From: Chris Lattner Date: Sat, 12 Apr 2008 20:28:24 +0000 (+0000) Subject: Do an initial hack at replacing one of the incredibly inefficient X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=5c9dc5ac75de8d620311cdc20223998e0293d61f;p=clang Do an initial hack at replacing one of the incredibly inefficient (but simple!) datastructures in the rewriter with a more complex but more efficient one. This replaces the Deltas vector with a specialized BTree that makes delta lookups much more efficient. This speeds up -emit-html on a 500K .i file from 157.154 to 27.127 seconds on my machine (5.8x). While this code is functional, it isn't very pretty, I have much refactoring planned for it, and will remove the USE_VECTOR ifdef. Stay tuned. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@49586 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/clang.xcodeproj/project.pbxproj b/clang.xcodeproj/project.pbxproj index 1c7311d5fd..3ffb3a0877 100644 --- a/clang.xcodeproj/project.pbxproj +++ b/clang.xcodeproj/project.pbxproj @@ -457,6 +457,7 @@ DEF2F00F0C6CFED5000C4259 /* SemaChecking.cpp */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.cpp.cpp; name = SemaChecking.cpp; path = lib/Sema/SemaChecking.cpp; sourceTree = ""; }; DEF7D9F60C9C8B1A0001F598 /* Rewriter.h */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.c.h; name = Rewriter.h; path = clang/Rewrite/Rewriter.h; sourceTree = ""; }; DEF7D9F80C9C8B1D0001F598 /* Rewriter.cpp */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.cpp.cpp; name = Rewriter.cpp; path = lib/Rewrite/Rewriter.cpp; sourceTree = ""; }; + DEFFECA30DB093D100B4E7C3 /* DeltaTree.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = DeltaTree.h; path = clang/Rewrite/DeltaTree.h; sourceTree = ""; }; F0226FD00C18084500141F42 /* TextDiagnosticPrinter.cpp */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.cpp.cpp; name = TextDiagnosticPrinter.cpp; path = Driver/TextDiagnosticPrinter.cpp; sourceTree = ""; }; F0226FD10C18084500141F42 /* TextDiagnosticPrinter.h */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.c.h; name = TextDiagnosticPrinter.h; path = Driver/TextDiagnosticPrinter.h; sourceTree = ""; }; /* End PBXFileReference section */ @@ -890,6 +891,7 @@ DEF7D9F40C9C8B020001F598 /* Rewrite */ = { isa = PBXGroup; children = ( + DEFFECA30DB093D100B4E7C3 /* DeltaTree.h */, 35F2BE7B0DAC2963006E7668 /* HTMLRewrite.h */, DEF7D9F60C9C8B1A0001F598 /* Rewriter.h */, DE53370B0CE2D96F00D9A028 /* RewriteRope.h */, diff --git a/include/clang/Rewrite/DeltaTree.h b/include/clang/Rewrite/DeltaTree.h new file mode 100644 index 0000000000..7ad66d092c --- /dev/null +++ b/include/clang/Rewrite/DeltaTree.h @@ -0,0 +1,418 @@ +//===--- DeltaTree.h - B-Tree for Rewrite Delta tracking --------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file defines the DeltaTree class. +// +//===----------------------------------------------------------------------===// + +#ifndef CLANG_REWRITE_DELTATREE_H +#define CLANG_REWRITE_DELTATREE_H + +#include "llvm/Support/Casting.h" + +namespace clang { + using llvm::cast; + using llvm::dyn_cast; + class DeltaTreeInteriorNode; + + /// SourceDelta - As code in the original input buffer is added and deleted, + /// SourceDelta records are used to keep track of how the input SourceLocation + /// object is mapped into the output buffer. + struct SourceDelta { + unsigned FileLoc; + int Delta; + + static SourceDelta get(unsigned Loc, int D) { + SourceDelta Delta; + Delta.FileLoc = Loc; + Delta.Delta = D; + return Delta; + } + }; + + /// The DeltaTree class is a multiway search tree (BTree) structure with some + /// fancy features. B-Trees are are generally more memory and cache efficient + /// than binary trees, because they store multiple keys/values in each node. + /// + /// DeltaTree implements a key/value mapping from FileIndex to Delta, allowing + /// fast lookup by FileIndex. However, an added (important) bonus is that it + /// can also efficiently tell us the full accumulated delta for a specific + /// file offset as well, without traversing the whole tree. + /// + /// The nodes of the tree are made up of instances of two classes: + /// DeltaTreeNode and DeltaTreeInteriorNode. The later subclasses the + /// former and adds children pointers. Each node knows the full delta of all + /// entries (recursively) contained inside of it, which allows us to get the + /// full delta implied by a whole subtree in constant time. + + /// DeltaTreeNode - The common part of all nodes. + /// + class DeltaTreeNode { + friend class DeltaTreeInteriorNode; + + /// WidthFactor - This controls the number of K/V slots held in the BTree: + /// how wide it is. Each level of the BTree is guaranteed to have at least + /// WidthFactor-1 K/V pairs (unless the whole tree is less full than that) + /// and may have at most 2*WidthFactor-1 K/V pairs. + enum { WidthFactor = 8 }; + + /// Values - This tracks the SourceDelta's currently in this node. + /// + SourceDelta Values[2*WidthFactor-1]; + + /// NumValuesUsed - This tracks the number of values this node currently + /// holds. + unsigned char NumValuesUsed; + + /// IsLeaf - This is true if this is a leaf of the btree. If false, this is + /// an interior node, and is actually an instance of DeltaTreeInteriorNode. + bool IsLeaf; + + /// FullDelta - This is the full delta of all the values in this node and + /// all children nodes. + int FullDelta; + public: + DeltaTreeNode(bool isLeaf = true) + : NumValuesUsed(0), IsLeaf(isLeaf), FullDelta(0) {} + + bool isLeaf() const { return IsLeaf; } + int getFullDelta() const { return FullDelta; } + bool isFull() const { return NumValuesUsed == 2*WidthFactor-1; } + + unsigned getNumValuesUsed() const { return NumValuesUsed; } + const SourceDelta &getValue(unsigned i) const { + assert(i < NumValuesUsed && "Invalid value #"); + return Values[i]; + } + SourceDelta &getValue(unsigned i) { + assert(i < NumValuesUsed && "Invalid value #"); + return Values[i]; + } + + /// AddDeltaNonFull - Add a delta to this tree and/or it's children, knowing + /// that this node is not currently full. + void AddDeltaNonFull(unsigned FileIndex, int Delta); + + /// RecomputeFullDeltaLocally - Recompute the FullDelta field by doing a + /// local walk over our contained deltas. + void RecomputeFullDeltaLocally(); + + void Destroy(); + + static inline bool classof(const DeltaTreeNode *) { return true; } + }; + + /// DeltaTreeInteriorNode - When isLeaf = false, a node has child pointers. + /// This class tracks them. + class DeltaTreeInteriorNode : public DeltaTreeNode { + DeltaTreeNode *Children[2*WidthFactor]; + ~DeltaTreeInteriorNode() { + for (unsigned i = 0, e = NumValuesUsed+1; i != e; ++i) + Children[i]->Destroy(); + } + friend class DeltaTreeNode; + public: + DeltaTreeInteriorNode() : DeltaTreeNode(false /*nonleaf*/) {} + + DeltaTreeInteriorNode(DeltaTreeNode *FirstChild) + : DeltaTreeNode(false /*nonleaf*/) { + FullDelta = FirstChild->FullDelta; + Children[0] = FirstChild; + } + + const DeltaTreeNode *getChild(unsigned i) const { + assert(i < getNumValuesUsed()+1 && "Invalid child"); + return Children[i]; + } + DeltaTreeNode *getChild(unsigned i) { + assert(i < getNumValuesUsed()+1 && "Invalid child"); + return Children[i]; + } + + static inline bool classof(const DeltaTreeInteriorNode *) { return true; } + static inline bool classof(const DeltaTreeNode *N) { return !N->isLeaf(); } + private: + void SplitChild(unsigned ChildNo); + }; + + /// Destroy - A 'virtual' destructor. + inline void DeltaTreeNode::Destroy() { + if (isLeaf()) + delete this; + else + delete cast(this); + } + + /// RecomputeFullDeltaLocally - Recompute the FullDelta field by doing a + /// local walk over our contained deltas. + inline void DeltaTreeNode::RecomputeFullDeltaLocally() { + int NewFullDelta = 0; + for (unsigned i = 0, e = getNumValuesUsed(); i != e; ++i) + NewFullDelta += Values[i].Delta; + if (DeltaTreeInteriorNode *IN = dyn_cast(this)) + for (unsigned i = 0, e = getNumValuesUsed()+1; i != e; ++i) + NewFullDelta += IN->getChild(i)->getFullDelta(); + FullDelta = NewFullDelta; + } + + + /// AddDeltaNonFull - Add a delta to this tree and/or it's children, knowing + /// that this node is not currently full. + inline void DeltaTreeNode::AddDeltaNonFull(unsigned FileIndex, int Delta) { + assert(!isFull() && "AddDeltaNonFull on a full tree?"); + + // Maintain full delta for this node. + FullDelta += Delta; + + // Find the insertion point, the first delta whose index is >= FileIndex. + unsigned i = 0, e = getNumValuesUsed(); + while (i != e && FileIndex > getValue(i).FileLoc) + ++i; + + // If we found an a record for exactly this file index, just merge this + // value into the preexisting record and finish early. + if (i != e && getValue(i).FileLoc == FileIndex) { + // NOTE: Delta could drop to zero here. This means that the next delta + // entry is useless and could be removed. Supporting erases is + // significantly more complex though, so we just leave an entry with + // Delta=0 in the tree. + Values[i].Delta += Delta; + return; + } + + if (DeltaTreeInteriorNode *IN = dyn_cast(this)) { + // Insertion into an interior node propagates the value down to a child. + DeltaTreeNode *Child = IN->getChild(i); + + // If the child tree is full, split it, pulling an element up into our + // node. + if (Child->isFull()) { + IN->SplitChild(i); + SourceDelta &MedianVal = getValue(i); + + // If the median value we pulled up is exactly our insert position, add + // the delta and return. + if (MedianVal.FileLoc == FileIndex) { + MedianVal.Delta += Delta; + return; + } + + // If the median value pulled up is less than our current search point, + // include those deltas and search down the RHS now. + if (MedianVal.FileLoc < FileIndex) + Child = IN->getChild(i+1); + } + + Child->AddDeltaNonFull(FileIndex, Delta); + } else { + // For an insertion into a non-full leaf node, just insert the value in + // its sorted position. This requires moving later values over. + if (i != e) + memmove(&Values[i+1], &Values[i], sizeof(Values[0])*(e-i)); + Values[i] = SourceDelta::get(FileIndex, Delta); + ++NumValuesUsed; + } + } + + /// SplitChild - At this point, we know that the current node is not full and + /// that the specified child of this node is. Split the child in half at its + /// median, propagating one value up into us. Child may be either an interior + /// or leaf node. + inline void DeltaTreeInteriorNode::SplitChild(unsigned ChildNo) { + //printf("SplitChild: %p %d\n", (void*)this, ChildNo); + + DeltaTreeNode *Child = getChild(ChildNo); + assert(!isFull() && Child->isFull() && "Inconsistent constraints"); + + // Since the child is full, it contains 2*WidthFactor-1 values. We move + // the first 'WidthFactor-1' values to the LHS child (which we leave in the + // original child), propagate one value up into us, and move the last + // 'WidthFactor-1' values into thew RHS child. + + // Create the new child node. + DeltaTreeNode *NewNode; + if (DeltaTreeInteriorNode *CIN = dyn_cast(Child)) { + // If the child is an interior node, also move over 'WidthFactor' grand + // children into the new node. + NewNode = new DeltaTreeInteriorNode(); + memcpy(&((DeltaTreeInteriorNode*)NewNode)->Children[0], + &CIN->Children[WidthFactor], + WidthFactor*sizeof(CIN->Children[0])); + } else { + // Just create the child node. + NewNode = new DeltaTreeNode(); + } + + // Move over the last 'WidthFactor-1' values from Child to NewNode. + memcpy(&NewNode->Values[0], &Child->Values[WidthFactor], + (WidthFactor-1)*sizeof(Child->Values[0])); + + // Decrease the number of values in the two children. + NewNode->NumValuesUsed = Child->NumValuesUsed = WidthFactor-1; + + // Recompute the two children's full delta. Our delta hasn't changed, but + // their delta has. + NewNode->RecomputeFullDeltaLocally(); + Child->RecomputeFullDeltaLocally(); + + // Now that we have two nodes and a new element, insert the median value + // into ourself by moving all the later values/children down, then inserting + // the new one. + if (getNumValuesUsed() != ChildNo) + memmove(&Children[ChildNo+2], &Children[ChildNo+1], + (getNumValuesUsed()-ChildNo)*sizeof(Children[0])); + Children[ChildNo+1] = NewNode; + + if (getNumValuesUsed() != ChildNo) + memmove(&Values[ChildNo+1], &Values[ChildNo], + (getNumValuesUsed()-ChildNo)*sizeof(Values[0])); + Values[ChildNo] = Child->Values[WidthFactor-1]; + ++NumValuesUsed; + } + + + + /// DeltaTree - a multiway search tree (BTree) structure with some fancy + /// features. B-Trees are are generally more memory and cache efficient than + /// binary trees, because they store multiple keys/values in each node. This + /// implements a key/value mapping from index to delta, and allows fast lookup + /// on index. However, an added (important) bonus is that it can also + /// efficiently tell us the full accumulated delta for a specific file offset + /// as well, without traversing the whole tree. + class DeltaTree { + DeltaTreeNode *Root; + void operator=(const DeltaTree&); // DO NOT IMPLEMENT + public: + DeltaTree() { + Root = new DeltaTreeNode(); + } + DeltaTree(const DeltaTree &RHS) { + // Currently we only support copying when the RHS is empty. + assert(RHS.empty() && "Can only copy empty tree"); + Root = new DeltaTreeNode(); + } + + ~DeltaTree() { + Root->Destroy(); + } + + bool empty() const { + return Root->getNumValuesUsed() == 0; + } + + /// getDeltaAt - Return the accumulated delta at the specified file offset. + /// This includes all insertions or delections that occurred *before* the + /// specified file index. + int getDeltaAt(unsigned FileIndex) const { + const DeltaTreeNode *Node = Root; + + int Result = 0; + + // Walk down the tree. + while (1) { + // For all nodes, include any local deltas before the specified file + // index by summing them up directly. Keep track of how many were + // included. + unsigned NumValsGreater = 0; + for (unsigned e = Node->getNumValuesUsed(); NumValsGreater != e; + ++NumValsGreater) { + const SourceDelta &Val = Node->getValue(NumValsGreater); + + if (Val.FileLoc >= FileIndex) + break; + Result += Val.Delta; + } + + // If we have an interior node, include information about children and + // recurse. Otherwise, if we have a leaf, we're done. + const DeltaTreeInteriorNode *IN = dyn_cast(Node); + if (!IN) return Result; + + // Include any children to the left of the values we skipped, all of + // their deltas should be included as well. + for (unsigned i = 0; i != NumValsGreater; ++i) + Result += IN->getChild(i)->getFullDelta(); + + // If we found exactly the value we were looking for, break off the + // search early. There is no need to search the RHS of the value for + // partial results. + if (NumValsGreater != Node->getNumValuesUsed() && + Node->getValue(NumValsGreater).FileLoc == FileIndex) + return Result; + + // Otherwise, traverse down the tree. The selected subtree may be + // partially included in the range. + Node = IN->getChild(NumValsGreater); + } + // NOT REACHED. + } + + + /// AddDelta - When a change is made that shifts around the text buffer, + /// this method is used to record that info. It inserts a delta of 'Delta' + /// into the current DeltaTree at offset FileIndex. + void AddDelta(unsigned FileIndex, int Delta) { + assert(Delta && "Adding a noop?"); + //printf("Add: %d %d\n", FileIndex, Delta); + //if (FileIndex == 9251) + //printf("Here\n"); + + // If the root is full, create a new dummy (non-empty) interior node that + // points to it, allowing the old root to be split. + if (Root->isFull()) + Root = new DeltaTreeInteriorNode(Root); + + Root->AddDeltaNonFull(FileIndex, Delta); + + //VerifyTree(Root); + } + + void VerifyTree(const DeltaTreeNode *N) const { + const DeltaTreeInteriorNode *IN = dyn_cast(N); + if (IN == 0) { + // Verify leaves, just ensure that FullDelta matches up and the elements + // are in proper order. + int FullDelta = 0; + for (unsigned i = 0, e = N->getNumValuesUsed(); i != e; ++i) { + if (i) + assert(N->getValue(i-1).FileLoc < N->getValue(i).FileLoc); + FullDelta += N->getValue(i).Delta; + } + assert(FullDelta == N->getFullDelta()); + return; + } + + // Verify interior nodes: Ensure that FullDelta matches up and the + // elements are in proper order and the children are in proper order. + int FullDelta = 0; + for (unsigned i = 0, e = IN->getNumValuesUsed(); i != e; ++i) { + const SourceDelta &IVal = N->getValue(i); + const DeltaTreeNode *IChild = IN->getChild(i); + if (i) + assert(IN->getValue(i-1).FileLoc < IVal.FileLoc); + FullDelta += IVal.Delta; + FullDelta += IChild->getFullDelta(); + + // The largest value in child #i should be smaller than FileLoc. + assert(IChild->getValue(IChild->getNumValuesUsed()-1).FileLoc < + IVal.FileLoc); + + // The smallest value in child #i+1 should be larger than FileLoc. + assert(IN->getChild(i+1)->getValue(0).FileLoc > IVal.FileLoc); + VerifyTree(IChild); + } + + FullDelta += IN->getChild(IN->getNumValuesUsed())->getFullDelta(); + + assert(FullDelta == N->getFullDelta()); + } + }; +} // end namespace llvm + +#endif diff --git a/include/clang/Rewrite/Rewriter.h b/include/clang/Rewrite/Rewriter.h index 56befec7e8..e141c79fc3 100644 --- a/include/clang/Rewrite/Rewriter.h +++ b/include/clang/Rewrite/Rewriter.h @@ -21,28 +21,15 @@ #include #include #include +#include "clang/Rewrite/DeltaTree.h" + +//#define USE_VECTOR 1 namespace clang { class SourceManager; class Rewriter; class Stmt; -/// SourceDelta - As code in the original input buffer is added and deleted, -/// SourceDelta records are used to keep track of how the input SourceLocation -/// object is mapped into the output buffer. -struct SourceDelta { - unsigned FileLoc; - int Delta; - - static SourceDelta get(unsigned Loc, int D) { - SourceDelta Delta; - Delta.FileLoc = Loc; - Delta.Delta = D; - return Delta; - } -}; - - /// RewriteBuffer - As code is rewritten, SourceBuffer's from the original /// input with modifications get a new RewriteBuffer associated with them. The /// RewriteBuffer captures the modified text itself as well as information used @@ -51,9 +38,13 @@ struct SourceDelta { /// locations after the insertion point have to be mapped. class RewriteBuffer { friend class Rewriter; +#ifdef USE_VECTOR /// Deltas - Keep track of all the deltas in the source code due to insertions /// and deletions. These are kept in sorted order based on the FileLoc. std::vector Deltas; +#else + DeltaTree Deltas; +#endif /// Buffer - This is the actual buffer itself. Note that using a vector or /// string is a horribly inefficient way to do this, we should use a rope diff --git a/lib/Rewrite/Rewriter.cpp b/lib/Rewrite/Rewriter.cpp index 7b35cf1c59..e3c27eaad1 100644 --- a/lib/Rewrite/Rewriter.cpp +++ b/lib/Rewrite/Rewriter.cpp @@ -19,12 +19,16 @@ #include using namespace clang; + /// getMappedOffset - Given an offset into the original SourceBuffer that this /// RewriteBuffer is based on, map it into the offset space of the /// RewriteBuffer. unsigned RewriteBuffer::getMappedOffset(unsigned OrigOffset, bool AfterInserts) const { - unsigned ResultOffset = OrigOffset; + unsigned ResultOffset = 0; +#if !defined(USE_VECTOR) + ResultOffset += Deltas.getDeltaAt(OrigOffset+AfterInserts); +#else unsigned DeltaIdx = 0; // Move past any deltas that are relevant. @@ -37,13 +41,19 @@ unsigned RewriteBuffer::getMappedOffset(unsigned OrigOffset, for (; DeltaIdx != Deltas.size() && OrigOffset == Deltas[DeltaIdx].FileLoc; ++DeltaIdx) ResultOffset += Deltas[DeltaIdx].Delta; +#endif - return ResultOffset; + // printf("Map: %d/%d -> %d\n", OrigOffset, AfterInserts, ResultOffset); + return ResultOffset+OrigOffset; } /// AddDelta - When a change is made that shifts around the text buffer, this /// method is used to record that info. void RewriteBuffer::AddDelta(unsigned OrigOffset, int Change) { + // printf("AddDelta: %d/%d\n", OrigOffset, Change); +#if !defined(USE_VECTOR) + return Deltas.AddDelta(OrigOffset, Change); +#else assert(Change != 0 && "Not changing anything"); unsigned DeltaIdx = 0; @@ -82,6 +92,7 @@ void RewriteBuffer::AddDelta(unsigned OrigOffset, int Change) { // If it is now dead, remove it. if (Deltas[DeltaIdx].Delta == 0) Deltas.erase(Deltas.begin()+DeltaIdx); +#endif }