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 45019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Andersontemplate<typename T> 46305b515c2787f47adecbe120e4b4bef55c5e5525Chandler Carruthinline void RemoveFromVector(std::vector<T*> &V, T *N) { 47019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson typename std::vector<T*>::iterator I = std::find(V.begin(), V.end(), N); 48019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson assert(I != V.end() && "N is not in this list!"); 49019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson V.erase(I); 50019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson} 510bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner 5253c279b1949f7fa626ccbc399ebbe2d7dc9599a4Devang Patelclass DominatorTree; 538fc2f2072de83665ae20e06929e28317f449bcdfChris Lattnerclass LoopInfo; 54c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohmanclass Loop; 55ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmondclass MDNode; 569fc5cdf77c812aaa80419036de27576d45894d0dChris Lattnerclass PHINode; 57209cb5b56bb90f1ceee570efabe9c04121cb0bebJakub Staszakclass raw_ostream; 5836b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hinestemplate<class N> class DominatorTreeBase; 59c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohmantemplate<class N, class M> class LoopInfoBase; 60c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohmantemplate<class N, class M> class LoopBase; 610bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner 620bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner//===----------------------------------------------------------------------===// 63131bd2ecf721749666111ec2dd1d32a20ae049b2Chris Lattner/// LoopBase class - Instances of this class are used to represent loops that 64131bd2ecf721749666111ec2dd1d32a20ae049b2Chris Lattner/// are detected in the flow graph 652b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner/// 66c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohmantemplate<class BlockT, class LoopT> 67019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Andersonclass LoopBase { 68c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman LoopT *ParentLoop; 69131bd2ecf721749666111ec2dd1d32a20ae049b2Chris Lattner // SubLoops - Loops contained entirely within this one. 70c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman std::vector<LoopT *> SubLoops; 71131bd2ecf721749666111ec2dd1d32a20ae049b2Chris Lattner 72131bd2ecf721749666111ec2dd1d32a20ae049b2Chris Lattner // Blocks - The list of blocks in this loop. First entry is the header node. 73131bd2ecf721749666111ec2dd1d32a20ae049b2Chris Lattner std::vector<BlockT*> Blocks; 74019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson 75887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei SmallPtrSet<const BlockT*, 8> DenseBlockSet; 76887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei 77de8091708f2d5ade958507aa6d37907a6277e9f2Craig Topper LoopBase(const LoopBase<BlockT, LoopT> &) LLVM_DELETED_FUNCTION; 78de8091708f2d5ade958507aa6d37907a6277e9f2Craig Topper const LoopBase<BlockT, LoopT>& 79de8091708f2d5ade958507aa6d37907a6277e9f2Craig Topper operator=(const LoopBase<BlockT, LoopT> &) LLVM_DELETED_FUNCTION; 800bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattnerpublic: 8146758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// Loop ctor - This creates an empty loop. 82dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines LoopBase() : ParentLoop(nullptr) {} 83019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson ~LoopBase() { 8434cd4a484e532cc463fd5a4bf59b88d13c5467c1Evan Cheng for (size_t i = 0, e = SubLoops.size(); i != e; ++i) 854e55b7d2c62de7efa0147e0579980de8b1df9123Chris Lattner delete SubLoops[i]; 864e55b7d2c62de7efa0147e0579980de8b1df9123Chris Lattner } 870bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner 88ba42d2b937160c970c8c6ea57573113c9265325fDan Gohman /// getLoopDepth - Return the nesting level of this loop. An outer-most 89ba42d2b937160c970c8c6ea57573113c9265325fDan Gohman /// loop has depth 1, for consistency with loop depth values used for basic 90ba42d2b937160c970c8c6ea57573113c9265325fDan Gohman /// blocks, where depth 0 is used for blocks not inside any loops. 91072b163424491c85df6664a4e056aae5e07dc64dChris Lattner unsigned getLoopDepth() const { 92ba42d2b937160c970c8c6ea57573113c9265325fDan Gohman unsigned D = 1; 93c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman for (const LoopT *CurLoop = ParentLoop; CurLoop; 94019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson CurLoop = CurLoop->ParentLoop) 95072b163424491c85df6664a4e056aae5e07dc64dChris Lattner ++D; 96072b163424491c85df6664a4e056aae5e07dc64dChris Lattner return D; 97072b163424491c85df6664a4e056aae5e07dc64dChris Lattner } 98019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson BlockT *getHeader() const { return Blocks.front(); } 99c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman LoopT *getParentLoop() const { return ParentLoop; } 1000bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner 10137aa33bc11c01a7142bfa2428a5a4d219b07b6c3Andrew Trick /// setParentLoop is a raw interface for bypassing addChildLoop. 10237aa33bc11c01a7142bfa2428a5a4d219b07b6c3Andrew Trick void setParentLoop(LoopT *L) { ParentLoop = L; } 10337aa33bc11c01a7142bfa2428a5a4d219b07b6c3Andrew Trick 10492329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman /// contains - Return true if the specified loop is contained within in 10592329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman /// this loop. 10692329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman /// 10792329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman bool contains(const LoopT *L) const { 10892329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman if (L == this) return true; 109dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines if (!L) return false; 11092329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman return contains(L->getParentLoop()); 11192329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman } 112fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 11392329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman /// contains - Return true if the specified basic block is in this loop. 114fbdf4bf1799bf9ea566fc0fc0507752590a6d559Misha Brukman /// 115019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson bool contains(const BlockT *BB) const { 116887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei return DenseBlockSet.count(BB); 117019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson } 1180bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner 11992329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman /// contains - Return true if the specified instruction is in this loop. 12092329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman /// 12192329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman template<class InstT> 12292329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman bool contains(const InstT *Inst) const { 12392329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman return contains(Inst->getParent()); 12492329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman } 12592329c7fbe572892c17aa2d2542a10e3ea16132fDan Gohman 126329c1c6c949d07e3fe9722ec633b4258217fd99dChris Lattner /// iterator/begin/end - Return the loops contained entirely within this loop. 1272b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// 128c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman const std::vector<LoopT *> &getSubLoops() const { return SubLoops; } 12937aa33bc11c01a7142bfa2428a5a4d219b07b6c3Andrew Trick std::vector<LoopT *> &getSubLoopsVector() { return SubLoops; } 130c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman typedef typename std::vector<LoopT *>::const_iterator iterator; 131c9b1e25493b393013b28e5d457f2fb2845a4dd9fAndrew Trick typedef typename std::vector<LoopT *>::const_reverse_iterator 132c9b1e25493b393013b28e5d457f2fb2845a4dd9fAndrew Trick reverse_iterator; 133329c1c6c949d07e3fe9722ec633b4258217fd99dChris Lattner iterator begin() const { return SubLoops.begin(); } 134329c1c6c949d07e3fe9722ec633b4258217fd99dChris Lattner iterator end() const { return SubLoops.end(); } 135c9b1e25493b393013b28e5d457f2fb2845a4dd9fAndrew Trick reverse_iterator rbegin() const { return SubLoops.rbegin(); } 136c9b1e25493b393013b28e5d457f2fb2845a4dd9fAndrew Trick reverse_iterator rend() const { return SubLoops.rend(); } 13721c276d2fa99914d5ed958ac0aec7d78e3dd87cfDan Gohman bool empty() const { return SubLoops.empty(); } 138fe3ae1ed660925f06159ec89460d92148e049ffdChris Lattner 139fe3ae1ed660925f06159ec89460d92148e049ffdChris Lattner /// getBlocks - Get a list of the basic blocks which make up this loop. 140fe3ae1ed660925f06159ec89460d92148e049ffdChris Lattner /// 141019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson const std::vector<BlockT*> &getBlocks() const { return Blocks; } 142019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson typedef typename std::vector<BlockT*>::const_iterator block_iterator; 1434e77cc46ac688e7bee98747049f90e19e2902227Chris Lattner block_iterator block_begin() const { return Blocks.begin(); } 1444e77cc46ac688e7bee98747049f90e19e2902227Chris Lattner block_iterator block_end() const { return Blocks.end(); } 145fe3ae1ed660925f06159ec89460d92148e049ffdChris Lattner 146306afdf443a0e2d5d89c1a3ece00cfe18be1c4c4Andrew Trick /// getNumBlocks - Get the number of blocks in this loop in constant time. 147b1eede12818d91a32adac928c6fffcf6d2800dc0Andrew Trick unsigned getNumBlocks() const { 148306afdf443a0e2d5d89c1a3ece00cfe18be1c4c4Andrew Trick return Blocks.size(); 149b1eede12818d91a32adac928c6fffcf6d2800dc0Andrew Trick } 150b1eede12818d91a32adac928c6fffcf6d2800dc0Andrew Trick 151d146e986c818165cca866ee05751451706ccf36aDan Gohman /// isLoopExiting - True if terminator in the block can branch to another 152d146e986c818165cca866ee05751451706ccf36aDan Gohman /// block that is outside of the current loop. 153fe3ae1ed660925f06159ec89460d92148e049ffdChris Lattner /// 15432663b719b4996b3a735f22bba80d771d50f96e7Dan Gohman bool isLoopExiting(const BlockT *BB) const { 15564bf55af6f3cc6c6db985d3840547b5869e57222Jakub Staszak typedef GraphTraits<const BlockT*> BlockTraits; 156d735ee85dbab8e4f66f9ec157f19956e0d11ec7aOwen Anderson for (typename BlockTraits::ChildIteratorType SI = 15764bf55af6f3cc6c6db985d3840547b5869e57222Jakub Staszak BlockTraits::child_begin(BB), 15864bf55af6f3cc6c6db985d3840547b5869e57222Jakub Staszak SE = BlockTraits::child_end(BB); SI != SE; ++SI) { 159019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson if (!contains(*SI)) 160019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson return true; 161019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson } 162019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson return false; 163019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson } 1646b290a54409f6bb6a0cc1c0446cd2b170a4b7addMisha Brukman 165fe3ae1ed660925f06159ec89460d92148e049ffdChris Lattner /// getNumBackEdges - Calculate the number of back edges to the loop header 166fe3ae1ed660925f06159ec89460d92148e049ffdChris Lattner /// 167019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson unsigned getNumBackEdges() const { 168019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson unsigned NumBackEdges = 0; 169019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson BlockT *H = getHeader(); 170019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson 171d735ee85dbab8e4f66f9ec157f19956e0d11ec7aOwen Anderson typedef GraphTraits<Inverse<BlockT*> > InvBlockTraits; 172d735ee85dbab8e4f66f9ec157f19956e0d11ec7aOwen Anderson for (typename InvBlockTraits::ChildIteratorType I = 17364bf55af6f3cc6c6db985d3840547b5869e57222Jakub Staszak InvBlockTraits::child_begin(H), 17464bf55af6f3cc6c6db985d3840547b5869e57222Jakub Staszak E = InvBlockTraits::child_end(H); I != E; ++I) 175019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson if (contains(*I)) 176019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson ++NumBackEdges; 177019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson 178019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson return NumBackEdges; 179019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson } 1809474dd68e8a050193ca4003940ac399e2b17cb6aChris Lattner 181e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner //===--------------------------------------------------------------------===// 182e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner // APIs for simple analysis of the loop. 183e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner // 184e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner // Note that all of these methods can fail on general loops (ie, there may not 185e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner // be a preheader, etc). For best success, the loop simplification and 186e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner // induction variable canonicalization pass should be used to normalize loops 187e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner // for easy analysis. These methods assume canonical loops. 188e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner 1897466ebf045fa5097ee0d7d2728eed7fd5945c8bcChris Lattner /// getExitingBlocks - Return all blocks inside the loop that have successors 1907466ebf045fa5097ee0d7d2728eed7fd5945c8bcChris Lattner /// outside of the loop. These are the blocks _inside of the current loop_ 1917466ebf045fa5097ee0d7d2728eed7fd5945c8bcChris Lattner /// which branch out. The returned list is always unique. 1927466ebf045fa5097ee0d7d2728eed7fd5945c8bcChris Lattner /// 193cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick void getExitingBlocks(SmallVectorImpl<BlockT *> &ExitingBlocks) const; 1947466ebf045fa5097ee0d7d2728eed7fd5945c8bcChris Lattner 195c83324682f3409c15dad992cd62928426c9ad83dDan Gohman /// getExitingBlock - If getExitingBlocks would return exactly one block, 196c83324682f3409c15dad992cd62928426c9ad83dDan Gohman /// return that block. Otherwise return null. 197cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick BlockT *getExitingBlock() const; 198c83324682f3409c15dad992cd62928426c9ad83dDan Gohman 199f1ab4b4eac5603d19c20f4a508f93a118a52bdd5Chris Lattner /// getExitBlocks - Return all of the successor blocks of this loop. These 200f1ab4b4eac5603d19c20f4a508f93a118a52bdd5Chris Lattner /// are the blocks _outside of the current loop_ which are branched to. 201f1ab4b4eac5603d19c20f4a508f93a118a52bdd5Chris Lattner /// 202cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick void getExitBlocks(SmallVectorImpl<BlockT*> &ExitBlocks) const; 203f1ab4b4eac5603d19c20f4a508f93a118a52bdd5Chris Lattner 2041827e8263c9cb5dc29eea4999d8729f7376af4e1Dan Gohman /// getExitBlock - If getExitBlocks would return exactly one block, 2051827e8263c9cb5dc29eea4999d8729f7376af4e1Dan Gohman /// return that block. Otherwise return null. 206cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick BlockT *getExitBlock() const; 2071827e8263c9cb5dc29eea4999d8729f7376af4e1Dan Gohman 20860f422f894ae9aff2f508f34733be36f5a0ed20aLang Hames /// Edge type. 209cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick typedef std::pair<const BlockT*, const BlockT*> Edge; 21060f422f894ae9aff2f508f34733be36f5a0ed20aLang Hames 21155e354ac0e294bde258420f80a2cc11ea19db482Daniel Dunbar /// getExitEdges - Return all pairs of (_inside_block_,_outside_block_). 212cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick void getExitEdges(SmallVectorImpl<Edge> &ExitEdges) const; 21355e354ac0e294bde258420f80a2cc11ea19db482Daniel Dunbar 2142b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// getLoopPreheader - If there is a preheader for this loop, return it. A 2152b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// loop has a preheader if there is only one edge to the header of the loop 2162b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// from outside of the loop. If this is the case, the block branching to the 217e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner /// header of the loop is the preheader node. 2182b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// 219e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner /// This method returns null if there is no preheader for the loop. 2202b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// 221cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick BlockT *getLoopPreheader() const; 2225cf27f81f49b4516b1e9d269f070c88fa3228f9eDan Gohman 2235cf27f81f49b4516b1e9d269f070c88fa3228f9eDan Gohman /// getLoopPredecessor - If the given loop's header has exactly one unique 2245cf27f81f49b4516b1e9d269f070c88fa3228f9eDan Gohman /// predecessor outside the loop, return it. Otherwise return null. 2255cf27f81f49b4516b1e9d269f070c88fa3228f9eDan Gohman /// This is less strict that the loop "preheader" concept, which requires 2265cf27f81f49b4516b1e9d269f070c88fa3228f9eDan Gohman /// the predecessor to have exactly one successor. 2275cf27f81f49b4516b1e9d269f070c88fa3228f9eDan Gohman /// 228cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick BlockT *getLoopPredecessor() const; 2292b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner 230b317143ba851ce2853fb262fb2185ef5f1be030dDan Gohman /// getLoopLatch - If there is a single latch block for this loop, return it. 231b317143ba851ce2853fb262fb2185ef5f1be030dDan Gohman /// A latch block is a block that contains a branch back to the header. 232cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick BlockT *getLoopLatch() const; 233e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner 23436b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines /// getLoopLatches - Return all loop latch blocks of this loop. A latch block 23536b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines /// is a block that contains a branch back to the header. 23636b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines void getLoopLatches(SmallVectorImpl<BlockT *> &LoopLatches) const { 23736b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines BlockT *H = getHeader(); 23836b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines typedef GraphTraits<Inverse<BlockT*> > InvBlockTraits; 23936b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines for (typename InvBlockTraits::ChildIteratorType I = 24036b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines InvBlockTraits::child_begin(H), 24136b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines E = InvBlockTraits::child_end(H); I != E; ++I) 24236b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines if (contains(*I)) 24336b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines LoopLatches.push_back(*I); 24436b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines } 24536b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines 246e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner //===--------------------------------------------------------------------===// 247e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner // APIs for updating loop information after changing the CFG 248e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner // 249e725cb0d5a8e017b66768eaf186718b36ffea193Chris Lattner 250fe3ae1ed660925f06159ec89460d92148e049ffdChris Lattner /// addBasicBlockToLoop - This method is used by other analyses to update loop 251fe3ae1ed660925f06159ec89460d92148e049ffdChris Lattner /// information. NewBB is set to be a new member of the current loop. 2522b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// Because of this, it is added as a member of all parent loops, and is added 2532b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// to the specified LoopInfo object as being in the current basic block. It 2542b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// is not valid to replace the loop header with this method. 2552b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// 256c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman void addBasicBlockToLoop(BlockT *NewBB, LoopInfoBase<BlockT, LoopT> &LI); 2572b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner 25846758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// replaceChildLoopWith - This is used when splitting loops up. It replaces 25946758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// the OldChild entry in our children list with NewChild, and updates the 26046758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// parent pointer of OldChild to be null and the NewChild to be this loop. 26146758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// This updates the loop depth of the new child. 262cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick void replaceChildLoopWith(LoopT *OldChild, LoopT *NewChild); 26346758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner 26446758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// addChildLoop - Add the specified loop to be a child of this loop. This 26546758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// updates the loop depth of the new child. 26646758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// 267c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman void addChildLoop(LoopT *NewChild) { 268dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines assert(!NewChild->ParentLoop && "NewChild already has a parent!"); 269c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman NewChild->ParentLoop = static_cast<LoopT *>(this); 270019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson SubLoops.push_back(NewChild); 271019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson } 27246758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner 27346758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// removeChildLoop - This removes the specified child from being a subloop of 27446758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// this loop. The loop is not deleted, as it will presumably be inserted 27546758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// into another loop. 276c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman LoopT *removeChildLoop(iterator I) { 277019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson assert(I != SubLoops.end() && "Cannot remove end iterator!"); 278c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman LoopT *Child = *I; 279019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson assert(Child->ParentLoop == this && "Child is not a child of this loop!"); 280019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson SubLoops.erase(SubLoops.begin()+(I-begin())); 281dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines Child->ParentLoop = nullptr; 282019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson return Child; 283019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson } 28446758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner 28546758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// addBlockEntry - This adds a basic block directly to the basic block list. 28646758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// This should only be used by transformations that create new loops. Other 28746758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// transformations should use addBasicBlockToLoop. 288019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson void addBlockEntry(BlockT *BB) { 28946758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner Blocks.push_back(BB); 290887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei DenseBlockSet.insert(BB); 291887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei } 292887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei 293887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei /// reverseBlocks - interface to reverse Blocks[from, end of loop] in this loop 294887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei void reverseBlock(unsigned from) { 295887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei std::reverse(Blocks.begin() + from, Blocks.end()); 296887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei } 297887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei 298887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei /// reserveBlocks- interface to do reserve() for Blocks 299887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei void reserveBlocks(unsigned size) { 300887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei Blocks.reserve(size); 30146758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner } 30246758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner 30351a4ad475b095aed49caff176b98c0754e421af4Chris Lattner /// moveToHeader - This method is used to move BB (which must be part of this 30451a4ad475b095aed49caff176b98c0754e421af4Chris Lattner /// loop) to be the loop header of the loop (the block that dominates all 30551a4ad475b095aed49caff176b98c0754e421af4Chris Lattner /// others). 306019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson void moveToHeader(BlockT *BB) { 30751a4ad475b095aed49caff176b98c0754e421af4Chris Lattner if (Blocks[0] == BB) return; 30851a4ad475b095aed49caff176b98c0754e421af4Chris Lattner for (unsigned i = 0; ; ++i) { 30951a4ad475b095aed49caff176b98c0754e421af4Chris Lattner assert(i != Blocks.size() && "Loop does not contain BB!"); 31051a4ad475b095aed49caff176b98c0754e421af4Chris Lattner if (Blocks[i] == BB) { 31151a4ad475b095aed49caff176b98c0754e421af4Chris Lattner Blocks[i] = Blocks[0]; 31251a4ad475b095aed49caff176b98c0754e421af4Chris Lattner Blocks[0] = BB; 31351a4ad475b095aed49caff176b98c0754e421af4Chris Lattner return; 31451a4ad475b095aed49caff176b98c0754e421af4Chris Lattner } 31551a4ad475b095aed49caff176b98c0754e421af4Chris Lattner } 31651a4ad475b095aed49caff176b98c0754e421af4Chris Lattner } 31751a4ad475b095aed49caff176b98c0754e421af4Chris Lattner 31846758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// removeBlockFromLoop - This removes the specified basic block from the 319f1ab4b4eac5603d19c20f4a508f93a118a52bdd5Chris Lattner /// current loop, updating the Blocks as appropriate. This does not update 320f1ab4b4eac5603d19c20f4a508f93a118a52bdd5Chris Lattner /// the mapping in the LoopInfo class. 321019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson void removeBlockFromLoop(BlockT *BB) { 322019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson RemoveFromVector(Blocks, BB); 323887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei DenseBlockSet.erase(BB); 324019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson } 32546758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner 32658e0ef1e90c3f6dbae213612b44e56f7d6d65ea7Devang Patel /// verifyLoop - Verify loop structure 327cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick void verifyLoop() const; 328019b92a70c11319f5ab96c9f5e66e4e111a972f8Owen Anderson 3295c89b5240c90eb8171f999e5f06f815502d0321cDan Gohman /// verifyLoop - Verify loop structure of this loop and all nested loops. 330cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick void verifyLoopNest(DenseSet<const LoopT*> *Loops) const; 33158e0ef1e90c3f6dbae213612b44e56f7d6d65ea7Devang Patel 332cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick void print(raw_ostream &OS, unsigned Depth = 0) const; 333dda30cd4af1c5f88fc00fd40b673f8e27c61379dDan Gohman 334c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohmanprotected: 335c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman friend class LoopInfoBase<BlockT, LoopT>; 336dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines explicit LoopBase(BlockT *BB) : ParentLoop(nullptr) { 337072b163424491c85df6664a4e056aae5e07dc64dChris Lattner Blocks.push_back(BB); 338887f9c5ec15582aec34aa6c28955d01e4e9961e2Wan Xiaofei DenseBlockSet.insert(BB); 3390bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner } 3400bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner}; 3410bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner 3426a0dc079efe7acf7e71cc4c0948fe814f35ba091Jakob Stoklund Olesentemplate<class BlockT, class LoopT> 3436a0dc079efe7acf7e71cc4c0948fe814f35ba091Jakob Stoklund Olesenraw_ostream& operator<<(raw_ostream &OS, const LoopBase<BlockT, LoopT> &Loop) { 3446a0dc079efe7acf7e71cc4c0948fe814f35ba091Jakob Stoklund Olesen Loop.print(OS); 3456a0dc079efe7acf7e71cc4c0948fe814f35ba091Jakob Stoklund Olesen return OS; 3466a0dc079efe7acf7e71cc4c0948fe814f35ba091Jakob Stoklund Olesen} 3476a0dc079efe7acf7e71cc4c0948fe814f35ba091Jakob Stoklund Olesen 34860c7d5bc2cbeff9eff16716295ffd6a5374dc6bcAndrew Trick// Implementation in LoopInfoImpl.h 34960c7d5bc2cbeff9eff16716295ffd6a5374dc6bcAndrew Trick#ifdef __GNUC__ 35060c7d5bc2cbeff9eff16716295ffd6a5374dc6bcAndrew Trick__extension__ extern template class LoopBase<BasicBlock, Loop>; 35160c7d5bc2cbeff9eff16716295ffd6a5374dc6bcAndrew Trick#endif 35260c7d5bc2cbeff9eff16716295ffd6a5374dc6bcAndrew Trick 353c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohmanclass Loop : public LoopBase<BasicBlock, Loop> { 354c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohmanpublic: 355c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman Loop() {} 35616a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman 35716a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman /// isLoopInvariant - Return true if the specified value is loop invariant 35816a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman /// 35916a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman bool isLoopInvariant(Value *V) const; 36016a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman 361adc799112dc180b3cd099038c05101b85d217716Chris Lattner /// hasLoopInvariantOperands - Return true if all the operands of the 362fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick /// specified instruction are loop invariant. 363adc799112dc180b3cd099038c05101b85d217716Chris Lattner bool hasLoopInvariantOperands(Instruction *I) const; 364a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman 365206613b289f60b71a76e9190d36b9ea9e47a701eDan Gohman /// makeLoopInvariant - If the given value is an instruction inside of the 366a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// loop and it can be hoisted, do so to make it trivially loop-invariant. 367a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// Return true if the value after any hoisting is loop invariant. This 368a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// function can be used as a slightly more aggressive replacement for 369a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// isLoopInvariant. 370a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// 371a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// If InsertPt is specified, it is the point to hoist instructions to. 372a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// If null, the terminator of the loop preheader is used. 373a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// 374bdc017edacb713119b24ab269d250a82d62fffebDan Gohman bool makeLoopInvariant(Value *V, bool &Changed, 375dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines Instruction *InsertPt = nullptr) const; 376a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman 377a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// makeLoopInvariant - If the given instruction is inside of the 378a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// loop and it can be hoisted, do so to make it trivially loop-invariant. 379a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// Return true if the instruction after any hoisting is loop invariant. This 380a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// function can be used as a slightly more aggressive replacement for 381a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// isLoopInvariant. 382a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// 383a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// If InsertPt is specified, it is the point to hoist instructions to. 384a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// If null, the terminator of the loop preheader is used. 385a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman /// 386bdc017edacb713119b24ab269d250a82d62fffebDan Gohman bool makeLoopInvariant(Instruction *I, bool &Changed, 387dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines Instruction *InsertPt = nullptr) const; 388a342026504e65e2c8dc5600dab4b45ab4f94026dDan Gohman 38916a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman /// getCanonicalInductionVariable - Check to see if the loop has a canonical 39016a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman /// induction variable: an integer recurrence that starts at 0 and increments 39116a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman /// by one each time through the loop. If so, return the phi node that 39216a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman /// corresponds to it. 39316a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman /// 39416a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman /// The IndVarSimplify pass transforms loops to have a canonical induction 39516a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman /// variable. 39616a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman /// 39716a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman PHINode *getCanonicalInductionVariable() const; 39816a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman 39916a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman /// isLCSSAForm - Return true if the Loop is in LCSSA form 400bbf81d88116d23fb0776412b5916f7d0b8b3ca7eDan Gohman bool isLCSSAForm(DominatorTree &DT) const; 40116a2c927e95c29a316d0271c93e0490ce3bc06ceDan Gohman 402937738649386b8188524d0cd61943214a5b93cf6Dan Gohman /// isLoopSimplifyForm - Return true if the Loop is in the form that 403937738649386b8188524d0cd61943214a5b93cf6Dan Gohman /// the LoopSimplify form transforms loops to, which is sometimes called 404937738649386b8188524d0cd61943214a5b93cf6Dan Gohman /// normal form. 405937738649386b8188524d0cd61943214a5b93cf6Dan Gohman bool isLoopSimplifyForm() const; 406937738649386b8188524d0cd61943214a5b93cf6Dan Gohman 407d9fc1ce8096f7138c60edc3a6655583bf209780eAndrew Trick /// isSafeToClone - Return true if the loop body is safe to clone in practice. 408d9fc1ce8096f7138c60edc3a6655583bf209780eAndrew Trick bool isSafeToClone() const; 409d9fc1ce8096f7138c60edc3a6655583bf209780eAndrew Trick 4105d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen /// Returns true if the loop is annotated parallel. 4115d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen /// 4125d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen /// A parallel loop can be assumed to not contain any dependencies between 4135d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen /// iterations by the compiler. That is, any loop-carried dependency checking 4145d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen /// can be skipped completely when parallelizing the loop on the target 4155d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen /// machine. Thus, if the parallel loop information originates from the 4165d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen /// programmer, e.g. via the OpenMP parallel for pragma, it is the 4175d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen /// programmer's responsibility to ensure there are no loop-carried 4185d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen /// dependencies. The final execution order of the instructions across 4195d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen /// iterations is not guaranteed, thus, the end result might or might not 4205d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen /// implement actual concurrent execution of instructions across multiple 4215d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen /// iterations. 4225d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen bool isAnnotatedParallel() const; 4235d0ce79e26f40141f35cc0002dc5cc6060382359Pekka Jaaskelainen 424ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// Return the llvm.loop loop id metadata node for this loop if it is present. 425ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// 426ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// If this loop contains the same llvm.loop metadata on each branch to the 427ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// header then the node is returned. If any latch instruction does not 428ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// contain llvm.loop or or if multiple latches contain different nodes then 429ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// 0 is returned. 430ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond MDNode *getLoopID() const; 431ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// Set the llvm.loop loop id metadata for this loop. 432ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// 433ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// The LoopID metadata node will be added to each terminator instruction in 434ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// the loop that branches to the loop header. 435ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// 436ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// The LoopID metadata node should have one or more operands and the first 437ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond /// operand should should be the node itself. 438ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond void setLoopID(MDNode *LoopID) const; 439ee21b6f7b41e3fc19031f6d410b2ebe6a1a2f361Paul Redmond 440f17e9511f15a0e007ff47d0789d1a52502e8c1fbDan Gohman /// hasDedicatedExits - Return true if no exit block for the loop 441f17e9511f15a0e007ff47d0789d1a52502e8c1fbDan Gohman /// has a predecessor that is outside the loop. 442f17e9511f15a0e007ff47d0789d1a52502e8c1fbDan Gohman bool hasDedicatedExits() const; 443f17e9511f15a0e007ff47d0789d1a52502e8c1fbDan Gohman 444fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick /// getUniqueExitBlocks - Return all unique successor blocks of this loop. 445f0608d829a7b8929108ac6718bd866adf710e936Dan Gohman /// These are the blocks _outside of the current loop_ which are branched to. 446050959cd08db6c0efb8208271a1d64ce58893e20Dan Gohman /// This assumes that loop exits are in canonical form. 447f0608d829a7b8929108ac6718bd866adf710e936Dan Gohman /// 448f0608d829a7b8929108ac6718bd866adf710e936Dan Gohman void getUniqueExitBlocks(SmallVectorImpl<BasicBlock *> &ExitBlocks) const; 449f0608d829a7b8929108ac6718bd866adf710e936Dan Gohman 450f0608d829a7b8929108ac6718bd866adf710e936Dan Gohman /// getUniqueExitBlock - If getUniqueExitBlocks would return exactly one 451f0608d829a7b8929108ac6718bd866adf710e936Dan Gohman /// block, return that block. Otherwise return null. 452f0608d829a7b8929108ac6718bd866adf710e936Dan Gohman BasicBlock *getUniqueExitBlock() const; 453f0608d829a7b8929108ac6718bd866adf710e936Dan Gohman 454dda30cd4af1c5f88fc00fd40b673f8e27c61379dDan Gohman void dump() const; 455fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 456dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines /// \brief Return the debug location of the start of this loop. 457dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines /// This looks for a BB terminating instruction with a known debug 458dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines /// location by looking at the preheader and header blocks. If it 459dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines /// cannot find a terminating instruction with location information, 460dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines /// it returns an unknown location. 461dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines DebugLoc getStartLoc() const { 462dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines DebugLoc StartLoc; 463dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines BasicBlock *HeadBB; 464dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines 465dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines // Try the pre-header first. 466dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines if ((HeadBB = getLoopPreheader()) != nullptr) { 467dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines StartLoc = HeadBB->getTerminator()->getDebugLoc(); 468dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines if (!StartLoc.isUnknown()) 469dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines return StartLoc; 470dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines } 471dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines 472dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines // If we have no pre-header or there are no instructions with debug 473dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines // info in it, try the header. 474dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines HeadBB = getHeader(); 475dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines if (HeadBB) 476dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines StartLoc = HeadBB->getTerminator()->getDebugLoc(); 477dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines 478dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines return StartLoc; 479dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines } 480dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines 481c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohmanprivate: 482c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman friend class LoopInfoBase<BasicBlock, Loop>; 483c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman explicit Loop(BasicBlock *BB) : LoopBase<BasicBlock, Loop>(BB) {} 484c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman}; 4850bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner 4860bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner//===----------------------------------------------------------------------===// 4872b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner/// LoopInfo - This class builds and contains all of the top level loop 4882b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner/// structures in the specified function. 4892b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner/// 49044a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson 491c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohmantemplate<class BlockT, class LoopT> 49244a95e06cc0bb3a2d617fe94235aee92b1951910Owen Andersonclass LoopInfoBase { 4930bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner // BBMap - Mapping of basic blocks to the inner most loop they occur in 49472851059224b90a3ae74ecd62fbd927a0c54a9f0Cameron Zwarich DenseMap<BlockT *, LoopT *> BBMap; 495c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman std::vector<LoopT *> TopLevelLoops; 496c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman friend class LoopBase<BlockT, LoopT>; 4975434c1e73b6e56756719d2aebb952ac7bb3829e0Andrew Trick friend class LoopInfo; 4989d59d9f8495b0361c9ffd1dc82888d8e7ba5070eDan Gohman 499de8091708f2d5ade958507aa6d37907a6277e9f2Craig Topper void operator=(const LoopInfoBase &) LLVM_DELETED_FUNCTION; 500de8091708f2d5ade958507aa6d37907a6277e9f2Craig Topper LoopInfoBase(const LoopInfo &) LLVM_DELETED_FUNCTION; 5010bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattnerpublic: 50244a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson LoopInfoBase() { } 50344a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson ~LoopInfoBase() { releaseMemory(); } 504fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 50544a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson void releaseMemory() { 506c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman for (typename std::vector<LoopT *>::iterator I = 50744a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson TopLevelLoops.begin(), E = TopLevelLoops.end(); I != E; ++I) 50844a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson delete *I; // Delete all of the loops... 5090bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner 510131bd2ecf721749666111ec2dd1d32a20ae049b2Chris Lattner BBMap.clear(); // Reset internal state of analysis 51144a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson TopLevelLoops.clear(); 51244a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson } 513fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 514329c1c6c949d07e3fe9722ec633b4258217fd99dChris Lattner /// iterator/begin/end - The interface to the top-level loops in the current 515329c1c6c949d07e3fe9722ec633b4258217fd99dChris Lattner /// function. 516329c1c6c949d07e3fe9722ec633b4258217fd99dChris Lattner /// 517c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman typedef typename std::vector<LoopT *>::const_iterator iterator; 518c9b1e25493b393013b28e5d457f2fb2845a4dd9fAndrew Trick typedef typename std::vector<LoopT *>::const_reverse_iterator 519c9b1e25493b393013b28e5d457f2fb2845a4dd9fAndrew Trick reverse_iterator; 520329c1c6c949d07e3fe9722ec633b4258217fd99dChris Lattner iterator begin() const { return TopLevelLoops.begin(); } 521329c1c6c949d07e3fe9722ec633b4258217fd99dChris Lattner iterator end() const { return TopLevelLoops.end(); } 522c9b1e25493b393013b28e5d457f2fb2845a4dd9fAndrew Trick reverse_iterator rbegin() const { return TopLevelLoops.rbegin(); } 523c9b1e25493b393013b28e5d457f2fb2845a4dd9fAndrew Trick reverse_iterator rend() const { return TopLevelLoops.rend(); } 524a8c763b3071ae1a58ee8baeb282331245527e004Dan Gohman bool empty() const { return TopLevelLoops.empty(); } 525fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 5262b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// getLoopFor - Return the inner most loop that BB lives in. If a basic 5272b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// block is in no loop (for example the entry node), null is returned. 5282b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// 529c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman LoopT *getLoopFor(const BlockT *BB) const { 530da69f3b357097e75fbf9a5a2bbe1e7273d4b4271Benjamin Kramer return BBMap.lookup(const_cast<BlockT*>(BB)); 5310bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner } 532fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 5332b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// operator[] - same as getLoopFor... 5342b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// 535c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman const LoopT *operator[](const BlockT *BB) const { 5360bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner return getLoopFor(BB); 5370bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner } 538fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 539ba42d2b937160c970c8c6ea57573113c9265325fDan Gohman /// getLoopDepth - Return the loop nesting level of the specified block. A 540ba42d2b937160c970c8c6ea57573113c9265325fDan Gohman /// depth of 0 means the block is not inside any loop. 5412b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// 54244a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson unsigned getLoopDepth(const BlockT *BB) const { 543c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman const LoopT *L = getLoopFor(BB); 5440bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner return L ? L->getLoopDepth() : 0; 5450bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner } 5460bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner 5470bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner // isLoopHeader - True if the block is a loop header node 54844a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson bool isLoopHeader(BlockT *BB) const { 549c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman const LoopT *L = getLoopFor(BB); 55050f5490842d501e269a4c6085d0d132cae0d31f8Chris Lattner return L && L->getHeader() == BB; 5510bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner } 552fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 55344a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// removeLoop - This removes the specified top-level loop from this loop info 55444a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// object. The loop is not deleted, as it will presumably be inserted into 55544a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// another loop. 556c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman LoopT *removeLoop(iterator I) { 55744a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson assert(I != end() && "Cannot remove end iterator!"); 558c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman LoopT *L = *I; 559dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines assert(!L->getParentLoop() && "Not a top-level loop!"); 56044a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson TopLevelLoops.erase(TopLevelLoops.begin() + (I-begin())); 56144a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson return L; 56244a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson } 563fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 56444a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// changeLoopFor - Change the top-level loop that contains BB to the 56544a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// specified loop. This should be used by transformations that restructure 56644a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// the loop hierarchy tree. 567c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman void changeLoopFor(BlockT *BB, LoopT *L) { 568fb62b8deb3c837bc5f4cf98543b89d08e7db9f84Andrew Trick if (!L) { 569da69f3b357097e75fbf9a5a2bbe1e7273d4b4271Benjamin Kramer BBMap.erase(BB); 570fb62b8deb3c837bc5f4cf98543b89d08e7db9f84Andrew Trick return; 571fb62b8deb3c837bc5f4cf98543b89d08e7db9f84Andrew Trick } 572fb62b8deb3c837bc5f4cf98543b89d08e7db9f84Andrew Trick BBMap[BB] = L; 57344a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson } 574fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 57544a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// changeTopLevelLoop - Replace the specified loop in the top-level loops 57644a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// list with the indicated loop. 577c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman void changeTopLevelLoop(LoopT *OldLoop, 578c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman LoopT *NewLoop) { 579c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman typename std::vector<LoopT *>::iterator I = 58044a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson std::find(TopLevelLoops.begin(), TopLevelLoops.end(), OldLoop); 58144a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson assert(I != TopLevelLoops.end() && "Old loop not at top level!"); 58244a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson *I = NewLoop; 583dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines assert(!NewLoop->ParentLoop && !OldLoop->ParentLoop && 58444a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson "Loops already embedded into a subloop!"); 58544a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson } 586fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 58744a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// addTopLevelLoop - This adds the specified loop to the collection of 58844a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// top-level loops. 589c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman void addTopLevelLoop(LoopT *New) { 590dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines assert(!New->getParentLoop() && "Loop already in subloop!"); 59144a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson TopLevelLoops.push_back(New); 59244a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson } 593fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 59444a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// removeBlock - This method completely removes BB from all data structures, 59544a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// including all of the Loop objects it is nested in and our mapping from 59644a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// BasicBlocks to loops. 59744a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson void removeBlock(BlockT *BB) { 59872851059224b90a3ae74ecd62fbd927a0c54a9f0Cameron Zwarich typename DenseMap<BlockT *, LoopT *>::iterator I = BBMap.find(BB); 59944a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson if (I != BBMap.end()) { 600c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman for (LoopT *L = I->second; L; L = L->getParentLoop()) 60144a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson L->removeBlockFromLoop(BB); 60244a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson 60344a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson BBMap.erase(I); 60444a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson } 60544a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson } 606fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 60744a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson // Internals 608fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 609c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman static bool isNotAlreadyContainedIn(const LoopT *SubLoop, 610c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman const LoopT *ParentLoop) { 611dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines if (!SubLoop) return true; 61244a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson if (SubLoop == ParentLoop) return false; 61344a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson return isNotAlreadyContainedIn(SubLoop->getParentLoop(), ParentLoop); 61444a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson } 615fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 61637aa33bc11c01a7142bfa2428a5a4d219b07b6c3Andrew Trick /// Create the loop forest using a stable algorithm. 61737aa33bc11c01a7142bfa2428a5a4d219b07b6c3Andrew Trick void Analyze(DominatorTreeBase<BlockT> &DomTree); 61837aa33bc11c01a7142bfa2428a5a4d219b07b6c3Andrew Trick 61944a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson // Debugging 620fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 621cbf24b4e58c2f621f480883c5bb1f2f2b2b8d497Andrew Trick void print(raw_ostream &OS) const; 62244a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson}; 62344a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson 62460c7d5bc2cbeff9eff16716295ffd6a5374dc6bcAndrew Trick// Implementation in LoopInfoImpl.h 62560c7d5bc2cbeff9eff16716295ffd6a5374dc6bcAndrew Trick#ifdef __GNUC__ 62660c7d5bc2cbeff9eff16716295ffd6a5374dc6bcAndrew Trick__extension__ extern template class LoopInfoBase<BasicBlock, Loop>; 62760c7d5bc2cbeff9eff16716295ffd6a5374dc6bcAndrew Trick#endif 62860c7d5bc2cbeff9eff16716295ffd6a5374dc6bcAndrew Trick 62944a95e06cc0bb3a2d617fe94235aee92b1951910Owen Andersonclass LoopInfo : public FunctionPass { 630c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman LoopInfoBase<BasicBlock, Loop> LI; 631c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman friend class LoopBase<BasicBlock, Loop>; 6329d59d9f8495b0361c9ffd1dc82888d8e7ba5070eDan Gohman 633de8091708f2d5ade958507aa6d37907a6277e9f2Craig Topper void operator=(const LoopInfo &) LLVM_DELETED_FUNCTION; 634de8091708f2d5ade958507aa6d37907a6277e9f2Craig Topper LoopInfo(const LoopInfo &) LLVM_DELETED_FUNCTION; 63544a95e06cc0bb3a2d617fe94235aee92b1951910Owen Andersonpublic: 63644a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson static char ID; // Pass identification, replacement for typeid 63744a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson 638081c34b725980f995be9080eaec24cd3dfaaf065Owen Anderson LoopInfo() : FunctionPass(ID) { 639081c34b725980f995be9080eaec24cd3dfaaf065Owen Anderson initializeLoopInfoPass(*PassRegistry::getPassRegistry()); 640081c34b725980f995be9080eaec24cd3dfaaf065Owen Anderson } 64144a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson 642c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman LoopInfoBase<BasicBlock, Loop>& getBase() { return LI; } 643d735ee85dbab8e4f66f9ec157f19956e0d11ec7aOwen Anderson 64444a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// iterator/begin/end - The interface to the top-level loops in the current 64544a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// function. 64644a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// 647c8d76d5afb023a1c6b439941be3b62789fcc0ed3Dan Gohman typedef LoopInfoBase<BasicBlock, Loop>::iterator iterator; 648c9b1e25493b393013b28e5d457f2fb2845a4dd9fAndrew Trick typedef LoopInfoBase<BasicBlock, Loop>::reverse_iterator reverse_iterator; 6499d59d9f8495b0361c9ffd1dc82888d8e7ba5070eDan Gohman inline iterator begin() const { return LI.begin(); } 6509d59d9f8495b0361c9ffd1dc82888d8e7ba5070eDan Gohman inline iterator end() const { return LI.end(); } 651c9b1e25493b393013b28e5d457f2fb2845a4dd9fAndrew Trick inline reverse_iterator rbegin() const { return LI.rbegin(); } 652c9b1e25493b393013b28e5d457f2fb2845a4dd9fAndrew Trick inline reverse_iterator rend() const { return LI.rend(); } 6539d59d9f8495b0361c9ffd1dc82888d8e7ba5070eDan Gohman bool empty() const { return LI.empty(); } 65444a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson 65544a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// getLoopFor - Return the inner most loop that BB lives in. If a basic 65644a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// block is in no loop (for example the entry node), null is returned. 65744a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// 65844a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson inline Loop *getLoopFor(const BasicBlock *BB) const { 6599d59d9f8495b0361c9ffd1dc82888d8e7ba5070eDan Gohman return LI.getLoopFor(BB); 66044a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson } 66144a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson 66244a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// operator[] - same as getLoopFor... 66344a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// 66444a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson inline const Loop *operator[](const BasicBlock *BB) const { 6659d59d9f8495b0361c9ffd1dc82888d8e7ba5070eDan Gohman return LI.getLoopFor(BB); 66644a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson } 66744a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson 668ba42d2b937160c970c8c6ea57573113c9265325fDan Gohman /// getLoopDepth - Return the loop nesting level of the specified block. A 669ba42d2b937160c970c8c6ea57573113c9265325fDan Gohman /// depth of 0 means the block is not inside any loop. 67044a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson /// 67144a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson inline unsigned getLoopDepth(const BasicBlock *BB) const { 6729d59d9f8495b0361c9ffd1dc82888d8e7ba5070eDan Gohman return LI.getLoopDepth(BB); 67344a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson } 67444a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson 67544a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson // isLoopHeader - True if the block is a loop header node 67644a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson inline bool isLoopHeader(BasicBlock *BB) const { 6779d59d9f8495b0361c9ffd1dc82888d8e7ba5070eDan Gohman return LI.isLoopHeader(BB); 67844a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson } 6790bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner 6802b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// runOnFunction - Calculate the natural loop information. 6812b7bb7a986545b5ec877416278dc126a35ab6970Chris Lattner /// 68236b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines bool runOnFunction(Function &F) override; 683facd752d3afaeca7dee46648f2a2ae209a94e5e9Chris Lattner 68436b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines void verifyAnalysis() const override; 6855c89b5240c90eb8171f999e5f06f815502d0321cDan Gohman 68636b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines void releaseMemory() override { LI.releaseMemory(); } 6875c7e326585f3a543388ba871c3425f7664cd9143Bill Wendling 688dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines void print(raw_ostream &O, const Module* M = nullptr) const override; 689fbfb806e3fe697fd8ee2a59f8fd3e0790ccf0d3cAndrew Trick 69036b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines void getAnalysisUsage(AnalysisUsage &AU) const override; 691f57b845547302d24ecb6a9e79d7bc386f761a6c9Chris Lattner 6924e55b7d2c62de7efa0147e0579980de8b1df9123Chris Lattner /// removeLoop - This removes the specified top-level loop from this loop info 6934e55b7d2c62de7efa0147e0579980de8b1df9123Chris Lattner /// object. The loop is not deleted, as it will presumably be inserted into 6944e55b7d2c62de7efa0147e0579980de8b1df9123Chris Lattner /// another loop. 6959d59d9f8495b0361c9ffd1dc82888d8e7ba5070eDan Gohman inline Loop *removeLoop(iterator I) { return LI.removeLoop(I); } 6964e55b7d2c62de7efa0147e0579980de8b1df9123Chris Lattner 69746758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// changeLoopFor - Change the top-level loop that contains BB to the 69846758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// specified loop. This should be used by transformations that restructure 69946758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// the loop hierarchy tree. 70044a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson inline void changeLoopFor(BasicBlock *BB, Loop *L) { 7019d59d9f8495b0361c9ffd1dc82888d8e7ba5070eDan Gohman LI.changeLoopFor(BB, L); 70244a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson } 70346758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner 70446758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// changeTopLevelLoop - Replace the specified loop in the top-level loops 70546758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner /// list with the indicated loop. 70644a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson inline void changeTopLevelLoop(Loop *OldLoop, Loop *NewLoop) { 7079d59d9f8495b0361c9ffd1dc82888d8e7ba5070eDan Gohman LI.changeTopLevelLoop(OldLoop, NewLoop); 70844a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson } 70946758a894f5d9ca7adc8ec03dd6adeb36b7eadb3Chris Lattner 710072b163424491c85df6664a4e056aae5e07dc64dChris Lattner /// addTopLevelLoop - This adds the specified loop to the collection of 711072b163424491c85df6664a4e056aae5e07dc64dChris Lattner /// top-level loops. 71244a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson inline void addTopLevelLoop(Loop *New) { 7139d59d9f8495b0361c9ffd1dc82888d8e7ba5070eDan Gohman LI.addTopLevelLoop(New); 714072b163424491c85df6664a4e056aae5e07dc64dChris Lattner } 715072b163424491c85df6664a4e056aae5e07dc64dChris Lattner 7169afb24bf0847b9f2ff0bf3f7f7405dcbe42fa38bChris Lattner /// removeBlock - This method completely removes BB from all data structures, 7179afb24bf0847b9f2ff0bf3f7f7405dcbe42fa38bChris Lattner /// including all of the Loop objects it is nested in and our mapping from 7189afb24bf0847b9f2ff0bf3f7f7405dcbe42fa38bChris Lattner /// BasicBlocks to loops. 71944a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson void removeBlock(BasicBlock *BB) { 7209d59d9f8495b0361c9ffd1dc82888d8e7ba5070eDan Gohman LI.removeBlock(BB); 72144a95e06cc0bb3a2d617fe94235aee92b1951910Owen Anderson } 722d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands 723fb62b8deb3c837bc5f4cf98543b89d08e7db9f84Andrew Trick /// updateUnloop - Update LoopInfo after removing the last backedge from a 724fb62b8deb3c837bc5f4cf98543b89d08e7db9f84Andrew Trick /// loop--now the "unloop". This updates the loop forest and parent loops for 725fb62b8deb3c837bc5f4cf98543b89d08e7db9f84Andrew Trick /// each block so that Unloop is no longer referenced, but the caller must 726fb62b8deb3c837bc5f4cf98543b89d08e7db9f84Andrew Trick /// actually delete the Unloop object. 727fb62b8deb3c837bc5f4cf98543b89d08e7db9f84Andrew Trick void updateUnloop(Loop *Unloop); 728fb62b8deb3c837bc5f4cf98543b89d08e7db9f84Andrew Trick 729d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands /// replacementPreservesLCSSAForm - Returns true if replacing From with To 730d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands /// everywhere is guaranteed to preserve LCSSA form. 731d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands bool replacementPreservesLCSSAForm(Instruction *From, Value *To) { 732d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands // Preserving LCSSA form is only problematic if the replacing value is an 733d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands // instruction. 734d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands Instruction *I = dyn_cast<Instruction>(To); 735d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands if (!I) return true; 7369bc6a90146417af03144fa2f7dd94f9945b57c06Duncan Sands // If both instructions are defined in the same basic block then replacement 7379bc6a90146417af03144fa2f7dd94f9945b57c06Duncan Sands // cannot break LCSSA form. 7389bc6a90146417af03144fa2f7dd94f9945b57c06Duncan Sands if (I->getParent() == From->getParent()) 7399bc6a90146417af03144fa2f7dd94f9945b57c06Duncan Sands return true; 740d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands // If the instruction is not defined in a loop then it can safely replace 741d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands // anything. 742d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands Loop *ToLoop = getLoopFor(I->getParent()); 743d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands if (!ToLoop) return true; 744d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands // If the replacing instruction is defined in the same loop as the original 745d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands // instruction, or in a loop that contains it as an inner loop, then using 746d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands // it as a replacement will not break LCSSA form. 7473b0aed19f0f9ed62362c04f7e18e2ada686f4055Duncan Sands return ToLoop->contains(getLoopFor(From->getParent())); 748d0c6f3dafd7c3e9137d4e6415014c94137fcd3fcDuncan Sands } 7490bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner}; 7500bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner 751e0b6b78e095f7dea9589e8df5ec4521e346ad005Anand Shukla 7521db0a400370466e187ae06c96a1586c2c21409ddChris Lattner// Allow clients to walk the list of nested loops... 7531db0a400370466e187ae06c96a1586c2c21409ddChris Lattnertemplate <> struct GraphTraits<const Loop*> { 7541db0a400370466e187ae06c96a1586c2c21409ddChris Lattner typedef const Loop NodeType; 7559d59d9f8495b0361c9ffd1dc82888d8e7ba5070eDan Gohman typedef LoopInfo::iterator ChildIteratorType; 7561db0a400370466e187ae06c96a1586c2c21409ddChris Lattner 7571db0a400370466e187ae06c96a1586c2c21409ddChris Lattner static NodeType *getEntryNode(const Loop *L) { return L; } 7589769ab22265b313171d201b5928688524a01bd87Misha Brukman static inline ChildIteratorType child_begin(NodeType *N) { 759329c1c6c949d07e3fe9722ec633b4258217fd99dChris Lattner return N->begin(); 7601db0a400370466e187ae06c96a1586c2c21409ddChris Lattner } 7619769ab22265b313171d201b5928688524a01bd87Misha Brukman static inline ChildIteratorType child_end(NodeType *N) { 762329c1c6c949d07e3fe9722ec633b4258217fd99dChris Lattner return N->end(); 7631db0a400370466e187ae06c96a1586c2c21409ddChris Lattner } 7641db0a400370466e187ae06c96a1586c2c21409ddChris Lattner}; 7651db0a400370466e187ae06c96a1586c2c21409ddChris Lattner 7661db0a400370466e187ae06c96a1586c2c21409ddChris Lattnertemplate <> struct GraphTraits<Loop*> { 7671db0a400370466e187ae06c96a1586c2c21409ddChris Lattner typedef Loop NodeType; 7689d59d9f8495b0361c9ffd1dc82888d8e7ba5070eDan Gohman typedef LoopInfo::iterator ChildIteratorType; 7691db0a400370466e187ae06c96a1586c2c21409ddChris Lattner 7701db0a400370466e187ae06c96a1586c2c21409ddChris Lattner static NodeType *getEntryNode(Loop *L) { return L; } 7719769ab22265b313171d201b5928688524a01bd87Misha Brukman static inline ChildIteratorType child_begin(NodeType *N) { 772329c1c6c949d07e3fe9722ec633b4258217fd99dChris Lattner return N->begin(); 7731db0a400370466e187ae06c96a1586c2c21409ddChris Lattner } 7749769ab22265b313171d201b5928688524a01bd87Misha Brukman static inline ChildIteratorType child_end(NodeType *N) { 775329c1c6c949d07e3fe9722ec633b4258217fd99dChris Lattner return N->end(); 7761db0a400370466e187ae06c96a1586c2c21409ddChris Lattner } 7771db0a400370466e187ae06c96a1586c2c21409ddChris Lattner}; 7781db0a400370466e187ae06c96a1586c2c21409ddChris Lattner 779d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke} // End llvm namespace 780d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke 7810bbe58f073b4b4a6f68b3e2ee6074fc314e8d19fChris Lattner#endif 782