xref: /freebsd/contrib/llvm-project/llvm/include/llvm/CodeGen/SlotIndexes.h (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
1 //===- llvm/CodeGen/SlotIndexes.h - Slot indexes representation -*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements SlotIndex and related classes. The purpose of SlotIndex
10 // is to describe a position at which a register can become live, or cease to
11 // be live.
12 //
13 // SlotIndex is mostly a proxy for entries of the SlotIndexList, a class which
14 // is held is LiveIntervals and provides the real numbering. This allows
15 // LiveIntervals to perform largely transparent renumbering.
16 //===----------------------------------------------------------------------===//
17 
18 #ifndef LLVM_CODEGEN_SLOTINDEXES_H
19 #define LLVM_CODEGEN_SLOTINDEXES_H
20 
21 #include "llvm/ADT/DenseMap.h"
22 #include "llvm/ADT/IntervalMap.h"
23 #include "llvm/ADT/PointerIntPair.h"
24 #include "llvm/ADT/SmallVector.h"
25 #include "llvm/ADT/simple_ilist.h"
26 #include "llvm/CodeGen/MachineBasicBlock.h"
27 #include "llvm/CodeGen/MachineFunction.h"
28 #include "llvm/CodeGen/MachineFunctionPass.h"
29 #include "llvm/CodeGen/MachineInstr.h"
30 #include "llvm/CodeGen/MachineInstrBundle.h"
31 #include "llvm/CodeGen/MachinePassManager.h"
32 #include "llvm/Support/Allocator.h"
33 #include <algorithm>
34 #include <cassert>
35 #include <iterator>
36 #include <utility>
37 
38 namespace llvm {
39 
40 class raw_ostream;
41 
42   /// This class represents an entry in the slot index list held in the
43   /// SlotIndexes pass. It should not be used directly. See the
44   /// SlotIndex & SlotIndexes classes for the public interface to this
45   /// information.
46   class IndexListEntry : public ilist_node<IndexListEntry> {
47     MachineInstr *mi;
48     unsigned index;
49 
50   public:
IndexListEntry(MachineInstr * mi,unsigned index)51     IndexListEntry(MachineInstr *mi, unsigned index) : mi(mi), index(index) {}
52 
getInstr()53     MachineInstr* getInstr() const { return mi; }
setInstr(MachineInstr * mi)54     void setInstr(MachineInstr *mi) {
55       this->mi = mi;
56     }
57 
getIndex()58     unsigned getIndex() const { return index; }
setIndex(unsigned index)59     void setIndex(unsigned index) {
60       this->index = index;
61     }
62   };
63 
64   /// SlotIndex - An opaque wrapper around machine indexes.
65   class SlotIndex {
66     friend class SlotIndexes;
67 
68     enum Slot {
69       /// Basic block boundary.  Used for live ranges entering and leaving a
70       /// block without being live in the layout neighbor.  Also used as the
71       /// def slot of PHI-defs.
72       Slot_Block,
73 
74       /// Early-clobber register use/def slot.  A live range defined at
75       /// Slot_EarlyClobber interferes with normal live ranges killed at
76       /// Slot_Register.  Also used as the kill slot for live ranges tied to an
77       /// early-clobber def.
78       Slot_EarlyClobber,
79 
80       /// Normal register use/def slot.  Normal instructions kill and define
81       /// register live ranges at this slot.
82       Slot_Register,
83 
84       /// Dead def kill point.  Kill slot for a live range that is defined by
85       /// the same instruction (Slot_Register or Slot_EarlyClobber), but isn't
86       /// used anywhere.
87       Slot_Dead,
88 
89       Slot_Count
90     };
91 
92     PointerIntPair<IndexListEntry*, 2, unsigned> lie;
93 
listEntry()94     IndexListEntry* listEntry() const {
95       assert(isValid() && "Attempt to compare reserved index.");
96       return lie.getPointer();
97     }
98 
getIndex()99     unsigned getIndex() const {
100       return listEntry()->getIndex() | getSlot();
101     }
102 
103     /// Returns the slot for this SlotIndex.
getSlot()104     Slot getSlot() const {
105       return static_cast<Slot>(lie.getInt());
106     }
107 
108   public:
109     enum {
110       /// The default distance between instructions as returned by distance().
111       /// This may vary as instructions are inserted and removed.
112       InstrDist = 4 * Slot_Count
113     };
114 
115     /// Construct an invalid index.
116     SlotIndex() = default;
117 
118     // Creates a SlotIndex from an IndexListEntry and a slot. Generally should
119     // not be used. This method is only public to facilitate writing certain
120     // unit tests.
SlotIndex(IndexListEntry * entry,unsigned slot)121     SlotIndex(IndexListEntry *entry, unsigned slot) : lie(entry, slot) {}
122 
123     // Construct a new slot index from the given one, and set the slot.
SlotIndex(const SlotIndex & li,Slot s)124     SlotIndex(const SlotIndex &li, Slot s) : lie(li.listEntry(), unsigned(s)) {
125       assert(isValid() && "Attempt to construct index with 0 pointer.");
126     }
127 
128     /// Returns true if this is a valid index. Invalid indices do
129     /// not point into an index table, and cannot be compared.
isValid()130     bool isValid() const {
131       return lie.getPointer();
132     }
133 
134     /// Return true for a valid index.
135     explicit operator bool() const { return isValid(); }
136 
137     /// Print this index to the given raw_ostream.
138     void print(raw_ostream &os) const;
139 
140     /// Dump this index to stderr.
141     void dump() const;
142 
143     /// Compare two SlotIndex objects for equality.
144     bool operator==(SlotIndex other) const {
145       return lie == other.lie;
146     }
147     /// Compare two SlotIndex objects for inequality.
148     bool operator!=(SlotIndex other) const {
149       return lie != other.lie;
150     }
151 
152     /// Compare two SlotIndex objects. Return true if the first index
153     /// is strictly lower than the second.
154     bool operator<(SlotIndex other) const {
155       return getIndex() < other.getIndex();
156     }
157     /// Compare two SlotIndex objects. Return true if the first index
158     /// is lower than, or equal to, the second.
159     bool operator<=(SlotIndex other) const {
160       return getIndex() <= other.getIndex();
161     }
162 
163     /// Compare two SlotIndex objects. Return true if the first index
164     /// is greater than the second.
165     bool operator>(SlotIndex other) const {
166       return getIndex() > other.getIndex();
167     }
168 
169     /// Compare two SlotIndex objects. Return true if the first index
170     /// is greater than, or equal to, the second.
171     bool operator>=(SlotIndex other) const {
172       return getIndex() >= other.getIndex();
173     }
174 
175     /// isSameInstr - Return true if A and B refer to the same instruction.
isSameInstr(SlotIndex A,SlotIndex B)176     static bool isSameInstr(SlotIndex A, SlotIndex B) {
177       return A.listEntry() == B.listEntry();
178     }
179 
180     /// isEarlierInstr - Return true if A refers to an instruction earlier than
181     /// B. This is equivalent to A < B && !isSameInstr(A, B).
isEarlierInstr(SlotIndex A,SlotIndex B)182     static bool isEarlierInstr(SlotIndex A, SlotIndex B) {
183       return A.listEntry()->getIndex() < B.listEntry()->getIndex();
184     }
185 
186     /// Return true if A refers to the same instruction as B or an earlier one.
187     /// This is equivalent to !isEarlierInstr(B, A).
isEarlierEqualInstr(SlotIndex A,SlotIndex B)188     static bool isEarlierEqualInstr(SlotIndex A, SlotIndex B) {
189       return !isEarlierInstr(B, A);
190     }
191 
192     /// Return the distance from this index to the given one.
distance(SlotIndex other)193     int distance(SlotIndex other) const {
194       return other.getIndex() - getIndex();
195     }
196 
197     /// Return the scaled distance from this index to the given one, where all
198     /// slots on the same instruction have zero distance, assuming that the slot
199     /// indices are packed as densely as possible. There are normally gaps
200     /// between instructions, so this assumption often doesn't hold. This
201     /// results in this function often returning a value greater than the actual
202     /// instruction distance.
getApproxInstrDistance(SlotIndex other)203     int getApproxInstrDistance(SlotIndex other) const {
204       return (other.listEntry()->getIndex() - listEntry()->getIndex())
205         / Slot_Count;
206     }
207 
208     /// isBlock - Returns true if this is a block boundary slot.
isBlock()209     bool isBlock() const { return getSlot() == Slot_Block; }
210 
211     /// isEarlyClobber - Returns true if this is an early-clobber slot.
isEarlyClobber()212     bool isEarlyClobber() const { return getSlot() == Slot_EarlyClobber; }
213 
214     /// isRegister - Returns true if this is a normal register use/def slot.
215     /// Note that early-clobber slots may also be used for uses and defs.
isRegister()216     bool isRegister() const { return getSlot() == Slot_Register; }
217 
218     /// isDead - Returns true if this is a dead def kill slot.
isDead()219     bool isDead() const { return getSlot() == Slot_Dead; }
220 
221     /// Returns the base index for associated with this index. The base index
222     /// is the one associated with the Slot_Block slot for the instruction
223     /// pointed to by this index.
getBaseIndex()224     SlotIndex getBaseIndex() const {
225       return SlotIndex(listEntry(), Slot_Block);
226     }
227 
228     /// Returns the boundary index for associated with this index. The boundary
229     /// index is the one associated with the Slot_Block slot for the instruction
230     /// pointed to by this index.
getBoundaryIndex()231     SlotIndex getBoundaryIndex() const {
232       return SlotIndex(listEntry(), Slot_Dead);
233     }
234 
235     /// Returns the register use/def slot in the current instruction for a
236     /// normal or early-clobber def.
237     SlotIndex getRegSlot(bool EC = false) const {
238       return SlotIndex(listEntry(), EC ? Slot_EarlyClobber : Slot_Register);
239     }
240 
241     /// Returns the dead def kill slot for the current instruction.
getDeadSlot()242     SlotIndex getDeadSlot() const {
243       return SlotIndex(listEntry(), Slot_Dead);
244     }
245 
246     /// Returns the next slot in the index list. This could be either the
247     /// next slot for the instruction pointed to by this index or, if this
248     /// index is a STORE, the first slot for the next instruction.
249     /// WARNING: This method is considerably more expensive than the methods
250     /// that return specific slots (getUseIndex(), etc). If you can - please
251     /// use one of those methods.
getNextSlot()252     SlotIndex getNextSlot() const {
253       Slot s = getSlot();
254       if (s == Slot_Dead) {
255         return SlotIndex(&*++listEntry()->getIterator(), Slot_Block);
256       }
257       return SlotIndex(listEntry(), s + 1);
258     }
259 
260     /// Returns the next index. This is the index corresponding to the this
261     /// index's slot, but for the next instruction.
getNextIndex()262     SlotIndex getNextIndex() const {
263       return SlotIndex(&*++listEntry()->getIterator(), getSlot());
264     }
265 
266     /// Returns the previous slot in the index list. This could be either the
267     /// previous slot for the instruction pointed to by this index or, if this
268     /// index is a Slot_Block, the last slot for the previous instruction.
269     /// WARNING: This method is considerably more expensive than the methods
270     /// that return specific slots (getUseIndex(), etc). If you can - please
271     /// use one of those methods.
getPrevSlot()272     SlotIndex getPrevSlot() const {
273       Slot s = getSlot();
274       if (s == Slot_Block) {
275         return SlotIndex(&*--listEntry()->getIterator(), Slot_Dead);
276       }
277       return SlotIndex(listEntry(), s - 1);
278     }
279 
280     /// Returns the previous index. This is the index corresponding to this
281     /// index's slot, but for the previous instruction.
getPrevIndex()282     SlotIndex getPrevIndex() const {
283       return SlotIndex(&*--listEntry()->getIterator(), getSlot());
284     }
285   };
286 
287   inline raw_ostream& operator<<(raw_ostream &os, SlotIndex li) {
288     li.print(os);
289     return os;
290   }
291 
292   using IdxMBBPair = std::pair<SlotIndex, MachineBasicBlock *>;
293 
294   /// SlotIndexes pass.
295   ///
296   /// This pass assigns indexes to each instruction.
297   class SlotIndexes {
298     friend class SlotIndexesWrapperPass;
299 
300   private:
301     // IndexListEntry allocator.
302     BumpPtrAllocator ileAllocator;
303 
304     using IndexList = simple_ilist<IndexListEntry>;
305     IndexList indexList;
306 
307     MachineFunction *mf = nullptr;
308 
309     using Mi2IndexMap = DenseMap<const MachineInstr *, SlotIndex>;
310     Mi2IndexMap mi2iMap;
311 
312     /// MBBRanges - Map MBB number to (start, stop) indexes.
313     SmallVector<std::pair<SlotIndex, SlotIndex>, 8> MBBRanges;
314 
315     /// Idx2MBBMap - Sorted list of pairs of index of first instruction
316     /// and MBB id.
317     SmallVector<IdxMBBPair, 8> idx2MBBMap;
318 
319     // For legacy pass manager.
320     SlotIndexes() = default;
321 
322     void clear();
323 
324     void analyze(MachineFunction &MF);
325 
createEntry(MachineInstr * mi,unsigned index)326     IndexListEntry* createEntry(MachineInstr *mi, unsigned index) {
327       IndexListEntry *entry =
328           static_cast<IndexListEntry *>(ileAllocator.Allocate(
329               sizeof(IndexListEntry), alignof(IndexListEntry)));
330 
331       new (entry) IndexListEntry(mi, index);
332 
333       return entry;
334     }
335 
336     /// Renumber locally after inserting curItr.
337     void renumberIndexes(IndexList::iterator curItr);
338 
339   public:
340     SlotIndexes(SlotIndexes &&) = default;
341 
SlotIndexes(MachineFunction & MF)342     SlotIndexes(MachineFunction &MF) { analyze(MF); }
343 
344     ~SlotIndexes();
345 
reanalyze(MachineFunction & MF)346     void reanalyze(MachineFunction &MF) {
347       clear();
348       analyze(MF);
349     }
350 
351     void print(raw_ostream &OS) const;
352 
353     /// Dump the indexes.
354     void dump() const;
355 
356     /// Repair indexes after adding and removing instructions.
357     void repairIndexesInRange(MachineBasicBlock *MBB,
358                               MachineBasicBlock::iterator Begin,
359                               MachineBasicBlock::iterator End);
360 
361     /// Returns the zero index for this analysis.
getZeroIndex()362     SlotIndex getZeroIndex() {
363       assert(indexList.front().getIndex() == 0 && "First index is not 0?");
364       return SlotIndex(&indexList.front(), 0);
365     }
366 
367     /// Returns the base index of the last slot in this analysis.
getLastIndex()368     SlotIndex getLastIndex() {
369       return SlotIndex(&indexList.back(), 0);
370     }
371 
372     /// Returns true if the given machine instr is mapped to an index,
373     /// otherwise returns false.
hasIndex(const MachineInstr & instr)374     bool hasIndex(const MachineInstr &instr) const {
375       return mi2iMap.count(&instr);
376     }
377 
378     /// Returns the base index for the given instruction.
379     SlotIndex getInstructionIndex(const MachineInstr &MI,
380                                   bool IgnoreBundle = false) const {
381       // Instructions inside a bundle have the same number as the bundle itself.
382       auto BundleStart = getBundleStart(MI.getIterator());
383       auto BundleEnd = getBundleEnd(MI.getIterator());
384       // Use the first non-debug instruction in the bundle to get SlotIndex.
385       const MachineInstr &BundleNonDebug =
386           IgnoreBundle ? MI
387                        : *skipDebugInstructionsForward(BundleStart, BundleEnd);
388       assert(!BundleNonDebug.isDebugInstr() &&
389              "Could not use a debug instruction to query mi2iMap.");
390       Mi2IndexMap::const_iterator itr = mi2iMap.find(&BundleNonDebug);
391       assert(itr != mi2iMap.end() && "Instruction not found in maps.");
392       return itr->second;
393     }
394 
395     /// Returns the instruction for the given index, or null if the given
396     /// index has no instruction associated with it.
getInstructionFromIndex(SlotIndex index)397     MachineInstr* getInstructionFromIndex(SlotIndex index) const {
398       return index.listEntry()->getInstr();
399     }
400 
401     /// Returns the next non-null index, if one exists.
402     /// Otherwise returns getLastIndex().
getNextNonNullIndex(SlotIndex Index)403     SlotIndex getNextNonNullIndex(SlotIndex Index) {
404       IndexList::iterator I = Index.listEntry()->getIterator();
405       IndexList::iterator E = indexList.end();
406       while (++I != E)
407         if (I->getInstr())
408           return SlotIndex(&*I, Index.getSlot());
409       // We reached the end of the function.
410       return getLastIndex();
411     }
412 
413     /// getIndexBefore - Returns the index of the last indexed instruction
414     /// before MI, or the start index of its basic block.
415     /// MI is not required to have an index.
getIndexBefore(const MachineInstr & MI)416     SlotIndex getIndexBefore(const MachineInstr &MI) const {
417       const MachineBasicBlock *MBB = MI.getParent();
418       assert(MBB && "MI must be inserted in a basic block");
419       MachineBasicBlock::const_iterator I = MI, B = MBB->begin();
420       while (true) {
421         if (I == B)
422           return getMBBStartIdx(MBB);
423         --I;
424         Mi2IndexMap::const_iterator MapItr = mi2iMap.find(&*I);
425         if (MapItr != mi2iMap.end())
426           return MapItr->second;
427       }
428     }
429 
430     /// getIndexAfter - Returns the index of the first indexed instruction
431     /// after MI, or the end index of its basic block.
432     /// MI is not required to have an index.
getIndexAfter(const MachineInstr & MI)433     SlotIndex getIndexAfter(const MachineInstr &MI) const {
434       const MachineBasicBlock *MBB = MI.getParent();
435       assert(MBB && "MI must be inserted in a basic block");
436       MachineBasicBlock::const_iterator I = MI, E = MBB->end();
437       while (true) {
438         ++I;
439         if (I == E)
440           return getMBBEndIdx(MBB);
441         Mi2IndexMap::const_iterator MapItr = mi2iMap.find(&*I);
442         if (MapItr != mi2iMap.end())
443           return MapItr->second;
444       }
445     }
446 
447     /// Return the (start,end) range of the given basic block number.
448     const std::pair<SlotIndex, SlotIndex> &
getMBBRange(unsigned Num)449     getMBBRange(unsigned Num) const {
450       return MBBRanges[Num];
451     }
452 
453     /// Return the (start,end) range of the given basic block.
454     const std::pair<SlotIndex, SlotIndex> &
getMBBRange(const MachineBasicBlock * MBB)455     getMBBRange(const MachineBasicBlock *MBB) const {
456       return getMBBRange(MBB->getNumber());
457     }
458 
459     /// Returns the first index in the given basic block number.
getMBBStartIdx(unsigned Num)460     SlotIndex getMBBStartIdx(unsigned Num) const {
461       return getMBBRange(Num).first;
462     }
463 
464     /// Returns the first index in the given basic block.
getMBBStartIdx(const MachineBasicBlock * mbb)465     SlotIndex getMBBStartIdx(const MachineBasicBlock *mbb) const {
466       return getMBBRange(mbb).first;
467     }
468 
469     /// Returns the last index in the given basic block number.
getMBBEndIdx(unsigned Num)470     SlotIndex getMBBEndIdx(unsigned Num) const {
471       return getMBBRange(Num).second;
472     }
473 
474     /// Returns the last index in the given basic block.
getMBBEndIdx(const MachineBasicBlock * mbb)475     SlotIndex getMBBEndIdx(const MachineBasicBlock *mbb) const {
476       return getMBBRange(mbb).second;
477     }
478 
479     /// Iterator over the idx2MBBMap (sorted pairs of slot index of basic block
480     /// begin and basic block)
481     using MBBIndexIterator = SmallVectorImpl<IdxMBBPair>::const_iterator;
482 
483     /// Get an iterator pointing to the first IdxMBBPair with SlotIndex greater
484     /// than or equal to \p Idx. If \p Start is provided, only search the range
485     /// from \p Start to the end of the function.
getMBBLowerBound(MBBIndexIterator Start,SlotIndex Idx)486     MBBIndexIterator getMBBLowerBound(MBBIndexIterator Start,
487                                       SlotIndex Idx) const {
488       return std::lower_bound(
489           Start, MBBIndexEnd(), Idx,
490           [](const IdxMBBPair &IM, SlotIndex Idx) { return IM.first < Idx; });
491     }
getMBBLowerBound(SlotIndex Idx)492     MBBIndexIterator getMBBLowerBound(SlotIndex Idx) const {
493       return getMBBLowerBound(MBBIndexBegin(), Idx);
494     }
495 
496     /// Get an iterator pointing to the first IdxMBBPair with SlotIndex greater
497     /// than \p Idx.
getMBBUpperBound(SlotIndex Idx)498     MBBIndexIterator getMBBUpperBound(SlotIndex Idx) const {
499       return std::upper_bound(
500           MBBIndexBegin(), MBBIndexEnd(), Idx,
501           [](SlotIndex Idx, const IdxMBBPair &IM) { return Idx < IM.first; });
502     }
503 
504     /// Returns an iterator for the begin of the idx2MBBMap.
MBBIndexBegin()505     MBBIndexIterator MBBIndexBegin() const {
506       return idx2MBBMap.begin();
507     }
508 
509     /// Return an iterator for the end of the idx2MBBMap.
MBBIndexEnd()510     MBBIndexIterator MBBIndexEnd() const {
511       return idx2MBBMap.end();
512     }
513 
514     /// Returns the basic block which the given index falls in.
getMBBFromIndex(SlotIndex index)515     MachineBasicBlock* getMBBFromIndex(SlotIndex index) const {
516       if (MachineInstr *MI = getInstructionFromIndex(index))
517         return MI->getParent();
518 
519       MBBIndexIterator I = std::prev(getMBBUpperBound(index));
520       assert(I != MBBIndexEnd() && I->first <= index &&
521              index < getMBBEndIdx(I->second) &&
522              "index does not correspond to an MBB");
523       return I->second;
524     }
525 
526     /// Insert the given machine instruction into the mapping. Returns the
527     /// assigned index.
528     /// If Late is set and there are null indexes between mi's neighboring
529     /// instructions, create the new index after the null indexes instead of
530     /// before them.
531     SlotIndex insertMachineInstrInMaps(MachineInstr &MI, bool Late = false) {
532       assert(!MI.isInsideBundle() &&
533              "Instructions inside bundles should use bundle start's slot.");
534       assert(!mi2iMap.contains(&MI) && "Instr already indexed.");
535       // Numbering debug instructions could cause code generation to be
536       // affected by debug information.
537       assert(!MI.isDebugInstr() && "Cannot number debug instructions.");
538 
539       assert(MI.getParent() != nullptr && "Instr must be added to function.");
540 
541       // Get the entries where MI should be inserted.
542       IndexList::iterator prevItr, nextItr;
543       if (Late) {
544         // Insert MI's index immediately before the following instruction.
545         nextItr = getIndexAfter(MI).listEntry()->getIterator();
546         prevItr = std::prev(nextItr);
547       } else {
548         // Insert MI's index immediately after the preceding instruction.
549         prevItr = getIndexBefore(MI).listEntry()->getIterator();
550         nextItr = std::next(prevItr);
551       }
552 
553       // Get a number for the new instr, or 0 if there's no room currently.
554       // In the latter case we'll force a renumber later.
555       unsigned dist = ((nextItr->getIndex() - prevItr->getIndex())/2) & ~3u;
556       unsigned newNumber = prevItr->getIndex() + dist;
557 
558       // Insert a new list entry for MI.
559       IndexList::iterator newItr =
560           indexList.insert(nextItr, *createEntry(&MI, newNumber));
561 
562       // Renumber locally if we need to.
563       if (dist == 0)
564         renumberIndexes(newItr);
565 
566       SlotIndex newIndex(&*newItr, SlotIndex::Slot_Block);
567       mi2iMap.insert(std::make_pair(&MI, newIndex));
568       return newIndex;
569     }
570 
571     /// Removes machine instruction (bundle) \p MI from the mapping.
572     /// This should be called before MachineInstr::eraseFromParent() is used to
573     /// remove a whole bundle or an unbundled instruction.
574     /// If \p AllowBundled is set then this can be used on a bundled
575     /// instruction; however, this exists to support handleMoveIntoBundle,
576     /// and in general removeSingleMachineInstrFromMaps should be used instead.
577     void removeMachineInstrFromMaps(MachineInstr &MI,
578                                     bool AllowBundled = false);
579 
580     /// Removes a single machine instruction \p MI from the mapping.
581     /// This should be called before MachineInstr::eraseFromBundle() is used to
582     /// remove a single instruction (out of a bundle).
583     void removeSingleMachineInstrFromMaps(MachineInstr &MI);
584 
585     /// ReplaceMachineInstrInMaps - Replacing a machine instr with a new one in
586     /// maps used by register allocator. \returns the index where the new
587     /// instruction was inserted.
replaceMachineInstrInMaps(MachineInstr & MI,MachineInstr & NewMI)588     SlotIndex replaceMachineInstrInMaps(MachineInstr &MI, MachineInstr &NewMI) {
589       Mi2IndexMap::iterator mi2iItr = mi2iMap.find(&MI);
590       if (mi2iItr == mi2iMap.end())
591         return SlotIndex();
592       SlotIndex replaceBaseIndex = mi2iItr->second;
593       IndexListEntry *miEntry(replaceBaseIndex.listEntry());
594       assert(miEntry->getInstr() == &MI &&
595              "Mismatched instruction in index tables.");
596       miEntry->setInstr(&NewMI);
597       mi2iMap.erase(mi2iItr);
598       mi2iMap.insert(std::make_pair(&NewMI, replaceBaseIndex));
599       return replaceBaseIndex;
600     }
601 
602     /// Add the given MachineBasicBlock into the maps.
603     /// If it contains any instructions then they must already be in the maps.
604     /// This is used after a block has been split by moving some suffix of its
605     /// instructions into a newly created block.
insertMBBInMaps(MachineBasicBlock * mbb)606     void insertMBBInMaps(MachineBasicBlock *mbb) {
607       assert(mbb != &mbb->getParent()->front() &&
608              "Can't insert a new block at the beginning of a function.");
609       auto prevMBB = std::prev(MachineFunction::iterator(mbb));
610 
611       // Create a new entry to be used for the start of mbb and the end of
612       // prevMBB.
613       IndexListEntry *startEntry = createEntry(nullptr, 0);
614       IndexListEntry *endEntry = getMBBEndIdx(&*prevMBB).listEntry();
615       IndexListEntry *insEntry =
616           mbb->empty() ? endEntry
617                        : getInstructionIndex(mbb->front()).listEntry();
618       IndexList::iterator newItr =
619           indexList.insert(insEntry->getIterator(), *startEntry);
620 
621       SlotIndex startIdx(startEntry, SlotIndex::Slot_Block);
622       SlotIndex endIdx(endEntry, SlotIndex::Slot_Block);
623 
624       MBBRanges[prevMBB->getNumber()].second = startIdx;
625 
626       assert(unsigned(mbb->getNumber()) == MBBRanges.size() &&
627              "Blocks must be added in order");
628       MBBRanges.push_back(std::make_pair(startIdx, endIdx));
629       idx2MBBMap.push_back(IdxMBBPair(startIdx, mbb));
630 
631       renumberIndexes(newItr);
632       llvm::sort(idx2MBBMap, less_first());
633     }
634 
635     /// Renumber all indexes using the default instruction distance.
636     void packIndexes();
637   };
638 
639   // Specialize IntervalMapInfo for half-open slot index intervals.
640   template <>
641   struct IntervalMapInfo<SlotIndex> : IntervalMapHalfOpenInfo<SlotIndex> {
642   };
643 
644   class SlotIndexesAnalysis : public AnalysisInfoMixin<SlotIndexesAnalysis> {
645     friend AnalysisInfoMixin<SlotIndexesAnalysis>;
646     static AnalysisKey Key;
647 
648   public:
649     using Result = SlotIndexes;
650     Result run(MachineFunction &MF, MachineFunctionAnalysisManager &);
651   };
652 
653   class SlotIndexesPrinterPass : public PassInfoMixin<SlotIndexesPrinterPass> {
654     raw_ostream &OS;
655 
656   public:
657     explicit SlotIndexesPrinterPass(raw_ostream &OS) : OS(OS) {}
658     PreservedAnalyses run(MachineFunction &MF,
659                           MachineFunctionAnalysisManager &MFAM);
660     static bool isRequired() { return true; }
661   };
662 
663   class SlotIndexesWrapperPass : public MachineFunctionPass {
664     SlotIndexes SI;
665 
666   public:
667     static char ID;
668 
669     SlotIndexesWrapperPass();
670 
671     void getAnalysisUsage(AnalysisUsage &au) const override;
672     void releaseMemory() override { SI.clear(); }
673 
674     bool runOnMachineFunction(MachineFunction &fn) override {
675       SI.analyze(fn);
676       return false;
677     }
678 
679     SlotIndexes &getSI() { return SI; }
680   };
681 
682 } // end namespace llvm
683 
684 #endif // LLVM_CODEGEN_SLOTINDEXES_H
685