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| author | Xuan Zhang <144393379+xuanzh-meta@users.noreply.github.com> | 2024-06-07 09:50:13 -0400 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2024-06-07 06:50:13 -0700 |
| commit | 3b16630c26505060a876f578e4b2ba701c780e9a (patch) | |
| tree | ce66ddefb69a4aca074a635c0547aeb65a4b6953 /llvm/lib/CodeGen/MachineOutliner.cpp | |
| parent | 2afea7296812b7e12c6ec683e6858bd4cbe8dd8d (diff) | |
| download | llvm-3b16630c26505060a876f578e4b2ba701c780e9a.zip llvm-3b16630c26505060a876f578e4b2ba701c780e9a.tar.gz llvm-3b16630c26505060a876f578e4b2ba701c780e9a.tar.bz2 | |
[MachineOutliner] Sort by Benefit to Cost Ratio (#90264)
This PR depends on https://github.com/llvm/llvm-project/pull/90260
We changed the order in which functions are outlined in Machine
Outliner.
The formula for priority is found via a black-box Bayesian optimization
toolbox. Using this formula for sorting consistently reduces the
uncompressed size of large real-world mobile apps. We also ran a few
benchmarks using LLVM test suites, and showed that sorting by priority
consistently reduces the text segment size.
|run (CTMark/) |baseline (1)|priority (2)|diff (1 -> 2)|
|----------------|------------|------------|-------------|
|lencod |349624 |349264 |-0.1030% |
|SPASS |219672 |219480 |-0.0874% |
|kc |271956 |251200 |-7.6321% |
|sqlite3 |223920 |223708 |-0.0947% |
|7zip-benchmark |405364 |402624 |-0.6759% |
|bullet |139820 |139500 |-0.2289% |
|consumer-typeset|295684 |290196 |-1.8560% |
|pairlocalalign |72236 |72092 |-0.1993% |
|tramp3d-v4 |189572 |189292 |-0.1477% |
This is part of an enhanced version of machine outliner -- see
[RFC](https://discourse.llvm.org/t/rfc-enhanced-machine-outliner-part-1-fulllto-part-2-thinlto-nolto-to-come/78732).
Diffstat (limited to 'llvm/lib/CodeGen/MachineOutliner.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/MachineOutliner.cpp | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/llvm/lib/CodeGen/MachineOutliner.cpp b/llvm/lib/CodeGen/MachineOutliner.cpp index 626e577..9e2e631 100644 --- a/llvm/lib/CodeGen/MachineOutliner.cpp +++ b/llvm/lib/CodeGen/MachineOutliner.cpp @@ -828,10 +828,12 @@ bool MachineOutliner::outline(Module &M, << "\n"); bool OutlinedSomething = false; - // Sort by benefit. The most beneficial functions should be outlined first. + // Sort by priority where priority := getNotOutlinedCost / getOutliningCost. + // The function with highest priority should be outlined first. stable_sort(FunctionList, [](const OutlinedFunction &LHS, const OutlinedFunction &RHS) { - return LHS.getBenefit() > RHS.getBenefit(); + return LHS.getNotOutlinedCost() * RHS.getOutliningCost() > + RHS.getNotOutlinedCost() * LHS.getOutliningCost(); }); // Walk over each function, outlining them as we go along. Functions are |