/Users/buildslave/jenkins/sharedspace/clang-stage2-coverage-R@2/llvm/lib/Analysis/CallGraphSCCPass.cpp
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1 | | //===- CallGraphSCCPass.cpp - Pass that operates BU on call graph ---------===// |
2 | | // |
3 | | // The LLVM Compiler Infrastructure |
4 | | // |
5 | | // This file is distributed under the University of Illinois Open Source |
6 | | // License. See LICENSE.TXT for details. |
7 | | // |
8 | | //===----------------------------------------------------------------------===// |
9 | | // |
10 | | // This file implements the CallGraphSCCPass class, which is used for passes |
11 | | // which are implemented as bottom-up traversals on the call graph. Because |
12 | | // there may be cycles in the call graph, passes of this type operate on the |
13 | | // call-graph in SCC order: that is, they process function bottom-up, except for |
14 | | // recursive functions, which they process all at once. |
15 | | // |
16 | | //===----------------------------------------------------------------------===// |
17 | | |
18 | | #include "llvm/Analysis/CallGraphSCCPass.h" |
19 | | #include "llvm/ADT/DenseMap.h" |
20 | | #include "llvm/ADT/SCCIterator.h" |
21 | | #include "llvm/ADT/Statistic.h" |
22 | | #include "llvm/Analysis/CallGraph.h" |
23 | | #include "llvm/IR/CallSite.h" |
24 | | #include "llvm/IR/Function.h" |
25 | | #include "llvm/IR/Intrinsics.h" |
26 | | #include "llvm/IR/LLVMContext.h" |
27 | | #include "llvm/IR/LegacyPassManagers.h" |
28 | | #include "llvm/IR/Module.h" |
29 | | #include "llvm/IR/OptBisect.h" |
30 | | #include "llvm/Pass.h" |
31 | | #include "llvm/Support/CommandLine.h" |
32 | | #include "llvm/Support/Debug.h" |
33 | | #include "llvm/Support/Timer.h" |
34 | | #include "llvm/Support/raw_ostream.h" |
35 | | #include <cassert> |
36 | | #include <string> |
37 | | #include <utility> |
38 | | #include <vector> |
39 | | |
40 | | using namespace llvm; |
41 | | |
42 | | #define DEBUG_TYPE "cgscc-passmgr" |
43 | | |
44 | | static cl::opt<unsigned> |
45 | | MaxIterations("max-cg-scc-iterations", cl::ReallyHidden, cl::init(4)); |
46 | | |
47 | | STATISTIC(MaxSCCIterations, "Maximum CGSCCPassMgr iterations on one SCC"); |
48 | | |
49 | | //===----------------------------------------------------------------------===// |
50 | | // CGPassManager |
51 | | // |
52 | | /// CGPassManager manages FPPassManagers and CallGraphSCCPasses. |
53 | | |
54 | | namespace { |
55 | | |
56 | | class CGPassManager : public ModulePass, public PMDataManager { |
57 | | public: |
58 | | static char ID; |
59 | | |
60 | 26.4k | explicit CGPassManager() : ModulePass(ID), PMDataManager() {} |
61 | | |
62 | | /// Execute all of the passes scheduled for execution. Keep track of |
63 | | /// whether any of the passes modifies the module, and if so, return true. |
64 | | bool runOnModule(Module &M) override; |
65 | | |
66 | | using ModulePass::doInitialization; |
67 | | using ModulePass::doFinalization; |
68 | | |
69 | | bool doInitialization(CallGraph &CG); |
70 | | bool doFinalization(CallGraph &CG); |
71 | | |
72 | | /// Pass Manager itself does not invalidate any analysis info. |
73 | 26.4k | void getAnalysisUsage(AnalysisUsage &Info) const override { |
74 | 26.4k | // CGPassManager walks SCC and it needs CallGraph. |
75 | 26.4k | Info.addRequired<CallGraphWrapperPass>(); |
76 | 26.4k | Info.setPreservesAll(); |
77 | 26.4k | } |
78 | | |
79 | 2 | StringRef getPassName() const override { return "CallGraph Pass Manager"; } |
80 | | |
81 | 26.5k | PMDataManager *getAsPMDataManager() override { return this; } |
82 | 3.23M | Pass *getAsPass() override { return this; } |
83 | | |
84 | | // Print passes managed by this manager |
85 | 12 | void dumpPassStructure(unsigned Offset) override { |
86 | 12 | errs().indent(Offset*2) << "Call Graph SCC Pass Manager\n"; |
87 | 48 | for (unsigned Index = 0; Index < getNumContainedPasses()48 ; ++Index36 ) { |
88 | 36 | Pass *P = getContainedPass(Index); |
89 | 36 | P->dumpPassStructure(Offset + 1); |
90 | 36 | dumpLastUses(P, Offset+1); |
91 | 36 | } |
92 | 12 | } |
93 | | |
94 | 4.33M | Pass *getContainedPass(unsigned N) { |
95 | 4.33M | assert(N < PassVector.size() && "Pass number out of range!"); |
96 | 4.33M | return static_cast<Pass *>(PassVector[N]); |
97 | 4.33M | } |
98 | | |
99 | 211k | PassManagerType getPassManagerType() const override { |
100 | 211k | return PMT_CallGraphPassManager; |
101 | 211k | } |
102 | | |
103 | | private: |
104 | | bool RunAllPassesOnSCC(CallGraphSCC &CurSCC, CallGraph &CG, |
105 | | bool &DevirtualizedCall); |
106 | | |
107 | | bool RunPassOnSCC(Pass *P, CallGraphSCC &CurSCC, |
108 | | CallGraph &CG, bool &CallGraphUpToDate, |
109 | | bool &DevirtualizedCall); |
110 | | bool RefreshCallGraph(const CallGraphSCC &CurSCC, CallGraph &CG, |
111 | | bool IsCheckingMode); |
112 | | }; |
113 | | |
114 | | } // end anonymous namespace. |
115 | | |
116 | | char CGPassManager::ID = 0; |
117 | | |
118 | | bool CGPassManager::RunPassOnSCC(Pass *P, CallGraphSCC &CurSCC, |
119 | | CallGraph &CG, bool &CallGraphUpToDate, |
120 | 3.97M | bool &DevirtualizedCall) { |
121 | 3.97M | bool Changed = false; |
122 | 3.97M | PMDataManager *PM = P->getAsPMDataManager(); |
123 | 3.97M | |
124 | 3.97M | if (!PM3.97M ) { |
125 | 3.17M | CallGraphSCCPass *CGSP = (CallGraphSCCPass*)P; |
126 | 3.17M | if (!CallGraphUpToDate3.17M ) { |
127 | 14.8k | DevirtualizedCall |= RefreshCallGraph(CurSCC, CG, false); |
128 | 14.8k | CallGraphUpToDate = true; |
129 | 14.8k | } |
130 | 3.17M | |
131 | 3.17M | { |
132 | 3.17M | TimeRegion PassTimer(getPassTimer(CGSP)); |
133 | 3.17M | Changed = CGSP->runOnSCC(CurSCC); |
134 | 3.17M | } |
135 | 3.17M | |
136 | 3.17M | // After the CGSCCPass is done, when assertions are enabled, use |
137 | 3.17M | // RefreshCallGraph to verify that the callgraph was correctly updated. |
138 | | #ifndef NDEBUG |
139 | | if (Changed) |
140 | | RefreshCallGraph(CurSCC, CG, true); |
141 | | #endif |
142 | | |
143 | 3.17M | return Changed; |
144 | 3.17M | } |
145 | 798k | |
146 | 3.97M | assert(PM->getPassManagerType() == PMT_FunctionPassManager && |
147 | 798k | "Invalid CGPassManager member"); |
148 | 798k | FPPassManager *FPP = (FPPassManager*)P; |
149 | 798k | |
150 | 798k | // Run pass P on all functions in the current SCC. |
151 | 799k | for (CallGraphNode *CGN : CurSCC) { |
152 | 799k | if (Function *F799k = CGN->getFunction()) { |
153 | 764k | dumpPassInfo(P, EXECUTION_MSG, ON_FUNCTION_MSG, F->getName()); |
154 | 764k | { |
155 | 764k | TimeRegion PassTimer(getPassTimer(FPP)); |
156 | 764k | Changed |= FPP->runOnFunction(*F); |
157 | 764k | } |
158 | 764k | F->getContext().yield(); |
159 | 764k | } |
160 | 799k | } |
161 | 798k | |
162 | 798k | // The function pass(es) modified the IR, they may have clobbered the |
163 | 798k | // callgraph. |
164 | 798k | if (Changed && 798k CallGraphUpToDate232k ) { |
165 | 232k | DEBUG(dbgs() << "CGSCCPASSMGR: Pass Dirtied SCC: " |
166 | 232k | << P->getPassName() << '\n'); |
167 | 232k | CallGraphUpToDate = false; |
168 | 232k | } |
169 | 3.97M | return Changed; |
170 | 3.97M | } |
171 | | |
172 | | /// Scan the functions in the specified CFG and resync the |
173 | | /// callgraph with the call sites found in it. This is used after |
174 | | /// FunctionPasses have potentially munged the callgraph, and can be used after |
175 | | /// CallGraphSCC passes to verify that they correctly updated the callgraph. |
176 | | /// |
177 | | /// This function returns true if it devirtualized an existing function call, |
178 | | /// meaning it turned an indirect call into a direct call. This happens when |
179 | | /// a function pass like GVN optimizes away stuff feeding the indirect call. |
180 | | /// This never happens in checking mode. |
181 | | bool CGPassManager::RefreshCallGraph(const CallGraphSCC &CurSCC, CallGraph &CG, |
182 | 232k | bool CheckingMode) { |
183 | 232k | DenseMap<Value*, CallGraphNode*> CallSites; |
184 | 232k | |
185 | 232k | DEBUG(dbgs() << "CGSCCPASSMGR: Refreshing SCC with " << CurSCC.size() |
186 | 232k | << " nodes:\n"; |
187 | 232k | for (CallGraphNode *CGN : CurSCC) |
188 | 232k | CGN->dump(); |
189 | 232k | ); |
190 | 232k | |
191 | 232k | bool MadeChange = false; |
192 | 232k | bool DevirtualizedCall = false; |
193 | 232k | |
194 | 232k | // Scan all functions in the SCC. |
195 | 232k | unsigned FunctionNo = 0; |
196 | 232k | for (CallGraphSCC::iterator SCCIdx = CurSCC.begin(), E = CurSCC.end(); |
197 | 465k | SCCIdx != E465k ; ++SCCIdx, ++FunctionNo233k ) { |
198 | 233k | CallGraphNode *CGN = *SCCIdx; |
199 | 233k | Function *F = CGN->getFunction(); |
200 | 233k | if (!F || 233k F->isDeclaration()233k ) continue0 ; |
201 | 233k | |
202 | 233k | // Walk the function body looking for call sites. Sync up the call sites in |
203 | 233k | // CGN with those actually in the function. |
204 | 233k | |
205 | 233k | // Keep track of the number of direct and indirect calls that were |
206 | 233k | // invalidated and removed. |
207 | 233k | unsigned NumDirectRemoved = 0, NumIndirectRemoved = 0; |
208 | 233k | |
209 | 233k | // Get the set of call sites currently in the function. |
210 | 1.65M | for (CallGraphNode::iterator I = CGN->begin(), E = CGN->end(); I != E1.65M ; ) { |
211 | 1.42M | // If this call site is null, then the function pass deleted the call |
212 | 1.42M | // entirely and the WeakTrackingVH nulled it out. |
213 | 1.42M | if (!I->first || |
214 | 1.42M | // If we've already seen this call site, then the FunctionPass RAUW'd |
215 | 1.42M | // one call with another, which resulted in two "uses" in the edge |
216 | 1.42M | // list of the same call. |
217 | 1.37M | CallSites.count(I->first) || |
218 | 1.42M | |
219 | 1.42M | // If the call edge is not from a call or invoke, or it is a |
220 | 1.42M | // instrinsic call, then the function pass RAUW'd a call with |
221 | 1.42M | // another value. This can happen when constant folding happens |
222 | 1.42M | // of well known functions etc. |
223 | 1.37M | !CallSite(I->first) || |
224 | 1.37M | (CallSite(I->first).getCalledFunction() && |
225 | 1.32M | CallSite(I->first).getCalledFunction()->isIntrinsic() && |
226 | 6 | Intrinsic::isLeaf( |
227 | 1.42M | CallSite(I->first).getCalledFunction()->getIntrinsicID()))) { |
228 | 46.2k | assert(!CheckingMode && |
229 | 46.2k | "CallGraphSCCPass did not update the CallGraph correctly!"); |
230 | 46.2k | |
231 | 46.2k | // If this was an indirect call site, count it. |
232 | 46.2k | if (!I->second->getFunction()) |
233 | 441 | ++NumIndirectRemoved; |
234 | 46.2k | else |
235 | 45.8k | ++NumDirectRemoved; |
236 | 46.2k | |
237 | 46.2k | // Just remove the edge from the set of callees, keep track of whether |
238 | 46.2k | // I points to the last element of the vector. |
239 | 46.2k | bool WasLast = I + 1 == E; |
240 | 46.2k | CGN->removeCallEdge(I); |
241 | 46.2k | |
242 | 46.2k | // If I pointed to the last element of the vector, we have to bail out: |
243 | 46.2k | // iterator checking rejects comparisons of the resultant pointer with |
244 | 46.2k | // end. |
245 | 46.2k | if (WasLast) |
246 | 2.26k | break; |
247 | 43.9k | E = CGN->end(); |
248 | 43.9k | continue; |
249 | 43.9k | } |
250 | 1.37M | |
251 | 1.42M | assert(!CallSites.count(I->first) && |
252 | 1.37M | "Call site occurs in node multiple times"); |
253 | 1.37M | |
254 | 1.37M | CallSite CS(I->first); |
255 | 1.37M | if (CS1.37M ) { |
256 | 1.37M | Function *Callee = CS.getCalledFunction(); |
257 | 1.37M | // Ignore intrinsics because they're not really function calls. |
258 | 1.37M | if (!Callee || 1.37M !(Callee->isIntrinsic())1.32M ) |
259 | 1.37M | CallSites.insert(std::make_pair(I->first, I->second)); |
260 | 1.37M | } |
261 | 1.42M | ++I; |
262 | 1.42M | } |
263 | 233k | |
264 | 233k | // Loop over all of the instructions in the function, getting the callsites. |
265 | 233k | // Keep track of the number of direct/indirect calls added. |
266 | 233k | unsigned NumDirectAdded = 0, NumIndirectAdded = 0; |
267 | 233k | |
268 | 233k | for (BasicBlock &BB : *F) |
269 | 3.07M | for (Instruction &I : BB) 3.07M { |
270 | 16.8M | CallSite CS(&I); |
271 | 16.8M | if (!CS16.8M ) continue15.0M ; |
272 | 1.72M | Function *Callee = CS.getCalledFunction(); |
273 | 1.72M | if (Callee && 1.72M Callee->isIntrinsic()1.67M ) continue293k ; |
274 | 1.43M | |
275 | 1.43M | // If this call site already existed in the callgraph, just verify it |
276 | 1.43M | // matches up to expectations and remove it from CallSites. |
277 | 1.43M | DenseMap<Value*, CallGraphNode*>::iterator ExistingIt = |
278 | 1.43M | CallSites.find(CS.getInstruction()); |
279 | 1.43M | if (ExistingIt != CallSites.end()1.43M ) { |
280 | 1.37M | CallGraphNode *ExistingNode = ExistingIt->second; |
281 | 1.37M | |
282 | 1.37M | // Remove from CallSites since we have now seen it. |
283 | 1.37M | CallSites.erase(ExistingIt); |
284 | 1.37M | |
285 | 1.37M | // Verify that the callee is right. |
286 | 1.37M | if (ExistingNode->getFunction() == CS.getCalledFunction()) |
287 | 1.37M | continue; |
288 | 232 | |
289 | 232 | // If we are in checking mode, we are not allowed to actually mutate |
290 | 232 | // the callgraph. If this is a case where we can infer that the |
291 | 232 | // callgraph is less precise than it could be (e.g. an indirect call |
292 | 232 | // site could be turned direct), don't reject it in checking mode, and |
293 | 232 | // don't tweak it to be more precise. |
294 | 232 | if (232 CheckingMode && 232 CS.getCalledFunction()0 && |
295 | 0 | ExistingNode->getFunction() == nullptr) |
296 | 0 | continue; |
297 | 232 | |
298 | 0 | assert(!CheckingMode && |
299 | 232 | "CallGraphSCCPass did not update the CallGraph correctly!"); |
300 | 232 | |
301 | 232 | // If not, we either went from a direct call to indirect, indirect to |
302 | 232 | // direct, or direct to different direct. |
303 | 232 | CallGraphNode *CalleeNode; |
304 | 232 | if (Function *Callee232 = CS.getCalledFunction()) { |
305 | 232 | CalleeNode = CG.getOrInsertFunction(Callee); |
306 | 232 | // Keep track of whether we turned an indirect call into a direct |
307 | 232 | // one. |
308 | 232 | if (!ExistingNode->getFunction()232 ) { |
309 | 230 | DevirtualizedCall = true; |
310 | 230 | DEBUG(dbgs() << " CGSCCPASSMGR: Devirtualized call to '" |
311 | 230 | << Callee->getName() << "'\n"); |
312 | 230 | } |
313 | 0 | } else { |
314 | 0 | CalleeNode = CG.getCallsExternalNode(); |
315 | 0 | } |
316 | 1.37M | |
317 | 1.37M | // Update the edge target in CGN. |
318 | 1.37M | CGN->replaceCallEdge(CS, CS, CalleeNode); |
319 | 1.37M | MadeChange = true; |
320 | 1.37M | continue; |
321 | 1.37M | } |
322 | 60.2k | |
323 | 1.43M | assert(!CheckingMode && |
324 | 60.2k | "CallGraphSCCPass did not update the CallGraph correctly!"); |
325 | 60.2k | |
326 | 60.2k | // If the call site didn't exist in the CGN yet, add it. |
327 | 60.2k | CallGraphNode *CalleeNode; |
328 | 60.2k | if (Function *Callee60.2k = CS.getCalledFunction()) { |
329 | 57.5k | CalleeNode = CG.getOrInsertFunction(Callee); |
330 | 57.5k | ++NumDirectAdded; |
331 | 60.2k | } else { |
332 | 2.62k | CalleeNode = CG.getCallsExternalNode(); |
333 | 2.62k | ++NumIndirectAdded; |
334 | 2.62k | } |
335 | 3.07M | |
336 | 3.07M | CGN->addCalledFunction(CS, CalleeNode); |
337 | 3.07M | MadeChange = true; |
338 | 3.07M | } |
339 | 233k | |
340 | 233k | // We scanned the old callgraph node, removing invalidated call sites and |
341 | 233k | // then added back newly found call sites. One thing that can happen is |
342 | 233k | // that an old indirect call site was deleted and replaced with a new direct |
343 | 233k | // call. In this case, we have devirtualized a call, and CGSCCPM would like |
344 | 233k | // to iteratively optimize the new code. Unfortunately, we don't really |
345 | 233k | // have a great way to detect when this happens. As an approximation, we |
346 | 233k | // just look at whether the number of indirect calls is reduced and the |
347 | 233k | // number of direct calls is increased. There are tons of ways to fool this |
348 | 233k | // (e.g. DCE'ing an indirect call and duplicating an unrelated block with a |
349 | 233k | // direct call) but this is close enough. |
350 | 233k | if (NumIndirectRemoved > NumIndirectAdded && |
351 | 116 | NumDirectRemoved < NumDirectAdded) |
352 | 12 | DevirtualizedCall = true; |
353 | 233k | |
354 | 233k | // After scanning this function, if we still have entries in callsites, then |
355 | 233k | // they are dangling pointers. WeakTrackingVH should save us for this, so |
356 | 233k | // abort if |
357 | 233k | // this happens. |
358 | 233k | assert(CallSites.empty() && "Dangling pointers found in call sites map"); |
359 | 233k | |
360 | 233k | // Periodically do an explicit clear to remove tombstones when processing |
361 | 233k | // large scc's. |
362 | 233k | if ((FunctionNo & 15) == 15) |
363 | 16 | CallSites.clear(); |
364 | 233k | } |
365 | 232k | |
366 | 232k | DEBUG(if (MadeChange) { |
367 | 232k | dbgs() << "CGSCCPASSMGR: Refreshed SCC is now:\n"; |
368 | 232k | for (CallGraphNode *CGN : CurSCC) |
369 | 232k | CGN->dump(); |
370 | 232k | if (DevirtualizedCall) |
371 | 232k | dbgs() << "CGSCCPASSMGR: Refresh devirtualized a call!\n"; |
372 | 232k | |
373 | 232k | } else { |
374 | 232k | dbgs() << "CGSCCPASSMGR: SCC Refresh didn't change call graph.\n"; |
375 | 232k | } |
376 | 232k | ); |
377 | 232k | (void)MadeChange; |
378 | 232k | |
379 | 232k | return DevirtualizedCall; |
380 | 232k | } |
381 | | |
382 | | /// Execute the body of the entire pass manager on the specified SCC. |
383 | | /// This keeps track of whether a function pass devirtualizes |
384 | | /// any calls and returns it in DevirtualizedCall. |
385 | | bool CGPassManager::RunAllPassesOnSCC(CallGraphSCC &CurSCC, CallGraph &CG, |
386 | 901k | bool &DevirtualizedCall) { |
387 | 901k | bool Changed = false; |
388 | 901k | |
389 | 901k | // Keep track of whether the callgraph is known to be up-to-date or not. |
390 | 901k | // The CGSSC pass manager runs two types of passes: |
391 | 901k | // CallGraphSCC Passes and other random function passes. Because other |
392 | 901k | // random function passes are not CallGraph aware, they may clobber the |
393 | 901k | // call graph by introducing new calls or deleting other ones. This flag |
394 | 901k | // is set to false when we run a function pass so that we know to clean up |
395 | 901k | // the callgraph when we need to run a CGSCCPass again. |
396 | 901k | bool CallGraphUpToDate = true; |
397 | 901k | |
398 | 901k | // Run all passes on current SCC. |
399 | 901k | for (unsigned PassNo = 0, e = getNumContainedPasses(); |
400 | 4.87M | PassNo != e4.87M ; ++PassNo3.97M ) { |
401 | 3.97M | Pass *P = getContainedPass(PassNo); |
402 | 3.97M | |
403 | 3.97M | // If we're in -debug-pass=Executions mode, construct the SCC node list, |
404 | 3.97M | // otherwise avoid constructing this string as it is expensive. |
405 | 3.97M | if (isPassDebuggingExecutionsOrMore()3.97M ) { |
406 | 4 | std::string Functions; |
407 | | #ifndef NDEBUG |
408 | | raw_string_ostream OS(Functions); |
409 | | for (CallGraphSCC::iterator I = CurSCC.begin(), E = CurSCC.end(); |
410 | | I != E; ++I) { |
411 | | if (I != CurSCC.begin()) OS << ", "; |
412 | | (*I)->print(OS); |
413 | | } |
414 | | OS.flush(); |
415 | | #endif |
416 | | dumpPassInfo(P, EXECUTION_MSG, ON_CG_MSG, Functions); |
417 | 4 | } |
418 | 3.97M | dumpRequiredSet(P); |
419 | 3.97M | |
420 | 3.97M | initializeAnalysisImpl(P); |
421 | 3.97M | |
422 | 3.97M | // Actually run this pass on the current SCC. |
423 | 3.97M | Changed |= RunPassOnSCC(P, CurSCC, CG, |
424 | 3.97M | CallGraphUpToDate, DevirtualizedCall); |
425 | 3.97M | |
426 | 3.97M | if (Changed) |
427 | 625k | dumpPassInfo(P, MODIFICATION_MSG, ON_CG_MSG, ""); |
428 | 3.97M | dumpPreservedSet(P); |
429 | 3.97M | |
430 | 3.97M | verifyPreservedAnalysis(P); |
431 | 3.97M | removeNotPreservedAnalysis(P); |
432 | 3.97M | recordAvailableAnalysis(P); |
433 | 3.97M | removeDeadPasses(P, "", ON_CG_MSG); |
434 | 3.97M | } |
435 | 901k | |
436 | 901k | // If the callgraph was left out of date (because the last pass run was a |
437 | 901k | // functionpass), refresh it before we move on to the next SCC. |
438 | 901k | if (!CallGraphUpToDate) |
439 | 217k | DevirtualizedCall |= RefreshCallGraph(CurSCC, CG, false); |
440 | 901k | return Changed; |
441 | 901k | } |
442 | | |
443 | | /// Execute all of the passes scheduled for execution. Keep track of |
444 | | /// whether any of the passes modifies the module, and if so, return true. |
445 | 26.4k | bool CGPassManager::runOnModule(Module &M) { |
446 | 26.4k | CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph(); |
447 | 26.4k | bool Changed = doInitialization(CG); |
448 | 26.4k | |
449 | 26.4k | // Walk the callgraph in bottom-up SCC order. |
450 | 26.4k | scc_iterator<CallGraph*> CGI = scc_begin(&CG); |
451 | 26.4k | |
452 | 26.4k | CallGraphSCC CurSCC(CG, &CGI); |
453 | 927k | while (!CGI.isAtEnd()927k ) { |
454 | 901k | // Copy the current SCC and increment past it so that the pass can hack |
455 | 901k | // on the SCC if it wants to without invalidating our iterator. |
456 | 901k | const std::vector<CallGraphNode *> &NodeVec = *CGI; |
457 | 901k | CurSCC.initialize(NodeVec); |
458 | 901k | ++CGI; |
459 | 901k | |
460 | 901k | // At the top level, we run all the passes in this pass manager on the |
461 | 901k | // functions in this SCC. However, we support iterative compilation in the |
462 | 901k | // case where a function pass devirtualizes a call to a function. For |
463 | 901k | // example, it is very common for a function pass (often GVN or instcombine) |
464 | 901k | // to eliminate the addressing that feeds into a call. With that improved |
465 | 901k | // information, we would like the call to be an inline candidate, infer |
466 | 901k | // mod-ref information etc. |
467 | 901k | // |
468 | 901k | // Because of this, we allow iteration up to a specified iteration count. |
469 | 901k | // This only happens in the case of a devirtualized call, so we only burn |
470 | 901k | // compile time in the case that we're making progress. We also have a hard |
471 | 901k | // iteration count limit in case there is crazy code. |
472 | 901k | unsigned Iteration = 0; |
473 | 901k | bool DevirtualizedCall = false; |
474 | 901k | do { |
475 | 901k | DEBUG(if (Iteration) |
476 | 901k | dbgs() << " SCCPASSMGR: Re-visiting SCC, iteration #" |
477 | 901k | << Iteration << '\n'); |
478 | 901k | DevirtualizedCall = false; |
479 | 901k | Changed |= RunAllPassesOnSCC(CurSCC, CG, DevirtualizedCall); |
480 | 901k | } while (Iteration++ < MaxIterations && 901k DevirtualizedCall901k ); |
481 | 901k | |
482 | 901k | if (DevirtualizedCall) |
483 | 901k | DEBUG(dbgs() << " CGSCCPASSMGR: Stopped iteration after " << Iteration |
484 | 901k | << " times, due to -max-cg-scc-iterations\n"); |
485 | 901k | |
486 | 901k | MaxSCCIterations.updateMax(Iteration); |
487 | 901k | } |
488 | 26.4k | Changed |= doFinalization(CG); |
489 | 26.4k | return Changed; |
490 | 26.4k | } |
491 | | |
492 | | /// Initialize CG |
493 | 26.4k | bool CGPassManager::doInitialization(CallGraph &CG) { |
494 | 26.4k | bool Changed = false; |
495 | 125k | for (unsigned i = 0, e = getNumContainedPasses(); i != e125k ; ++i98.8k ) { |
496 | 98.8k | if (PMDataManager *PM98.8k = getContainedPass(i)->getAsPMDataManager()) { |
497 | 20.6k | assert(PM->getPassManagerType() == PMT_FunctionPassManager && |
498 | 20.6k | "Invalid CGPassManager member"); |
499 | 20.6k | Changed |= ((FPPassManager*)PM)->doInitialization(CG.getModule()); |
500 | 98.8k | } else { |
501 | 78.1k | Changed |= ((CallGraphSCCPass*)getContainedPass(i))->doInitialization(CG); |
502 | 78.1k | } |
503 | 98.8k | } |
504 | 26.4k | return Changed; |
505 | 26.4k | } |
506 | | |
507 | | /// Finalize CG |
508 | 26.4k | bool CGPassManager::doFinalization(CallGraph &CG) { |
509 | 26.4k | bool Changed = false; |
510 | 125k | for (unsigned i = 0, e = getNumContainedPasses(); i != e125k ; ++i98.7k ) { |
511 | 98.7k | if (PMDataManager *PM98.7k = getContainedPass(i)->getAsPMDataManager()) { |
512 | 20.6k | assert(PM->getPassManagerType() == PMT_FunctionPassManager && |
513 | 20.6k | "Invalid CGPassManager member"); |
514 | 20.6k | Changed |= ((FPPassManager*)PM)->doFinalization(CG.getModule()); |
515 | 98.7k | } else { |
516 | 78.1k | Changed |= ((CallGraphSCCPass*)getContainedPass(i))->doFinalization(CG); |
517 | 78.1k | } |
518 | 98.7k | } |
519 | 26.4k | return Changed; |
520 | 26.4k | } |
521 | | |
522 | | //===----------------------------------------------------------------------===// |
523 | | // CallGraphSCC Implementation |
524 | | //===----------------------------------------------------------------------===// |
525 | | |
526 | | /// This informs the SCC and the pass manager that the specified |
527 | | /// Old node has been deleted, and New is to be used in its place. |
528 | 2.70k | void CallGraphSCC::ReplaceNode(CallGraphNode *Old, CallGraphNode *New) { |
529 | 2.70k | assert(Old != New && "Should not replace node with self"); |
530 | 2.70k | for (unsigned i = 0; ; ++i0 ) { |
531 | 2.70k | assert(i != Nodes.size() && "Node not in SCC"); |
532 | 2.70k | if (Nodes[i] != Old2.70k ) continue0 ; |
533 | 2.70k | Nodes[i] = New; |
534 | 2.70k | break; |
535 | 2.70k | } |
536 | 2.70k | |
537 | 2.70k | // Update the active scc_iterator so that it doesn't contain dangling |
538 | 2.70k | // pointers to the old CallGraphNode. |
539 | 2.70k | scc_iterator<CallGraph*> *CGI = (scc_iterator<CallGraph*>*)Context; |
540 | 2.70k | CGI->ReplaceNode(Old, New); |
541 | 2.70k | } |
542 | | |
543 | | //===----------------------------------------------------------------------===// |
544 | | // CallGraphSCCPass Implementation |
545 | | //===----------------------------------------------------------------------===// |
546 | | |
547 | | /// Assign pass manager to manage this pass. |
548 | | void CallGraphSCCPass::assignPassManager(PMStack &PMS, |
549 | 78.1k | PassManagerType PreferredType) { |
550 | 78.1k | // Find CGPassManager |
551 | 79.6k | while (!PMS.empty() && |
552 | 79.6k | PMS.top()->getPassManagerType() > PMT_CallGraphPassManager) |
553 | 1.48k | PMS.pop(); |
554 | 78.1k | |
555 | 78.1k | assert(!PMS.empty() && "Unable to handle Call Graph Pass"); |
556 | 78.1k | CGPassManager *CGP; |
557 | 78.1k | |
558 | 78.1k | if (PMS.top()->getPassManagerType() == PMT_CallGraphPassManager) |
559 | 51.6k | CGP = (CGPassManager*)PMS.top(); |
560 | 26.4k | else { |
561 | 26.4k | // Create new Call Graph SCC Pass Manager if it does not exist. |
562 | 26.4k | assert(!PMS.empty() && "Unable to create Call Graph Pass Manager"); |
563 | 26.4k | PMDataManager *PMD = PMS.top(); |
564 | 26.4k | |
565 | 26.4k | // [1] Create new Call Graph Pass Manager |
566 | 26.4k | CGP = new CGPassManager(); |
567 | 26.4k | |
568 | 26.4k | // [2] Set up new manager's top level manager |
569 | 26.4k | PMTopLevelManager *TPM = PMD->getTopLevelManager(); |
570 | 26.4k | TPM->addIndirectPassManager(CGP); |
571 | 26.4k | |
572 | 26.4k | // [3] Assign manager to manage this new manager. This may create |
573 | 26.4k | // and push new managers into PMS |
574 | 26.4k | Pass *P = CGP; |
575 | 26.4k | TPM->schedulePass(P); |
576 | 26.4k | |
577 | 26.4k | // [4] Push new manager into PMS |
578 | 26.4k | PMS.push(CGP); |
579 | 26.4k | } |
580 | 78.1k | |
581 | 78.1k | CGP->add(this); |
582 | 78.1k | } |
583 | | |
584 | | /// For this class, we declare that we require and preserve the call graph. |
585 | | /// If the derived class implements this method, it should |
586 | | /// always explicitly call the implementation here. |
587 | 76.6k | void CallGraphSCCPass::getAnalysisUsage(AnalysisUsage &AU) const { |
588 | 76.6k | AU.addRequired<CallGraphWrapperPass>(); |
589 | 76.6k | AU.addPreserved<CallGraphWrapperPass>(); |
590 | 76.6k | } |
591 | | |
592 | | //===----------------------------------------------------------------------===// |
593 | | // PrintCallGraphPass Implementation |
594 | | //===----------------------------------------------------------------------===// |
595 | | |
596 | | namespace { |
597 | | |
598 | | /// PrintCallGraphPass - Print a Module corresponding to a call graph. |
599 | | /// |
600 | | class PrintCallGraphPass : public CallGraphSCCPass { |
601 | | std::string Banner; |
602 | | raw_ostream &OS; // raw_ostream to print on. |
603 | | |
604 | | public: |
605 | | static char ID; |
606 | | |
607 | | PrintCallGraphPass(const std::string &B, raw_ostream &OS) |
608 | 4 | : CallGraphSCCPass(ID), Banner(B), OS(OS) {} |
609 | | |
610 | 4 | void getAnalysisUsage(AnalysisUsage &AU) const override { |
611 | 4 | AU.setPreservesAll(); |
612 | 4 | } |
613 | | |
614 | 8 | bool runOnSCC(CallGraphSCC &SCC) override { |
615 | 8 | bool BannerPrinted = false; |
616 | 8 | auto PrintBannerOnce = [&] () { |
617 | 8 | if (BannerPrinted) |
618 | 0 | return; |
619 | 8 | OS << Banner; |
620 | 8 | BannerPrinted = true; |
621 | 8 | }; |
622 | 8 | for (CallGraphNode *CGN : SCC) { |
623 | 8 | if (Function *F8 = CGN->getFunction()) { |
624 | 4 | if (!F->isDeclaration() && 4 isFunctionInPrintList(F->getName())4 ) { |
625 | 4 | PrintBannerOnce(); |
626 | 4 | F->print(OS); |
627 | 4 | } |
628 | 8 | } else if (4 isFunctionInPrintList("*")4 ) { |
629 | 4 | PrintBannerOnce(); |
630 | 4 | OS << "\nPrinting <null> Function\n"; |
631 | 4 | } |
632 | 8 | } |
633 | 8 | return false; |
634 | 8 | } |
635 | | |
636 | 0 | StringRef getPassName() const override { return "Print CallGraph IR"; } |
637 | | }; |
638 | | |
639 | | } // end anonymous namespace. |
640 | | |
641 | | char PrintCallGraphPass::ID = 0; |
642 | | |
643 | | Pass *CallGraphSCCPass::createPrinterPass(raw_ostream &OS, |
644 | 4 | const std::string &Banner) const { |
645 | 4 | return new PrintCallGraphPass(Banner, OS); |
646 | 4 | } |
647 | | |
648 | 3.01M | bool CallGraphSCCPass::skipSCC(CallGraphSCC &SCC) const { |
649 | 3.01M | return !SCC.getCallGraph().getModule() |
650 | 3.01M | .getContext() |
651 | 3.01M | .getOptBisect() |
652 | 3.01M | .shouldRunPass(this, SCC); |
653 | 3.01M | } |
654 | | |
655 | | char DummyCGSCCPass::ID = 0; |
656 | | |
657 | | INITIALIZE_PASS(DummyCGSCCPass, "DummyCGSCCPass", "DummyCGSCCPass", false, |
658 | | false) |