LiveInterval.cpp revision 6f0d024a534af18d9e60b3ea757376cd8a3a980e
1f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)//===-- LiveInterval.cpp - Live Interval Representation -------------------===// 2f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)// 3f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)// The LLVM Compiler Infrastructure 4f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)// 5f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)// This file is distributed under the University of Illinois Open Source 6f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)// License. See LICENSE.TXT for details. 7f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)// 8f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)//===----------------------------------------------------------------------===// 90529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch// 10f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)// This file implements the LiveRange and LiveInterval classes. Given some 11f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)// numbering of each the machine instructions an interval [i, j) is said to be a 12f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)// live interval for register v if there is no instruction with number j' > j 13f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)// such that v is live at j' abd there is no instruction with number i' < i such 14f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles)// that v is live at i'. In this implementation intervals can have holes, 15a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles)// i.e. an interval might look like [1,20), [50,65), [1000,1001). Each 16f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)// individual range is represented as an instance of LiveRange, and the whole 17a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles)// interval is represented as an instance of LiveInterval. 18f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)// 19f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)//===----------------------------------------------------------------------===// 20f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) 215d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)#include "llvm/CodeGen/LiveInterval.h" 225d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)#include "llvm/ADT/SmallSet.h" 235d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)#include "llvm/ADT/STLExtras.h" 245d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)#include "llvm/Support/Streams.h" 25f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)#include "llvm/Target/TargetRegisterInfo.h" 26f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)#include <algorithm> 27f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)#include <ostream> 28f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)using namespace llvm; 29f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) 30f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)// An example for liveAt(): 31f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)// 32f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)// this = [1,4), liveAt(0) will return false. The instruction defining this 33a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles)// spans slots [0,3]. The interval belongs to an spilled definition of the 34f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)// variable it represents. This is because slot 1 is used (def slot) and spans 35f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)// up to slot 3 (store slot). 36f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)// 37f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)bool LiveInterval::liveAt(unsigned I) const { 385d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) Ranges::const_iterator r = std::upper_bound(ranges.begin(), ranges.end(), I); 395d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 40a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) if (r == ranges.begin()) 41a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) return false; 42f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) 43f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) --r; 44f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) return r->contains(I); 45f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)} 465d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 47a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles)// overlaps - Return true if the intersection of the two live intervals is 48f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles)// not empty. 49f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles)// 50f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)// An example for overlaps(): 51cedac228d2dd51db4b79ea1e72c7f249408ee061Torne (Richard Coles)// 52cedac228d2dd51db4b79ea1e72c7f249408ee061Torne (Richard Coles)// 0: A = ... 530529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch// 4: B = ... 540529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch// 8: C = A + B ;; last use of A 55a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles)// 56a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles)// The live intervals should look like: 57a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles)// 58a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles)// A = [3, 11) 59a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles)// B = [7, x) 60a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles)// C = [11, y) 61a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles)// 62a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles)// A->overlaps(C) should return false since we want to be able to join 63a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles)// A and C. 64a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles)// 65a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles)bool LiveInterval::overlapsFrom(const LiveInterval& other, 66a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) const_iterator StartPos) const { 67a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) const_iterator i = begin(); 68f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) const_iterator ie = end(); 69f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) const_iterator j = StartPos; 70f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) const_iterator je = other.end(); 71116680a4aac90f2aa7413d9095a592090648e557Ben Murdoch 72f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) assert((StartPos->start <= i->start || StartPos == other.begin()) && 73f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) StartPos != other.end() && "Bogus start position hint!"); 74f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) 75f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) if (i->start < j->start) { 76f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) i = std::upper_bound(i, ie, j->start); 77f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) if (i != ranges.begin()) --i; 785d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) } else if (j->start < i->start) { 795d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) ++StartPos; 805d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) if (StartPos != other.end() && StartPos->start <= i->start) { 81f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) assert(StartPos < other.end() && i < end()); 82f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) j = std::upper_bound(j, je, i->start); 83f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) if (j != other.ranges.begin()) --j; 84f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) } 85f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) } else { 86f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) return true; 87f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) } 88f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) 895d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) if (j == je) return false; 90f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) 91f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) while (i != ie) { 92116680a4aac90f2aa7413d9095a592090648e557Ben Murdoch if (i->start > j->start) { 93116680a4aac90f2aa7413d9095a592090648e557Ben Murdoch std::swap(i, j); 94116680a4aac90f2aa7413d9095a592090648e557Ben Murdoch std::swap(ie, je); 95116680a4aac90f2aa7413d9095a592090648e557Ben Murdoch } 965d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 975d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) if (i->end > j->start) 98f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) return true; 99f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) ++i; 100f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) } 101f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) 102f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) return false; 1035d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)} 1045d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 105f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles)/// extendIntervalEndTo - This method is used when we want to extend the range 106a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles)/// specified by I to end at the specified endpoint. To do this, we should 107f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles)/// merge and eliminate all ranges that this will overlap with. The iterator is 108f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles)/// not invalidated. 109f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles)void LiveInterval::extendIntervalEndTo(Ranges::iterator I, unsigned NewEnd) { 110f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles) assert(I != ranges.end() && "Not a valid interval!"); 111a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) VNInfo *ValNo = I->valno; 1125d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) unsigned OldEnd = I->end; 1135d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 1145d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) // Search for the first interval that we can't merge with. 115f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) Ranges::iterator MergeTo = next(I); 116f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) for (; MergeTo != ranges.end() && NewEnd >= MergeTo->end; ++MergeTo) { 1175d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) assert(MergeTo->valno == ValNo && "Cannot merge with differing values!"); 118116680a4aac90f2aa7413d9095a592090648e557Ben Murdoch } 119116680a4aac90f2aa7413d9095a592090648e557Ben Murdoch 1205d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) // If NewEnd was in the middle of an interval, make sure to get its endpoint. 121f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) I->end = std::max(NewEnd, prior(MergeTo)->end); 122f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) 123a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) // Erase any dead ranges. 124a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) ranges.erase(next(I), MergeTo); 125a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) 126a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) // Update kill info. 127a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) removeKills(ValNo, OldEnd, I->end-1); 128a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) 129a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) // If the newly formed range now touches the range after it and if they have 130a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) // the same value number, merge the two ranges into one range. 131a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) Ranges::iterator Next = next(I); 132a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) if (Next != ranges.end() && Next->start <= I->end && Next->valno == ValNo) { 133f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) I->end = Next->end; 134f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) ranges.erase(Next); 135cedac228d2dd51db4b79ea1e72c7f249408ee061Torne (Richard Coles) } 1365d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)} 1375d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 1385d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 139f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)/// extendIntervalStartTo - This method is used when we want to extend the range 140f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)/// specified by I to start at the specified endpoint. To do this, we should 141f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)/// merge and eliminate all ranges that this will overlap with. 142f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)LiveInterval::Ranges::iterator 143f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)LiveInterval::extendIntervalStartTo(Ranges::iterator I, unsigned NewStart) { 144f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) assert(I != ranges.end() && "Not a valid interval!"); 145f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) VNInfo *ValNo = I->valno; 1465d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 1475d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) // Search for the first interval that we can't merge with. 1485d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) Ranges::iterator MergeTo = I; 1495d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) do { 1505d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) if (MergeTo == ranges.begin()) { 1515d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) I->start = NewStart; 152f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) ranges.erase(MergeTo, I); 153f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) return I; 154f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) } 155f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) assert(MergeTo->valno == ValNo && "Cannot merge with differing values!"); 156f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) --MergeTo; 157f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) } while (NewStart <= MergeTo->start); 158f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) 159f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) // If we start in the middle of another interval, just delete a range and 160f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) // extend that interval. 161f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) if (MergeTo->end >= NewStart && MergeTo->valno == ValNo) { 162f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) MergeTo->end = I->end; 163f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) } else { 164f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) // Otherwise, extend the interval right after. 165f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) ++MergeTo; 166f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) MergeTo->start = NewStart; 167f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) MergeTo->end = I->end; 168f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) } 169f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) 170f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) ranges.erase(next(MergeTo), next(I)); 171f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) return MergeTo; 172f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)} 173f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) 174f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)LiveInterval::iterator 175f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)LiveInterval::addRangeFrom(LiveRange LR, iterator From) { 176f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) unsigned Start = LR.start, End = LR.end; 177a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) iterator it = std::upper_bound(From, ranges.end(), Start); 178a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) 179116680a4aac90f2aa7413d9095a592090648e557Ben Murdoch // If the inserted interval starts in the middle or right at the end of 180a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) // another interval, just extend that interval to contain the range of LR. 181a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) if (it != ranges.begin()) { 182f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) iterator B = prior(it); 183f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) if (LR.valno == B->valno) { 184f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) if (B->start <= Start && B->end >= Start) { 185f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) extendIntervalEndTo(B, End); 186f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) return B; 187f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) } 188f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) } else { 1895d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) // Check to make sure that we are not overlapping two live ranges with 1905d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) // different valno's. 1915d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) assert(B->end <= Start && 192a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) "Cannot overlap two LiveRanges with differing ValID's" 193a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) " (did you def the same reg twice in a MachineInstr?)"); 194a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) } 195a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) } 196a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) 197a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) // Otherwise, if this range ends in the middle of, or right next to, another 198a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) // interval, merge it into that interval. 199a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) if (it != ranges.end()) 200f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles) if (LR.valno == it->valno) { 201f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles) if (it->start <= End) { 202f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles) it = extendIntervalStartTo(it, Start); 203116680a4aac90f2aa7413d9095a592090648e557Ben Murdoch 204116680a4aac90f2aa7413d9095a592090648e557Ben Murdoch // If LR is a complete superset of an interval, we may need to grow its 205116680a4aac90f2aa7413d9095a592090648e557Ben Murdoch // endpoint as well. 206f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) if (End > it->end) 207f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) extendIntervalEndTo(it, End); 208f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) else if (End < it->end) 209f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) // Overlapping intervals, there might have been a kill here. 210f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) removeKill(it->valno, End); 211 return it; 212 } 213 } else { 214 // Check to make sure that we are not overlapping two live ranges with 215 // different valno's. 216 assert(it->start >= End && 217 "Cannot overlap two LiveRanges with differing ValID's"); 218 } 219 220 // Otherwise, this is just a new range that doesn't interact with anything. 221 // Insert it. 222 return ranges.insert(it, LR); 223} 224 225 226/// removeRange - Remove the specified range from this interval. Note that 227/// the range must already be in this interval in its entirety. 228void LiveInterval::removeRange(unsigned Start, unsigned End) { 229 // Find the LiveRange containing this span. 230 Ranges::iterator I = std::upper_bound(ranges.begin(), ranges.end(), Start); 231 assert(I != ranges.begin() && "Range is not in interval!"); 232 --I; 233 assert(I->contains(Start) && I->contains(End-1) && 234 "Range is not entirely in interval!"); 235 236 // If the span we are removing is at the start of the LiveRange, adjust it. 237 if (I->start == Start) { 238 if (I->end == End) { 239 removeKills(I->valno, Start, End); 240 ranges.erase(I); // Removed the whole LiveRange. 241 } else 242 I->start = End; 243 return; 244 } 245 246 // Otherwise if the span we are removing is at the end of the LiveRange, 247 // adjust the other way. 248 if (I->end == End) { 249 removeKills(I->valno, Start, End); 250 I->end = Start; 251 return; 252 } 253 254 // Otherwise, we are splitting the LiveRange into two pieces. 255 unsigned OldEnd = I->end; 256 I->end = Start; // Trim the old interval. 257 258 // Insert the new one. 259 ranges.insert(next(I), LiveRange(End, OldEnd, I->valno)); 260} 261 262/// getLiveRangeContaining - Return the live range that contains the 263/// specified index, or null if there is none. 264LiveInterval::const_iterator 265LiveInterval::FindLiveRangeContaining(unsigned Idx) const { 266 const_iterator It = std::upper_bound(begin(), end(), Idx); 267 if (It != ranges.begin()) { 268 --It; 269 if (It->contains(Idx)) 270 return It; 271 } 272 273 return end(); 274} 275 276LiveInterval::iterator 277LiveInterval::FindLiveRangeContaining(unsigned Idx) { 278 iterator It = std::upper_bound(begin(), end(), Idx); 279 if (It != begin()) { 280 --It; 281 if (It->contains(Idx)) 282 return It; 283 } 284 285 return end(); 286} 287 288/// join - Join two live intervals (this, and other) together. This applies 289/// mappings to the value numbers in the LHS/RHS intervals as specified. If 290/// the intervals are not joinable, this aborts. 291void LiveInterval::join(LiveInterval &Other, const int *LHSValNoAssignments, 292 const int *RHSValNoAssignments, 293 SmallVector<VNInfo*, 16> &NewVNInfo) { 294 // Determine if any of our live range values are mapped. This is uncommon, so 295 // we want to avoid the interval scan if not. 296 bool MustMapCurValNos = false; 297 unsigned NumVals = getNumValNums(); 298 unsigned NumNewVals = NewVNInfo.size(); 299 for (unsigned i = 0; i != NumVals; ++i) { 300 unsigned LHSValID = LHSValNoAssignments[i]; 301 if (i != LHSValID || 302 (NewVNInfo[LHSValID] && NewVNInfo[LHSValID] != getValNumInfo(i))) 303 MustMapCurValNos = true; 304 } 305 306 // If we have to apply a mapping to our base interval assignment, rewrite it 307 // now. 308 if (MustMapCurValNos) { 309 // Map the first live range. 310 iterator OutIt = begin(); 311 OutIt->valno = NewVNInfo[LHSValNoAssignments[OutIt->valno->id]]; 312 ++OutIt; 313 for (iterator I = OutIt, E = end(); I != E; ++I) { 314 OutIt->valno = NewVNInfo[LHSValNoAssignments[I->valno->id]]; 315 316 // If this live range has the same value # as its immediate predecessor, 317 // and if they are neighbors, remove one LiveRange. This happens when we 318 // have [0,3:0)[4,7:1) and map 0/1 onto the same value #. 319 if (OutIt->valno == (OutIt-1)->valno && (OutIt-1)->end == OutIt->start) { 320 (OutIt-1)->end = OutIt->end; 321 } else { 322 if (I != OutIt) { 323 OutIt->start = I->start; 324 OutIt->end = I->end; 325 } 326 327 // Didn't merge, on to the next one. 328 ++OutIt; 329 } 330 } 331 332 // If we merge some live ranges, chop off the end. 333 ranges.erase(OutIt, end()); 334 } 335 336 // Remember assignements because val# ids are changing. 337 SmallVector<unsigned, 16> OtherAssignments; 338 for (iterator I = Other.begin(), E = Other.end(); I != E; ++I) 339 OtherAssignments.push_back(RHSValNoAssignments[I->valno->id]); 340 341 // Update val# info. Renumber them and make sure they all belong to this 342 // LiveInterval now. Also remove dead val#'s. 343 unsigned NumValNos = 0; 344 for (unsigned i = 0; i < NumNewVals; ++i) { 345 VNInfo *VNI = NewVNInfo[i]; 346 if (VNI) { 347 if (i >= NumVals) 348 valnos.push_back(VNI); 349 else 350 valnos[NumValNos] = VNI; 351 VNI->id = NumValNos++; // Renumber val#. 352 } 353 } 354 if (NumNewVals < NumVals) 355 valnos.resize(NumNewVals); // shrinkify 356 357 // Okay, now insert the RHS live ranges into the LHS. 358 iterator InsertPos = begin(); 359 unsigned RangeNo = 0; 360 for (iterator I = Other.begin(), E = Other.end(); I != E; ++I, ++RangeNo) { 361 // Map the valno in the other live range to the current live range. 362 I->valno = NewVNInfo[OtherAssignments[RangeNo]]; 363 assert(I->valno && "Adding a dead range?"); 364 InsertPos = addRangeFrom(*I, InsertPos); 365 } 366 367 weight += Other.weight; 368 if (Other.preference && !preference) 369 preference = Other.preference; 370} 371 372/// MergeRangesInAsValue - Merge all of the intervals in RHS into this live 373/// interval as the specified value number. The LiveRanges in RHS are 374/// allowed to overlap with LiveRanges in the current interval, but only if 375/// the overlapping LiveRanges have the specified value number. 376void LiveInterval::MergeRangesInAsValue(const LiveInterval &RHS, 377 VNInfo *LHSValNo) { 378 // TODO: Make this more efficient. 379 iterator InsertPos = begin(); 380 for (const_iterator I = RHS.begin(), E = RHS.end(); I != E; ++I) { 381 // Map the valno in the other live range to the current live range. 382 LiveRange Tmp = *I; 383 Tmp.valno = LHSValNo; 384 InsertPos = addRangeFrom(Tmp, InsertPos); 385 } 386} 387 388 389/// MergeValueInAsValue - Merge all of the live ranges of a specific val# 390/// in RHS into this live interval as the specified value number. 391/// The LiveRanges in RHS are allowed to overlap with LiveRanges in the 392/// current interval, it will replace the value numbers of the overlaped 393/// live ranges with the specified value number. 394void LiveInterval::MergeValueInAsValue(const LiveInterval &RHS, 395 const VNInfo *RHSValNo, VNInfo *LHSValNo) { 396 SmallVector<VNInfo*, 4> ReplacedValNos; 397 iterator IP = begin(); 398 for (const_iterator I = RHS.begin(), E = RHS.end(); I != E; ++I) { 399 if (I->valno != RHSValNo) 400 continue; 401 unsigned Start = I->start, End = I->end; 402 IP = std::upper_bound(IP, end(), Start); 403 // If the start of this range overlaps with an existing liverange, trim it. 404 if (IP != begin() && IP[-1].end > Start) { 405 if (IP[-1].valno != LHSValNo) { 406 ReplacedValNos.push_back(IP[-1].valno); 407 IP[-1].valno = LHSValNo; // Update val#. 408 } 409 Start = IP[-1].end; 410 // Trimmed away the whole range? 411 if (Start >= End) continue; 412 } 413 // If the end of this range overlaps with an existing liverange, trim it. 414 if (IP != end() && End > IP->start) { 415 if (IP->valno != LHSValNo) { 416 ReplacedValNos.push_back(IP->valno); 417 IP->valno = LHSValNo; // Update val#. 418 } 419 End = IP->start; 420 // If this trimmed away the whole range, ignore it. 421 if (Start == End) continue; 422 } 423 424 // Map the valno in the other live range to the current live range. 425 IP = addRangeFrom(LiveRange(Start, End, LHSValNo), IP); 426 } 427 428 429 SmallSet<VNInfo*, 4> Seen; 430 for (unsigned i = 0, e = ReplacedValNos.size(); i != e; ++i) { 431 VNInfo *V1 = ReplacedValNos[i]; 432 if (Seen.insert(V1)) { 433 bool isDead = true; 434 for (const_iterator I = begin(), E = end(); I != E; ++I) 435 if (I->valno == V1) { 436 isDead = false; 437 break; 438 } 439 if (isDead) { 440 // Now that V1 is dead, remove it. If it is the largest value number, 441 // just nuke it (and any other deleted values neighboring it), otherwise 442 // mark it as ~1U so it can be nuked later. 443 if (V1->id == getNumValNums()-1) { 444 do { 445 VNInfo *VNI = valnos.back(); 446 valnos.pop_back(); 447 VNI->~VNInfo(); 448 } while (valnos.back()->def == ~1U); 449 } else { 450 V1->def = ~1U; 451 } 452 } 453 } 454 } 455} 456 457 458/// MergeInClobberRanges - For any live ranges that are not defined in the 459/// current interval, but are defined in the Clobbers interval, mark them 460/// used with an unknown definition value. 461void LiveInterval::MergeInClobberRanges(const LiveInterval &Clobbers, 462 BumpPtrAllocator &VNInfoAllocator) { 463 if (Clobbers.begin() == Clobbers.end()) return; 464 465 // Find a value # to use for the clobber ranges. If there is already a value# 466 // for unknown values, use it. 467 // FIXME: Use a single sentinal number for these! 468 VNInfo *ClobberValNo = getNextValue(~0U, 0, VNInfoAllocator); 469 470 iterator IP = begin(); 471 for (const_iterator I = Clobbers.begin(), E = Clobbers.end(); I != E; ++I) { 472 unsigned Start = I->start, End = I->end; 473 IP = std::upper_bound(IP, end(), Start); 474 475 // If the start of this range overlaps with an existing liverange, trim it. 476 if (IP != begin() && IP[-1].end > Start) { 477 Start = IP[-1].end; 478 // Trimmed away the whole range? 479 if (Start >= End) continue; 480 } 481 // If the end of this range overlaps with an existing liverange, trim it. 482 if (IP != end() && End > IP->start) { 483 End = IP->start; 484 // If this trimmed away the whole range, ignore it. 485 if (Start == End) continue; 486 } 487 488 // Insert the clobber interval. 489 IP = addRangeFrom(LiveRange(Start, End, ClobberValNo), IP); 490 } 491} 492 493/// MergeValueNumberInto - This method is called when two value nubmers 494/// are found to be equivalent. This eliminates V1, replacing all 495/// LiveRanges with the V1 value number with the V2 value number. This can 496/// cause merging of V1/V2 values numbers and compaction of the value space. 497void LiveInterval::MergeValueNumberInto(VNInfo *V1, VNInfo *V2) { 498 assert(V1 != V2 && "Identical value#'s are always equivalent!"); 499 500 // This code actually merges the (numerically) larger value number into the 501 // smaller value number, which is likely to allow us to compactify the value 502 // space. The only thing we have to be careful of is to preserve the 503 // instruction that defines the result value. 504 505 // Make sure V2 is smaller than V1. 506 if (V1->id < V2->id) { 507 copyValNumInfo(V1, V2); 508 std::swap(V1, V2); 509 } 510 511 // Merge V1 live ranges into V2. 512 for (iterator I = begin(); I != end(); ) { 513 iterator LR = I++; 514 if (LR->valno != V1) continue; // Not a V1 LiveRange. 515 516 // Okay, we found a V1 live range. If it had a previous, touching, V2 live 517 // range, extend it. 518 if (LR != begin()) { 519 iterator Prev = LR-1; 520 if (Prev->valno == V2 && Prev->end == LR->start) { 521 Prev->end = LR->end; 522 523 // Erase this live-range. 524 ranges.erase(LR); 525 I = Prev+1; 526 LR = Prev; 527 } 528 } 529 530 // Okay, now we have a V1 or V2 live range that is maximally merged forward. 531 // Ensure that it is a V2 live-range. 532 LR->valno = V2; 533 534 // If we can merge it into later V2 live ranges, do so now. We ignore any 535 // following V1 live ranges, as they will be merged in subsequent iterations 536 // of the loop. 537 if (I != end()) { 538 if (I->start == LR->end && I->valno == V2) { 539 LR->end = I->end; 540 ranges.erase(I); 541 I = LR+1; 542 } 543 } 544 } 545 546 // Now that V1 is dead, remove it. If it is the largest value number, just 547 // nuke it (and any other deleted values neighboring it), otherwise mark it as 548 // ~1U so it can be nuked later. 549 if (V1->id == getNumValNums()-1) { 550 do { 551 VNInfo *VNI = valnos.back(); 552 valnos.pop_back(); 553 VNI->~VNInfo(); 554 } while (valnos.back()->def == ~1U); 555 } else { 556 V1->def = ~1U; 557 } 558} 559 560void LiveInterval::Copy(const LiveInterval &RHS, 561 BumpPtrAllocator &VNInfoAllocator) { 562 ranges.clear(); 563 valnos.clear(); 564 preference = RHS.preference; 565 weight = RHS.weight; 566 for (unsigned i = 0, e = RHS.getNumValNums(); i != e; ++i) { 567 const VNInfo *VNI = RHS.getValNumInfo(i); 568 VNInfo *NewVNI = getNextValue(~0U, 0, VNInfoAllocator); 569 copyValNumInfo(NewVNI, VNI); 570 } 571 for (unsigned i = 0, e = RHS.ranges.size(); i != e; ++i) { 572 const LiveRange &LR = RHS.ranges[i]; 573 addRange(LiveRange(LR.start, LR.end, getValNumInfo(LR.valno->id))); 574 } 575} 576 577unsigned LiveInterval::getSize() const { 578 unsigned Sum = 0; 579 for (const_iterator I = begin(), E = end(); I != E; ++I) 580 Sum += I->end - I->start; 581 return Sum; 582} 583 584std::ostream& llvm::operator<<(std::ostream& os, const LiveRange &LR) { 585 return os << '[' << LR.start << ',' << LR.end << ':' << LR.valno->id << ")"; 586} 587 588void LiveRange::dump() const { 589 cerr << *this << "\n"; 590} 591 592void LiveInterval::print(std::ostream &OS, 593 const TargetRegisterInfo *TRI) const { 594 if (TRI && TargetRegisterInfo::isPhysicalRegister(reg)) 595 OS << TRI->getName(reg); 596 else 597 OS << "%reg" << reg; 598 599 OS << ',' << weight; 600 601 if (empty()) 602 OS << "EMPTY"; 603 else { 604 OS << " = "; 605 for (LiveInterval::Ranges::const_iterator I = ranges.begin(), 606 E = ranges.end(); I != E; ++I) 607 OS << *I; 608 } 609 610 // Print value number info. 611 if (getNumValNums()) { 612 OS << " "; 613 unsigned vnum = 0; 614 for (const_vni_iterator i = vni_begin(), e = vni_end(); i != e; 615 ++i, ++vnum) { 616 const VNInfo *vni = *i; 617 if (vnum) OS << " "; 618 OS << vnum << "@"; 619 if (vni->def == ~1U) { 620 OS << "x"; 621 } else { 622 if (vni->def == ~0U) 623 OS << "?"; 624 else 625 OS << vni->def; 626 unsigned ee = vni->kills.size(); 627 if (ee) { 628 OS << "-("; 629 for (unsigned j = 0; j != ee; ++j) { 630 OS << vni->kills[j]; 631 if (j != ee-1) 632 OS << " "; 633 } 634 if (vni->hasPHIKill) 635 OS << " phi"; 636 OS << ")"; 637 } 638 } 639 } 640 } 641} 642 643void LiveInterval::dump() const { 644 cerr << *this << "\n"; 645} 646 647 648void LiveRange::print(std::ostream &os) const { 649 os << *this; 650} 651