diff options
| -rw-r--r-- | llvm/include/llvm/Support/GenericDomTreeConstruction.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/llvm/include/llvm/Support/GenericDomTreeConstruction.h b/llvm/include/llvm/Support/GenericDomTreeConstruction.h index 103ff8ca476..977f209f92b 100644 --- a/llvm/include/llvm/Support/GenericDomTreeConstruction.h +++ b/llvm/include/llvm/Support/GenericDomTreeConstruction.h @@ -1186,6 +1186,20 @@ struct SemiNCAInfo { << '\t' << U << "\n"); LLVM_DEBUG(dbgs() << "\n"); + // Recalculate the DominatorTree when the number of updates + // exceeds a threshold, which usually makes direct updating slower than + // recalculation. We select this threshold proportional to the + // size of the DominatorTree. The constant is selected + // by choosing the one with an acceptable performance on some real-world + // inputs. + + // Make unittests of the incremental algorithm work + if (DT.DomTreeNodes.size() <= 100) { + if (NumLegalized > DT.DomTreeNodes.size()) + CalculateFromScratch(DT, &BUI); + } else if (NumLegalized > DT.DomTreeNodes.size() / 40) + CalculateFromScratch(DT, &BUI); + // If the DominatorTree was recalculated at some point, stop the batch // updates. Full recalculations ignore batch updates and look at the actual // CFG. |
