From ab528fe0fb7caa96ce789bf872d7058aec8ae7c8 Mon Sep 17 00:00:00 2001 From: Owen Anderson Date: Sun, 30 Sep 2007 04:17:16 +0000 Subject: [PATCH] Template-ize more of the DomTree internal implementation details. Only the calculate() methods for DomTree and PostDomTree remain to be merged/template-ized. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@42476 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/Analysis/DominatorInternals.h | 135 +++++++++++++++++++- include/llvm/Analysis/Dominators.h | 13 +- lib/Analysis/PostDominatorCalculation.h | 7 +- lib/VMCore/DominatorCalculation.h | 6 +- lib/VMCore/DominatorInternals.cpp | 140 --------------------- 5 files changed, 145 insertions(+), 156 deletions(-) delete mode 100644 lib/VMCore/DominatorInternals.cpp diff --git a/include/llvm/Analysis/DominatorInternals.h b/include/llvm/Analysis/DominatorInternals.h index f84c8a60668..972a6d80462 100644 --- a/include/llvm/Analysis/DominatorInternals.h +++ b/include/llvm/Analysis/DominatorInternals.h @@ -6,17 +6,31 @@ // the University of Illinois Open Source License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// -// -// This file defines shared implementation details of dominator and -// postdominator calculation. This file SHOULD NOT BE INCLUDED outside -// of the dominator and postdominator implementation files. -// -//===----------------------------------------------------------------------===// #ifndef LLVM_ANALYSIS_DOMINATOR_INTERNALS_H #define LLVM_ANALYSIS_DOMINATOR_INTERNALS_H #include "llvm/Analysis/Dominators.h" +#include "llvm/ADT/DenseMap.h" +#include "llvm/ADT/SmallPtrSet.h" +//===----------------------------------------------------------------------===// +// +// DominatorTree construction - This pass constructs immediate dominator +// information for a flow-graph based on the algorithm described in this +// document: +// +// A Fast Algorithm for Finding Dominators in a Flowgraph +// T. Lengauer & R. Tarjan, ACM TOPLAS July 1979, pgs 121-141. +// +// This implements both the O(n*ack(n)) and the O(n*log(n)) versions of EVAL and +// LINK, but it turns out that the theoretically slower O(n*log(n)) +// implementation is actually faster than the "efficient" algorithm (even for +// large CFGs) because the constant overheads are substantially smaller. The +// lower-complexity version can be enabled with the following #define: +// +#define BALANCE_IDOM_TREE 0 +// +//===----------------------------------------------------------------------===// namespace llvm { @@ -85,6 +99,115 @@ unsigned DFSPass(DominatorTreeBase& DT, typename GraphT::NodeType* V, return N; } +template +void Compress(DominatorTreeBase& DT, typename GraphT::NodeType *VIn) { + std::vector Work; + SmallPtrSet Visited; + typename GraphT::NodeType* VInAncestor = DT.Info[VIn].Ancestor; + DominatorTreeBase::InfoRec &VInVAInfo = DT.Info[VInAncestor]; + + if (VInVAInfo.Ancestor != 0) + Work.push_back(VIn); + + while (!Work.empty()) { + typename GraphT::NodeType* V = Work.back(); + DominatorTree::InfoRec &VInfo = DT.Info[V]; + typename GraphT::NodeType* VAncestor = VInfo.Ancestor; + DominatorTreeBase::InfoRec &VAInfo = DT.Info[VAncestor]; + + // Process Ancestor first + if (Visited.insert(VAncestor) && + VAInfo.Ancestor != 0) { + Work.push_back(VAncestor); + continue; + } + Work.pop_back(); + + // Update VInfo based on Ancestor info + if (VAInfo.Ancestor == 0) + continue; + typename GraphT::NodeType* VAncestorLabel = VAInfo.Label; + typename GraphT::NodeType* VLabel = VInfo.Label; + if (DT.Info[VAncestorLabel].Semi < DT.Info[VLabel].Semi) + VInfo.Label = VAncestorLabel; + VInfo.Ancestor = VAInfo.Ancestor; + } +} + +template +typename GraphT::NodeType* Eval(DominatorTreeBase& DT, + typename GraphT::NodeType *V) { + DominatorTreeBase::InfoRec &VInfo = DT.Info[V]; +#if !BALANCE_IDOM_TREE + // Higher-complexity but faster implementation + if (VInfo.Ancestor == 0) + return V; + Compress(DT, V); + return VInfo.Label; +#else + // Lower-complexity but slower implementation + if (VInfo.Ancestor == 0) + return VInfo.Label; + Compress(DT, V); + GraphT::NodeType* VLabel = VInfo.Label; + + GraphT::NodeType* VAncestorLabel = DT.Info[VInfo.Ancestor].Label; + if (DT.Info[VAncestorLabel].Semi >= DT.Info[VLabel].Semi) + return VLabel; + else + return VAncestorLabel; +#endif +} + +template +void Link(DominatorTreeBase& DT, typename GraphT::NodeType* V, + typename GraphT::NodeType* W, DominatorTreeBase::InfoRec &WInfo) { +#if !BALANCE_IDOM_TREE + // Higher-complexity but faster implementation + WInfo.Ancestor = V; +#else + // Lower-complexity but slower implementation + GraphT::NodeType* WLabel = WInfo.Label; + unsigned WLabelSemi = DT.Info[WLabel].Semi; + GraphT::NodeType* S = W; + InfoRec *SInfo = &DT.Info[S]; + + GraphT::NodeType* SChild = SInfo->Child; + InfoRec *SChildInfo = &DT.Info[SChild]; + + while (WLabelSemi < DT.Info[SChildInfo->Label].Semi) { + GraphT::NodeType* SChildChild = SChildInfo->Child; + if (SInfo->Size+DT.Info[SChildChild].Size >= 2*SChildInfo->Size) { + SChildInfo->Ancestor = S; + SInfo->Child = SChild = SChildChild; + SChildInfo = &DT.Info[SChild]; + } else { + SChildInfo->Size = SInfo->Size; + S = SInfo->Ancestor = SChild; + SInfo = SChildInfo; + SChild = SChildChild; + SChildInfo = &DT.Info[SChild]; + } + } + + DominatorTreeBase::InfoRec &VInfo = DT.Info[V]; + SInfo->Label = WLabel; + + assert(V != W && "The optimization here will not work in this case!"); + unsigned WSize = WInfo.Size; + unsigned VSize = (VInfo.Size += WSize); + + if (VSize < 2*WSize) + std::swap(S, VInfo.Child); + + while (S) { + SInfo = &DT.Info[S]; + SInfo->Ancestor = V; + S = SInfo->Child; + } +#endif +} + } #endif diff --git a/include/llvm/Analysis/Dominators.h b/include/llvm/Analysis/Dominators.h index b14e6196a75..f16d16874f7 100644 --- a/include/llvm/Analysis/Dominators.h +++ b/include/llvm/Analysis/Dominators.h @@ -275,10 +275,15 @@ public: virtual void dump(); protected: - friend void Compress(DominatorTreeBase& DT, BasicBlock *VIn); - friend BasicBlock *Eval(DominatorTreeBase& DT, BasicBlock *V); - friend void Link(DominatorTreeBase& DT, BasicBlock *V, - BasicBlock *W, InfoRec &WInfo); + template friend void Compress(DominatorTreeBase& DT, + typename GraphT::NodeType* VIn); + template friend typename GraphT::NodeType* Eval( + DominatorTreeBase& DT, + typename GraphT::NodeType* V); + template friend void Link(DominatorTreeBase& DT, + typename GraphT::NodeType* V, + typename GraphT::NodeType* W, + InfoRec &WInfo); template friend unsigned DFSPass(DominatorTreeBase& DT, typename GraphT::NodeType* V, diff --git a/lib/Analysis/PostDominatorCalculation.h b/lib/Analysis/PostDominatorCalculation.h index c02bb33928c..5aa692eb37f 100644 --- a/lib/Analysis/PostDominatorCalculation.h +++ b/lib/Analysis/PostDominatorCalculation.h @@ -50,7 +50,8 @@ void PDTcalculate(PostDominatorTree& PDT, Function &F) { // Step #2: Calculate the semidominators of all vertices for (succ_iterator SI = succ_begin(W), SE = succ_end(W); SI != SE; ++SI) if (PDT.Info.count(*SI)) { // Only if this predecessor is reachable! - unsigned SemiU = PDT.Info[Eval(PDT, *SI)].Semi; + unsigned SemiU = + PDT.Info[Eval > >(PDT, *SI)].Semi; if (SemiU < WInfo.Semi) WInfo.Semi = SemiU; } @@ -58,14 +59,14 @@ void PDTcalculate(PostDominatorTree& PDT, Function &F) { PDT.Info[PDT.Vertex[WInfo.Semi]].Bucket.push_back(W); BasicBlock *WParent = WInfo.Parent; - Link(PDT, WParent, W, WInfo); + Link > >(PDT, WParent, W, WInfo); // Step #3: Implicitly define the immediate dominator of vertices std::vector &WParentBucket = PDT.Info[WParent].Bucket; while (!WParentBucket.empty()) { BasicBlock *V = WParentBucket.back(); WParentBucket.pop_back(); - BasicBlock *U = Eval(PDT, V); + BasicBlock *U = Eval > >(PDT, V); PDT.IDoms[V] = PDT.Info[U].Semi < PDT.Info[V].Semi ? U : WParent; } } diff --git a/lib/VMCore/DominatorCalculation.h b/lib/VMCore/DominatorCalculation.h index bf90a97a4ea..a9118d8063f 100644 --- a/lib/VMCore/DominatorCalculation.h +++ b/lib/VMCore/DominatorCalculation.h @@ -53,7 +53,7 @@ void DTcalculate(DominatorTree& DT, Function &F) { // Step #2: Calculate the semidominators of all vertices for (pred_iterator PI = pred_begin(W), E = pred_end(W); PI != E; ++PI) if (DT.Info.count(*PI)) { // Only if this predecessor is reachable! - unsigned SemiU = DT.Info[Eval(DT, *PI)].Semi; + unsigned SemiU = DT.Info[Eval >(DT, *PI)].Semi; if (SemiU < WInfo.Semi) WInfo.Semi = SemiU; } @@ -61,14 +61,14 @@ void DTcalculate(DominatorTree& DT, Function &F) { DT.Info[DT.Vertex[WInfo.Semi]].Bucket.push_back(W); BasicBlock *WParent = WInfo.Parent; - Link(DT, WParent, W, WInfo); + Link >(DT, WParent, W, WInfo); // Step #3: Implicitly define the immediate dominator of vertices std::vector &WParentBucket = DT.Info[WParent].Bucket; while (!WParentBucket.empty()) { BasicBlock *V = WParentBucket.back(); WParentBucket.pop_back(); - BasicBlock *U = Eval(DT, V); + BasicBlock *U = Eval >(DT, V); DT.IDoms[V] = DT.Info[U].Semi < DT.Info[V].Semi ? U : WParent; } } diff --git a/lib/VMCore/DominatorInternals.cpp b/lib/VMCore/DominatorInternals.cpp deleted file mode 100644 index abb87cd3818..00000000000 --- a/lib/VMCore/DominatorInternals.cpp +++ /dev/null @@ -1,140 +0,0 @@ -//==- DominatorInternals.cpp - Dominator Calculation -------------*- C++ -*-==// -// -// The LLVM Compiler Infrastructure -// -// This file was developed by Owen Anderson and is distributed under -// the University of Illinois Open Source License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// - -#include "llvm/Analysis/Dominators.h" -#include "llvm/ADT/DenseMap.h" -#include "llvm/ADT/SmallPtrSet.h" -//===----------------------------------------------------------------------===// -// -// DominatorTree construction - This pass constructs immediate dominator -// information for a flow-graph based on the algorithm described in this -// document: -// -// A Fast Algorithm for Finding Dominators in a Flowgraph -// T. Lengauer & R. Tarjan, ACM TOPLAS July 1979, pgs 121-141. -// -// This implements both the O(n*ack(n)) and the O(n*log(n)) versions of EVAL and -// LINK, but it turns out that the theoretically slower O(n*log(n)) -// implementation is actually faster than the "efficient" algorithm (even for -// large CFGs) because the constant overheads are substantially smaller. The -// lower-complexity version can be enabled with the following #define: -// -#define BALANCE_IDOM_TREE 0 -// -//===----------------------------------------------------------------------===// - -namespace llvm { - -void Compress(DominatorTreeBase& DT, BasicBlock *VIn) { - - std::vector Work; - SmallPtrSet Visited; - BasicBlock *VInAncestor = DT.Info[VIn].Ancestor; - DominatorTreeBase::InfoRec &VInVAInfo = DT.Info[VInAncestor]; - - if (VInVAInfo.Ancestor != 0) - Work.push_back(VIn); - - while (!Work.empty()) { - BasicBlock *V = Work.back(); - DominatorTree::InfoRec &VInfo = DT.Info[V]; - BasicBlock *VAncestor = VInfo.Ancestor; - DominatorTreeBase::InfoRec &VAInfo = DT.Info[VAncestor]; - - // Process Ancestor first - if (Visited.insert(VAncestor) && - VAInfo.Ancestor != 0) { - Work.push_back(VAncestor); - continue; - } - Work.pop_back(); - - // Update VInfo based on Ancestor info - if (VAInfo.Ancestor == 0) - continue; - BasicBlock *VAncestorLabel = VAInfo.Label; - BasicBlock *VLabel = VInfo.Label; - if (DT.Info[VAncestorLabel].Semi < DT.Info[VLabel].Semi) - VInfo.Label = VAncestorLabel; - VInfo.Ancestor = VAInfo.Ancestor; - } -} - -BasicBlock *Eval(DominatorTreeBase& DT, BasicBlock *V) { - DominatorTreeBase::InfoRec &VInfo = DT.Info[V]; -#if !BALANCE_IDOM_TREE - // Higher-complexity but faster implementation - if (VInfo.Ancestor == 0) - return V; - Compress(DT, V); - return VInfo.Label; -#else - // Lower-complexity but slower implementation - if (VInfo.Ancestor == 0) - return VInfo.Label; - Compress(DT, V); - BasicBlock *VLabel = VInfo.Label; - - BasicBlock *VAncestorLabel = DT.Info[VInfo.Ancestor].Label; - if (DT.Info[VAncestorLabel].Semi >= DT.Info[VLabel].Semi) - return VLabel; - else - return VAncestorLabel; -#endif -} - -void Link(DominatorTreeBase& DT, BasicBlock *V, BasicBlock *W, - DominatorTreeBase::InfoRec &WInfo) { -#if !BALANCE_IDOM_TREE - // Higher-complexity but faster implementation - WInfo.Ancestor = V; -#else - // Lower-complexity but slower implementation - BasicBlock *WLabel = WInfo.Label; - unsigned WLabelSemi = DT.Info[WLabel].Semi; - BasicBlock *S = W; - InfoRec *SInfo = &DT.Info[S]; - - BasicBlock *SChild = SInfo->Child; - InfoRec *SChildInfo = &DT.Info[SChild]; - - while (WLabelSemi < DT.Info[SChildInfo->Label].Semi) { - BasicBlock *SChildChild = SChildInfo->Child; - if (SInfo->Size+DT.Info[SChildChild].Size >= 2*SChildInfo->Size) { - SChildInfo->Ancestor = S; - SInfo->Child = SChild = SChildChild; - SChildInfo = &DT.Info[SChild]; - } else { - SChildInfo->Size = SInfo->Size; - S = SInfo->Ancestor = SChild; - SInfo = SChildInfo; - SChild = SChildChild; - SChildInfo = &DT.Info[SChild]; - } - } - - DominatorTreeBase::InfoRec &VInfo = DT.Info[V]; - SInfo->Label = WLabel; - - assert(V != W && "The optimization here will not work in this case!"); - unsigned WSize = WInfo.Size; - unsigned VSize = (VInfo.Size += WSize); - - if (VSize < 2*WSize) - std::swap(S, VInfo.Child); - - while (S) { - SInfo = &DT.Info[S]; - SInfo->Ancestor = V; - S = SInfo->Child; - } -#endif -} - -} -- 2.34.1