148486893f46d2e12e926682a3ecb908716bc66c4Chris Lattner//===- llvm/Analysis/LoopInfo.h - Natural Loop Calculator -------*- C++ -*-===// 29769ab22265b313171d201b5928688524a01bd87Misha Brukman// 36fbcc26f1460eaee4e0eb8b426fc1ff0c7af11beJohn Criswell// The LLVM Compiler Infrastructure 46fbcc26f1460eaee4e0eb8b426fc1ff0c7af11beJohn Criswell// 57ed47a13356daed2a34cd2209a31f92552e3bdd8Chris Lattner// This file is distributed under the University of Illinois Open Source 67ed47a13356daed2a34cd2209a31f92552e3bdd8Chris Lattner// License. See LICENSE.TXT for details. 79769ab22265b313171d201b5928688524a01bd87Misha Brukman// 86fbcc26f1460eaee4e0eb8b426fc1ff0c7af11beJohn Criswell//===----------------------------------------------------------------------===// 90bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner// 100bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner// This file defines the LoopInfo class that is used to identify natural loops 11b7532e254810aba26da9b65ee2c65788695f8c30Dan Gohman// and determine the loop depth of various nodes of the CFG. A natural loop 12b7532e254810aba26da9b65ee2c65788695f8c30Dan Gohman// has exactly one entry-point, which is called the header. Note that natural 1346758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner// loops may actually be several loops that share the same header node. 14fe3ae1ed660925f06159ec89460d92148e049ffdChris Lattner// 15fe3ae1ed660925f06159ec89460d92148e049ffdChris Lattner// This analysis calculates the nesting structure of loops in a function. For 16fe3ae1ed660925f06159ec89460d92148e049ffdChris Lattner// each natural loop identified, this analysis identifies natural loops 17072b163424491c85df6664a4e056aae5e07dc64dChris Lattner// contained entirely within the loop and the basic blocks the make up the loop. 18fe3ae1ed660925f06159ec89460d92148e049ffdChris Lattner// 19072b163424491c85df6664a4e056aae5e07dc64dChris Lattner// It can calculate on the fly various bits of information, for example: 20072b163424491c85df6664a4e056aae5e07dc64dChris Lattner// 21072b163424491c85df6664a4e056aae5e07dc64dChris Lattner// * whether there is a preheader for the loop 22072b163424491c85df6664a4e056aae5e07dc64dChris Lattner// * the number of back edges to the header 23072b163424491c85df6664a4e056aae5e07dc64dChris Lattner// * whether or not a particular block branches out of the loop 24072b163424491c85df6664a4e056aae5e07dc64dChris Lattner// * the successor blocks of the loop 25072b163424491c85df6664a4e056aae5e07dc64dChris Lattner// * the loop depth 26072b163424491c85df6664a4e056aae5e07dc64dChris Lattner// * etc... 270bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner// 280bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner//===----------------------------------------------------------------------===// 290bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner 30674be02d525d4e24bc6943ed9274958c580bcfbcJakub Staszak#ifndef LLVM_ANALYSIS_LOOPINFO_H 31674be02d525d4e24bc6943ed9274958c580bcfbcJakub Staszak#define LLVM_ANALYSIS_LOOPINFO_H 320bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner 3372851059224b90a3ae74ecd62fbd927a0c54a9f0Cameron Zwarich#include "llvm/ADT/DenseMap.h" 345434c1e73b6e56756719d2aebb952ac7bb3829e0Andrew Trick#include "llvm/ADT/DenseSet.h" 35551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/GraphTraits.h" 3636b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines#include "llvm/ADT/SmallPtrSet.h" 37255f89faee13dc491cb64fbeae3c763e7e2ea4e6Chandler Carruth#include "llvm/ADT/SmallVector.h" 3836b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines#include "llvm/IR/CFG.h" 3936b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines#include "llvm/IR/Instruction.h" 40255f89faee13dc491cb64fbeae3c763e7e2ea4e6Chandler Carruth#include "llvm/Pass.h" 41019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson#include <algorithm> 42019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson 431d5562f72e3f7d9e17a2bf95afa54a98dac95894Dan Gohmannamespace llvm { 441d5562f72e3f7d9e17a2bf95afa54a98dac95894Dan Gohman 45ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines// FIXME: Replace this brittle forward declaration with the include of the new 46ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines// PassManager.h when doing so doesn't break the PassManagerBuilder. 47ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename IRUnitT> class AnalysisManager; 48ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinesclass PreservedAnalyses; 49ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 50019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Andersontemplate<typename T> 51305b515c2787f47adecbe120e4b4bef55c5e5525Chandler Carruthinline void RemoveFromVector(std::vector<T*> &V, T *N) { 52019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson typename std::vector<T*>::iterator I = std::find(V.begin(), V.end(), N); 53019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson assert(I != V.end() && "N is not in this list!"); 54019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson V.erase(I); 55019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson} 560bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner 5753c279b1949f7fa626ccbc399ebbe2d7dc9599a4Devang Patelclass DominatorTree; 588fc2f2072de83665ae20e06929e28317f449bcdfChris Lattnerclass LoopInfo; 59c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohmanclass Loop; 60ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmondclass MDNode; 619fc5cdf77c812aaa80419036de27576d45894d0dChris Lattnerclass PHINode; 62209cb5b56bb90f1ceee570efabe9c04121cb0bebJakub Staszakclass raw_ostream; 6336b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hinestemplate<class N> class DominatorTreeBase; 64c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohmantemplate<class N, class M> class LoopInfoBase; 65c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohmantemplate<class N, class M> class LoopBase; 660bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner 670bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner//===----------------------------------------------------------------------===// 68131bd2ecf721749666111ec2dd1d32a20ae049b2Chris Lattner/// LoopBase class - Instances of this class are used to represent loops that 69131bd2ecf721749666111ec2dd1d32a20ae049b2Chris Lattner/// are detected in the flow graph 702b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner/// 71c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohmantemplate<class BlockT, class LoopT> 72019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Andersonclass LoopBase { 73c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman LoopT *ParentLoop; 74131bd2ecf721749666111ec2dd1d32a20ae049b2Chris Lattner // SubLoops - Loops contained entirely within this one. 75c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman std::vector<LoopT *> SubLoops; 76131bd2ecf721749666111ec2dd1d32a20ae049b2Chris Lattner 77131bd2ecf721749666111ec2dd1d32a20ae049b2Chris Lattner // Blocks - The list of blocks in this loop. First entry is the header node. 78131bd2ecf721749666111ec2dd1d32a20ae049b2Chris Lattner std::vector<BlockT*> Blocks; 79019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson 80887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei SmallPtrSet<const BlockT*, 8> DenseBlockSet; 81887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei 82ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines LoopBase(const LoopBase<BlockT, LoopT> &) = delete; 83de8091708f2d5ade958507aa6d37907a6277e9f2Craig Topper const LoopBase<BlockT, LoopT>& 84ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines operator=(const LoopBase<BlockT, LoopT> &) = delete; 850bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattnerpublic: 8646758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// Loop ctor - This creates an empty loop. 87dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines LoopBase() : ParentLoop(nullptr) {} 88019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson ~LoopBase() { 8934cd4a484e532cc463fd5a4bf59b88d13c5467c1Evan Cheng for (size_t i = 0, e = SubLoops.size(); i != e; ++i) 904e55b7d2c62de7efa0147e0579980de8b1df9123Chris Lattner delete SubLoops[i]; 914e55b7d2c62de7efa0147e0579980de8b1df9123Chris Lattner } 920bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner 93ba42d2b937160c970c8c6ea57573113c9265325fDan Gohman /// getLoopDepth - Return the nesting level of this loop. An outer-most 94ba42d2b937160c970c8c6ea57573113c9265325fDan Gohman /// loop has depth 1, for consistency with loop depth values used for basic 95ba42d2b937160c970c8c6ea57573113c9265325fDan Gohman /// blocks, where depth 0 is used for blocks not inside any loops. 96072b163424491c85df6664a4e056aae5e07dc64dChris Lattner unsigned getLoopDepth() const { 97ba42d2b937160c970c8c6ea57573113c9265325fDan Gohman unsigned D = 1; 98c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman for (const LoopT *CurLoop = ParentLoop; CurLoop; 99019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson CurLoop = CurLoop->ParentLoop) 100072b163424491c85df6664a4e056aae5e07dc64dChris Lattner ++D; 101072b163424491c85df6664a4e056aae5e07dc64dChris Lattner return D; 102072b163424491c85df6664a4e056aae5e07dc64dChris Lattner } 103019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson BlockT *getHeader() const { return Blocks.front(); } 104c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman LoopT *getParentLoop() const { return ParentLoop; } 1050bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner 10637aa33bc11c01a7142bfa2428a5a4d219b07b6c3Andrew Trick /// setParentLoop is a raw interface for bypassing addChildLoop. 10737aa33bc11c01a7142bfa2428a5a4d219b07b6c3Andrew Trick void setParentLoop(LoopT *L) { ParentLoop = L; } 10837aa33bc11c01a7142bfa2428a5a4d219b07b6c3Andrew Trick 10992329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman /// contains - Return true if the specified loop is contained within in 11092329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman /// this loop. 11192329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman /// 11292329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman bool contains(const LoopT *L) const { 11392329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman if (L == this) return true; 114dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines if (!L) return false; 11592329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman return contains(L->getParentLoop()); 11692329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman } 117fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 11892329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman /// contains - Return true if the specified basic block is in this loop. 119fbdf4bf1799bf9ea566fc0fc0507752590a6d559Misha Brukman /// 120019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson bool contains(const BlockT *BB) const { 121887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei return DenseBlockSet.count(BB); 122019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson } 1230bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner 12492329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman /// contains - Return true if the specified instruction is in this loop. 12592329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman /// 12692329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman template<class InstT> 12792329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman bool contains(const InstT *Inst) const { 12892329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman return contains(Inst->getParent()); 12992329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman } 13092329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman 131329c1c6c949d07e3fe9722ec633b4258217fd99dChris Lattner /// iterator/begin/end - Return the loops contained entirely within this loop. 1322b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// 133c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman const std::vector<LoopT *> &getSubLoops() const { return SubLoops; } 13437aa33bc11c01a7142bfa2428a5a4d219b07b6c3Andrew Trick std::vector<LoopT *> &getSubLoopsVector() { return SubLoops; } 135c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman typedef typename std::vector<LoopT *>::const_iterator iterator; 136c9b1e25493b393013b28e5d457f2fb2845a4dd9fAndrew Trick typedef typename std::vector<LoopT *>::const_reverse_iterator 137c9b1e25493b393013b28e5d457f2fb2845a4dd9fAndrew Trick reverse_iterator; 138329c1c6c949d07e3fe9722ec633b4258217fd99dChris Lattner iterator begin() const { return SubLoops.begin(); } 139329c1c6c949d07e3fe9722ec633b4258217fd99dChris Lattner iterator end() const { return SubLoops.end(); } 140c9b1e25493b393013b28e5d457f2fb2845a4dd9fAndrew Trick reverse_iterator rbegin() const { return SubLoops.rbegin(); } 141c9b1e25493b393013b28e5d457f2fb2845a4dd9fAndrew Trick reverse_iterator rend() const { return SubLoops.rend(); } 14221c276d2fa99914d5ed958ac0aec7d78e3dd87cfDan Gohman bool empty() const { return SubLoops.empty(); } 143fe3ae1ed660925f06159ec89460d92148e049ffdChris Lattner 144fe3ae1ed660925f06159ec89460d92148e049ffdChris Lattner /// getBlocks - Get a list of the basic blocks which make up this loop. 145fe3ae1ed660925f06159ec89460d92148e049ffdChris Lattner /// 146019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson const std::vector<BlockT*> &getBlocks() const { return Blocks; } 147019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson typedef typename std::vector<BlockT*>::const_iterator block_iterator; 1484e77cc46ac688e7bee98747049f90e19e2902227Chris Lattner block_iterator block_begin() const { return Blocks.begin(); } 1494e77cc46ac688e7bee98747049f90e19e2902227Chris Lattner block_iterator block_end() const { return Blocks.end(); } 150fe3ae1ed660925f06159ec89460d92148e049ffdChris Lattner 151306afdf443a0e2d5d89c1a3ece00cfe18be1c4c4Andrew Trick /// getNumBlocks - Get the number of blocks in this loop in constant time. 152b1eede12818d91a32adac928c6fffcf6d2800dc0Andrew Trick unsigned getNumBlocks() const { 153306afdf443a0e2d5d89c1a3ece00cfe18be1c4c4Andrew Trick return Blocks.size(); 154b1eede12818d91a32adac928c6fffcf6d2800dc0Andrew Trick } 155b1eede12818d91a32adac928c6fffcf6d2800dc0Andrew Trick 156d146e986c818165cca866ee05751451706ccf36aDan Gohman /// isLoopExiting - True if terminator in the block can branch to another 157d146e986c818165cca866ee05751451706ccf36aDan Gohman /// block that is outside of the current loop. 158fe3ae1ed660925f06159ec89460d92148e049ffdChris Lattner /// 15932663b719b4996b3a735f22bba80d771d50f96e7Dan Gohman bool isLoopExiting(const BlockT *BB) const { 16064bf55af6f3cc6c6db985d3840547b5869e57222Jakub Staszak typedef GraphTraits<const BlockT*> BlockTraits; 161d735ee85dbab8e4f66f9ec157f19956e0d11ec7aOwen Anderson for (typename BlockTraits::ChildIteratorType SI = 16264bf55af6f3cc6c6db985d3840547b5869e57222Jakub Staszak BlockTraits::child_begin(BB), 16364bf55af6f3cc6c6db985d3840547b5869e57222Jakub Staszak SE = BlockTraits::child_end(BB); SI != SE; ++SI) { 164019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson if (!contains(*SI)) 165019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson return true; 166019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson } 167019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson return false; 168019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson } 1696b290a54409f6bb6a0cc1c0446cd2b170a4b7addMisha Brukman 170fe3ae1ed660925f06159ec89460d92148e049ffdChris Lattner /// getNumBackEdges - Calculate the number of back edges to the loop header 171fe3ae1ed660925f06159ec89460d92148e049ffdChris Lattner /// 172019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson unsigned getNumBackEdges() const { 173019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson unsigned NumBackEdges = 0; 174019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson BlockT *H = getHeader(); 175019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson 176d735ee85dbab8e4f66f9ec157f19956e0d11ec7aOwen Anderson typedef GraphTraits<Inverse<BlockT*> > InvBlockTraits; 177d735ee85dbab8e4f66f9ec157f19956e0d11ec7aOwen Anderson for (typename InvBlockTraits::ChildIteratorType I = 17864bf55af6f3cc6c6db985d3840547b5869e57222Jakub Staszak InvBlockTraits::child_begin(H), 17964bf55af6f3cc6c6db985d3840547b5869e57222Jakub Staszak E = InvBlockTraits::child_end(H); I != E; ++I) 180019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson if (contains(*I)) 181019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson ++NumBackEdges; 182019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson 183019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson return NumBackEdges; 184019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson } 1859474dd68e8a050193ca4003940ac399e2b17cb6aChris Lattner 186e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner //===--------------------------------------------------------------------===// 187e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner // APIs for simple analysis of the loop. 188e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner // 189e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner // Note that all of these methods can fail on general loops (ie, there may not 190e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner // be a preheader, etc). For best success, the loop simplification and 191e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner // induction variable canonicalization pass should be used to normalize loops 192e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner // for easy analysis. These methods assume canonical loops. 193e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner 1947466ebf045fa5097ee0d7d2728eed7fd5945c8bcChris Lattner /// getExitingBlocks - Return all blocks inside the loop that have successors 1957466ebf045fa5097ee0d7d2728eed7fd5945c8bcChris Lattner /// outside of the loop. These are the blocks _inside of the current loop_ 1967466ebf045fa5097ee0d7d2728eed7fd5945c8bcChris Lattner /// which branch out. The returned list is always unique. 1977466ebf045fa5097ee0d7d2728eed7fd5945c8bcChris Lattner /// 198cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick void getExitingBlocks(SmallVectorImpl<BlockT *> &ExitingBlocks) const; 1997466ebf045fa5097ee0d7d2728eed7fd5945c8bcChris Lattner 200c83324682f3409c15dad992cd62928426c9ad83dDan Gohman /// getExitingBlock - If getExitingBlocks would return exactly one block, 201c83324682f3409c15dad992cd62928426c9ad83dDan Gohman /// return that block. Otherwise return null. 202cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick BlockT *getExitingBlock() const; 203c83324682f3409c15dad992cd62928426c9ad83dDan Gohman 204f1ab4b4eac5603d19c20f4a508f93a118a52bdd5Chris Lattner /// getExitBlocks - Return all of the successor blocks of this loop. These 205f1ab4b4eac5603d19c20f4a508f93a118a52bdd5Chris Lattner /// are the blocks _outside of the current loop_ which are branched to. 206f1ab4b4eac5603d19c20f4a508f93a118a52bdd5Chris Lattner /// 207cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick void getExitBlocks(SmallVectorImpl<BlockT*> &ExitBlocks) const; 208f1ab4b4eac5603d19c20f4a508f93a118a52bdd5Chris Lattner 2091827e8263c9cb5dc29eea4999d8729f7376af4e1Dan Gohman /// getExitBlock - If getExitBlocks would return exactly one block, 2101827e8263c9cb5dc29eea4999d8729f7376af4e1Dan Gohman /// return that block. Otherwise return null. 211cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick BlockT *getExitBlock() const; 2121827e8263c9cb5dc29eea4999d8729f7376af4e1Dan Gohman 21360f422f894ae9aff2f508f34733be36f5a0ed20aLang Hames /// Edge type. 214cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick typedef std::pair<const BlockT*, const BlockT*> Edge; 21560f422f894ae9aff2f508f34733be36f5a0ed20aLang Hames 21655e354ac0e294bde258420f80a2cc11ea19db482Daniel Dunbar /// getExitEdges - Return all pairs of (_inside_block_,_outside_block_). 217cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick void getExitEdges(SmallVectorImpl<Edge> &ExitEdges) const; 21855e354ac0e294bde258420f80a2cc11ea19db482Daniel Dunbar 2192b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// getLoopPreheader - If there is a preheader for this loop, return it. A 2202b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// loop has a preheader if there is only one edge to the header of the loop 2212b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// from outside of the loop. If this is the case, the block branching to the 222e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner /// header of the loop is the preheader node. 2232b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// 224e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner /// This method returns null if there is no preheader for the loop. 2252b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// 226cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick BlockT *getLoopPreheader() const; 2275cf27f81f49b4516b1e9d269f070c88fa3228f9eDan Gohman 2285cf27f81f49b4516b1e9d269f070c88fa3228f9eDan Gohman /// getLoopPredecessor - If the given loop's header has exactly one unique 2295cf27f81f49b4516b1e9d269f070c88fa3228f9eDan Gohman /// predecessor outside the loop, return it. Otherwise return null. 2305cf27f81f49b4516b1e9d269f070c88fa3228f9eDan Gohman /// This is less strict that the loop "preheader" concept, which requires 2315cf27f81f49b4516b1e9d269f070c88fa3228f9eDan Gohman /// the predecessor to have exactly one successor. 2325cf27f81f49b4516b1e9d269f070c88fa3228f9eDan Gohman /// 233cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick BlockT *getLoopPredecessor() const; 2342b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner 235b317143ba851ce2853fb262fb2185ef5f1be030dDan Gohman /// getLoopLatch - If there is a single latch block for this loop, return it. 236b317143ba851ce2853fb262fb2185ef5f1be030dDan Gohman /// A latch block is a block that contains a branch back to the header. 237cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick BlockT *getLoopLatch() const; 238e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner 23936b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines /// getLoopLatches - Return all loop latch blocks of this loop. A latch block 24036b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines /// is a block that contains a branch back to the header. 24136b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines void getLoopLatches(SmallVectorImpl<BlockT *> &LoopLatches) const { 24236b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines BlockT *H = getHeader(); 24336b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines typedef GraphTraits<Inverse<BlockT*> > InvBlockTraits; 24436b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines for (typename InvBlockTraits::ChildIteratorType I = 24536b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines InvBlockTraits::child_begin(H), 24636b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines E = InvBlockTraits::child_end(H); I != E; ++I) 24736b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines if (contains(*I)) 24836b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines LoopLatches.push_back(*I); 24936b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines } 25036b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines 251e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner //===--------------------------------------------------------------------===// 252e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner // APIs for updating loop information after changing the CFG 253e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner // 254e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner 255fe3ae1ed660925f06159ec89460d92148e049ffdChris Lattner /// addBasicBlockToLoop - This method is used by other analyses to update loop 256fe3ae1ed660925f06159ec89460d92148e049ffdChris Lattner /// information. NewBB is set to be a new member of the current loop. 2572b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// Because of this, it is added as a member of all parent loops, and is added 2582b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// to the specified LoopInfo object as being in the current basic block. It 2592b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// is not valid to replace the loop header with this method. 2602b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// 261c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman void addBasicBlockToLoop(BlockT *NewBB, LoopInfoBase<BlockT, LoopT> &LI); 2622b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner 26346758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// replaceChildLoopWith - This is used when splitting loops up. It replaces 26446758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// the OldChild entry in our children list with NewChild, and updates the 26546758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// parent pointer of OldChild to be null and the NewChild to be this loop. 26646758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// This updates the loop depth of the new child. 267cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick void replaceChildLoopWith(LoopT *OldChild, LoopT *NewChild); 26846758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner 26946758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// addChildLoop - Add the specified loop to be a child of this loop. This 27046758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// updates the loop depth of the new child. 27146758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// 272c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman void addChildLoop(LoopT *NewChild) { 273dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines assert(!NewChild->ParentLoop && "NewChild already has a parent!"); 274c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman NewChild->ParentLoop = static_cast<LoopT *>(this); 275019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson SubLoops.push_back(NewChild); 276019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson } 27746758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner 27846758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// removeChildLoop - This removes the specified child from being a subloop of 27946758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// this loop. The loop is not deleted, as it will presumably be inserted 28046758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// into another loop. 281c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman LoopT *removeChildLoop(iterator I) { 282019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson assert(I != SubLoops.end() && "Cannot remove end iterator!"); 283c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman LoopT *Child = *I; 284019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson assert(Child->ParentLoop == this && "Child is not a child of this loop!"); 285019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson SubLoops.erase(SubLoops.begin()+(I-begin())); 286dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines Child->ParentLoop = nullptr; 287019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson return Child; 288019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson } 28946758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner 29046758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// addBlockEntry - This adds a basic block directly to the basic block list. 29146758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// This should only be used by transformations that create new loops. Other 29246758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// transformations should use addBasicBlockToLoop. 293019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson void addBlockEntry(BlockT *BB) { 29446758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner Blocks.push_back(BB); 295887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei DenseBlockSet.insert(BB); 296887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei } 297887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei 298887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei /// reverseBlocks - interface to reverse Blocks[from, end of loop] in this loop 299887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei void reverseBlock(unsigned from) { 300887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei std::reverse(Blocks.begin() + from, Blocks.end()); 301887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei } 302887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei 303887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei /// reserveBlocks- interface to do reserve() for Blocks 304887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei void reserveBlocks(unsigned size) { 305887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei Blocks.reserve(size); 30646758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner } 30746758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner 30851a4ad475b095aed49caff176b98c0754e421af4Chris Lattner /// moveToHeader - This method is used to move BB (which must be part of this 30951a4ad475b095aed49caff176b98c0754e421af4Chris Lattner /// loop) to be the loop header of the loop (the block that dominates all 31051a4ad475b095aed49caff176b98c0754e421af4Chris Lattner /// others). 311019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson void moveToHeader(BlockT *BB) { 31251a4ad475b095aed49caff176b98c0754e421af4Chris Lattner if (Blocks[0] == BB) return; 31351a4ad475b095aed49caff176b98c0754e421af4Chris Lattner for (unsigned i = 0; ; ++i) { 31451a4ad475b095aed49caff176b98c0754e421af4Chris Lattner assert(i != Blocks.size() && "Loop does not contain BB!"); 31551a4ad475b095aed49caff176b98c0754e421af4Chris Lattner if (Blocks[i] == BB) { 31651a4ad475b095aed49caff176b98c0754e421af4Chris Lattner Blocks[i] = Blocks[0]; 31751a4ad475b095aed49caff176b98c0754e421af4Chris Lattner Blocks[0] = BB; 31851a4ad475b095aed49caff176b98c0754e421af4Chris Lattner return; 31951a4ad475b095aed49caff176b98c0754e421af4Chris Lattner } 32051a4ad475b095aed49caff176b98c0754e421af4Chris Lattner } 32151a4ad475b095aed49caff176b98c0754e421af4Chris Lattner } 32251a4ad475b095aed49caff176b98c0754e421af4Chris Lattner 32346758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// removeBlockFromLoop - This removes the specified basic block from the 324f1ab4b4eac5603d19c20f4a508f93a118a52bdd5Chris Lattner /// current loop, updating the Blocks as appropriate. This does not update 325f1ab4b4eac5603d19c20f4a508f93a118a52bdd5Chris Lattner /// the mapping in the LoopInfo class. 326019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson void removeBlockFromLoop(BlockT *BB) { 327019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson RemoveFromVector(Blocks, BB); 328887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei DenseBlockSet.erase(BB); 329019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson } 33046758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner 33158e0ef1e90c3f6dbae213612b44e56f7d6d65ea7Devang Patel /// verifyLoop - Verify loop structure 332cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick void verifyLoop() const; 333019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson 3345c89b5240c90eb8171f999e5f06f815502d0321cDan Gohman /// verifyLoop - Verify loop structure of this loop and all nested loops. 335cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick void verifyLoopNest(DenseSet<const LoopT*> *Loops) const; 33658e0ef1e90c3f6dbae213612b44e56f7d6d65ea7Devang Patel 337cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick void print(raw_ostream &OS, unsigned Depth = 0) const; 338dda30cd4af1c5f88fc00fd40b673f8e27c61379dDan Gohman 339c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohmanprotected: 340c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman friend class LoopInfoBase<BlockT, LoopT>; 341dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines explicit LoopBase(BlockT *BB) : ParentLoop(nullptr) { 342072b163424491c85df6664a4e056aae5e07dc64dChris Lattner Blocks.push_back(BB); 343887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei DenseBlockSet.insert(BB); 3440bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner } 3450bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner}; 3460bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner 3476a0dc079efe7acf7e71cc4c0948fe814f35ba091Jakob Stoklund Olesentemplate<class BlockT, class LoopT> 3486a0dc079efe7acf7e71cc4c0948fe814f35ba091Jakob Stoklund Olesenraw_ostream& operator<<(raw_ostream &OS, const LoopBase<BlockT, LoopT> &Loop) { 3496a0dc079efe7acf7e71cc4c0948fe814f35ba091Jakob Stoklund Olesen Loop.print(OS); 3506a0dc079efe7acf7e71cc4c0948fe814f35ba091Jakob Stoklund Olesen return OS; 3516a0dc079efe7acf7e71cc4c0948fe814f35ba091Jakob Stoklund Olesen} 3526a0dc079efe7acf7e71cc4c0948fe814f35ba091Jakob Stoklund Olesen 35360c7d5bc2cbeff9eff16716295ffd6a5374dc6bcAndrew Trick// Implementation in LoopInfoImpl.h 35460c7d5bc2cbeff9eff16716295ffd6a5374dc6bcAndrew Trick#ifdef __GNUC__ 35560c7d5bc2cbeff9eff16716295ffd6a5374dc6bcAndrew Trick__extension__ extern template class LoopBase<BasicBlock, Loop>; 35660c7d5bc2cbeff9eff16716295ffd6a5374dc6bcAndrew Trick#endif 35760c7d5bc2cbeff9eff16716295ffd6a5374dc6bcAndrew Trick 358c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohmanclass Loop : public LoopBase<BasicBlock, Loop> { 359c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohmanpublic: 360c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman Loop() {} 36116a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman 36216a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman /// isLoopInvariant - Return true if the specified value is loop invariant 36316a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman /// 36416a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman bool isLoopInvariant(Value *V) const; 36516a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman 366adc799112dc180b3cd099038c05101b85d217716Chris Lattner /// hasLoopInvariantOperands - Return true if all the operands of the 367fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick /// specified instruction are loop invariant. 368adc799112dc180b3cd099038c05101b85d217716Chris Lattner bool hasLoopInvariantOperands(Instruction *I) const; 369a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman 370206613b289f60b71a76e9190d36b9ea9e47a701eDan Gohman /// makeLoopInvariant - If the given value is an instruction inside of the 371a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// loop and it can be hoisted, do so to make it trivially loop-invariant. 372a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// Return true if the value after any hoisting is loop invariant. This 373a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// function can be used as a slightly more aggressive replacement for 374a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// isLoopInvariant. 375a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// 376a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// If InsertPt is specified, it is the point to hoist instructions to. 377a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// If null, the terminator of the loop preheader is used. 378a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// 379bdc017edacb713119b24ab269d250a82d62fffebDan Gohman bool makeLoopInvariant(Value *V, bool &Changed, 380dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines Instruction *InsertPt = nullptr) const; 381a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman 382a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// makeLoopInvariant - If the given instruction is inside of the 383a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// loop and it can be hoisted, do so to make it trivially loop-invariant. 384a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// Return true if the instruction after any hoisting is loop invariant. This 385a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// function can be used as a slightly more aggressive replacement for 386a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// isLoopInvariant. 387a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// 388a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// If InsertPt is specified, it is the point to hoist instructions to. 389a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// If null, the terminator of the loop preheader is used. 390a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// 391bdc017edacb713119b24ab269d250a82d62fffebDan Gohman bool makeLoopInvariant(Instruction *I, bool &Changed, 392dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines Instruction *InsertPt = nullptr) const; 393a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman 39416a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman /// getCanonicalInductionVariable - Check to see if the loop has a canonical 39516a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman /// induction variable: an integer recurrence that starts at 0 and increments 39616a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman /// by one each time through the loop. If so, return the phi node that 39716a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman /// corresponds to it. 39816a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman /// 39916a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman /// The IndVarSimplify pass transforms loops to have a canonical induction 40016a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman /// variable. 40116a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman /// 40216a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman PHINode *getCanonicalInductionVariable() const; 40316a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman 40416a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman /// isLCSSAForm - Return true if the Loop is in LCSSA form 405bbf81d88116d23fb0776412b5916f7d0b8b3ca7eDan Gohman bool isLCSSAForm(DominatorTree &DT) const; 40616a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman 407937738649386b8188524d0cd61943214a5b93cf6Dan Gohman /// isLoopSimplifyForm - Return true if the Loop is in the form that 408937738649386b8188524d0cd61943214a5b93cf6Dan Gohman /// the LoopSimplify form transforms loops to, which is sometimes called 409937738649386b8188524d0cd61943214a5b93cf6Dan Gohman /// normal form. 410937738649386b8188524d0cd61943214a5b93cf6Dan Gohman bool isLoopSimplifyForm() const; 411937738649386b8188524d0cd61943214a5b93cf6Dan Gohman 412d9fc1ce8096f7138c60edc3a6655583bf209780eAndrew Trick /// isSafeToClone - Return true if the loop body is safe to clone in practice. 413d9fc1ce8096f7138c60edc3a6655583bf209780eAndrew Trick bool isSafeToClone() const; 414d9fc1ce8096f7138c60edc3a6655583bf209780eAndrew Trick 4155d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen /// Returns true if the loop is annotated parallel. 4165d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen /// 4175d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen /// A parallel loop can be assumed to not contain any dependencies between 4185d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen /// iterations by the compiler. That is, any loop-carried dependency checking 4195d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen /// can be skipped completely when parallelizing the loop on the target 4205d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen /// machine. Thus, if the parallel loop information originates from the 4215d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen /// programmer, e.g. via the OpenMP parallel for pragma, it is the 4225d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen /// programmer's responsibility to ensure there are no loop-carried 4235d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen /// dependencies. The final execution order of the instructions across 4245d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen /// iterations is not guaranteed, thus, the end result might or might not 4255d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen /// implement actual concurrent execution of instructions across multiple 4265d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen /// iterations. 4275d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen bool isAnnotatedParallel() const; 4285d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen 429ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// Return the llvm.loop loop id metadata node for this loop if it is present. 430ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// 431ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// If this loop contains the same llvm.loop metadata on each branch to the 432ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// header then the node is returned. If any latch instruction does not 433ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// contain llvm.loop or or if multiple latches contain different nodes then 434ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// 0 is returned. 435ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond MDNode *getLoopID() const; 436ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// Set the llvm.loop loop id metadata for this loop. 437ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// 438ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// The LoopID metadata node will be added to each terminator instruction in 439ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// the loop that branches to the loop header. 440ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// 441ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// The LoopID metadata node should have one or more operands and the first 442ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// operand should should be the node itself. 443ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond void setLoopID(MDNode *LoopID) const; 444ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond 445f17e9511f15a0e007ff47d0789d1a52502e8c1fbDan Gohman /// hasDedicatedExits - Return true if no exit block for the loop 446f17e9511f15a0e007ff47d0789d1a52502e8c1fbDan Gohman /// has a predecessor that is outside the loop. 447f17e9511f15a0e007ff47d0789d1a52502e8c1fbDan Gohman bool hasDedicatedExits() const; 448f17e9511f15a0e007ff47d0789d1a52502e8c1fbDan Gohman 449fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick /// getUniqueExitBlocks - Return all unique successor blocks of this loop. 450f0608d829a7b8929108ac6718bd866adf710e936Dan Gohman /// These are the blocks _outside of the current loop_ which are branched to. 451050959cd08db6c0efb8208271a1d64ce58893e20Dan Gohman /// This assumes that loop exits are in canonical form. 452f0608d829a7b8929108ac6718bd866adf710e936Dan Gohman /// 453f0608d829a7b8929108ac6718bd866adf710e936Dan Gohman void getUniqueExitBlocks(SmallVectorImpl<BasicBlock *> &ExitBlocks) const; 454f0608d829a7b8929108ac6718bd866adf710e936Dan Gohman 455f0608d829a7b8929108ac6718bd866adf710e936Dan Gohman /// getUniqueExitBlock - If getUniqueExitBlocks would return exactly one 456f0608d829a7b8929108ac6718bd866adf710e936Dan Gohman /// block, return that block. Otherwise return null. 457f0608d829a7b8929108ac6718bd866adf710e936Dan Gohman BasicBlock *getUniqueExitBlock() const; 458f0608d829a7b8929108ac6718bd866adf710e936Dan Gohman 459dda30cd4af1c5f88fc00fd40b673f8e27c61379dDan Gohman void dump() const; 460fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 461dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines /// \brief Return the debug location of the start of this loop. 462dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines /// This looks for a BB terminating instruction with a known debug 463dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines /// location by looking at the preheader and header blocks. If it 464dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines /// cannot find a terminating instruction with location information, 465dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines /// it returns an unknown location. 466dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines DebugLoc getStartLoc() const { 467dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines BasicBlock *HeadBB; 468dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines 469dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines // Try the pre-header first. 4702c3e0051c31c3f5b2328b447eadf1cf9c4427442Pirama Arumuga Nainar if ((HeadBB = getLoopPreheader()) != nullptr) 4712c3e0051c31c3f5b2328b447eadf1cf9c4427442Pirama Arumuga Nainar if (DebugLoc DL = HeadBB->getTerminator()->getDebugLoc()) 4722c3e0051c31c3f5b2328b447eadf1cf9c4427442Pirama Arumuga Nainar return DL; 473dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines 474dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines // If we have no pre-header or there are no instructions with debug 475dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines // info in it, try the header. 476dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines HeadBB = getHeader(); 477dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines if (HeadBB) 4782c3e0051c31c3f5b2328b447eadf1cf9c4427442Pirama Arumuga Nainar return HeadBB->getTerminator()->getDebugLoc(); 479dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines 4802c3e0051c31c3f5b2328b447eadf1cf9c4427442Pirama Arumuga Nainar return DebugLoc(); 481dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines } 482dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines 483c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohmanprivate: 484c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman friend class LoopInfoBase<BasicBlock, Loop>; 485c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman explicit Loop(BasicBlock *BB) : LoopBase<BasicBlock, Loop>(BB) {} 486c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman}; 4870bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner 4880bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner//===----------------------------------------------------------------------===// 4892b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner/// LoopInfo - This class builds and contains all of the top level loop 4902b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner/// structures in the specified function. 4912b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner/// 49244a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson 493c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohmantemplate<class BlockT, class LoopT> 49444a95e06cc0bb3a2d617fe94235aee92b1951910Owen Andersonclass LoopInfoBase { 4950bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner // BBMap - Mapping of basic blocks to the inner most loop they occur in 49672851059224b90a3ae74ecd62fbd927a0c54a9f0Cameron Zwarich DenseMap<BlockT *, LoopT *> BBMap; 497c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman std::vector<LoopT *> TopLevelLoops; 498c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman friend class LoopBase<BlockT, LoopT>; 4995434c1e73b6e56756719d2aebb952ac7bb3829e0Andrew Trick friend class LoopInfo; 5009d59d9f8495b0361c9ffd1dc82888d8e7ba5070eDan Gohman 501ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines void operator=(const LoopInfoBase &) = delete; 502ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines LoopInfoBase(const LoopInfoBase &) = delete; 5030bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattnerpublic: 50444a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson LoopInfoBase() { } 50544a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson ~LoopInfoBase() { releaseMemory(); } 506fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 507ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines LoopInfoBase(LoopInfoBase &&Arg) 508ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines : BBMap(std::move(Arg.BBMap)), 509ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines TopLevelLoops(std::move(Arg.TopLevelLoops)) { 510ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines // We have to clear the arguments top level loops as we've taken ownership. 511ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines Arg.TopLevelLoops.clear(); 512ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines } 513ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines LoopInfoBase &operator=(LoopInfoBase &&RHS) { 514ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines BBMap = std::move(RHS.BBMap); 515ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 516ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines for (auto *L : TopLevelLoops) 517ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines delete L; 518ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines TopLevelLoops = std::move(RHS.TopLevelLoops); 519ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines RHS.TopLevelLoops.clear(); 520ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return *this; 521ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines } 522ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 52344a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson void releaseMemory() { 524ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines BBMap.clear(); 5250bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner 526ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines for (auto *L : TopLevelLoops) 527ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines delete L; 52844a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson TopLevelLoops.clear(); 52944a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson } 530fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 531329c1c6c949d07e3fe9722ec633b4258217fd99dChris Lattner /// iterator/begin/end - The interface to the top-level loops in the current 532329c1c6c949d07e3fe9722ec633b4258217fd99dChris Lattner /// function. 533329c1c6c949d07e3fe9722ec633b4258217fd99dChris Lattner /// 534c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman typedef typename std::vector<LoopT *>::const_iterator iterator; 535c9b1e25493b393013b28e5d457f2fb2845a4dd9fAndrew Trick typedef typename std::vector<LoopT *>::const_reverse_iterator 536c9b1e25493b393013b28e5d457f2fb2845a4dd9fAndrew Trick reverse_iterator; 537329c1c6c949d07e3fe9722ec633b4258217fd99dChris Lattner iterator begin() const { return TopLevelLoops.begin(); } 538329c1c6c949d07e3fe9722ec633b4258217fd99dChris Lattner iterator end() const { return TopLevelLoops.end(); } 539c9b1e25493b393013b28e5d457f2fb2845a4dd9fAndrew Trick reverse_iterator rbegin() const { return TopLevelLoops.rbegin(); } 540c9b1e25493b393013b28e5d457f2fb2845a4dd9fAndrew Trick reverse_iterator rend() const { return TopLevelLoops.rend(); } 541a8c763b3071ae1a58ee8baeb282331245527e004Dan Gohman bool empty() const { return TopLevelLoops.empty(); } 542fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 5432b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// getLoopFor - Return the inner most loop that BB lives in. If a basic 5442b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// block is in no loop (for example the entry node), null is returned. 5452b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// 546c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman LoopT *getLoopFor(const BlockT *BB) const { 547da69f3b357097e75fbf9a5a2bbe1e7273d4b4271Benjamin Kramer return BBMap.lookup(const_cast<BlockT*>(BB)); 5480bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner } 549fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 5502b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// operator[] - same as getLoopFor... 5512b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// 552c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman const LoopT *operator[](const BlockT *BB) const { 5530bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner return getLoopFor(BB); 5540bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner } 555fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 556ba42d2b937160c970c8c6ea57573113c9265325fDan Gohman /// getLoopDepth - Return the loop nesting level of the specified block. A 557ba42d2b937160c970c8c6ea57573113c9265325fDan Gohman /// depth of 0 means the block is not inside any loop. 5582b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// 55944a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson unsigned getLoopDepth(const BlockT *BB) const { 560c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman const LoopT *L = getLoopFor(BB); 5610bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner return L ? L->getLoopDepth() : 0; 5620bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner } 5630bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner 5640bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner // isLoopHeader - True if the block is a loop header node 56544a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson bool isLoopHeader(BlockT *BB) const { 566c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman const LoopT *L = getLoopFor(BB); 56750f5490842d501e269a4c6085d0d132cae0d31f8Chris Lattner return L && L->getHeader() == BB; 5680bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner } 569fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 57044a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// removeLoop - This removes the specified top-level loop from this loop info 57144a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// object. The loop is not deleted, as it will presumably be inserted into 57244a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// another loop. 573c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman LoopT *removeLoop(iterator I) { 57444a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson assert(I != end() && "Cannot remove end iterator!"); 575c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman LoopT *L = *I; 576dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines assert(!L->getParentLoop() && "Not a top-level loop!"); 57744a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson TopLevelLoops.erase(TopLevelLoops.begin() + (I-begin())); 57844a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson return L; 57944a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson } 580fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 58144a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// changeLoopFor - Change the top-level loop that contains BB to the 58244a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// specified loop. This should be used by transformations that restructure 58344a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// the loop hierarchy tree. 584c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman void changeLoopFor(BlockT *BB, LoopT *L) { 585fb62b8deb3c837bc5f4cf98543b89d08e7db9f84Andrew Trick if (!L) { 586da69f3b357097e75fbf9a5a2bbe1e7273d4b4271Benjamin Kramer BBMap.erase(BB); 587fb62b8deb3c837bc5f4cf98543b89d08e7db9f84Andrew Trick return; 588fb62b8deb3c837bc5f4cf98543b89d08e7db9f84Andrew Trick } 589fb62b8deb3c837bc5f4cf98543b89d08e7db9f84Andrew Trick BBMap[BB] = L; 59044a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson } 591fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 59244a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// changeTopLevelLoop - Replace the specified loop in the top-level loops 59344a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// list with the indicated loop. 594c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman void changeTopLevelLoop(LoopT *OldLoop, 595c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman LoopT *NewLoop) { 596ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines auto I = std::find(TopLevelLoops.begin(), TopLevelLoops.end(), OldLoop); 59744a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson assert(I != TopLevelLoops.end() && "Old loop not at top level!"); 59844a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson *I = NewLoop; 599dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines assert(!NewLoop->ParentLoop && !OldLoop->ParentLoop && 60044a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson "Loops already embedded into a subloop!"); 60144a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson } 602fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 60344a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// addTopLevelLoop - This adds the specified loop to the collection of 60444a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// top-level loops. 605c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman void addTopLevelLoop(LoopT *New) { 606dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines assert(!New->getParentLoop() && "Loop already in subloop!"); 60744a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson TopLevelLoops.push_back(New); 60844a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson } 609fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 61044a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// removeBlock - This method completely removes BB from all data structures, 61144a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// including all of the Loop objects it is nested in and our mapping from 61244a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// BasicBlocks to loops. 61344a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson void removeBlock(BlockT *BB) { 614ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines auto I = BBMap.find(BB); 61544a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson if (I != BBMap.end()) { 616c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman for (LoopT *L = I->second; L; L = L->getParentLoop()) 61744a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson L->removeBlockFromLoop(BB); 61844a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson 61944a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson BBMap.erase(I); 62044a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson } 62144a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson } 622fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 62344a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson // Internals 624fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 625c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman static bool isNotAlreadyContainedIn(const LoopT *SubLoop, 626c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman const LoopT *ParentLoop) { 627dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines if (!SubLoop) return true; 62844a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson if (SubLoop == ParentLoop) return false; 62944a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson return isNotAlreadyContainedIn(SubLoop->getParentLoop(), ParentLoop); 63044a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson } 631fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 63237aa33bc11c01a7142bfa2428a5a4d219b07b6c3Andrew Trick /// Create the loop forest using a stable algorithm. 63337aa33bc11c01a7142bfa2428a5a4d219b07b6c3Andrew Trick void Analyze(DominatorTreeBase<BlockT> &DomTree); 63437aa33bc11c01a7142bfa2428a5a4d219b07b6c3Andrew Trick 63544a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson // Debugging 636cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick void print(raw_ostream &OS) const; 637ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 638ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines void verify() const; 63944a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson}; 64044a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson 64160c7d5bc2cbeff9eff16716295ffd6a5374dc6bcAndrew Trick// Implementation in LoopInfoImpl.h 64260c7d5bc2cbeff9eff16716295ffd6a5374dc6bcAndrew Trick#ifdef __GNUC__ 64360c7d5bc2cbeff9eff16716295ffd6a5374dc6bcAndrew Trick__extension__ extern template class LoopInfoBase<BasicBlock, Loop>; 64460c7d5bc2cbeff9eff16716295ffd6a5374dc6bcAndrew Trick#endif 64560c7d5bc2cbeff9eff16716295ffd6a5374dc6bcAndrew Trick 646ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinesclass LoopInfo : public LoopInfoBase<BasicBlock, Loop> { 647ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines typedef LoopInfoBase<BasicBlock, Loop> BaseT; 648ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 649c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman friend class LoopBase<BasicBlock, Loop>; 6509d59d9f8495b0361c9ffd1dc82888d8e7ba5070eDan Gohman 651ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines void operator=(const LoopInfo &) = delete; 652ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines LoopInfo(const LoopInfo &) = delete; 65344a95e06cc0bb3a2d617fe94235aee92b1951910Owen Andersonpublic: 654ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines LoopInfo() {} 655d735ee85dbab8e4f66f9ec157f19956e0d11ec7aOwen Anderson 656ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines LoopInfo(LoopInfo &&Arg) : BaseT(std::move(static_cast<BaseT &>(Arg))) {} 657ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines LoopInfo &operator=(LoopInfo &&RHS) { 658ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines BaseT::operator=(std::move(static_cast<BaseT &>(RHS))); 659ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return *this; 66044a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson } 66144a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson 662ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines // Most of the public interface is provided via LoopInfoBase. 663d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands 664fb62b8deb3c837bc5f4cf98543b89d08e7db9f84Andrew Trick /// updateUnloop - Update LoopInfo after removing the last backedge from a 665fb62b8deb3c837bc5f4cf98543b89d08e7db9f84Andrew Trick /// loop--now the "unloop". This updates the loop forest and parent loops for 666fb62b8deb3c837bc5f4cf98543b89d08e7db9f84Andrew Trick /// each block so that Unloop is no longer referenced, but the caller must 667fb62b8deb3c837bc5f4cf98543b89d08e7db9f84Andrew Trick /// actually delete the Unloop object. 668fb62b8deb3c837bc5f4cf98543b89d08e7db9f84Andrew Trick void updateUnloop(Loop *Unloop); 669fb62b8deb3c837bc5f4cf98543b89d08e7db9f84Andrew Trick 670d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands /// replacementPreservesLCSSAForm - Returns true if replacing From with To 671d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands /// everywhere is guaranteed to preserve LCSSA form. 672d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands bool replacementPreservesLCSSAForm(Instruction *From, Value *To) { 673d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands // Preserving LCSSA form is only problematic if the replacing value is an 674d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands // instruction. 675d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands Instruction *I = dyn_cast<Instruction>(To); 676d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands if (!I) return true; 6779bc6a90146417af03144fa2f7dd94f9945b57c06Duncan Sands // If both instructions are defined in the same basic block then replacement 6789bc6a90146417af03144fa2f7dd94f9945b57c06Duncan Sands // cannot break LCSSA form. 6799bc6a90146417af03144fa2f7dd94f9945b57c06Duncan Sands if (I->getParent() == From->getParent()) 6809bc6a90146417af03144fa2f7dd94f9945b57c06Duncan Sands return true; 681d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands // If the instruction is not defined in a loop then it can safely replace 682d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands // anything. 683d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands Loop *ToLoop = getLoopFor(I->getParent()); 684d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands if (!ToLoop) return true; 685d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands // If the replacing instruction is defined in the same loop as the original 686d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands // instruction, or in a loop that contains it as an inner loop, then using 687d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands // it as a replacement will not break LCSSA form. 6883b0aed19f0f9ed62362c04f7e18e2ada686f4055Duncan Sands return ToLoop->contains(getLoopFor(From->getParent())); 689d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands } 6900bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner}; 6910bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner 6921db0a400370466e187ae06c96a1586c2c21409ddChris Lattner// Allow clients to walk the list of nested loops... 6931db0a400370466e187ae06c96a1586c2c21409ddChris Lattnertemplate <> struct GraphTraits<const Loop*> { 6941db0a400370466e187ae06c96a1586c2c21409ddChris Lattner typedef const Loop NodeType; 6959d59d9f8495b0361c9ffd1dc82888d8e7ba5070eDan Gohman typedef LoopInfo::iterator ChildIteratorType; 6961db0a400370466e187ae06c96a1586c2c21409ddChris Lattner 6971db0a400370466e187ae06c96a1586c2c21409ddChris Lattner static NodeType *getEntryNode(const Loop *L) { return L; } 6989769ab22265b313171d201b5928688524a01bd87Misha Brukman static inline ChildIteratorType child_begin(NodeType *N) { 699329c1c6c949d07e3fe9722ec633b4258217fd99dChris Lattner return N->begin(); 7001db0a400370466e187ae06c96a1586c2c21409ddChris Lattner } 7019769ab22265b313171d201b5928688524a01bd87Misha Brukman static inline ChildIteratorType child_end(NodeType *N) { 702329c1c6c949d07e3fe9722ec633b4258217fd99dChris Lattner return N->end(); 7031db0a400370466e187ae06c96a1586c2c21409ddChris Lattner } 7041db0a400370466e187ae06c96a1586c2c21409ddChris Lattner}; 7051db0a400370466e187ae06c96a1586c2c21409ddChris Lattner 7061db0a400370466e187ae06c96a1586c2c21409ddChris Lattnertemplate <> struct GraphTraits<Loop*> { 7071db0a400370466e187ae06c96a1586c2c21409ddChris Lattner typedef Loop NodeType; 7089d59d9f8495b0361c9ffd1dc82888d8e7ba5070eDan Gohman typedef LoopInfo::iterator ChildIteratorType; 7091db0a400370466e187ae06c96a1586c2c21409ddChris Lattner 7101db0a400370466e187ae06c96a1586c2c21409ddChris Lattner static NodeType *getEntryNode(Loop *L) { return L; } 7119769ab22265b313171d201b5928688524a01bd87Misha Brukman static inline ChildIteratorType child_begin(NodeType *N) { 712329c1c6c949d07e3fe9722ec633b4258217fd99dChris Lattner return N->begin(); 7131db0a400370466e187ae06c96a1586c2c21409ddChris Lattner } 7149769ab22265b313171d201b5928688524a01bd87Misha Brukman static inline ChildIteratorType child_end(NodeType *N) { 715329c1c6c949d07e3fe9722ec633b4258217fd99dChris Lattner return N->end(); 7161db0a400370466e187ae06c96a1586c2c21409ddChris Lattner } 7171db0a400370466e187ae06c96a1586c2c21409ddChris Lattner}; 7181db0a400370466e187ae06c96a1586c2c21409ddChris Lattner 719ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// \brief Analysis pass that exposes the \c LoopInfo for a function. 720ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinesclass LoopAnalysis { 721ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static char PassID; 722ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 723ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinespublic: 724ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines typedef LoopInfo Result; 725ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 726ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines /// \brief Opaque, unique identifier for this analysis pass. 727ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static void *ID() { return (void *)&PassID; } 728ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 729ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines /// \brief Provide a name for the analysis for debugging and logging. 730ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static StringRef name() { return "LoopAnalysis"; } 731ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 732ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines LoopAnalysis() {} 733ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines LoopAnalysis(const LoopAnalysis &Arg) {} 734ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines LoopAnalysis(LoopAnalysis &&Arg) {} 735ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines LoopAnalysis &operator=(const LoopAnalysis &RHS) { return *this; } 736ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines LoopAnalysis &operator=(LoopAnalysis &&RHS) { return *this; } 737ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 738ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines LoopInfo run(Function &F, AnalysisManager<Function> *AM); 739ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines}; 740ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 741ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// \brief Printer pass for the \c LoopAnalysis results. 742ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinesclass LoopPrinterPass { 743ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines raw_ostream &OS; 744ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 745ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinespublic: 746ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines explicit LoopPrinterPass(raw_ostream &OS) : OS(OS) {} 747ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines PreservedAnalyses run(Function &F, AnalysisManager<Function> *AM); 748ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 749ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static StringRef name() { return "LoopPrinterPass"; } 750ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines}; 751ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 752ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// \brief The legacy pass manager's analysis pass to compute loop information. 753ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinesclass LoopInfoWrapperPass : public FunctionPass { 754ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines LoopInfo LI; 755ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 756ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinespublic: 757ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static char ID; // Pass identification, replacement for typeid 758ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 759ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines LoopInfoWrapperPass() : FunctionPass(ID) { 760ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines initializeLoopInfoWrapperPassPass(*PassRegistry::getPassRegistry()); 761ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines } 762ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 763ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines LoopInfo &getLoopInfo() { return LI; } 764ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines const LoopInfo &getLoopInfo() const { return LI; } 765ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 766ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines /// \brief Calculate the natural loop information for a given function. 767ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines bool runOnFunction(Function &F) override; 768ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 769ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines void verifyAnalysis() const override; 770ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 771ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines void releaseMemory() override { LI.releaseMemory(); } 772ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 773ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines void print(raw_ostream &O, const Module *M = nullptr) const override; 774ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 775ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines void getAnalysisUsage(AnalysisUsage &AU) const override; 776ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines}; 777ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 778d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke} // End llvm namespace 779d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke 7800bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner#endif 781