LLVM 20.0.0git
RegionPass.cpp
Go to the documentation of this file.
1//===- RegionPass.cpp - Region Pass and Region Pass Manager ---------------===//
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 RegionPass and RGPassManager. All region optimization
10// and transformation passes are derived from RegionPass. RGPassManager is
11// responsible for managing RegionPasses.
12// Most of this code has been COPIED from LoopPass.cpp
13//
14//===----------------------------------------------------------------------===//
15
18#include "llvm/IR/OptBisect.h"
20#include "llvm/IR/PrintPasses.h"
21#include "llvm/Support/Debug.h"
22#include "llvm/Support/Timer.h"
24
25using namespace llvm;
26
27#define DEBUG_TYPE "regionpassmgr"
28
29//===----------------------------------------------------------------------===//
30// RGPassManager
31//
32
33char RGPassManager::ID = 0;
34
36 RI = nullptr;
37 CurrentRegion = nullptr;
38}
39
40// Recurse through all subregions and all regions into RQ.
41static void addRegionIntoQueue(Region &R, std::deque<Region *> &RQ) {
42 RQ.push_back(&R);
43 for (const auto &E : R)
44 addRegionIntoQueue(*E, RQ);
45}
46
47/// Pass Manager itself does not invalidate any analysis info.
49 Info.addRequired<RegionInfoPass>();
50 Info.setPreservesAll();
51}
52
53/// run - Execute all of the passes scheduled for execution. Keep track of
54/// whether any of the passes modifies the function, and if so, return true.
56 RI = &getAnalysis<RegionInfoPass>().getRegionInfo();
57 bool Changed = false;
58
59 // Collect inherited analysis from Module level pass manager.
61
63
64 if (RQ.empty()) // No regions, skip calling finalizers
65 return false;
66
67 // Initialization
68 for (Region *R : RQ) {
69 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
71 Changed |= RP->doInitialization(R, *this);
72 }
73 }
74
75 // Walk Regions
76 while (!RQ.empty()) {
77
78 CurrentRegion = RQ.back();
79
80 // Run all passes on the current Region.
81 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
83
86 CurrentRegion->getNameStr());
88 }
89
91
92 bool LocalChanged = false;
93 {
94 PassManagerPrettyStackEntry X(P, *CurrentRegion->getEntry());
95
96 TimeRegion PassTimer(getPassTimer(P));
97#ifdef EXPENSIVE_CHECKS
98 uint64_t RefHash = P->structuralHash(F);
99#endif
100 LocalChanged = P->runOnRegion(CurrentRegion, *this);
101
102#ifdef EXPENSIVE_CHECKS
103 if (!LocalChanged && (RefHash != P->structuralHash(F))) {
104 llvm::errs() << "Pass modifies its input and doesn't report it: "
105 << P->getPassName() << "\n";
106 llvm_unreachable("Pass modifies its input and doesn't report it");
107 }
108#endif
109
110 Changed |= LocalChanged;
111 }
112
114 if (LocalChanged)
116 CurrentRegion->getNameStr());
118 }
119
120 // Manually check that this region is still healthy. This is done
121 // instead of relying on RegionInfo::verifyRegion since RegionInfo
122 // is a function pass and it's really expensive to verify every
123 // Region in the function every time. That level of checking can be
124 // enabled with the -verify-region-info option.
125 {
126 TimeRegion PassTimer(getPassTimer(P));
127 CurrentRegion->verifyRegion();
128 }
129
130 // Then call the regular verifyAnalysis functions.
132
133 if (LocalChanged)
138 ? "<deleted>"
139 : CurrentRegion->getNameStr(),
141 }
142
143 // Pop the region from queue after running all passes.
144 RQ.pop_back();
145
146 // Free all region nodes created in region passes.
147 RI->clearNodeCache();
148 }
149
150 // Finalization
151 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
153 Changed |= P->doFinalization();
154 }
155
156 // Print the region tree after all pass.
157 LLVM_DEBUG(dbgs() << "\nRegion tree of function " << F.getName()
158 << " after all region Pass:\n";
159 RI->dump(); dbgs() << "\n";);
160
161 return Changed;
162}
163
164/// Print passes managed by this manager
166 errs().indent(Offset*2) << "Region Pass Manager\n";
167 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
169 P->dumpPassStructure(Offset + 1);
171 }
172}
173
174namespace {
175//===----------------------------------------------------------------------===//
176// PrintRegionPass
177class PrintRegionPass : public RegionPass {
178private:
179 std::string Banner;
180 raw_ostream &Out; // raw_ostream to print on.
181
182public:
183 static char ID;
184 PrintRegionPass(const std::string &B, raw_ostream &o)
185 : RegionPass(ID), Banner(B), Out(o) {}
186
187 void getAnalysisUsage(AnalysisUsage &AU) const override {
188 AU.setPreservesAll();
189 }
190
191 bool runOnRegion(Region *R, RGPassManager &RGM) override {
192 if (!isFunctionInPrintList(R->getEntry()->getParent()->getName()))
193 return false;
194 Out << Banner;
195 for (const auto *BB : R->blocks()) {
196 if (BB)
197 BB->print(Out);
198 else
199 Out << "Printing <null> Block";
200 }
201
202 return false;
203 }
204
205 StringRef getPassName() const override { return "Print Region IR"; }
206};
207
208char PrintRegionPass::ID = 0;
209} //end anonymous namespace
210
211//===----------------------------------------------------------------------===//
212// RegionPass
213
214// Check if this pass is suitable for the current RGPassManager, if
215// available. This pass P is not suitable for a RGPassManager if P
216// is not preserving higher level analysis info used by other
217// RGPassManager passes. In such case, pop RGPassManager from the
218// stack. This will force assignPassManager() to create new
219// LPPassManger as expected.
221
222 // Find RGPassManager
223 while (!PMS.empty() &&
225 PMS.pop();
226
227
228 // If this pass is destroying high level information that is used
229 // by other passes that are managed by LPM then do not insert
230 // this pass in current LPM. Use new RGPassManager.
232 !PMS.top()->preserveHigherLevelAnalysis(this))
233 PMS.pop();
234}
235
236/// Assign pass manager to manage this pass.
238 PassManagerType PreferredType) {
239 // Find RGPassManager
240 while (!PMS.empty() &&
242 PMS.pop();
243
244 RGPassManager *RGPM;
245
246 // Create new Region Pass Manager if it does not exist.
248 RGPM = (RGPassManager*)PMS.top();
249 else {
250
251 assert (!PMS.empty() && "Unable to create Region Pass Manager");
252 PMDataManager *PMD = PMS.top();
253
254 // [1] Create new Region Pass Manager
255 RGPM = new RGPassManager();
256 RGPM->populateInheritedAnalysis(PMS);
257
258 // [2] Set up new manager's top level manager
260 TPM->addIndirectPassManager(RGPM);
261
262 // [3] Assign manager to manage this new manager. This may create
263 // and push new managers into PMS
264 TPM->schedulePass(RGPM);
265
266 // [4] Push new manager into PMS
267 PMS.push(RGPM);
268 }
269
270 RGPM->add(this);
271}
272
273/// Get the printer pass
275 const std::string &Banner) const {
276 return new PrintRegionPass(Banner, O);
277}
278
279static std::string getDescription(const Region &R) {
280 return "region";
281}
282
284 Function &F = *R.getEntry()->getParent();
285 OptPassGate &Gate = F.getContext().getOptPassGate();
286 if (Gate.isEnabled() &&
287 !Gate.shouldRunPass(this->getPassName(), getDescription(R)))
288 return true;
289
290 if (F.hasOptNone()) {
291 // Report this only once per function.
292 if (R.getEntry() == &F.getEntryBlock())
293 LLVM_DEBUG(dbgs() << "Skipping pass '" << getPassName()
294 << "' on function " << F.getName() << "\n");
295 return true;
296 }
297 return false;
298}
static GCRegistry::Add< OcamlGC > B("ocaml", "ocaml 3.10-compatible GC")
Analysis containing CSE Info
Definition: CSEInfo.cpp:27
static std::string getDescription(const CallGraphSCC &SCC)
#define LLVM_DEBUG(X)
Definition: Debug.h:101
static GCMetadataPrinterRegistry::Add< ErlangGCPrinter > X("erlang", "erlang-compatible garbage collector")
#define F(x, y, z)
Definition: MD5.cpp:55
This file declares the interface for bisecting optimizations.
#define P(N)
This header defines classes/functions to handle pass execution timing information with interfaces for...
static void addRegionIntoQueue(Region &R, std::deque< Region * > &RQ)
Definition: RegionPass.cpp:41
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
Represent the analysis usage information of a pass.
void setPreservesAll()
Set by analyses that do not transform their input at all.
FunctionPass class - This class is used to implement most global optimizations.
Definition: Pass.h:310
Extensions to this class implement mechanisms to disable passes and individual optimizations at compi...
Definition: OptBisect.h:24
virtual bool isEnabled() const
isEnabled() should return true before calling shouldRunPass().
Definition: OptBisect.h:36
virtual bool shouldRunPass(const StringRef PassName, StringRef IRDescription)
IRDescription is a textual description of the IR unit the pass is running over.
Definition: OptBisect.h:30
PMDataManager provides the common place to manage the analysis data used by pass managers.
void removeDeadPasses(Pass *P, StringRef Msg, enum PassDebuggingString)
Remove dead passes used by P.
void dumpLastUses(Pass *P, unsigned Offset) const
void recordAvailableAnalysis(Pass *P)
Augment AvailableAnalysis by adding analysis made available by pass P.
bool isPassDebuggingExecutionsOrMore() const
isPassDebuggingExecutionsOrMore - Return true if -debug-pass=Executions or higher is specified.
PMTopLevelManager * getTopLevelManager()
void dumpRequiredSet(const Pass *P) const
void initializeAnalysisImpl(Pass *P)
All Required analyses should be available to the pass as it runs! Here we fill in the AnalysisImpls m...
void verifyPreservedAnalysis(Pass *P)
verifyPreservedAnalysis – Verify analysis presreved by pass P.
bool preserveHigherLevelAnalysis(Pass *P)
unsigned getNumContainedPasses() const
virtual PassManagerType getPassManagerType() const
PMTopLevelManager * TPM
void add(Pass *P, bool ProcessAnalysis=true)
Add pass P into the PassVector.
void populateInheritedAnalysis(PMStack &PMS)
void dumpPreservedSet(const Pass *P) const
void removeNotPreservedAnalysis(Pass *P)
Remove Analysis that is not preserved by the pass.
void dumpPassInfo(Pass *P, enum PassDebuggingString S1, enum PassDebuggingString S2, StringRef Msg)
PMStack - This class implements a stack data structure of PMDataManager pointers.
PMDataManager * top() const
bool empty() const
void push(PMDataManager *PM)
PMTopLevelManager manages LastUser info and collects common APIs used by top level pass managers.
void addIndirectPassManager(PMDataManager *Manager)
void schedulePass(Pass *P)
Schedule pass P for execution.
PassManagerPrettyStackEntry - This is used to print informative information about what pass is runnin...
Pass interface - Implemented by all 'passes'.
Definition: Pass.h:94
virtual StringRef getPassName() const
getPassName - Return a nice clean name for a pass.
Definition: Pass.cpp:81
The pass manager to schedule RegionPasses.
Definition: RegionPass.h:87
void dumpPassStructure(unsigned Offset) override
Print passes managed by this manager.
Definition: RegionPass.cpp:165
Pass * getContainedPass(unsigned N)
Get passes contained by this manager.
Definition: RegionPass.h:114
static char ID
Definition: RegionPass.h:93
void getAnalysisUsage(AnalysisUsage &Info) const override
Pass Manager itself does not invalidate any analysis info.
Definition: RegionPass.cpp:48
bool runOnFunction(Function &F) override
Execute all of the passes scheduled for execution.
Definition: RegionPass.cpp:55
std::string getNameStr() const
Returns the name of the Region.
void verifyRegion() const
Verify if the region is a correct region.
BlockT * getEntry() const
Get the entry BasicBlock of the Region.
Definition: RegionInfo.h:320
void clearNodeCache()
Clear the Node Cache for all Regions.
Definition: RegionInfo.h:869
RegionT * getTopLevelRegion() const
Definition: RegionInfo.h:864
A pass that runs on each Region in a function.
Definition: RegionPass.h:32
void preparePassManager(PMStack &PMS) override
Check if available pass managers are suitable for this pass or not.
Definition: RegionPass.cpp:220
bool skipRegion(Region &R) const
Optional passes call this function to check whether the pass should be skipped.
Definition: RegionPass.cpp:283
void assignPassManager(PMStack &PMS, PassManagerType PMT=PMT_RegionPassManager) override
Assign pass manager to manage this pass.
Definition: RegionPass.cpp:237
Pass * createPrinterPass(raw_ostream &O, const std::string &Banner) const override
Get a pass to print the LLVM IR in the region.
Definition: RegionPass.cpp:274
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:50
The TimeRegion class is used as a helper class to call the startTimer() and stopTimer() methods of th...
Definition: Timer.h:143
This class implements an extremely fast bulk output stream that can only output to a stream.
Definition: raw_ostream.h:52
raw_ostream & indent(unsigned NumSpaces)
indent - Insert 'NumSpaces' spaces.
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
unsigned ID
LLVM IR allows to use arbitrary numbers as calling convention identifiers.
Definition: CallingConv.h:24
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
@ Offset
Definition: DWP.cpp:480
PassManagerType
Different types of internal pass managers.
Definition: Pass.h:55
@ PMT_RegionPassManager
RGPassManager.
Definition: Pass.h:61
Timer * getPassTimer(Pass *)
Request the timer for this legacy-pass-manager's pass instance.
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
Definition: Debug.cpp:163
bool isFunctionInPrintList(StringRef FunctionName)
@ MODIFICATION_MSG
raw_fd_ostream & errs()
This returns a reference to a raw_ostream for standard error.