LoopInfo.h revision 45cfe545ec8177262dabc70580ce05feaa1c3880
1b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru//===- llvm/Analysis/LoopInfo.h - Natural Loop Calculator -------*- C++ -*-===// 2b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru// 3fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius// The LLVM Compiler Infrastructure 4b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru// 5b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru// This file is distributed under the University of Illinois Open Source 6b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru// License. See LICENSE.TXT for details. 7b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru// 8b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru//===----------------------------------------------------------------------===// 9c69afcec261fc345fda8daf46f0ea6b4351dc777Jean-Baptiste Queru// 10fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius// This file defines the LoopInfo class that is used to identify natural loops 11c69afcec261fc345fda8daf46f0ea6b4351dc777Jean-Baptiste Queru// and determine the loop depth of various nodes of the CFG. Note that natural 12c69afcec261fc345fda8daf46f0ea6b4351dc777Jean-Baptiste Queru// loops may actually be several loops that share the same header node. 13c69afcec261fc345fda8daf46f0ea6b4351dc777Jean-Baptiste Queru// 14b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru// This analysis calculates the nesting structure of loops in a function. For 15b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru// each natural loop identified, this analysis identifies natural loops 16b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru// contained entirely within the loop and the basic blocks the make up the loop. 17b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru// 18b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru// It can calculate on the fly various bits of information, for example: 19b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru// 20b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru// * whether there is a preheader for the loop 21b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru// * the number of back edges to the header 22b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru// * whether or not a particular block branches out of the loop 23b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru// * the successor blocks of the loop 24b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru// * the loop depth 25b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru// * the trip count 26b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru// * etc... 27b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru// 28b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru//===----------------------------------------------------------------------===// 29b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 30b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru#ifndef LLVM_ANALYSIS_LOOP_INFO_H 31b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru#define LLVM_ANALYSIS_LOOP_INFO_H 32b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 33b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru#include "llvm/Pass.h" 34b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru#include "llvm/ADT/DepthFirstIterator.h" 35b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru#include "llvm/ADT/GraphTraits.h" 36b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru#include "llvm/ADT/SmallVector.h" 37b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru#include "llvm/Analysis/Dominators.h" 38b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru#include "llvm/Support/CFG.h" 39b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru#include "llvm/Support/Streams.h" 40b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru#include <algorithm> 41b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru#include <ostream> 42b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 43b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Querunamespace llvm { 44b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 45b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Querutemplate<typename T> 46b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Querustatic void RemoveFromVector(std::vector<T*> &V, T *N) { 47b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru typename std::vector<T*>::iterator I = std::find(V.begin(), V.end(), N); 48b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru assert(I != V.end() && "N is not in this list!"); 49b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru V.erase(I); 50b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru} 51b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 52b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queruclass DominatorTree; 53b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queruclass LoopInfo; 54b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queruclass Loop; 55b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Querutemplate<class N, class M> class LoopInfoBase; 56b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Querutemplate<class N, class M> class LoopBase; 57fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 58b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru//===----------------------------------------------------------------------===// 59b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru/// LoopBase class - Instances of this class are used to represent loops that 60b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru/// are detected in the flow graph 61b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru/// 62b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Querutemplate<class BlockT, class LoopT> 63b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queruclass LoopBase { 64b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru LoopT *ParentLoop; 65b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // SubLoops - Loops contained entirely within this one. 66b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru std::vector<LoopT *> SubLoops; 67b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 68fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // Blocks - The list of blocks in this loop. First entry is the header node. 69fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius std::vector<BlockT*> Blocks; 70b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 71b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // DO NOT IMPLEMENT 72b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru LoopBase(const LoopBase<BlockT, LoopT> &); 73b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // DO NOT IMPLEMENT 74fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius const LoopBase<BlockT, LoopT>&operator=(const LoopBase<BlockT, LoopT> &); 75fceb39872958b9fa2505e63f8b8699a9e0f882f4ccorneliuspublic: 76fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// Loop ctor - This creates an empty loop. 77b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru LoopBase() : ParentLoop(0) {} 78b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru ~LoopBase() { 79b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru for (size_t i = 0, e = SubLoops.size(); i != e; ++i) 80b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru delete SubLoops[i]; 81b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 82b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 83b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// getLoopDepth - Return the nesting level of this loop. An outer-most 84b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// loop has depth 1, for consistency with loop depth values used for basic 85fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// blocks, where depth 0 is used for blocks not inside any loops. 86fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius unsigned getLoopDepth() const { 87fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius unsigned D = 1; 88fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius for (const LoopT *CurLoop = ParentLoop; CurLoop; 89fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius CurLoop = CurLoop->ParentLoop) 90b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru ++D; 91b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru return D; 92fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius } 93b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru BlockT *getHeader() const { return Blocks.front(); } 94b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru LoopT *getParentLoop() const { return ParentLoop; } 95b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 96b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// contains - Return true if the specified basic block is in this loop 97fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// 98b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru bool contains(const BlockT *BB) const { 99b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru return std::find(block_begin(), block_end(), BB) != block_end(); 100b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 101fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 102b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// iterator/begin/end - Return the loops contained entirely within this loop. 103b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// 104fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius const std::vector<LoopT *> &getSubLoops() const { return SubLoops; } 105fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius typedef typename std::vector<LoopT *>::const_iterator iterator; 106b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru iterator begin() const { return SubLoops.begin(); } 107b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru iterator end() const { return SubLoops.end(); } 108b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru bool empty() const { return SubLoops.empty(); } 109b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 110fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// getBlocks - Get a list of the basic blocks which make up this loop. 111b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// 112b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru const std::vector<BlockT*> &getBlocks() const { return Blocks; } 113b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru typedef typename std::vector<BlockT*>::const_iterator block_iterator; 114b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru block_iterator block_begin() const { return Blocks.begin(); } 115b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru block_iterator block_end() const { return Blocks.end(); } 116b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 117b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// isLoopExit - True if terminator in the block can branch to another block 118b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// that is outside of the current loop. 119b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// 120b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru bool isLoopExit(const BlockT *BB) const { 121b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru typedef GraphTraits<BlockT*> BlockTraits; 122b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru for (typename BlockTraits::ChildIteratorType SI = 123b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru BlockTraits::child_begin(const_cast<BlockT*>(BB)), 124b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru SE = BlockTraits::child_end(const_cast<BlockT*>(BB)); SI != SE; ++SI) { 125b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (!contains(*SI)) 126b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru return true; 127dbc22bd174be483711cea006f3189d8289835830ccornelius } 128b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru return false; 129b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 130b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 131b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// getNumBackEdges - Calculate the number of back edges to the loop header 132b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// 133b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru unsigned getNumBackEdges() const { 134b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru unsigned NumBackEdges = 0; 135b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru BlockT *H = getHeader(); 136b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 137b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru typedef GraphTraits<Inverse<BlockT*> > InvBlockTraits; 138b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru for (typename InvBlockTraits::ChildIteratorType I = 139b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru InvBlockTraits::child_begin(const_cast<BlockT*>(H)), 140b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru E = InvBlockTraits::child_end(const_cast<BlockT*>(H)); I != E; ++I) 141b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (contains(*I)) 142b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru ++NumBackEdges; 143b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 144b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru return NumBackEdges; 145b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 146b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 147b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru //===--------------------------------------------------------------------===// 148b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // APIs for simple analysis of the loop. 149b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // 150b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // Note that all of these methods can fail on general loops (ie, there may not 151b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // be a preheader, etc). For best success, the loop simplification and 152b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // induction variable canonicalization pass should be used to normalize loops 153dbc22bd174be483711cea006f3189d8289835830ccornelius // for easy analysis. These methods assume canonical loops. 154b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 155b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// getExitingBlocks - Return all blocks inside the loop that have successors 156b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// outside of the loop. These are the blocks _inside of the current loop_ 157b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// which branch out. The returned list is always unique. 158b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// 159b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru void getExitingBlocks(SmallVectorImpl<BlockT *> &ExitingBlocks) const { 160b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // Sort the blocks vector so that we can use binary search to do quick 161b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // lookups. 162b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru SmallVector<BlockT*, 128> LoopBBs(block_begin(), block_end()); 163fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius std::sort(LoopBBs.begin(), LoopBBs.end()); 164fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 165fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius typedef GraphTraits<BlockT*> BlockTraits; 166fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius for (block_iterator BI = block_begin(), BE = block_end(); BI != BE; ++BI) 167fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius for (typename BlockTraits::ChildIteratorType I = 168fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius BlockTraits::child_begin(*BI), E = BlockTraits::child_end(*BI); 169fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius I != E; ++I) 170fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius if (!std::binary_search(LoopBBs.begin(), LoopBBs.end(), *I)) { 171fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // Not in current loop? It must be an exit block. 172fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius ExitingBlocks.push_back(*BI); 173b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru break; 174b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 175b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 176b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 177b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// getExitingBlock - If getExitingBlocks would return exactly one block, 178b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// return that block. Otherwise return null. 179b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru BlockT *getExitingBlock() const { 180b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru SmallVector<BlockT*, 8> ExitingBlocks; 181b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru getExitingBlocks(ExitingBlocks); 182b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (ExitingBlocks.size() == 1) 183b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru return ExitingBlocks[0]; 184b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru return 0; 185fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius } 186b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 187b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// getExitBlocks - Return all of the successor blocks of this loop. These 188b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// are the blocks _outside of the current loop_ which are branched to. 189b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// 190fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius void getExitBlocks(SmallVectorImpl<BlockT*> &ExitBlocks) const { 191b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // Sort the blocks vector so that we can use binary search to do quick 192b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // lookups. 193b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru SmallVector<BlockT*, 128> LoopBBs(block_begin(), block_end()); 194b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru std::sort(LoopBBs.begin(), LoopBBs.end()); 195b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 196b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru typedef GraphTraits<BlockT*> BlockTraits; 197b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru for (block_iterator BI = block_begin(), BE = block_end(); BI != BE; ++BI) 198b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru for (typename BlockTraits::ChildIteratorType I = 199b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru BlockTraits::child_begin(*BI), E = BlockTraits::child_end(*BI); 200b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru I != E; ++I) 201b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (!std::binary_search(LoopBBs.begin(), LoopBBs.end(), *I)) 202b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // Not in current loop? It must be an exit block. 203b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru ExitBlocks.push_back(*I); 204b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 205b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 206b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// getExitBlock - If getExitBlocks would return exactly one block, 207b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// return that block. Otherwise return null. 208b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru BlockT *getExitBlock() const { 209b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru SmallVector<BlockT*, 8> ExitBlocks; 210fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius getExitBlocks(ExitBlocks); 211b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (ExitBlocks.size() == 1) 212b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru return ExitBlocks[0]; 213b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru return 0; 214b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 215b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 216b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// getExitEdges - Return all pairs of (_inside_block_,_outside_block_). 217b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// (Modelled after getExitingBlocks().) 218b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru typedef std::pair<const BlockT*,const BlockT*> Edge; 219b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru void getExitEdges(SmallVectorImpl<Edge> &ExitEdges) const { 220b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // Sort the blocks vector so that we can use binary search to do quick 221b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // lookups. 222b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru SmallVector<BlockT*, 128> LoopBBs(block_begin(), block_end()); 223b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru std::sort(LoopBBs.begin(), LoopBBs.end()); 22454dcd9b6a06071f647dac967e9e267abb9410720Craig Cornelius 22554dcd9b6a06071f647dac967e9e267abb9410720Craig Cornelius typedef GraphTraits<BlockT*> BlockTraits; 226b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru for (block_iterator BI = block_begin(), BE = block_end(); BI != BE; ++BI) 227b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru for (typename BlockTraits::ChildIteratorType I = 228b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru BlockTraits::child_begin(*BI), E = BlockTraits::child_end(*BI); 229b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru I != E; ++I) 230b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (!std::binary_search(LoopBBs.begin(), LoopBBs.end(), *I)) 231b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // Not in current loop? It must be an exit block. 232b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru ExitEdges.push_back(std::make_pair(*BI, *I)); 233b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 234b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 235b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// getUniqueExitBlocks - Return all unique successor blocks of this loop. 236b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// These are the blocks _outside of the current loop_ which are branched to. 237b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// This assumes that loop is in canonical form. 238b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// 239b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru void getUniqueExitBlocks(SmallVectorImpl<BlockT*> &ExitBlocks) const { 240b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // Sort the blocks vector so that we can use binary search to do quick 241b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // lookups. 242b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru SmallVector<BlockT*, 128> LoopBBs(block_begin(), block_end()); 243b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru std::sort(LoopBBs.begin(), LoopBBs.end()); 244b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 245b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru std::vector<BlockT*> switchExitBlocks; 246b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 247b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru for (block_iterator BI = block_begin(), BE = block_end(); BI != BE; ++BI) { 248b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 249b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru BlockT *current = *BI; 250b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru switchExitBlocks.clear(); 251b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 252b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru typedef GraphTraits<BlockT*> BlockTraits; 253b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru typedef GraphTraits<Inverse<BlockT*> > InvBlockTraits; 254b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru for (typename BlockTraits::ChildIteratorType I = 25554dcd9b6a06071f647dac967e9e267abb9410720Craig Cornelius BlockTraits::child_begin(*BI), E = BlockTraits::child_end(*BI); 25654dcd9b6a06071f647dac967e9e267abb9410720Craig Cornelius I != E; ++I) { 257b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (std::binary_search(LoopBBs.begin(), LoopBBs.end(), *I)) 258b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // If block is inside the loop then it is not a exit block. 259b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru continue; 260b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 261b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru typename InvBlockTraits::ChildIteratorType PI = 262b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru InvBlockTraits::child_begin(*I); 263b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru BlockT *firstPred = *PI; 264b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 265b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // If current basic block is this exit block's first predecessor 266b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // then only insert exit block in to the output ExitBlocks vector. 267b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // This ensures that same exit block is not inserted twice into 268b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // ExitBlocks vector. 269b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (current != firstPred) 270b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru continue; 271fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 272fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // If a terminator has more then two successors, for example SwitchInst, 273b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // then it is possible that there are multiple edges from current block 274b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // to one exit block. 275b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (std::distance(BlockTraits::child_begin(current), 276b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru BlockTraits::child_end(current)) <= 2) { 277b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru ExitBlocks.push_back(*I); 278b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru continue; 279b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 280b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 281b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // In case of multiple edges from current block to exit block, collect 282b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // only one edge in ExitBlocks. Use switchExitBlocks to keep track of 283b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // duplicate edges. 284b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (std::find(switchExitBlocks.begin(), switchExitBlocks.end(), *I) 285b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru == switchExitBlocks.end()) { 286b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru switchExitBlocks.push_back(*I); 287b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru ExitBlocks.push_back(*I); 288fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius } 289fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius } 290fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius } 291b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 292b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 293b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// getUniqueExitBlock - If getUniqueExitBlocks would return exactly one 294b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// block, return that block. Otherwise return null. 295b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru BlockT *getUniqueExitBlock() const { 296b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru SmallVector<BlockT*, 8> UniqueExitBlocks; 297b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru getUniqueExitBlocks(UniqueExitBlocks); 298b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (UniqueExitBlocks.size() == 1) 299b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru return UniqueExitBlocks[0]; 300b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru return 0; 301b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 302b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 303b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// getLoopPreheader - If there is a preheader for this loop, return it. A 304b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// loop has a preheader if there is only one edge to the header of the loop 305b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// from outside of the loop. If this is the case, the block branching to the 306b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// header of the loop is the preheader node. 307b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// 308b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// This method returns null if there is no preheader for the loop. 309fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// 310fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius BlockT *getLoopPreheader() const { 311b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // Keep track of nodes outside the loop branching to the header... 312b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru BlockT *Out = 0; 313b0ac937921a2c196d8b9da665135bf6ba01a1ccfJean-Baptiste Queru 314b0ac937921a2c196d8b9da665135bf6ba01a1ccfJean-Baptiste Queru // Loop over the predecessors of the header node... 315b0ac937921a2c196d8b9da665135bf6ba01a1ccfJean-Baptiste Queru BlockT *Header = getHeader(); 316b0ac937921a2c196d8b9da665135bf6ba01a1ccfJean-Baptiste Queru typedef GraphTraits<BlockT*> BlockTraits; 317b0ac937921a2c196d8b9da665135bf6ba01a1ccfJean-Baptiste Queru typedef GraphTraits<Inverse<BlockT*> > InvBlockTraits; 318b0ac937921a2c196d8b9da665135bf6ba01a1ccfJean-Baptiste Queru for (typename InvBlockTraits::ChildIteratorType PI = 319b0ac937921a2c196d8b9da665135bf6ba01a1ccfJean-Baptiste Queru InvBlockTraits::child_begin(Header), 320b0ac937921a2c196d8b9da665135bf6ba01a1ccfJean-Baptiste Queru PE = InvBlockTraits::child_end(Header); PI != PE; ++PI) 32150294ead5e5d23f5bbfed76e00e6b510bd41eee1claireho if (!contains(*PI)) { // If the block is not in the loop... 322b0ac937921a2c196d8b9da665135bf6ba01a1ccfJean-Baptiste Queru if (Out && Out != *PI) 323b0ac937921a2c196d8b9da665135bf6ba01a1ccfJean-Baptiste Queru return 0; // Multiple predecessors outside the loop 324b0ac937921a2c196d8b9da665135bf6ba01a1ccfJean-Baptiste Queru Out = *PI; 325b0ac937921a2c196d8b9da665135bf6ba01a1ccfJean-Baptiste Queru } 326b0ac937921a2c196d8b9da665135bf6ba01a1ccfJean-Baptiste Queru 327b0ac937921a2c196d8b9da665135bf6ba01a1ccfJean-Baptiste Queru // Make sure there is only one exit out of the preheader. 328fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius assert(Out && "Header of loop has no predecessors from outside loop?"); 329fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius typename BlockTraits::ChildIteratorType SI = BlockTraits::child_begin(Out); 330fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius ++SI; 331fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius if (SI != BlockTraits::child_end(Out)) 332fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius return 0; // Multiple exits from the block, must not be a preheader. 333fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 334fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // If there is exactly one preheader, return it. If there was zero, then 335fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // Out is still null. 336fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius return Out; 337fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius } 338fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 339fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// getLoopLatch - If there is a single latch block for this loop, return it. 340fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// A latch block is a block that contains a branch back to the header. 341fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// A loop header in normal form has two edges into it: one from a preheader 342fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// and one from a latch block. 343fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius BlockT *getLoopLatch() const { 344fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius BlockT *Header = getHeader(); 345b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru typedef GraphTraits<Inverse<BlockT*> > InvBlockTraits; 346b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru typename InvBlockTraits::ChildIteratorType PI = 347b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru InvBlockTraits::child_begin(Header); 348b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru typename InvBlockTraits::ChildIteratorType PE = 349b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru InvBlockTraits::child_end(Header); 350b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (PI == PE) return 0; // no preds? 351b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 352b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru BlockT *Latch = 0; 353b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (contains(*PI)) 35454dcd9b6a06071f647dac967e9e267abb9410720Craig Cornelius Latch = *PI; 355b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru ++PI; 356b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (PI == PE) return 0; // only one pred? 357b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 358b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (contains(*PI)) { 359b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (Latch) return 0; // multiple backedges 360b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru Latch = *PI; 361b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 362b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru ++PI; 363b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (PI != PE) return 0; // more than two preds 364b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 365b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru return Latch; 366b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 367b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 368b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru //===--------------------------------------------------------------------===// 369b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // APIs for updating loop information after changing the CFG 370b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // 37154dcd9b6a06071f647dac967e9e267abb9410720Craig Cornelius 372b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// addBasicBlockToLoop - This method is used by other analyses to update loop 373b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// information. NewBB is set to be a new member of the current loop. 374b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// Because of this, it is added as a member of all parent loops, and is added 375b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// to the specified LoopInfo object as being in the current basic block. It 376b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// is not valid to replace the loop header with this method. 377b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// 378b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru void addBasicBlockToLoop(BlockT *NewBB, LoopInfoBase<BlockT, LoopT> &LI); 379b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 380b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// replaceChildLoopWith - This is used when splitting loops up. It replaces 381b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// the OldChild entry in our children list with NewChild, and updates the 382b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// parent pointer of OldChild to be null and the NewChild to be this loop. 383fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// This updates the loop depth of the new child. 384b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru void replaceChildLoopWith(LoopT *OldChild, 385b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru LoopT *NewChild) { 386b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru assert(OldChild->ParentLoop == this && "This loop is already broken!"); 387b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru assert(NewChild->ParentLoop == 0 && "NewChild already has a parent!"); 388b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru typename std::vector<LoopT *>::iterator I = 389b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru std::find(SubLoops.begin(), SubLoops.end(), OldChild); 390b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru assert(I != SubLoops.end() && "OldChild not in loop!"); 391b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru *I = NewChild; 392b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru OldChild->ParentLoop = 0; 393b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru NewChild->ParentLoop = static_cast<LoopT *>(this); 394b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 39554dcd9b6a06071f647dac967e9e267abb9410720Craig Cornelius 396b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// addChildLoop - Add the specified loop to be a child of this loop. This 397b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// updates the loop depth of the new child. 39854dcd9b6a06071f647dac967e9e267abb9410720Craig Cornelius /// 39954dcd9b6a06071f647dac967e9e267abb9410720Craig Cornelius void addChildLoop(LoopT *NewChild) { 400b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru assert(NewChild->ParentLoop == 0 && "NewChild already has a parent!"); 401b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru NewChild->ParentLoop = static_cast<LoopT *>(this); 402fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius SubLoops.push_back(NewChild); 403b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 404b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 405b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// removeChildLoop - This removes the specified child from being a subloop of 406b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// this loop. The loop is not deleted, as it will presumably be inserted 407b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// into another loop. 408b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru LoopT *removeChildLoop(iterator I) { 409b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru assert(I != SubLoops.end() && "Cannot remove end iterator!"); 410b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru LoopT *Child = *I; 4118393335b955da7340c9f19b1b4b2d6c0c2c04be7Craig Cornelius assert(Child->ParentLoop == this && "Child is not a child of this loop!"); 412b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru SubLoops.erase(SubLoops.begin()+(I-begin())); 4138393335b955da7340c9f19b1b4b2d6c0c2c04be7Craig Cornelius Child->ParentLoop = 0; 414b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru return Child; 4158393335b955da7340c9f19b1b4b2d6c0c2c04be7Craig Cornelius } 4168393335b955da7340c9f19b1b4b2d6c0c2c04be7Craig Cornelius 4178393335b955da7340c9f19b1b4b2d6c0c2c04be7Craig Cornelius /// addBlockEntry - This adds a basic block directly to the basic block list. 4188393335b955da7340c9f19b1b4b2d6c0c2c04be7Craig Cornelius /// This should only be used by transformations that create new loops. Other 4198393335b955da7340c9f19b1b4b2d6c0c2c04be7Craig Cornelius /// transformations should use addBasicBlockToLoop. 4208393335b955da7340c9f19b1b4b2d6c0c2c04be7Craig Cornelius void addBlockEntry(BlockT *BB) { 4218393335b955da7340c9f19b1b4b2d6c0c2c04be7Craig Cornelius Blocks.push_back(BB); 422b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 4238393335b955da7340c9f19b1b4b2d6c0c2c04be7Craig Cornelius 424b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// moveToHeader - This method is used to move BB (which must be part of this 425b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// loop) to be the loop header of the loop (the block that dominates all 4268393335b955da7340c9f19b1b4b2d6c0c2c04be7Craig Cornelius /// others). 427b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru void moveToHeader(BlockT *BB) { 428b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (Blocks[0] == BB) return; 4298393335b955da7340c9f19b1b4b2d6c0c2c04be7Craig Cornelius for (unsigned i = 0; ; ++i) { 430b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru assert(i != Blocks.size() && "Loop does not contain BB!"); 431b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (Blocks[i] == BB) { 432b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru Blocks[i] = Blocks[0]; 433b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru Blocks[0] = BB; 434b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru return; 435b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 436b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 437b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 438b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 439b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// removeBlockFromLoop - This removes the specified basic block from the 440b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// current loop, updating the Blocks as appropriate. This does not update 441b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// the mapping in the LoopInfo class. 442b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru void removeBlockFromLoop(BlockT *BB) { 443b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru RemoveFromVector(Blocks, BB); 444b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 445b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 446b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// verifyLoop - Verify loop structure 447b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru void verifyLoop() const { 448b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru#ifndef NDEBUG 449b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru assert (getHeader() && "Loop header is missing"); 450b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru assert (getLoopPreheader() && "Loop preheader is missing"); 451b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru assert (getLoopLatch() && "Loop latch is missing"); 452b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru for (iterator I = SubLoops.begin(), E = SubLoops.end(); I != E; ++I) 453b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru (*I)->verifyLoop(); 454b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru#endif 455b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 45659d709d503bab6e2b61931737e662dd293b40578ccornelius 457b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru void print(raw_ostream &OS, unsigned Depth = 0) const { 45859d709d503bab6e2b61931737e662dd293b40578ccornelius OS.indent(Depth*2) << "Loop at depth " << getLoopDepth() 45959d709d503bab6e2b61931737e662dd293b40578ccornelius << " containing: "; 46059d709d503bab6e2b61931737e662dd293b40578ccornelius 46159d709d503bab6e2b61931737e662dd293b40578ccornelius for (unsigned i = 0; i < getBlocks().size(); ++i) { 462b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (i) OS << ","; 463b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru BlockT *BB = getBlocks()[i]; 464b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru WriteAsOperand(OS, BB, false); 46559d709d503bab6e2b61931737e662dd293b40578ccornelius if (BB == getHeader()) OS << "<header>"; 466b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (BB == getLoopLatch()) OS << "<latch>"; 467fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius if (isLoopExit(BB)) OS << "<exit>"; 46859d709d503bab6e2b61931737e662dd293b40578ccornelius } 469b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru OS << "\n"; 470b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 471b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru for (iterator I = begin(), E = end(); I != E; ++I) 472b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru (*I)->print(OS, Depth+2); 473b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 474b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 475b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru void dump() const { 476b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru print(errs()); 477b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 478b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 479b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queruprotected: 480fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius friend class LoopInfoBase<BlockT, LoopT>; 481b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru explicit LoopBase(BlockT *BB) : ParentLoop(0) { 482b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru Blocks.push_back(BB); 483b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 484b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru}; 48554dcd9b6a06071f647dac967e9e267abb9410720Craig Cornelius 48654dcd9b6a06071f647dac967e9e267abb9410720Craig Corneliusclass Loop : public LoopBase<BasicBlock, Loop> { 48754dcd9b6a06071f647dac967e9e267abb9410720Craig Corneliuspublic: 488b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru Loop() {} 489b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 490b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// isLoopInvariant - Return true if the specified value is loop invariant 49154dcd9b6a06071f647dac967e9e267abb9410720Craig Cornelius /// 492b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru bool isLoopInvariant(Value *V) const; 493fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 494b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// isLoopInvariant - Return true if the specified instruction is 495b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// loop-invariant. 496b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// 497b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru bool isLoopInvariant(Instruction *I) const; 498b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 499b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// makeLoopInvariant - If the given value is an instruction inside of the 500b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// loop and it can be hoisted, do so to make it trivially loop-invariant. 501b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// Return true if the value after any hoisting is loop invariant. This 502b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// function can be used as a slightly more aggressive replacement for 503b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// isLoopInvariant. 504b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// 505b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// If InsertPt is specified, it is the point to hoist instructions to. 506b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// If null, the terminator of the loop preheader is used. 507b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// 508b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru bool makeLoopInvariant(Value *V, bool &Changed, 509b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru Instruction *InsertPt = 0) const; 510b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 511b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// makeLoopInvariant - If the given instruction is inside of the 512b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// loop and it can be hoisted, do so to make it trivially loop-invariant. 51354dcd9b6a06071f647dac967e9e267abb9410720Craig Cornelius /// Return true if the instruction after any hoisting is loop invariant. This 514b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// function can be used as a slightly more aggressive replacement for 515b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// isLoopInvariant. 516fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// 517fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// If InsertPt is specified, it is the point to hoist instructions to. 518fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// If null, the terminator of the loop preheader is used. 519fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// 520fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius bool makeLoopInvariant(Instruction *I, bool &Changed, 521fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius Instruction *InsertPt = 0) const; 522fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 523fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// getCanonicalInductionVariable - Check to see if the loop has a canonical 524fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// induction variable: an integer recurrence that starts at 0 and increments 525fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// by one each time through the loop. If so, return the phi node that 526fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// corresponds to it. 527fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// 528fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// The IndVarSimplify pass transforms loops to have a canonical induction 529fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// variable. 530fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// 531fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius PHINode *getCanonicalInductionVariable() const; 532fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 533fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// getCanonicalInductionVariableIncrement - Return the LLVM value that holds 534fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// the canonical induction variable value for the "next" iteration of the 535fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// loop. This always succeeds if getCanonicalInductionVariable succeeds. 536fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// 537fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius Instruction *getCanonicalInductionVariableIncrement() const; 538fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 539fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// getTripCount - Return a loop-invariant LLVM value indicating the number of 540fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// times the loop will be executed. Note that this means that the backedge 541fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// of the loop executes N-1 times. If the trip-count cannot be determined, 542fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// this returns null. 543fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// 544fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// The IndVarSimplify pass transforms loops to have a form that this 545fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// function easily understands. 546fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// 547fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius Value *getTripCount() const; 548b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 549b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// getSmallConstantTripCount - Returns the trip count of this loop as a 550b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// normal unsigned value, if possible. Returns 0 if the trip count is unknown 551fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// of not constant. Will also return 0 if the trip count is very large 552fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// (>= 2^32) 553fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius unsigned getSmallConstantTripCount() const; 554fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 555fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// getSmallConstantTripMultiple - Returns the largest constant divisor of the 556b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// trip count of this loop as a normal unsigned value, if possible. This 557b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// means that the actual trip count is always a multiple of the returned 558b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// value (don't forget the trip count could very well be zero as well!). 559b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// 560fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// Returns 1 if the trip count is unknown or not guaranteed to be the 561fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// multiple of a constant (which is also the case if the trip count is simply 562fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// constant, use getSmallConstantTripCount for that case), Will also return 1 563fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// if the trip count is very large (>= 2^32). 564fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius unsigned getSmallConstantTripMultiple() const; 565fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 566fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// isLCSSAForm - Return true if the Loop is in LCSSA form 567b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru bool isLCSSAForm() const; 568fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 569fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// isLoopSimplifyForm - Return true if the Loop is in the form that 570fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// the LoopSimplify form transforms loops to, which is sometimes called 571fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// normal form. 572fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius bool isLoopSimplifyForm() const; 573b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 57454dcd9b6a06071f647dac967e9e267abb9410720Craig Corneliusprivate: 575b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru friend class LoopInfoBase<BasicBlock, Loop>; 576b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru explicit Loop(BasicBlock *BB) : LoopBase<BasicBlock, Loop>(BB) {} 577fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius}; 578fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 579fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius//===----------------------------------------------------------------------===// 580fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius/// LoopInfo - This class builds and contains all of the top level loop 581fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius/// structures in the specified function. 582fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius/// 583fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 584fceb39872958b9fa2505e63f8b8699a9e0f882f4ccorneliustemplate<class BlockT, class LoopT> 585fceb39872958b9fa2505e63f8b8699a9e0f882f4ccorneliusclass LoopInfoBase { 586b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // BBMap - Mapping of basic blocks to the inner most loop they occur in 58754dcd9b6a06071f647dac967e9e267abb9410720Craig Cornelius std::map<BlockT *, LoopT *> BBMap; 588b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru std::vector<LoopT *> TopLevelLoops; 589b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru friend class LoopBase<BlockT, LoopT>; 590b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 591b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru void operator=(const LoopInfoBase &); // do not implement 592fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius LoopInfoBase(const LoopInfo &); // do not implement 593fceb39872958b9fa2505e63f8b8699a9e0f882f4ccorneliuspublic: 594b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru LoopInfoBase() { } 595b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru ~LoopInfoBase() { releaseMemory(); } 596b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 597b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru void releaseMemory() { 598b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru for (typename std::vector<LoopT *>::iterator I = 599fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius TopLevelLoops.begin(), E = TopLevelLoops.end(); I != E; ++I) 600b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru delete *I; // Delete all of the loops... 601b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 602b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru BBMap.clear(); // Reset internal state of analysis 603b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru TopLevelLoops.clear(); 604fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius } 605b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 606b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// iterator/begin/end - The interface to the top-level loops in the current 607b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// function. 608b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// 609b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru typedef typename std::vector<LoopT *>::const_iterator iterator; 610fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius iterator begin() const { return TopLevelLoops.begin(); } 611b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru iterator end() const { return TopLevelLoops.end(); } 612b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru bool empty() const { return TopLevelLoops.empty(); } 613b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 614b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// getLoopFor - Return the inner most loop that BB lives in. If a basic 615b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// block is in no loop (for example the entry node), null is returned. 616b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// 617b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru LoopT *getLoopFor(const BlockT *BB) const { 618b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru typename std::map<BlockT *, LoopT *>::const_iterator I= 619b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru BBMap.find(const_cast<BlockT*>(BB)); 620b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru return I != BBMap.end() ? I->second : 0; 621b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 622b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 623fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// operator[] - same as getLoopFor... 624b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// 625b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru const LoopT *operator[](const BlockT *BB) const { 626b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru return getLoopFor(BB); 627b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 628b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 629b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// getLoopDepth - Return the loop nesting level of the specified block. A 630b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// depth of 0 means the block is not inside any loop. 631b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// 632b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru unsigned getLoopDepth(const BlockT *BB) const { 633b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru const LoopT *L = getLoopFor(BB); 634b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru return L ? L->getLoopDepth() : 0; 635b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 636b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 637b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // isLoopHeader - True if the block is a loop header node 638b26ce3a7367e4ed2ee7ddddcdc3f3d3377a455c2claireho bool isLoopHeader(BlockT *BB) const { 63927f654740f2a26ad62a5c155af9199af9e69b889claireho const LoopT *L = getLoopFor(BB); 640b26ce3a7367e4ed2ee7ddddcdc3f3d3377a455c2claireho return L && L->getHeader() == BB; 641b26ce3a7367e4ed2ee7ddddcdc3f3d3377a455c2claireho } 642b26ce3a7367e4ed2ee7ddddcdc3f3d3377a455c2claireho 643b26ce3a7367e4ed2ee7ddddcdc3f3d3377a455c2claireho /// removeLoop - This removes the specified top-level loop from this loop info 644b26ce3a7367e4ed2ee7ddddcdc3f3d3377a455c2claireho /// object. The loop is not deleted, as it will presumably be inserted into 645b26ce3a7367e4ed2ee7ddddcdc3f3d3377a455c2claireho /// another loop. 646b26ce3a7367e4ed2ee7ddddcdc3f3d3377a455c2claireho LoopT *removeLoop(iterator I) { 647b26ce3a7367e4ed2ee7ddddcdc3f3d3377a455c2claireho assert(I != end() && "Cannot remove end iterator!"); 648103e9ffba2cba345d0078eb8b8db33249f81840aCraig Cornelius LoopT *L = *I; 64927f654740f2a26ad62a5c155af9199af9e69b889claireho assert(L->getParentLoop() == 0 && "Not a top-level loop!"); 65054dcd9b6a06071f647dac967e9e267abb9410720Craig Cornelius TopLevelLoops.erase(TopLevelLoops.begin() + (I-begin())); 65154dcd9b6a06071f647dac967e9e267abb9410720Craig Cornelius return L; 65254dcd9b6a06071f647dac967e9e267abb9410720Craig Cornelius } 65327f654740f2a26ad62a5c155af9199af9e69b889claireho 65427f654740f2a26ad62a5c155af9199af9e69b889claireho /// changeLoopFor - Change the top-level loop that contains BB to the 655b26ce3a7367e4ed2ee7ddddcdc3f3d3377a455c2claireho /// specified loop. This should be used by transformations that restructure 656b26ce3a7367e4ed2ee7ddddcdc3f3d3377a455c2claireho /// the loop hierarchy tree. 657b26ce3a7367e4ed2ee7ddddcdc3f3d3377a455c2claireho void changeLoopFor(BlockT *BB, LoopT *L) { 65827f654740f2a26ad62a5c155af9199af9e69b889claireho LoopT *&OldLoop = BBMap[BB]; 659b26ce3a7367e4ed2ee7ddddcdc3f3d3377a455c2claireho assert(OldLoop && "Block not in a loop yet!"); 660b26ce3a7367e4ed2ee7ddddcdc3f3d3377a455c2claireho OldLoop = L; 661b26ce3a7367e4ed2ee7ddddcdc3f3d3377a455c2claireho } 662103e9ffba2cba345d0078eb8b8db33249f81840aCraig Cornelius 663b26ce3a7367e4ed2ee7ddddcdc3f3d3377a455c2claireho /// changeTopLevelLoop - Replace the specified loop in the top-level loops 66454dcd9b6a06071f647dac967e9e267abb9410720Craig Cornelius /// list with the indicated loop. 66554dcd9b6a06071f647dac967e9e267abb9410720Craig Cornelius void changeTopLevelLoop(LoopT *OldLoop, 66654dcd9b6a06071f647dac967e9e267abb9410720Craig Cornelius LoopT *NewLoop) { 667b26ce3a7367e4ed2ee7ddddcdc3f3d3377a455c2claireho typename std::vector<LoopT *>::iterator I = 668b26ce3a7367e4ed2ee7ddddcdc3f3d3377a455c2claireho std::find(TopLevelLoops.begin(), TopLevelLoops.end(), OldLoop); 669fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius assert(I != TopLevelLoops.end() && "Old loop not at top level!"); 670fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius *I = NewLoop; 67127f654740f2a26ad62a5c155af9199af9e69b889claireho assert(NewLoop->ParentLoop == 0 && OldLoop->ParentLoop == 0 && 672fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius "Loops already embedded into a subloop!"); 673fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius } 674fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 675fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// addTopLevelLoop - This adds the specified loop to the collection of 676b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru /// top-level loops. 677fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius void addTopLevelLoop(LoopT *New) { 678fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius assert(New->getParentLoop() == 0 && "Loop already in subloop!"); 679fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius TopLevelLoops.push_back(New); 680fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius } 681fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 682fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// removeBlock - This method completely removes BB from all data structures, 683fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// including all of the Loop objects it is nested in and our mapping from 684fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// BasicBlocks to loops. 685fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius void removeBlock(BlockT *BB) { 686fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius typename std::map<BlockT *, LoopT *>::iterator I = BBMap.find(BB); 687fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius if (I != BBMap.end()) { 688fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius for (LoopT *L = I->second; L; L = L->getParentLoop()) 689fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius L->removeBlockFromLoop(BB); 690fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 691fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius BBMap.erase(I); 692fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius } 693fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius } 694fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 695fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // Internals 696fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 697fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius static bool isNotAlreadyContainedIn(const LoopT *SubLoop, 698fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius const LoopT *ParentLoop) { 699fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius if (SubLoop == 0) return true; 700fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius if (SubLoop == ParentLoop) return false; 701fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius return isNotAlreadyContainedIn(SubLoop->getParentLoop(), ParentLoop); 702fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius } 703fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 704b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru void Calculate(DominatorTreeBase<BlockT> &DT) { 705b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru BlockT *RootNode = DT.getRootNode()->getBlock(); 706fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 707fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius for (df_iterator<BlockT*> NI = df_begin(RootNode), 708fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius NE = df_end(RootNode); NI != NE; ++NI) 709fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius if (LoopT *L = ConsiderForLoop(*NI, DT)) 710fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius TopLevelLoops.push_back(L); 711fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius } 712b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 713fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius LoopT *ConsiderForLoop(BlockT *BB, DominatorTreeBase<BlockT> &DT) { 714b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (BBMap.find(BB) != BBMap.end()) return 0;// Haven't processed this node? 715fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 716fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius std::vector<BlockT *> TodoStack; 717b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 718b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // Scan the predecessors of BB, checking to see if BB dominates any of 719b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // them. This identifies backedges which target this node... 720b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru typedef GraphTraits<Inverse<BlockT*> > InvBlockTraits; 721fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius for (typename InvBlockTraits::ChildIteratorType I = 722fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius InvBlockTraits::child_begin(BB), E = InvBlockTraits::child_end(BB); 723fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius I != E; ++I) 724fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius if (DT.dominates(BB, *I)) // If BB dominates it's predecessor... 725b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru TodoStack.push_back(*I); 726fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 727b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (TodoStack.empty()) return 0; // No backedges to this block... 728b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 729fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // Create a new loop to represent this basic block... 730fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius LoopT *L = new LoopT(BB); 731fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius BBMap[BB] = L; 732fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 733fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius BlockT *EntryBlock = BB->getParent()->begin(); 734fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 735fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius while (!TodoStack.empty()) { // Process all the nodes in the loop 736fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius BlockT *X = TodoStack.back(); 737fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius TodoStack.pop_back(); 738fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 739b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (!L->contains(X) && // As of yet unprocessed?? 740fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius DT.dominates(EntryBlock, X)) { // X is reachable from entry block? 741fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // Check to see if this block already belongs to a loop. If this occurs 742fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // then we have a case where a loop that is supposed to be a child of 743b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // the current loop was processed before the current loop. When this 744b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // occurs, this child loop gets added to a part of the current loop, 745fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // making it a sibling to the current loop. We have to reparent this 746fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // loop. 747fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius if (LoopT *SubLoop = 748fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius const_cast<LoopT *>(getLoopFor(X))) 749fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius if (SubLoop->getHeader() == X && isNotAlreadyContainedIn(SubLoop, L)){ 750b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // Remove the subloop from it's current parent... 751b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru assert(SubLoop->ParentLoop && SubLoop->ParentLoop != L); 752fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius LoopT *SLP = SubLoop->ParentLoop; // SubLoopParent 753fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius typename std::vector<LoopT *>::iterator I = 754fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius std::find(SLP->SubLoops.begin(), SLP->SubLoops.end(), SubLoop); 755fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius assert(I != SLP->SubLoops.end() &&"SubLoop not a child of parent?"); 756fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius SLP->SubLoops.erase(I); // Remove from parent... 757fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 758fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // Add the subloop to THIS loop... 759fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius SubLoop->ParentLoop = L; 760fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius L->SubLoops.push_back(SubLoop); 761b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 762fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 763fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // Normal case, add the block to our loop... 764fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius L->Blocks.push_back(X); 765fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 766fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius typedef GraphTraits<Inverse<BlockT*> > InvBlockTraits; 767fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 768fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // Add all of the predecessors of X to the end of the work stack... 769fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius TodoStack.insert(TodoStack.end(), InvBlockTraits::child_begin(X), 770b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru InvBlockTraits::child_end(X)); 771b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru } 772fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius } 773fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 774fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // If there are any loops nested within this loop, create them now! 775fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius for (typename std::vector<BlockT*>::iterator I = L->Blocks.begin(), 776fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius E = L->Blocks.end(); I != E; ++I) 777b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (LoopT *NewLoop = ConsiderForLoop(*I, DT)) { 778b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru L->SubLoops.push_back(NewLoop); 779b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru NewLoop->ParentLoop = L; 780fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius } 781fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 782b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // Add the basic blocks that comprise this loop to the BBMap so that this 783c69afcec261fc345fda8daf46f0ea6b4351dc777Jean-Baptiste Queru // loop can be found for them. 784b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // 785b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru for (typename std::vector<BlockT*>::iterator I = L->Blocks.begin(), 786c69afcec261fc345fda8daf46f0ea6b4351dc777Jean-Baptiste Queru E = L->Blocks.end(); I != E; ++I) { 787b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru typename std::map<BlockT*, LoopT *>::iterator BBMI = BBMap.find(*I); 788b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (BBMI == BBMap.end()) // Not in map yet... 789fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius BBMap.insert(BBMI, std::make_pair(*I, L)); // Must be at this level 790fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius } 791b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 792fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // Now that we have a list of all of the child loops of this loop, check to 793b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // see if any of them should actually be nested inside of each other. We 794fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // can accidentally pull loops our of their parents, so we must make sure to 795fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // organize the loop nests correctly now. 796fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius { 797fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius std::map<BlockT *, LoopT *> ContainingLoops; 798103e9ffba2cba345d0078eb8b8db33249f81840aCraig Cornelius for (unsigned i = 0; i != L->SubLoops.size(); ++i) { 799fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius LoopT *Child = L->SubLoops[i]; 800fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius assert(Child->getParentLoop() == L && "Not proper child loop?"); 801fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 802fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius if (LoopT *ContainingLoop = ContainingLoops[Child->getHeader()]) { 803fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // If there is already a loop which contains this loop, move this loop 804fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // into the containing loop. 805b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru MoveSiblingLoopInto(Child, ContainingLoop); 806fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius --i; // The loop got removed from the SubLoops list. 807fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius } else { 808fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // This is currently considered to be a top-level loop. Check to see 809fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // if any of the contained blocks are loop headers for subloops we 810fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // have already processed. 811fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius for (unsigned b = 0, e = Child->Blocks.size(); b != e; ++b) { 812fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius LoopT *&BlockLoop = ContainingLoops[Child->Blocks[b]]; 813b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru if (BlockLoop == 0) { // Child block not processed yet... 814fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius BlockLoop = Child; 815fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius } else if (BlockLoop != Child) { 816b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru LoopT *SubLoop = BlockLoop; 817fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // Reparent all of the blocks which used to belong to BlockLoops 818fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius for (unsigned j = 0, e = SubLoop->Blocks.size(); j != e; ++j) 819b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru ContainingLoops[SubLoop->Blocks[j]] = Child; 820fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 821b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru // There is already a loop which contains this block, that means 822fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // that we should reparent the loop which the block is currently 823fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // considered to belong to to be a child of this loop. 824fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius MoveSiblingLoopInto(SubLoop, Child); 825fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius --i; // We just shrunk the SubLoops list. 826fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius } 827fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius } 828fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius } 829fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius } 830fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius } 831b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru 832b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru return L; 833fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius } 834fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 835fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// MoveSiblingLoopInto - This method moves the NewChild loop to live inside 836fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// of the NewParent Loop, instead of being a sibling of it. 837fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius void MoveSiblingLoopInto(LoopT *NewChild, 838fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius LoopT *NewParent) { 839fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius LoopT *OldParent = NewChild->getParentLoop(); 840fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius assert(OldParent && OldParent == NewParent->getParentLoop() && 841b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru NewChild != NewParent && "Not sibling loops!"); 842fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 843fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius // Remove NewChild from being a child of OldParent 844fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius typename std::vector<LoopT *>::iterator I = 845fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius std::find(OldParent->SubLoops.begin(), OldParent->SubLoops.end(), 846b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru NewChild); 847fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius assert(I != OldParent->SubLoops.end() && "Parent fields incorrect??"); 848fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius OldParent->SubLoops.erase(I); // Remove from parent's subloops list 849fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius NewChild->ParentLoop = 0; 850fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 851fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius InsertLoopInto(NewChild, NewParent); 852fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius } 853fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius 854fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// InsertLoopInto - This inserts loop L into the specified parent loop. If 855fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// the parent loop contains a loop which should contain L, the loop gets 856fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius /// inserted into L instead. 857b13da9df870a61b11249bf741347908dbea0edd8Jean-Baptiste Queru void InsertLoopInto(LoopT *L, LoopT *Parent) { 858fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius BlockT *LHeader = L->getHeader(); 859fceb39872958b9fa2505e63f8b8699a9e0f882f4ccornelius assert(Parent->contains(LHeader) && 860 "This loop should not be inserted here!"); 861 862 // Check to see if it belongs in a child loop... 863 for (unsigned i = 0, e = static_cast<unsigned>(Parent->SubLoops.size()); 864 i != e; ++i) 865 if (Parent->SubLoops[i]->contains(LHeader)) { 866 InsertLoopInto(L, Parent->SubLoops[i]); 867 return; 868 } 869 870 // If not, insert it here! 871 Parent->SubLoops.push_back(L); 872 L->ParentLoop = Parent; 873 } 874 875 // Debugging 876 877 void print(raw_ostream &OS) const { 878 for (unsigned i = 0; i < TopLevelLoops.size(); ++i) 879 TopLevelLoops[i]->print(OS); 880 #if 0 881 for (std::map<BasicBlock*, LoopT*>::const_iterator I = BBMap.begin(), 882 E = BBMap.end(); I != E; ++I) 883 OS << "BB '" << I->first->getName() << "' level = " 884 << I->second->getLoopDepth() << "\n"; 885 #endif 886 } 887}; 888 889class LoopInfo : public FunctionPass { 890 LoopInfoBase<BasicBlock, Loop> LI; 891 friend class LoopBase<BasicBlock, Loop>; 892 893 void operator=(const LoopInfo &); // do not implement 894 LoopInfo(const LoopInfo &); // do not implement 895public: 896 static char ID; // Pass identification, replacement for typeid 897 898 LoopInfo() : FunctionPass(&ID) {} 899 900 LoopInfoBase<BasicBlock, Loop>& getBase() { return LI; } 901 902 /// iterator/begin/end - The interface to the top-level loops in the current 903 /// function. 904 /// 905 typedef LoopInfoBase<BasicBlock, Loop>::iterator iterator; 906 inline iterator begin() const { return LI.begin(); } 907 inline iterator end() const { return LI.end(); } 908 bool empty() const { return LI.empty(); } 909 910 /// getLoopFor - Return the inner most loop that BB lives in. If a basic 911 /// block is in no loop (for example the entry node), null is returned. 912 /// 913 inline Loop *getLoopFor(const BasicBlock *BB) const { 914 return LI.getLoopFor(BB); 915 } 916 917 /// operator[] - same as getLoopFor... 918 /// 919 inline const Loop *operator[](const BasicBlock *BB) const { 920 return LI.getLoopFor(BB); 921 } 922 923 /// getLoopDepth - Return the loop nesting level of the specified block. A 924 /// depth of 0 means the block is not inside any loop. 925 /// 926 inline unsigned getLoopDepth(const BasicBlock *BB) const { 927 return LI.getLoopDepth(BB); 928 } 929 930 // isLoopHeader - True if the block is a loop header node 931 inline bool isLoopHeader(BasicBlock *BB) const { 932 return LI.isLoopHeader(BB); 933 } 934 935 /// runOnFunction - Calculate the natural loop information. 936 /// 937 virtual bool runOnFunction(Function &F); 938 939 virtual void releaseMemory() { LI.releaseMemory(); } 940 941 virtual void print(raw_ostream &O, const Module* M = 0) const; 942 943 virtual void getAnalysisUsage(AnalysisUsage &AU) const; 944 945 /// removeLoop - This removes the specified top-level loop from this loop info 946 /// object. The loop is not deleted, as it will presumably be inserted into 947 /// another loop. 948 inline Loop *removeLoop(iterator I) { return LI.removeLoop(I); } 949 950 /// changeLoopFor - Change the top-level loop that contains BB to the 951 /// specified loop. This should be used by transformations that restructure 952 /// the loop hierarchy tree. 953 inline void changeLoopFor(BasicBlock *BB, Loop *L) { 954 LI.changeLoopFor(BB, L); 955 } 956 957 /// changeTopLevelLoop - Replace the specified loop in the top-level loops 958 /// list with the indicated loop. 959 inline void changeTopLevelLoop(Loop *OldLoop, Loop *NewLoop) { 960 LI.changeTopLevelLoop(OldLoop, NewLoop); 961 } 962 963 /// addTopLevelLoop - This adds the specified loop to the collection of 964 /// top-level loops. 965 inline void addTopLevelLoop(Loop *New) { 966 LI.addTopLevelLoop(New); 967 } 968 969 /// removeBlock - This method completely removes BB from all data structures, 970 /// including all of the Loop objects it is nested in and our mapping from 971 /// BasicBlocks to loops. 972 void removeBlock(BasicBlock *BB) { 973 LI.removeBlock(BB); 974 } 975 976 static bool isNotAlreadyContainedIn(const Loop *SubLoop, 977 const Loop *ParentLoop) { 978 return 979 LoopInfoBase<BasicBlock, Loop>::isNotAlreadyContainedIn(SubLoop, 980 ParentLoop); 981 } 982}; 983 984 985// Allow clients to walk the list of nested loops... 986template <> struct GraphTraits<const Loop*> { 987 typedef const Loop NodeType; 988 typedef LoopInfo::iterator ChildIteratorType; 989 990 static NodeType *getEntryNode(const Loop *L) { return L; } 991 static inline ChildIteratorType child_begin(NodeType *N) { 992 return N->begin(); 993 } 994 static inline ChildIteratorType child_end(NodeType *N) { 995 return N->end(); 996 } 997}; 998 999template <> struct GraphTraits<Loop*> { 1000 typedef Loop NodeType; 1001 typedef LoopInfo::iterator ChildIteratorType; 1002 1003 static NodeType *getEntryNode(Loop *L) { return L; } 1004 static inline ChildIteratorType child_begin(NodeType *N) { 1005 return N->begin(); 1006 } 1007 static inline ChildIteratorType child_end(NodeType *N) { 1008 return N->end(); 1009 } 1010}; 1011 1012template<class BlockT, class LoopT> 1013void 1014LoopBase<BlockT, LoopT>::addBasicBlockToLoop(BlockT *NewBB, 1015 LoopInfoBase<BlockT, LoopT> &LIB) { 1016 assert((Blocks.empty() || LIB[getHeader()] == this) && 1017 "Incorrect LI specified for this loop!"); 1018 assert(NewBB && "Cannot add a null basic block to the loop!"); 1019 assert(LIB[NewBB] == 0 && "BasicBlock already in the loop!"); 1020 1021 LoopT *L = static_cast<LoopT *>(this); 1022 1023 // Add the loop mapping to the LoopInfo object... 1024 LIB.BBMap[NewBB] = L; 1025 1026 // Add the basic block to this loop and all parent loops... 1027 while (L) { 1028 L->Blocks.push_back(NewBB); 1029 L = L->getParentLoop(); 1030 } 1031} 1032 1033} // End llvm namespace 1034 1035#endif 1036