LLVM  4.0.0
LCSSA.cpp
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1 //===-- LCSSA.cpp - Convert loops into loop-closed SSA form ---------------===//
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 pass transforms loops by placing phi nodes at the end of the loops for
11 // all values that are live across the loop boundary. For example, it turns
12 // the left into the right code:
13 //
14 // for (...) for (...)
15 // if (c) if (c)
16 // X1 = ... X1 = ...
17 // else else
18 // X2 = ... X2 = ...
19 // X3 = phi(X1, X2) X3 = phi(X1, X2)
20 // ... = X3 + 4 X4 = phi(X3)
21 // ... = X4 + 4
22 //
23 // This is still valid LLVM; the extra phi nodes are purely redundant, and will
24 // be trivially eliminated by InstCombine. The major benefit of this
25 // transformation is that it makes many other loop optimizations, such as
26 // LoopUnswitching, simpler.
27 //
28 //===----------------------------------------------------------------------===//
29 
31 #include "llvm/ADT/STLExtras.h"
32 #include "llvm/ADT/Statistic.h"
36 #include "llvm/Analysis/LoopPass.h"
39 #include "llvm/IR/Constants.h"
40 #include "llvm/IR/Dominators.h"
41 #include "llvm/IR/Function.h"
42 #include "llvm/IR/Instructions.h"
44 #include "llvm/Pass.h"
45 #include "llvm/Transforms/Scalar.h"
48 using namespace llvm;
49 
50 #define DEBUG_TYPE "lcssa"
51 
52 STATISTIC(NumLCSSA, "Number of live out of a loop variables");
53 
54 #ifdef EXPENSIVE_CHECKS
55 static bool VerifyLoopLCSSA = true;
56 #else
57 static bool VerifyLoopLCSSA = false;
58 #endif
59 static cl::opt<bool,true>
61  cl::desc("Verify loop lcssa form (time consuming)"));
62 
63 /// Return true if the specified block is in the list.
64 static bool isExitBlock(BasicBlock *BB,
65  const SmallVectorImpl<BasicBlock *> &ExitBlocks) {
66  return is_contained(ExitBlocks, BB);
67 }
68 
69 /// For every instruction from the worklist, check to see if it has any uses
70 /// that are outside the current loop. If so, insert LCSSA PHI nodes and
71 /// rewrite the uses.
73  DominatorTree &DT, LoopInfo &LI) {
74  SmallVector<Use *, 16> UsesToRewrite;
75  SmallSetVector<PHINode *, 16> PHIsToRemove;
76  PredIteratorCache PredCache;
77  bool Changed = false;
78 
79  // Cache the Loop ExitBlocks across this loop. We expect to get a lot of
80  // instructions within the same loops, computing the exit blocks is
81  // expensive, and we're not mutating the loop structure.
83 
84  while (!Worklist.empty()) {
85  UsesToRewrite.clear();
86 
87  Instruction *I = Worklist.pop_back_val();
88  BasicBlock *InstBB = I->getParent();
89  Loop *L = LI.getLoopFor(InstBB);
90  if (!LoopExitBlocks.count(L))
91  L->getExitBlocks(LoopExitBlocks[L]);
92  assert(LoopExitBlocks.count(L));
93  const SmallVectorImpl<BasicBlock *> &ExitBlocks = LoopExitBlocks[L];
94 
95  if (ExitBlocks.empty())
96  continue;
97 
98  // Tokens cannot be used in PHI nodes, so we skip over them.
99  // We can run into tokens which are live out of a loop with catchswitch
100  // instructions in Windows EH if the catchswitch has one catchpad which
101  // is inside the loop and another which is not.
102  if (I->getType()->isTokenTy())
103  continue;
104 
105  for (Use &U : I->uses()) {
106  Instruction *User = cast<Instruction>(U.getUser());
107  BasicBlock *UserBB = User->getParent();
108  if (PHINode *PN = dyn_cast<PHINode>(User))
109  UserBB = PN->getIncomingBlock(U);
110 
111  if (InstBB != UserBB && !L->contains(UserBB))
112  UsesToRewrite.push_back(&U);
113  }
114 
115  // If there are no uses outside the loop, exit with no change.
116  if (UsesToRewrite.empty())
117  continue;
118 
119  ++NumLCSSA; // We are applying the transformation
120 
121  // Invoke instructions are special in that their result value is not
122  // available along their unwind edge. The code below tests to see whether
123  // DomBB dominates the value, so adjust DomBB to the normal destination
124  // block, which is effectively where the value is first usable.
125  BasicBlock *DomBB = InstBB;
126  if (InvokeInst *Inv = dyn_cast<InvokeInst>(I))
127  DomBB = Inv->getNormalDest();
128 
129  DomTreeNode *DomNode = DT.getNode(DomBB);
130 
131  SmallVector<PHINode *, 16> AddedPHIs;
132  SmallVector<PHINode *, 8> PostProcessPHIs;
133 
134  SmallVector<PHINode *, 4> InsertedPHIs;
135  SSAUpdater SSAUpdate(&InsertedPHIs);
136  SSAUpdate.Initialize(I->getType(), I->getName());
137 
138  // Insert the LCSSA phi's into all of the exit blocks dominated by the
139  // value, and add them to the Phi's map.
140  for (BasicBlock *ExitBB : ExitBlocks) {
141  if (!DT.dominates(DomNode, DT.getNode(ExitBB)))
142  continue;
143 
144  // If we already inserted something for this BB, don't reprocess it.
145  if (SSAUpdate.HasValueForBlock(ExitBB))
146  continue;
147 
148  PHINode *PN = PHINode::Create(I->getType(), PredCache.size(ExitBB),
149  I->getName() + ".lcssa", &ExitBB->front());
150 
151  // Add inputs from inside the loop for this PHI.
152  for (BasicBlock *Pred : PredCache.get(ExitBB)) {
153  PN->addIncoming(I, Pred);
154 
155  // If the exit block has a predecessor not within the loop, arrange for
156  // the incoming value use corresponding to that predecessor to be
157  // rewritten in terms of a different LCSSA PHI.
158  if (!L->contains(Pred))
159  UsesToRewrite.push_back(
161  PN->getNumIncomingValues() - 1)));
162  }
163 
164  AddedPHIs.push_back(PN);
165 
166  // Remember that this phi makes the value alive in this block.
167  SSAUpdate.AddAvailableValue(ExitBB, PN);
168 
169  // LoopSimplify might fail to simplify some loops (e.g. when indirect
170  // branches are involved). In such situations, it might happen that an
171  // exit for Loop L1 is the header of a disjoint Loop L2. Thus, when we
172  // create PHIs in such an exit block, we are also inserting PHIs into L2's
173  // header. This could break LCSSA form for L2 because these inserted PHIs
174  // can also have uses outside of L2. Remember all PHIs in such situation
175  // as to revisit than later on. FIXME: Remove this if indirectbr support
176  // into LoopSimplify gets improved.
177  if (auto *OtherLoop = LI.getLoopFor(ExitBB))
178  if (!L->contains(OtherLoop))
179  PostProcessPHIs.push_back(PN);
180  }
181 
182  // Rewrite all uses outside the loop in terms of the new PHIs we just
183  // inserted.
184  for (Use *UseToRewrite : UsesToRewrite) {
185  // If this use is in an exit block, rewrite to use the newly inserted PHI.
186  // This is required for correctness because SSAUpdate doesn't handle uses
187  // in the same block. It assumes the PHI we inserted is at the end of the
188  // block.
189  Instruction *User = cast<Instruction>(UseToRewrite->getUser());
190  BasicBlock *UserBB = User->getParent();
191  if (PHINode *PN = dyn_cast<PHINode>(User))
192  UserBB = PN->getIncomingBlock(*UseToRewrite);
193 
194  if (isa<PHINode>(UserBB->begin()) && isExitBlock(UserBB, ExitBlocks)) {
195  // Tell the VHs that the uses changed. This updates SCEV's caches.
196  if (UseToRewrite->get()->hasValueHandle())
197  ValueHandleBase::ValueIsRAUWd(*UseToRewrite, &UserBB->front());
198  UseToRewrite->set(&UserBB->front());
199  continue;
200  }
201 
202  // Otherwise, do full PHI insertion.
203  SSAUpdate.RewriteUse(*UseToRewrite);
204  }
205 
206  // SSAUpdater might have inserted phi-nodes inside other loops. We'll need
207  // to post-process them to keep LCSSA form.
208  for (PHINode *InsertedPN : InsertedPHIs) {
209  if (auto *OtherLoop = LI.getLoopFor(InsertedPN->getParent()))
210  if (!L->contains(OtherLoop))
211  PostProcessPHIs.push_back(InsertedPN);
212  }
213 
214  // Post process PHI instructions that were inserted into another disjoint
215  // loop and update their exits properly.
216  for (auto *PostProcessPN : PostProcessPHIs) {
217  if (PostProcessPN->use_empty())
218  continue;
219 
220  // Reprocess each PHI instruction.
221  Worklist.push_back(PostProcessPN);
222  }
223 
224  // Keep track of PHI nodes that we want to remove because they did not have
225  // any uses rewritten.
226  for (PHINode *PN : AddedPHIs)
227  if (PN->use_empty())
228  PHIsToRemove.insert(PN);
229 
230  Changed = true;
231  }
232  // Remove PHI nodes that did not have any uses rewritten.
233  for (PHINode *PN : PHIsToRemove) {
234  assert (PN->use_empty() && "Trying to remove a phi with uses.");
235  PN->eraseFromParent();
236  }
237  return Changed;
238 }
239 
240 /// Return true if the specified block dominates at least
241 /// one of the blocks in the specified list.
242 static bool
244  DominatorTree &DT,
245  const SmallVectorImpl<BasicBlock *> &ExitBlocks) {
246  DomTreeNode *DomNode = DT.getNode(BB);
247  return any_of(ExitBlocks, [&](BasicBlock *EB) {
248  return DT.dominates(DomNode, DT.getNode(EB));
249  });
250 }
251 
253  ScalarEvolution *SE) {
254  bool Changed = false;
255 
256  // Get the set of exiting blocks.
257  SmallVector<BasicBlock *, 8> ExitBlocks;
258  L.getExitBlocks(ExitBlocks);
259 
260  if (ExitBlocks.empty())
261  return false;
262 
264 
265  // Look at all the instructions in the loop, checking to see if they have uses
266  // outside the loop. If so, put them into the worklist to rewrite those uses.
267  for (BasicBlock *BB : L.blocks()) {
268  // For large loops, avoid use-scanning by using dominance information: In
269  // particular, if a block does not dominate any of the loop exits, then none
270  // of the values defined in the block could be used outside the loop.
271  if (!blockDominatesAnExit(BB, DT, ExitBlocks))
272  continue;
273 
274  for (Instruction &I : *BB) {
275  // Reject two common cases fast: instructions with no uses (like stores)
276  // and instructions with one use that is in the same block as this.
277  if (I.use_empty() ||
278  (I.hasOneUse() && I.user_back()->getParent() == BB &&
279  !isa<PHINode>(I.user_back())))
280  continue;
281 
282  Worklist.push_back(&I);
283  }
284  }
285  Changed = formLCSSAForInstructions(Worklist, DT, *LI);
286 
287  // If we modified the code, remove any caches about the loop from SCEV to
288  // avoid dangling entries.
289  // FIXME: This is a big hammer, can we clear the cache more selectively?
290  if (SE && Changed)
291  SE->forgetLoop(&L);
292 
293  assert(L.isLCSSAForm(DT));
294 
295  return Changed;
296 }
297 
298 /// Process a loop nest depth first.
300  ScalarEvolution *SE) {
301  bool Changed = false;
302 
303  // Recurse depth-first through inner loops.
304  for (Loop *SubLoop : L.getSubLoops())
305  Changed |= formLCSSARecursively(*SubLoop, DT, LI, SE);
306 
307  Changed |= formLCSSA(L, DT, LI, SE);
308  return Changed;
309 }
310 
311 /// Process all loops in the function, inner-most out.
313  ScalarEvolution *SE) {
314  bool Changed = false;
315  for (auto &L : *LI)
316  Changed |= formLCSSARecursively(*L, DT, LI, SE);
317  return Changed;
318 }
319 
320 namespace {
321 struct LCSSAWrapperPass : public FunctionPass {
322  static char ID; // Pass identification, replacement for typeid
323  LCSSAWrapperPass() : FunctionPass(ID) {
325  }
326 
327  // Cached analysis information for the current function.
328  DominatorTree *DT;
329  LoopInfo *LI;
330  ScalarEvolution *SE;
331 
332  bool runOnFunction(Function &F) override;
333  void verifyAnalysis() const override {
334  // This check is very expensive. On the loop intensive compiles it may cause
335  // up to 10x slowdown. Currently it's disabled by default. LPPassManager
336  // always does limited form of the LCSSA verification. Similar reasoning
337  // was used for the LoopInfo verifier.
338  if (VerifyLoopLCSSA) {
339  assert(all_of(*LI,
340  [&](Loop *L) {
341  return L->isRecursivelyLCSSAForm(*DT, *LI);
342  }) &&
343  "LCSSA form is broken!");
344  }
345  };
346 
347  /// This transformation requires natural loop information & requires that
348  /// loop preheaders be inserted into the CFG. It maintains both of these,
349  /// as well as the CFG. It also requires dominator information.
350  void getAnalysisUsage(AnalysisUsage &AU) const override {
351  AU.setPreservesCFG();
352 
361 
362  // This is needed to perform LCSSA verification inside LPPassManager
365  }
366 };
367 }
368 
369 char LCSSAWrapperPass::ID = 0;
370 INITIALIZE_PASS_BEGIN(LCSSAWrapperPass, "lcssa", "Loop-Closed SSA Form Pass",
371  false, false)
375 INITIALIZE_PASS_END(LCSSAWrapperPass, "lcssa", "Loop-Closed SSA Form Pass",
376  false, false)
377 
378 Pass *llvm::createLCSSAPass() { return new LCSSAWrapperPass(); }
380 
381 /// Transform \p F into loop-closed SSA form.
382 bool LCSSAWrapperPass::runOnFunction(Function &F) {
383  LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
384  DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
385  auto *SEWP = getAnalysisIfAvailable<ScalarEvolutionWrapperPass>();
386  SE = SEWP ? &SEWP->getSE() : nullptr;
387 
388  return formLCSSAOnAllLoops(LI, *DT, SE);
389 }
390 
392  auto &LI = AM.getResult<LoopAnalysis>(F);
393  auto &DT = AM.getResult<DominatorTreeAnalysis>(F);
394  auto *SE = AM.getCachedResult<ScalarEvolutionAnalysis>(F);
395  if (!formLCSSAOnAllLoops(&LI, DT, SE))
396  return PreservedAnalyses::all();
397 
398  // FIXME: This should also 'preserve the CFG'.
400  PA.preserve<BasicAA>();
401  PA.preserve<GlobalsAA>();
402  PA.preserve<SCEVAA>();
404  return PA;
405 }
Legacy wrapper pass to provide the GlobalsAAResult object.
MachineLoop * L
Pass interface - Implemented by all 'passes'.
Definition: Pass.h:81
void initializeLCSSAWrapperPassPass(PassRegistry &)
const Use & getOperandUse(unsigned i) const
Definition: User.h:158
iterator_range< use_iterator > uses()
Definition: Value.h:326
AnalysisUsage & addPreserved()
Add the specified Pass class to the set of analyses preserved by this pass.
Helper class for SSA formation on a set of values defined in multiple blocks.
Definition: SSAUpdater.h:38
void addIncoming(Value *V, BasicBlock *BB)
Add an incoming value to the end of the PHI list.
static PassRegistry * getPassRegistry()
getPassRegistry - Access the global registry object, which is automatically initialized at applicatio...
STATISTIC(NumFunctions,"Total number of functions")
This is the interface for a simple mod/ref and alias analysis over globals.
void Initialize(Type *Ty, StringRef Name)
Reset this object to get ready for a new set of SSA updates with type 'Ty'.
Definition: SSAUpdater.cpp:45
void AddAvailableValue(BasicBlock *BB, Value *V)
Indicate that a rewritten value is available in the specified block with the specified value...
Definition: SSAUpdater.cpp:58
The main scalar evolution driver.
Pass * createLCSSAPass()
Definition: LCSSA.cpp:378
bool isTokenTy() const
Return true if this is 'token'.
Definition: Type.h:192
bool all_of(R &&range, UnaryPredicate P)
Provide wrappers to std::all_of which take ranges instead of having to pass begin/end explicitly...
Definition: STLExtras.h:736
Analysis pass which computes a DominatorTree.
Definition: Dominators.h:189
LoopT * getLoopFor(const BlockT *BB) const
Return the inner most loop that BB lives in.
Definition: LoopInfo.h:575
StringRef getName() const
Return a constant reference to the value's name.
Definition: Value.cpp:191
bool formLCSSARecursively(Loop &L, DominatorTree &DT, LoopInfo *LI, ScalarEvolution *SE)
Put a loop nest into LCSSA form.
Definition: LCSSA.cpp:299
PassT::Result * getCachedResult(IRUnitT &IR) const
Get the cached result of an analysis pass for a given IR unit.
Definition: PassManager.h:670
INITIALIZE_PASS_BEGIN(LCSSAWrapperPass,"lcssa","Loop-Closed SSA Form Pass", false, false) INITIALIZE_PASS_END(LCSSAWrapperPass
static unsigned getOperandNumForIncomingValue(unsigned i)
AnalysisUsage & addRequired()
ArrayRef< BasicBlock * > get(BasicBlock *BB)
#define INITIALIZE_PASS_DEPENDENCY(depName)
Definition: PassSupport.h:53
This is the interface for a SCEV-based alias analysis.
A Use represents the edge between a Value definition and its users.
Definition: Use.h:56
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: APFloat.h:32
static cl::opt< bool, true > VerifyLoopLCSSAFlag("verify-loop-lcssa", cl::location(VerifyLoopLCSSA), cl::desc("Verify loop lcssa form (time consuming)"))
Analysis pass that exposes the LoopInfo for a function.
Definition: LoopInfo.h:806
LLVM_NODISCARD bool empty() const
Definition: SmallVector.h:60
void getExitBlocks(SmallVectorImpl< BlockT * > &ExitBlocks) const
Return all of the successor blocks of this loop.
Definition: LoopInfoImpl.h:65
#define F(x, y, z)
Definition: MD5.cpp:51
bool insert(const value_type &X)
Insert a new element into the SetVector.
Definition: SetVector.h:136
PredIteratorCache - This class is an extremely trivial cache for predecessor iterator queries...
Memory SSA
Definition: MemorySSA.cpp:55
Base class for the actual dominator tree node.
AnalysisUsage & addPreservedID(const void *ID)
static void ValueIsRAUWd(Value *Old, Value *New)
Definition: Value.cpp:837
LLVM_NODISCARD char front() const
front - Get the first character in the string.
Definition: StringRef.h:139
Concrete subclass of DominatorTreeBase that is used to compute a normal dominator tree...
Definition: Dominators.h:96
unsigned getNumIncomingValues() const
Return the number of incoming edges.
iterator_range< block_iterator > blocks() const
Definition: LoopInfo.h:143
A set of analyses that are preserved following a run of a transformation pass.
Definition: PassManager.h:107
PassT::Result & getResult(IRUnitT &IR, ExtraArgTs...ExtraArgs)
Get the result of an analysis pass for a given IR unit.
Definition: PassManager.h:653
LLVM Basic Block Representation.
Definition: BasicBlock.h:51
static bool VerifyLoopLCSSA
Definition: LCSSA.cpp:57
This file contains the declarations for the subclasses of Constant, which represent the different fla...
char & LCSSAID
Definition: LCSSA.cpp:379
bool isRecursivelyLCSSAForm(DominatorTree &DT, const LoopInfo &LI) const
Return true if this Loop and all inner subloops are in LCSSA form.
Definition: LoopInfo.cpp:181
Represent the analysis usage information of a pass.
bool any_of(R &&Range, UnaryPredicate P)
Provide wrappers to std::any_of which take ranges instead of having to pass begin/end explicitly...
Definition: STLExtras.h:743
Analysis pass providing a never-invalidated alias analysis result.
INITIALIZE_PASS_END(RegBankSelect, DEBUG_TYPE,"Assign register bank of generic virtual registers", false, false) RegBankSelect
FunctionPass class - This class is used to implement most global optimizations.
Definition: Pass.h:298
Analysis pass providing a never-invalidated alias analysis result.
bool HasValueForBlock(BasicBlock *BB) const
Return true if the SSAUpdater already has a value for the specified block.
Definition: SSAUpdater.cpp:54
static bool blockDominatesAnExit(BasicBlock *BB, DominatorTree &DT, const SmallVectorImpl< BasicBlock * > &ExitBlocks)
Return true if the specified block dominates at least one of the blocks in the specified list...
Definition: LCSSA.cpp:243
static PreservedAnalyses all()
Construct a special preserved set that preserves all passes.
Definition: PassManager.h:113
char & LoopSimplifyID
bool dominates(const Instruction *Def, const Use &U) const
Return true if Def dominates a use in User.
Definition: Dominators.cpp:218
static bool formLCSSAOnAllLoops(LoopInfo *LI, DominatorTree &DT, ScalarEvolution *SE)
Process all loops in the function, inner-most out.
Definition: LCSSA.cpp:312
bool formLCSSA(Loop &L, DominatorTree &DT, LoopInfo *LI, ScalarEvolution *SE)
Put loop into LCSSA form.
Definition: LCSSA.cpp:252
A SetVector that performs no allocations if smaller than a certain size.
Definition: SetVector.h:292
Legacy wrapper pass to provide the SCEVAAResult object.
bool formLCSSAForInstructions(SmallVectorImpl< Instruction * > &Worklist, DominatorTree &DT, LoopInfo &LI)
Ensures LCSSA form for every instruction from the Worklist in the scope of innermost containing loop...
Definition: LCSSA.cpp:72
bool isLCSSAForm(DominatorTree &DT) const
Return true if the Loop is in LCSSA form.
Definition: LoopInfo.cpp:174
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:843
Type * getType() const
All values are typed, get the type of this value.
Definition: Value.h:230
LLVM_NODISCARD T pop_back_val()
Definition: SmallVector.h:382
static PHINode * Create(Type *Ty, unsigned NumReservedValues, const Twine &NameStr="", Instruction *InsertBefore=nullptr)
Constructors - NumReservedValues is a hint for the number of incoming edges that this phi node will h...
void setPreservesCFG()
This function should be called by the pass, iff they do not:
Definition: Pass.cpp:276
size_type count(const KeyT &Val) const
Return 1 if the specified key is in the map, 0 otherwise.
Definition: DenseMap.h:122
PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM)
Definition: LCSSA.cpp:391
Loop Closed SSA Form false
Definition: LCSSA.cpp:375
Analysis pass that exposes the ScalarEvolution for a function.
lcssa
Definition: LCSSA.cpp:375
Analysis pass providing a never-invalidated alias analysis result.
void forgetLoop(const Loop *L)
This method should be called by the client when it has changed a loop in a way that may effect Scalar...
Represents a single loop in the control flow graph.
Definition: LoopInfo.h:368
#define I(x, y, z)
Definition: MD5.cpp:54
void preserve()
Mark an analysis as preserved.
Definition: PassManager.h:120
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
Invoke instruction.
const std::vector< LoopT * > & getSubLoops() const
Return the loops contained entirely within this loop.
Definition: LoopInfo.h:127
The legacy pass manager's analysis pass to compute loop information.
Definition: LoopInfo.h:831
static bool isExitBlock(BasicBlock *BB, const SmallVectorImpl< BasicBlock * > &ExitBlocks)
Return true if the specified block is in the list.
Definition: LCSSA.cpp:64
This is the interface for LLVM's primary stateless and local alias analysis.
A container for analyses that lazily runs them and caches their results.
Legacy analysis pass which computes a DominatorTree.
Definition: Dominators.h:217
DomTreeNodeBase< NodeT > * getNode(NodeT *BB) const
getNode - return the (Post)DominatorTree node for the specified basic block.
A wrapper pass to provide the legacy pass manager access to a suitably prepared AAResults object...
void RewriteUse(Use &U)
Rewrite a use of the symbolic value.
Definition: SSAUpdater.cpp:178
size_t size(BasicBlock *BB)
LocationClass< Ty > location(Ty &L)
Definition: CommandLine.h:411
const BasicBlock * getParent() const
Definition: Instruction.h:62
Legacy wrapper pass to provide the BasicAAResult object.
bool is_contained(R &&Range, const E &Element)
Wrapper function around std::find to detect if an element exists in a container.
Definition: STLExtras.h:783