LLVM 19.0.0git
SlotIndexes.cpp
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1//===-- SlotIndexes.cpp - Slot Indexes Pass ------------------------------===//
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
10#include "llvm/ADT/Statistic.h"
12#include "llvm/Config/llvm-config.h"
14#include "llvm/Support/Debug.h"
16
17using namespace llvm;
18
19#define DEBUG_TYPE "slotindexes"
20
21AnalysisKey SlotIndexesAnalysis::Key;
22
26 return Result(MF);
27}
28
32 OS << "Slot indexes in machine function: " << MF.getName() << '\n';
35}
37
40}
41
43 // The indexList's nodes are all allocated in the BumpPtrAllocator.
44 indexList.clear();
45}
46
48 false, false)
49
50STATISTIC(NumLocalRenum, "Number of local renumberings");
51
52void SlotIndexesWrapperPass::getAnalysisUsage(AnalysisUsage &au) const {
53 au.setPreservesAll();
55}
56
57void SlotIndexes::clear() {
58 mi2iMap.clear();
59 MBBRanges.clear();
60 idx2MBBMap.clear();
61 indexList.clear();
62 ileAllocator.Reset();
63}
64
65void SlotIndexes::analyze(MachineFunction &fn) {
66
67 // Compute numbering as follows:
68 // Grab an iterator to the start of the index list.
69 // Iterate over all MBBs, and within each MBB all MIs, keeping the MI
70 // iterator in lock-step (though skipping it over indexes which have
71 // null pointers in the instruction field).
72 // At each iteration assert that the instruction pointed to in the index
73 // is the same one pointed to by the MI iterator. This
74
75 // FIXME: This can be simplified. The mi2iMap_, Idx2MBBMap, etc. should
76 // only need to be set up once after the first numbering is computed.
77
78 mf = &fn;
79
80 // Check that the list contains only the sentinel.
81 assert(indexList.empty() && "Index list non-empty at initial numbering?");
82 assert(idx2MBBMap.empty() &&
83 "Index -> MBB mapping non-empty at initial numbering?");
84 assert(MBBRanges.empty() &&
85 "MBB -> Index mapping non-empty at initial numbering?");
86 assert(mi2iMap.empty() &&
87 "MachineInstr -> Index mapping non-empty at initial numbering?");
88
89 unsigned index = 0;
90 MBBRanges.resize(mf->getNumBlockIDs());
91 idx2MBBMap.reserve(mf->size());
92
93 indexList.push_back(*createEntry(nullptr, index));
94
95 // Iterate over the function.
96 for (MachineBasicBlock &MBB : *mf) {
97 // Insert an index for the MBB start.
98 SlotIndex blockStartIndex(&indexList.back(), SlotIndex::Slot_Block);
99
100 for (MachineInstr &MI : MBB) {
101 if (MI.isDebugOrPseudoInstr())
102 continue;
103
104 // Insert a store index for the instr.
105 indexList.push_back(*createEntry(&MI, index += SlotIndex::InstrDist));
106
107 // Save this base index in the maps.
108 mi2iMap.insert(std::make_pair(
109 &MI, SlotIndex(&indexList.back(), SlotIndex::Slot_Block)));
110 }
111
112 // We insert one blank instructions between basic blocks.
113 indexList.push_back(*createEntry(nullptr, index += SlotIndex::InstrDist));
114
115 MBBRanges[MBB.getNumber()].first = blockStartIndex;
116 MBBRanges[MBB.getNumber()].second = SlotIndex(&indexList.back(),
117 SlotIndex::Slot_Block);
118 idx2MBBMap.push_back(IdxMBBPair(blockStartIndex, &MBB));
119 }
120
121 // Sort the Idx2MBBMap
122 llvm::sort(idx2MBBMap, less_first());
123
124 LLVM_DEBUG(mf->print(dbgs(), this));
125}
126
128 bool AllowBundled) {
129 assert((AllowBundled || !MI.isBundledWithPred()) &&
130 "Use removeSingleMachineInstrFromMaps() instead");
131 Mi2IndexMap::iterator mi2iItr = mi2iMap.find(&MI);
132 if (mi2iItr == mi2iMap.end())
133 return;
134
135 SlotIndex MIIndex = mi2iItr->second;
136 IndexListEntry &MIEntry = *MIIndex.listEntry();
137 assert(MIEntry.getInstr() == &MI && "Instruction indexes broken.");
138 mi2iMap.erase(mi2iItr);
139 // FIXME: Eventually we want to actually delete these indexes.
140 MIEntry.setInstr(nullptr);
141}
142
144 Mi2IndexMap::iterator mi2iItr = mi2iMap.find(&MI);
145 if (mi2iItr == mi2iMap.end())
146 return;
147
148 SlotIndex MIIndex = mi2iItr->second;
149 IndexListEntry &MIEntry = *MIIndex.listEntry();
150 assert(MIEntry.getInstr() == &MI && "Instruction indexes broken.");
151 mi2iMap.erase(mi2iItr);
152
153 // When removing the first instruction of a bundle update mapping to next
154 // instruction.
155 if (MI.isBundledWithSucc()) {
156 // Only the first instruction of a bundle should have an index assigned.
157 assert(!MI.isBundledWithPred() && "Should be first bundle instruction");
158
159 MachineBasicBlock::instr_iterator Next = std::next(MI.getIterator());
160 MachineInstr &NextMI = *Next;
161 MIEntry.setInstr(&NextMI);
162 mi2iMap.insert(std::make_pair(&NextMI, MIIndex));
163 return;
164 } else {
165 // FIXME: Eventually we want to actually delete these indexes.
166 MIEntry.setInstr(nullptr);
167 }
168}
169
170// Renumber indexes locally after curItr was inserted, but failed to get a new
171// index.
172void SlotIndexes::renumberIndexes(IndexList::iterator curItr) {
173 // Number indexes with half the default spacing so we can catch up quickly.
174 const unsigned Space = SlotIndex::InstrDist/2;
175 static_assert((Space & 3) == 0, "InstrDist must be a multiple of 2*NUM");
176
177 IndexList::iterator startItr = std::prev(curItr);
178 unsigned index = startItr->getIndex();
179 do {
180 curItr->setIndex(index += Space);
181 ++curItr;
182 // If the next index is bigger, we have caught up.
183 } while (curItr != indexList.end() && curItr->getIndex() <= index);
184
185 LLVM_DEBUG(dbgs() << "\n*** Renumbered SlotIndexes " << startItr->getIndex()
186 << '-' << index << " ***\n");
187 ++NumLocalRenum;
188}
189
190// Repair indexes after adding and removing instructions.
194 bool includeStart = (Begin == MBB->begin());
195 SlotIndex startIdx;
196 if (includeStart)
197 startIdx = getMBBStartIdx(MBB);
198 else
199 startIdx = getInstructionIndex(*--Begin);
200
201 SlotIndex endIdx;
202 if (End == MBB->end())
203 endIdx = getMBBEndIdx(MBB);
204 else
205 endIdx = getInstructionIndex(*End);
206
207 // FIXME: Conceptually, this code is implementing an iterator on MBB that
208 // optionally includes an additional position prior to MBB->begin(), indicated
209 // by the includeStart flag. This is done so that we can iterate MIs in a MBB
210 // in parallel with SlotIndexes, but there should be a better way to do this.
211 IndexList::iterator ListB = startIdx.listEntry()->getIterator();
212 IndexList::iterator ListI = endIdx.listEntry()->getIterator();
214 bool pastStart = false;
215 while (ListI != ListB || MBBI != Begin || (includeStart && !pastStart)) {
216 assert(ListI->getIndex() >= startIdx.getIndex() &&
217 (includeStart || !pastStart) &&
218 "Decremented past the beginning of region to repair.");
219
220 MachineInstr *SlotMI = ListI->getInstr();
221 MachineInstr *MI = (MBBI != MBB->end() && !pastStart) ? &*MBBI : nullptr;
222 bool MBBIAtBegin = MBBI == Begin && (!includeStart || pastStart);
223
224 if (SlotMI == MI && !MBBIAtBegin) {
225 --ListI;
226 if (MBBI != Begin)
227 --MBBI;
228 else
229 pastStart = true;
230 } else if (MI && !mi2iMap.contains(MI)) {
231 if (MBBI != Begin)
232 --MBBI;
233 else
234 pastStart = true;
235 } else {
236 --ListI;
237 if (SlotMI)
239 }
240 }
241
242 // In theory this could be combined with the previous loop, but it is tricky
243 // to update the IndexList while we are iterating it.
244 for (MachineBasicBlock::iterator I = End; I != Begin;) {
245 --I;
246 MachineInstr &MI = *I;
247 if (!MI.isDebugOrPseudoInstr() && !mi2iMap.contains(&MI))
249 }
250}
251
253 for (auto [Index, Entry] : enumerate(indexList))
254 Entry.setIndex(Index * SlotIndex::InstrDist);
255}
256
258 for (const IndexListEntry &ILE : indexList) {
259 OS << ILE.getIndex() << ' ';
260
261 if (ILE.getInstr())
262 OS << *ILE.getInstr();
263 else
264 OS << '\n';
265 }
266
267 for (unsigned i = 0, e = MBBRanges.size(); i != e; ++i)
268 OS << "%bb." << i << "\t[" << MBBRanges[i].first << ';'
269 << MBBRanges[i].second << ")\n";
270}
271
272#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
274#endif
275
276// Print a SlotIndex to a raw_ostream.
278 if (isValid())
279 os << listEntry()->getIndex() << "Berd"[getSlot()];
280 else
281 os << "invalid";
282}
283
284#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
285// Dump a SlotIndex to stderr.
287 print(dbgs());
288 dbgs() << "\n";
289}
290#endif
MachineBasicBlock & MBB
MachineBasicBlock MachineBasicBlock::iterator MBBI
#define LLVM_DUMP_METHOD
Mark debug helper function definitions like dump() that should not be stripped from debug builds.
Definition: Compiler.h:537
#define LLVM_DEBUG(X)
Definition: Debug.h:101
bool End
Definition: ELF_riscv.cpp:480
#define DEBUG_TYPE
IRTranslator LLVM IR MI
#define I(x, y, z)
Definition: MD5.cpp:58
#define INITIALIZE_PASS(passName, arg, name, cfg, analysis)
Definition: PassSupport.h:38
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
raw_pwrite_stream & OS
Number of renumberings
Definition: SlotIndexes.cpp:50
This file defines the 'Statistic' class, which is designed to be an easy way to expose various metric...
#define STATISTIC(VARNAME, DESC)
Definition: Statistic.h:167
A container for analyses that lazily runs them and caches their results.
Definition: PassManager.h:253
PassT::Result & getResult(IRUnitT &IR, ExtraArgTs... ExtraArgs)
Get the result of an analysis pass for a given IR unit.
Definition: PassManager.h:405
Represent the analysis usage information of a pass.
void Reset()
Deallocate all but the current slab and reset the current pointer to the beginning of it,...
Definition: Allocator.h:123
iterator find(const_arg_type_t< KeyT > Val)
Definition: DenseMap.h:155
bool erase(const KeyT &Val)
Definition: DenseMap.h:345
bool empty() const
Definition: DenseMap.h:98
iterator end()
Definition: DenseMap.h:84
bool contains(const_arg_type_t< KeyT > Val) const
Return true if the specified key is in the map, false otherwise.
Definition: DenseMap.h:145
std::pair< iterator, bool > insert(const std::pair< KeyT, ValueT > &KV)
Definition: DenseMap.h:220
This class represents an entry in the slot index list held in the SlotIndexes pass.
Definition: SlotIndexes.h:46
void setInstr(MachineInstr *mi)
Definition: SlotIndexes.h:54
MachineInstr * getInstr() const
Definition: SlotIndexes.h:53
unsigned getIndex() const
Definition: SlotIndexes.h:58
int getNumber() const
MachineBasicBlocks are uniquely numbered at the function level, unless they're not in a MachineFuncti...
Instructions::iterator instr_iterator
MachineFunctionPass - This class adapts the FunctionPass interface to allow convenient creation of pa...
void getAnalysisUsage(AnalysisUsage &AU) const override
getAnalysisUsage - Subclasses that override getAnalysisUsage must call this.
StringRef getName() const
getName - Return the name of the corresponding LLVM function.
unsigned size() const
unsigned getNumBlockIDs() const
getNumBlockIDs - Return the number of MBB ID's allocated.
Representation of each machine instruction.
Definition: MachineInstr.h:69
static PassRegistry * getPassRegistry()
getPassRegistry - Access the global registry object, which is automatically initialized at applicatio...
A set of analyses that are preserved following a run of a transformation pass.
Definition: Analysis.h:111
static PreservedAnalyses all()
Construct a special preserved set that preserves all passes.
Definition: Analysis.h:117
SlotIndex - An opaque wrapper around machine indexes.
Definition: SlotIndexes.h:65
@ InstrDist
The default distance between instructions as returned by distance().
Definition: SlotIndexes.h:112
bool isValid() const
Returns true if this is a valid index.
Definition: SlotIndexes.h:130
void dump() const
Dump this index to stderr.
void print(raw_ostream &os) const
Print this index to the given raw_ostream.
Result run(MachineFunction &MF, MachineFunctionAnalysisManager &)
Definition: SlotIndexes.cpp:24
PreservedAnalyses run(MachineFunction &MF, MachineFunctionAnalysisManager &MFAM)
Definition: SlotIndexes.cpp:30
SlotIndexes pass.
Definition: SlotIndexes.h:297
SlotIndex insertMachineInstrInMaps(MachineInstr &MI, bool Late=false)
Insert the given machine instruction into the mapping.
Definition: SlotIndexes.h:531
void removeMachineInstrFromMaps(MachineInstr &MI, bool AllowBundled=false)
Removes machine instruction (bundle) MI from the mapping.
void dump() const
Dump the indexes.
void repairIndexesInRange(MachineBasicBlock *MBB, MachineBasicBlock::iterator Begin, MachineBasicBlock::iterator End)
Repair indexes after adding and removing instructions.
SlotIndex getMBBEndIdx(unsigned Num) const
Returns the last index in the given basic block number.
Definition: SlotIndexes.h:470
void removeSingleMachineInstrFromMaps(MachineInstr &MI)
Removes a single machine instruction MI from the mapping.
SlotIndex getInstructionIndex(const MachineInstr &MI, bool IgnoreBundle=false) const
Returns the base index for the given instruction.
Definition: SlotIndexes.h:379
SlotIndex getMBBStartIdx(unsigned Num) const
Returns the first index in the given basic block number.
Definition: SlotIndexes.h:460
void packIndexes()
Renumber all indexes using the default instruction distance.
void print(raw_ostream &OS) const
bool empty() const
Definition: SmallVector.h:94
void reserve(size_type N)
Definition: SmallVector.h:676
void push_back(const T &Elt)
Definition: SmallVector.h:426
self_iterator getIterator()
Definition: ilist_node.h:132
This class implements an extremely fast bulk output stream that can only output to a stream.
Definition: raw_ostream.h:52
reference back()
Definition: simple_ilist.h:146
void clear()
Clear the list; never deletes.
Definition: simple_ilist.h:236
typename ilist_select_iterator_type< OptionsT::has_iterator_bits, OptionsT, false, false >::type iterator
Definition: simple_ilist.h:97
bool empty() const
Check if the list is empty in constant time.
Definition: simple_ilist.h:139
void push_back(reference Node)
Insert a node at the back; never copies.
Definition: simple_ilist.h:153
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
auto enumerate(FirstRange &&First, RestRanges &&...Rest)
Given two or more input ranges, returns a new range whose values are are tuples (A,...
Definition: STLExtras.h:2400
std::pair< SlotIndex, MachineBasicBlock * > IdxMBBPair
Definition: SlotIndexes.h:292
Printable print(const GCNRegPressure &RP, const GCNSubtarget *ST=nullptr)
void sort(IteratorTy Start, IteratorTy End)
Definition: STLExtras.h:1647
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
Definition: Debug.cpp:163
void initializeSlotIndexesWrapperPassPass(PassRegistry &)
A special type used by analysis passes to provide an address that identifies that particular analysis...
Definition: Analysis.h:28
Function object to check whether the first component of a container supported by std::get (like std::...
Definition: STLExtras.h:1450