1 //===- IntervalPartition.cpp - Interval Partition module code -------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file contains the definition of the IntervalPartition class, which 11 // calculates and represent the interval partition of a function. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #include "llvm/Analysis/IntervalIterator.h" 16 using namespace llvm; 17 18 char IntervalPartition::ID = 0; 19 INITIALIZE_PASS(IntervalPartition, "intervals", 20 "Interval Partition Construction", true, true) 21 22 //===----------------------------------------------------------------------===// 23 // IntervalPartition Implementation 24 //===----------------------------------------------------------------------===// 25 26 // releaseMemory - Reset state back to before function was analyzed 27 void IntervalPartition::releaseMemory() { 28 for (unsigned i = 0, e = Intervals.size(); i != e; ++i) 29 delete Intervals[i]; 30 IntervalMap.clear(); 31 Intervals.clear(); 32 RootInterval = nullptr; 33 } 34 35 void IntervalPartition::print(raw_ostream &O, const Module*) const { 36 for(unsigned i = 0, e = Intervals.size(); i != e; ++i) 37 Intervals[i]->print(O); 38 } 39 40 // addIntervalToPartition - Add an interval to the internal list of intervals, 41 // and then add mappings from all of the basic blocks in the interval to the 42 // interval itself (in the IntervalMap). 43 // 44 void IntervalPartition::addIntervalToPartition(Interval *I) { 45 Intervals.push_back(I); 46 47 // Add mappings for all of the basic blocks in I to the IntervalPartition 48 for (Interval::node_iterator It = I->Nodes.begin(), End = I->Nodes.end(); 49 It != End; ++It) 50 IntervalMap.insert(std::make_pair(*It, I)); 51 } 52 53 // updatePredecessors - Interval generation only sets the successor fields of 54 // the interval data structures. After interval generation is complete, 55 // run through all of the intervals and propagate successor info as 56 // predecessor info. 57 // 58 void IntervalPartition::updatePredecessors(Interval *Int) { 59 BasicBlock *Header = Int->getHeaderNode(); 60 for (BasicBlock *Successor : Int->Successors) 61 getBlockInterval(Successor)->Predecessors.push_back(Header); 62 } 63 64 // IntervalPartition ctor - Build the first level interval partition for the 65 // specified function... 66 // 67 bool IntervalPartition::runOnFunction(Function &F) { 68 // Pass false to intervals_begin because we take ownership of it's memory 69 function_interval_iterator I = intervals_begin(&F, false); 70 assert(I != intervals_end(&F) && "No intervals in function!?!?!"); 71 72 addIntervalToPartition(RootInterval = *I); 73 74 ++I; // After the first one... 75 76 // Add the rest of the intervals to the partition. 77 for (function_interval_iterator E = intervals_end(&F); I != E; ++I) 78 addIntervalToPartition(*I); 79 80 // Now that we know all of the successor information, propagate this to the 81 // predecessors for each block. 82 for (unsigned i = 0, e = Intervals.size(); i != e; ++i) 83 updatePredecessors(Intervals[i]); 84 return false; 85 } 86 87 88 // IntervalPartition ctor - Build a reduced interval partition from an 89 // existing interval graph. This takes an additional boolean parameter to 90 // distinguish it from a copy constructor. Always pass in false for now. 91 // 92 IntervalPartition::IntervalPartition(IntervalPartition &IP, bool) 93 : FunctionPass(ID) { 94 assert(IP.getRootInterval() && "Cannot operate on empty IntervalPartitions!"); 95 96 // Pass false to intervals_begin because we take ownership of it's memory 97 interval_part_interval_iterator I = intervals_begin(IP, false); 98 assert(I != intervals_end(IP) && "No intervals in interval partition!?!?!"); 99 100 addIntervalToPartition(RootInterval = *I); 101 102 ++I; // After the first one... 103 104 // Add the rest of the intervals to the partition. 105 for (interval_part_interval_iterator E = intervals_end(IP); I != E; ++I) 106 addIntervalToPartition(*I); 107 108 // Now that we know all of the successor information, propagate this to the 109 // predecessors for each block. 110 for (unsigned i = 0, e = Intervals.size(); i != e; ++i) 111 updatePredecessors(Intervals[i]); 112 } 113 114
