f2ef07fcb9 (diff) | |
| download | llvm-b320ca264216cb09d70927792f6f3d04bca7f58b.zip llvm-b320ca264216cb09d70927792f6f3d04bca7f58b.tar.gz llvm-b320ca264216cb09d70927792f6f3d04bca7f58b.tar.bz2 | |
[MachineOutliner][NFC] Don't add MBBs with a size < 2 to the search space
The suffix tree won't ever consider sequences with a length less than 2.
Therefore, we really ought to not even consider them in the first place.
Also add a FIXME explaining that this should be defined in terms of the size
in B of an outlined call versus the size in B of the MBB.
llvm-svn: 342688
Diffstat (limited to 'llvm/lib/CodeGen/MachineOutliner.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/MachineOutliner.cpp | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/llvm/lib/CodeGen/MachineOutliner.cpp b/llvm/lib/CodeGen/MachineOutliner.cpp index 5cefaf4..4b65d97 100644 --- a/llvm/lib/CodeGen/MachineOutliner.cpp +++ b/llvm/lib/CodeGen/MachineOutliner.cpp @@ -1386,7 +1386,11 @@ void MachineOutliner::populateMapper(InstructionMapper &Mapper, Module &M, for (MachineBasicBlock &MBB : *MF) { // If there isn't anything in MBB, then there's no point in outlining from // it. - if (MBB.empty()) + // If there are fewer than 2 instructions in the MBB, then it can't ever + // contain something worth outlining. + // FIXME: This should be based off of the maximum size in B of an outlined + // call versus the size in B of the MBB. + if (MBB.empty() || MBB.size() < 2) continue; // Check if MBB could be the target of an indirect branch. If it is, then |