LLVM 17.0.0git
Local.h
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1//===- Local.h - Functions to perform local transformations -----*- 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 family of functions perform various local transformations to the
10// program.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_TRANSFORMS_UTILS_LOCAL_H
15#define LLVM_TRANSFORMS_UTILS_LOCAL_H
16
17#include "llvm/ADT/ArrayRef.h"
18#include "llvm/IR/Dominators.h"
21#include <cstdint>
22
23namespace llvm {
24
25class DataLayout;
26class Value;
27class WeakTrackingVH;
28class WeakVH;
29template <typename T> class SmallVectorImpl;
30class AAResults;
31class AllocaInst;
32class AssumptionCache;
33class BasicBlock;
34class BranchInst;
35class CallBase;
36class CallInst;
37class DbgVariableIntrinsic;
38class DIBuilder;
39class DomTreeUpdater;
40class Function;
41class Instruction;
42class InvokeInst;
43class LoadInst;
44class MDNode;
45class MemorySSAUpdater;
46class PHINode;
47class StoreInst;
48class TargetLibraryInfo;
49class TargetTransformInfo;
50
51//===----------------------------------------------------------------------===//
52// Local constant propagation.
53//
54
55/// If a terminator instruction is predicated on a constant value, convert it
56/// into an unconditional branch to the constant destination.
57/// This is a nontrivial operation because the successors of this basic block
58/// must have their PHI nodes updated.
59/// Also calls RecursivelyDeleteTriviallyDeadInstructions() on any branch/switch
60/// conditions and indirectbr addresses this might make dead if
61/// DeleteDeadConditions is true.
62bool ConstantFoldTerminator(BasicBlock *BB, bool DeleteDeadConditions = false,
63 const TargetLibraryInfo *TLI = nullptr,
64 DomTreeUpdater *DTU = nullptr);
65
66//===----------------------------------------------------------------------===//
67// Local dead code elimination.
68//
69
70/// Return true if the result produced by the instruction is not used, and the
71/// instruction will return. Certain side-effecting instructions are also
72/// considered dead if there are no uses of the instruction.
73bool isInstructionTriviallyDead(Instruction *I,
74 const TargetLibraryInfo *TLI = nullptr);
75
76/// Return true if the result produced by the instruction would have no side
77/// effects if it was not used. This is equivalent to checking whether
78/// isInstructionTriviallyDead would be true if the use count was 0.
79bool wouldInstructionBeTriviallyDead(Instruction *I,
80 const TargetLibraryInfo *TLI = nullptr);
81
82/// Return true if the result produced by the instruction has no side effects on
83/// any paths other than where it is used. This is less conservative than
84/// wouldInstructionBeTriviallyDead which is based on the assumption
85/// that the use count will be 0. An example usage of this API is for
86/// identifying instructions that can be sunk down to use(s).
88 Instruction *I, const TargetLibraryInfo *TLI = nullptr);
89
90/// If the specified value is a trivially dead instruction, delete it.
91/// If that makes any of its operands trivially dead, delete them too,
92/// recursively. Return true if any instructions were deleted.
94 Value *V, const TargetLibraryInfo *TLI = nullptr,
95 MemorySSAUpdater *MSSAU = nullptr,
96 std::function<void(Value *)> AboutToDeleteCallback =
97 std::function<void(Value *)>());
98
99/// Delete all of the instructions in `DeadInsts`, and all other instructions
100/// that deleting these in turn causes to be trivially dead.
101///
102/// The initial instructions in the provided vector must all have empty use
103/// lists and satisfy `isInstructionTriviallyDead`.
104///
105/// `DeadInsts` will be used as scratch storage for this routine and will be
106/// empty afterward.
108 SmallVectorImpl<WeakTrackingVH> &DeadInsts,
109 const TargetLibraryInfo *TLI = nullptr, MemorySSAUpdater *MSSAU = nullptr,
110 std::function<void(Value *)> AboutToDeleteCallback =
111 std::function<void(Value *)>());
112
113/// Same functionality as RecursivelyDeleteTriviallyDeadInstructions, but allow
114/// instructions that are not trivially dead. These will be ignored.
115/// Returns true if any changes were made, i.e. any instructions trivially dead
116/// were found and deleted.
118 SmallVectorImpl<WeakTrackingVH> &DeadInsts,
119 const TargetLibraryInfo *TLI = nullptr, MemorySSAUpdater *MSSAU = nullptr,
120 std::function<void(Value *)> AboutToDeleteCallback =
121 std::function<void(Value *)>());
122
123/// If the specified value is an effectively dead PHI node, due to being a
124/// def-use chain of single-use nodes that either forms a cycle or is terminated
125/// by a trivially dead instruction, delete it. If that makes any of its
126/// operands trivially dead, delete them too, recursively. Return true if a
127/// change was made.
128bool RecursivelyDeleteDeadPHINode(PHINode *PN,
129 const TargetLibraryInfo *TLI = nullptr,
130 MemorySSAUpdater *MSSAU = nullptr);
131
132/// Scan the specified basic block and try to simplify any instructions in it
133/// and recursively delete dead instructions.
134///
135/// This returns true if it changed the code, note that it can delete
136/// instructions in other blocks as well in this block.
137bool SimplifyInstructionsInBlock(BasicBlock *BB,
138 const TargetLibraryInfo *TLI = nullptr);
139
140/// Replace all the uses of an SSA value in @llvm.dbg intrinsics with
141/// undef. This is useful for signaling that a variable, e.g. has been
142/// found dead and hence it's unavailable at a given program point.
143/// Returns true if the dbg values have been changed.
144bool replaceDbgUsesWithUndef(Instruction *I);
145
146//===----------------------------------------------------------------------===//
147// Control Flow Graph Restructuring.
148//
149
150/// BB is a block with one predecessor and its predecessor is known to have one
151/// successor (BB!). Eliminate the edge between them, moving the instructions in
152/// the predecessor into BB. This deletes the predecessor block.
153void MergeBasicBlockIntoOnlyPred(BasicBlock *BB, DomTreeUpdater *DTU = nullptr);
154
155/// BB is known to contain an unconditional branch, and contains no instructions
156/// other than PHI nodes, potential debug intrinsics and the branch. If
157/// possible, eliminate BB by rewriting all the predecessors to branch to the
158/// successor block and return true. If we can't transform, return false.
160 DomTreeUpdater *DTU = nullptr);
161
162/// Check for and eliminate duplicate PHI nodes in this block. This doesn't try
163/// to be clever about PHI nodes which differ only in the order of the incoming
164/// values, but instcombine orders them so it usually won't matter.
165bool EliminateDuplicatePHINodes(BasicBlock *BB);
166
167/// This function is used to do simplification of a CFG. For example, it
168/// adjusts branches to branches to eliminate the extra hop, it eliminates
169/// unreachable basic blocks, and does other peephole optimization of the CFG.
170/// It returns true if a modification was made, possibly deleting the basic
171/// block that was pointed to. LoopHeaders is an optional input parameter
172/// providing the set of loop headers that SimplifyCFG should not eliminate.
173extern cl::opt<bool> RequireAndPreserveDomTree;
174bool simplifyCFG(BasicBlock *BB, const TargetTransformInfo &TTI,
175 DomTreeUpdater *DTU = nullptr,
176 const SimplifyCFGOptions &Options = {},
177 ArrayRef<WeakVH> LoopHeaders = {});
178
179/// This function is used to flatten a CFG. For example, it uses parallel-and
180/// and parallel-or mode to collapse if-conditions and merge if-regions with
181/// identical statements.
182bool FlattenCFG(BasicBlock *BB, AAResults *AA = nullptr);
183
184/// If this basic block is ONLY a setcc and a branch, and if a predecessor
185/// branches to us and one of our successors, fold the setcc into the
186/// predecessor and use logical operations to pick the right destination.
187bool FoldBranchToCommonDest(BranchInst *BI, llvm::DomTreeUpdater *DTU = nullptr,
188 MemorySSAUpdater *MSSAU = nullptr,
189 const TargetTransformInfo *TTI = nullptr,
190 unsigned BonusInstThreshold = 1);
191
192/// This function takes a virtual register computed by an Instruction and
193/// replaces it with a slot in the stack frame, allocated via alloca.
194/// This allows the CFG to be changed around without fear of invalidating the
195/// SSA information for the value. It returns the pointer to the alloca inserted
196/// to create a stack slot for X.
197AllocaInst *DemoteRegToStack(Instruction &X,
198 bool VolatileLoads = false,
199 Instruction *AllocaPoint = nullptr);
200
201/// This function takes a virtual register computed by a phi node and replaces
202/// it with a slot in the stack frame, allocated via alloca. The phi node is
203/// deleted and it returns the pointer to the alloca inserted.
204AllocaInst *DemotePHIToStack(PHINode *P, Instruction *AllocaPoint = nullptr);
205
206/// Try to ensure that the alignment of \p V is at least \p PrefAlign bytes. If
207/// the owning object can be modified and has an alignment less than \p
208/// PrefAlign, it will be increased and \p PrefAlign returned. If the alignment
209/// cannot be increased, the known alignment of the value is returned.
210///
211/// It is not always possible to modify the alignment of the underlying object,
212/// so if alignment is important, a more reliable approach is to simply align
213/// all global variables and allocation instructions to their preferred
214/// alignment from the beginning.
215Align getOrEnforceKnownAlignment(Value *V, MaybeAlign PrefAlign,
216 const DataLayout &DL,
217 const Instruction *CxtI = nullptr,
218 AssumptionCache *AC = nullptr,
219 const DominatorTree *DT = nullptr);
220
221/// Try to infer an alignment for the specified pointer.
223 const Instruction *CxtI = nullptr,
224 AssumptionCache *AC = nullptr,
225 const DominatorTree *DT = nullptr) {
226 return getOrEnforceKnownAlignment(V, MaybeAlign(), DL, CxtI, AC, DT);
227}
228
229/// Create a call that matches the invoke \p II in terms of arguments,
230/// attributes, debug information, etc. The call is not placed in a block and it
231/// will not have a name. The invoke instruction is not removed, nor are the
232/// uses replaced by the new call.
233CallInst *createCallMatchingInvoke(InvokeInst *II);
234
235/// This function converts the specified invoke into a normal call.
236CallInst *changeToCall(InvokeInst *II, DomTreeUpdater *DTU = nullptr);
237
238///===---------------------------------------------------------------------===//
239/// Dbg Intrinsic utilities
240///
241
242/// Inserts a llvm.dbg.value intrinsic before a store to an alloca'd value
243/// that has an associated llvm.dbg.declare or llvm.dbg.addr intrinsic.
244void ConvertDebugDeclareToDebugValue(DbgVariableIntrinsic *DII,
245 StoreInst *SI, DIBuilder &Builder);
246
247/// Inserts a llvm.dbg.value intrinsic before a load of an alloca'd value
248/// that has an associated llvm.dbg.declare or llvm.dbg.addr intrinsic.
249void ConvertDebugDeclareToDebugValue(DbgVariableIntrinsic *DII,
250 LoadInst *LI, DIBuilder &Builder);
251
252/// Inserts a llvm.dbg.value intrinsic after a phi that has an associated
253/// llvm.dbg.declare or llvm.dbg.addr intrinsic.
254void ConvertDebugDeclareToDebugValue(DbgVariableIntrinsic *DII,
255 PHINode *LI, DIBuilder &Builder);
256
257/// Lowers llvm.dbg.declare intrinsics into appropriate set of
258/// llvm.dbg.value intrinsics.
259bool LowerDbgDeclare(Function &F);
260
261/// Propagate dbg.value intrinsics through the newly inserted PHIs.
262void insertDebugValuesForPHIs(BasicBlock *BB,
263 SmallVectorImpl<PHINode *> &InsertedPHIs);
264
265/// Replaces llvm.dbg.declare instruction when the address it
266/// describes is replaced with a new value. If Deref is true, an
267/// additional DW_OP_deref is prepended to the expression. If Offset
268/// is non-zero, a constant displacement is added to the expression
269/// (between the optional Deref operations). Offset can be negative.
270bool replaceDbgDeclare(Value *Address, Value *NewAddress, DIBuilder &Builder,
271 uint8_t DIExprFlags, int Offset);
272
273/// Replaces multiple llvm.dbg.value instructions when the alloca it describes
274/// is replaced with a new value. If Offset is non-zero, a constant displacement
275/// is added to the expression (after the mandatory Deref). Offset can be
276/// negative. New llvm.dbg.value instructions are inserted at the locations of
277/// the instructions they replace.
278void replaceDbgValueForAlloca(AllocaInst *AI, Value *NewAllocaAddress,
279 DIBuilder &Builder, int Offset = 0);
280
281/// Assuming the instruction \p I is going to be deleted, attempt to salvage
282/// debug users of \p I by writing the effect of \p I in a DIExpression. If it
283/// cannot be salvaged changes its debug uses to undef.
284void salvageDebugInfo(Instruction &I);
285
286
287/// Implementation of salvageDebugInfo, applying only to instructions in
288/// \p Insns, rather than all debug users from findDbgUsers( \p I).
289/// Mark undef if salvaging cannot be completed.
290void salvageDebugInfoForDbgValues(Instruction &I,
291 ArrayRef<DbgVariableIntrinsic *> Insns);
292
293/// Given an instruction \p I and DIExpression \p DIExpr operating on
294/// it, append the effects of \p I to the DIExpression operand list
295/// \p Ops, or return \p nullptr if it cannot be salvaged.
296/// \p CurrentLocOps is the number of SSA values referenced by the
297/// incoming \p Ops. \return the first non-constant operand
298/// implicitly referred to by Ops. If \p I references more than one
299/// non-constant operand, any additional operands are added to
300/// \p AdditionalValues.
301///
302/// \example
303////
304/// I = add %a, i32 1
305///
306/// Return = %a
307/// Ops = llvm::dwarf::DW_OP_lit1 llvm::dwarf::DW_OP_add
308///
309/// I = add %a, %b
310///
311/// Return = %a
312/// Ops = llvm::dwarf::DW_OP_LLVM_arg0 llvm::dwarf::DW_OP_add
313/// AdditionalValues = %b
314Value *salvageDebugInfoImpl(Instruction &I, uint64_t CurrentLocOps,
315 SmallVectorImpl<uint64_t> &Ops,
316 SmallVectorImpl<Value *> &AdditionalValues);
317
318/// Point debug users of \p From to \p To or salvage them. Use this function
319/// only when replacing all uses of \p From with \p To, with a guarantee that
320/// \p From is going to be deleted.
321///
322/// Follow these rules to prevent use-before-def of \p To:
323/// . If \p To is a linked Instruction, set \p DomPoint to \p To.
324/// . If \p To is an unlinked Instruction, set \p DomPoint to the Instruction
325/// \p To will be inserted after.
326/// . If \p To is not an Instruction (e.g a Constant), the choice of
327/// \p DomPoint is arbitrary. Pick \p From for simplicity.
328///
329/// If a debug user cannot be preserved without reordering variable updates or
330/// introducing a use-before-def, it is either salvaged (\ref salvageDebugInfo)
331/// or deleted. Returns true if any debug users were updated.
332bool replaceAllDbgUsesWith(Instruction &From, Value &To, Instruction &DomPoint,
333 DominatorTree &DT);
334
335/// Remove all instructions from a basic block other than its terminator
336/// and any present EH pad instructions. Returns a pair where the first element
337/// is the number of instructions (excluding debug info intrinsics) that have
338/// been removed, and the second element is the number of debug info intrinsics
339/// that have been removed.
340std::pair<unsigned, unsigned>
342
343/// Insert an unreachable instruction before the specified
344/// instruction, making it and the rest of the code in the block dead.
345unsigned changeToUnreachable(Instruction *I, bool PreserveLCSSA = false,
346 DomTreeUpdater *DTU = nullptr,
347 MemorySSAUpdater *MSSAU = nullptr);
348
349/// Convert the CallInst to InvokeInst with the specified unwind edge basic
350/// block. This also splits the basic block where CI is located, because
351/// InvokeInst is a terminator instruction. Returns the newly split basic
352/// block.
353BasicBlock *changeToInvokeAndSplitBasicBlock(CallInst *CI,
354 BasicBlock *UnwindEdge,
355 DomTreeUpdater *DTU = nullptr);
356
357/// Replace 'BB's terminator with one that does not have an unwind successor
358/// block. Rewrites `invoke` to `call`, etc. Updates any PHIs in unwind
359/// successor. Returns the instruction that replaced the original terminator,
360/// which might be a call in case the original terminator was an invoke.
361///
362/// \param BB Block whose terminator will be replaced. Its terminator must
363/// have an unwind successor.
364Instruction *removeUnwindEdge(BasicBlock *BB, DomTreeUpdater *DTU = nullptr);
365
366/// Remove all blocks that can not be reached from the function's entry.
367///
368/// Returns true if any basic block was removed.
369bool removeUnreachableBlocks(Function &F, DomTreeUpdater *DTU = nullptr,
370 MemorySSAUpdater *MSSAU = nullptr);
371
372/// Combine the metadata of two instructions so that K can replace J. Some
373/// metadata kinds can only be kept if K does not move, meaning it dominated
374/// J in the original IR.
375///
376/// Metadata not listed as known via KnownIDs is removed
377void combineMetadata(Instruction *K, const Instruction *J,
378 ArrayRef<unsigned> KnownIDs, bool DoesKMove);
379
380/// Combine the metadata of two instructions so that K can replace J. This
381/// specifically handles the case of CSE-like transformations. Some
382/// metadata can only be kept if K dominates J. For this to be correct,
383/// K cannot be hoisted.
384///
385/// Unknown metadata is removed.
386void combineMetadataForCSE(Instruction *K, const Instruction *J,
387 bool DoesKMove);
388
389/// Copy the metadata from the source instruction to the destination (the
390/// replacement for the source instruction).
391void copyMetadataForLoad(LoadInst &Dest, const LoadInst &Source);
392
393/// Patch the replacement so that it is not more restrictive than the value
394/// being replaced. It assumes that the replacement does not get moved from
395/// its original position.
396void patchReplacementInstruction(Instruction *I, Value *Repl);
397
398// Replace each use of 'From' with 'To', if that use does not belong to basic
399// block where 'From' is defined. Returns the number of replacements made.
400unsigned replaceNonLocalUsesWith(Instruction *From, Value *To);
401
402/// Replace each use of 'From' with 'To' if that use is dominated by
403/// the given edge. Returns the number of replacements made.
404unsigned replaceDominatedUsesWith(Value *From, Value *To, DominatorTree &DT,
405 const BasicBlockEdge &Edge);
406/// Replace each use of 'From' with 'To' if that use is dominated by
407/// the end of the given BasicBlock. Returns the number of replacements made.
408unsigned replaceDominatedUsesWith(Value *From, Value *To, DominatorTree &DT,
409 const BasicBlock *BB);
410
411/// Return true if this call calls a gc leaf function.
412///
413/// A leaf function is a function that does not safepoint the thread during its
414/// execution. During a call or invoke to such a function, the callers stack
415/// does not have to be made parseable.
416///
417/// Most passes can and should ignore this information, and it is only used
418/// during lowering by the GC infrastructure.
419bool callsGCLeafFunction(const CallBase *Call, const TargetLibraryInfo &TLI);
420
421/// Copy a nonnull metadata node to a new load instruction.
422///
423/// This handles mapping it to range metadata if the new load is an integer
424/// load instead of a pointer load.
425void copyNonnullMetadata(const LoadInst &OldLI, MDNode *N, LoadInst &NewLI);
426
427/// Copy a range metadata node to a new load instruction.
428///
429/// This handles mapping it to nonnull metadata if the new load is a pointer
430/// load instead of an integer load and the range doesn't cover null.
431void copyRangeMetadata(const DataLayout &DL, const LoadInst &OldLI, MDNode *N,
432 LoadInst &NewLI);
433
434/// Remove the debug intrinsic instructions for the given instruction.
435void dropDebugUsers(Instruction &I);
436
437/// Hoist all of the instructions in the \p IfBlock to the dominant block
438/// \p DomBlock, by moving its instructions to the insertion point \p InsertPt.
439///
440/// The moved instructions receive the insertion point debug location values
441/// (DILocations) and their debug intrinsic instructions are removed.
442void hoistAllInstructionsInto(BasicBlock *DomBlock, Instruction *InsertPt,
443 BasicBlock *BB);
444
445//===----------------------------------------------------------------------===//
446// Intrinsic pattern matching
447//
448
449/// Try to match a bswap or bitreverse idiom.
450///
451/// If an idiom is matched, an intrinsic call is inserted before \c I. Any added
452/// instructions are returned in \c InsertedInsts. They will all have been added
453/// to a basic block.
454///
455/// A bitreverse idiom normally requires around 2*BW nodes to be searched (where
456/// BW is the bitwidth of the integer type). A bswap idiom requires anywhere up
457/// to BW / 4 nodes to be searched, so is significantly faster.
458///
459/// This function returns true on a successful match or false otherwise.
461 Instruction *I, bool MatchBSwaps, bool MatchBitReversals,
462 SmallVectorImpl<Instruction *> &InsertedInsts);
463
464//===----------------------------------------------------------------------===//
465// Sanitizer utilities
466//
467
468/// Given a CallInst, check if it calls a string function known to CodeGen,
469/// and mark it with NoBuiltin if so. To be used by sanitizers that intend
470/// to intercept string functions and want to avoid converting them to target
471/// specific instructions.
473 const TargetLibraryInfo *TLI);
474
475//===----------------------------------------------------------------------===//
476// Transform predicates
477//
478
479/// Given an instruction, is it legal to set operand OpIdx to a non-constant
480/// value?
481bool canReplaceOperandWithVariable(const Instruction *I, unsigned OpIdx);
482
483//===----------------------------------------------------------------------===//
484// Value helper functions
485//
486
487/// Invert the given true/false value, possibly reusing an existing copy.
488Value *invertCondition(Value *Condition);
489
490
491//===----------------------------------------------------------------------===//
492// Assorted
493//
494
495/// If we can infer one attribute from another on the declaration of a
496/// function, explicitly materialize the maximal set in the IR.
497bool inferAttributesFromOthers(Function &F);
498
499} // end namespace llvm
500
501#endif // LLVM_TRANSFORMS_UTILS_LOCAL_H
MachineBasicBlock MachineBasicBlock::iterator DebugLoc DL
BlockVerifier::State From
uint64_t Align
static GCMetadataPrinterRegistry::Add< ErlangGCPrinter > X("erlang", "erlang-compatible garbage collector")
static LVOptions Options
Definition: LVOptions.cpp:25
#define F(x, y, z)
Definition: MD5.cpp:55
#define I(x, y, z)
Definition: MD5.cpp:58
#define P(N)
@ SI
A cache of @llvm.assume calls within a function.
A parsed version of the target data layout string in and methods for querying it.
Definition: DataLayout.h:114
Concrete subclass of DominatorTreeBase that is used to compute a normal dominator tree.
Definition: Dominators.h:166
LLVM Value Representation.
Definition: Value.h:74
@ BasicBlock
Various leaf nodes.
Definition: ISDOpcodes.h:71
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
@ Offset
Definition: DWP.cpp:406
bool RecursivelyDeleteTriviallyDeadInstructions(Value *V, const TargetLibraryInfo *TLI=nullptr, MemorySSAUpdater *MSSAU=nullptr, std::function< void(Value *)> AboutToDeleteCallback=std::function< void(Value *)>())
If the specified value is a trivially dead instruction, delete it.
Definition: Local.cpp:537
BasicBlock * changeToInvokeAndSplitBasicBlock(CallInst *CI, BasicBlock *UnwindEdge, DomTreeUpdater *DTU=nullptr)
Convert the CallInst to InvokeInst with the specified unwind edge basic block.
Definition: Local.cpp:2329
bool ConstantFoldTerminator(BasicBlock *BB, bool DeleteDeadConditions=false, const TargetLibraryInfo *TLI=nullptr, DomTreeUpdater *DTU=nullptr)
If a terminator instruction is predicated on a constant value, convert it into an unconditional branc...
Definition: Local.cpp:126
bool FlattenCFG(BasicBlock *BB, AAResults *AA=nullptr)
This function is used to flatten a CFG.
Definition: FlattenCFG.cpp:546
std::pair< unsigned, unsigned > removeAllNonTerminatorAndEHPadInstructions(BasicBlock *BB)
Remove all instructions from a basic block other than its terminator and any present EH pad instructi...
Definition: Local.cpp:2220
unsigned replaceNonLocalUsesWith(Instruction *From, Value *To)
Definition: Local.cpp:2850
void salvageDebugInfoForDbgValues(Instruction &I, ArrayRef< DbgVariableIntrinsic * > Insns)
Implementation of salvageDebugInfo, applying only to instructions in Insns, rather than all debug use...
Definition: Local.cpp:1859
void salvageDebugInfo(const MachineRegisterInfo &MRI, MachineInstr &MI)
Assuming the instruction MI is going to be deleted, attempt to salvage debug users of MI by writing t...
Definition: Utils.cpp:1367
CallInst * changeToCall(InvokeInst *II, DomTreeUpdater *DTU=nullptr)
This function converts the specified invoke into a normal call.
Definition: Local.cpp:2309
void copyMetadataForLoad(LoadInst &Dest, const LoadInst &Source)
Copy the metadata from the source instruction to the destination (the replacement for the source inst...
Definition: Local.cpp:2747
bool SimplifyInstructionsInBlock(BasicBlock *BB, const TargetLibraryInfo *TLI=nullptr)
Scan the specified basic block and try to simplify any instructions in it and recursively delete dead...
Definition: Local.cpp:725
void insertDebugValuesForPHIs(BasicBlock *BB, SmallVectorImpl< PHINode * > &InsertedPHIs)
Propagate dbg.value intrinsics through the newly inserted PHIs.
Definition: Local.cpp:1705
Align getKnownAlignment(Value *V, const DataLayout &DL, const Instruction *CxtI=nullptr, AssumptionCache *AC=nullptr, const DominatorTree *DT=nullptr)
Try to infer an alignment for the specified pointer.
Definition: Local.h:222
bool isInstructionTriviallyDead(Instruction *I, const TargetLibraryInfo *TLI=nullptr)
Return true if the result produced by the instruction is not used, and the instruction will return.
Definition: Local.cpp:398
bool wouldInstructionBeTriviallyDead(Instruction *I, const TargetLibraryInfo *TLI=nullptr)
Return true if the result produced by the instruction would have no side effects if it was not used.
Definition: Local.cpp:417
bool FoldBranchToCommonDest(BranchInst *BI, llvm::DomTreeUpdater *DTU=nullptr, MemorySSAUpdater *MSSAU=nullptr, const TargetTransformInfo *TTI=nullptr, unsigned BonusInstThreshold=1)
If this basic block is ONLY a setcc and a branch, and if a predecessor branches to us and one of our ...
bool TryToSimplifyUncondBranchFromEmptyBlock(BasicBlock *BB, DomTreeUpdater *DTU=nullptr)
BB is known to contain an unconditional branch, and contains no instructions other than PHI nodes,...
Definition: Local.cpp:1070
bool recognizeBSwapOrBitReverseIdiom(Instruction *I, bool MatchBSwaps, bool MatchBitReversals, SmallVectorImpl< Instruction * > &InsertedInsts)
Try to match a bswap or bitreverse idiom.
Definition: Local.cpp:3293
Align getOrEnforceKnownAlignment(Value *V, MaybeAlign PrefAlign, const DataLayout &DL, const Instruction *CxtI=nullptr, AssumptionCache *AC=nullptr, const DominatorTree *DT=nullptr)
Try to ensure that the alignment of V is at least PrefAlign bytes.
Definition: Local.cpp:1433
bool wouldInstructionBeTriviallyDeadOnUnusedPaths(Instruction *I, const TargetLibraryInfo *TLI=nullptr)
Return true if the result produced by the instruction has no side effects on any paths other than whe...
Definition: Local.cpp:405
bool LowerDbgDeclare(Function &F)
Lowers llvm.dbg.declare intrinsics into appropriate set of llvm.dbg.value intrinsics.
Definition: Local.cpp:1631
CallInst * createCallMatchingInvoke(InvokeInst *II)
Create a call that matches the invoke II in terms of arguments, attributes, debug information,...
Definition: Local.cpp:2283
Instruction * removeUnwindEdge(BasicBlock *BB, DomTreeUpdater *DTU=nullptr)
Replace 'BB's terminator with one that does not have an unwind successor block.
Definition: Local.cpp:2570
void patchReplacementInstruction(Instruction *I, Value *Repl)
Patch the replacement so that it is not more restrictive than the value being replaced.
Definition: Local.cpp:2799
void ConvertDebugDeclareToDebugValue(DbgVariableIntrinsic *DII, StoreInst *SI, DIBuilder &Builder)
===------------------------------------------------------------------—===// Dbg Intrinsic utilities
Definition: Local.cpp:1517
unsigned replaceDominatedUsesWith(Value *From, Value *To, DominatorTree &DT, const BasicBlockEdge &Edge)
Replace each use of 'From' with 'To' if that use is dominated by the given edge.
Definition: Local.cpp:2865
void combineMetadata(Instruction *K, const Instruction *J, ArrayRef< unsigned > KnownIDs, bool DoesKMove)
Combine the metadata of two instructions so that K can replace J.
Definition: Local.cpp:2645
cl::opt< bool > RequireAndPreserveDomTree
This function is used to do simplification of a CFG.
unsigned changeToUnreachable(Instruction *I, bool PreserveLCSSA=false, DomTreeUpdater *DTU=nullptr, MemorySSAUpdater *MSSAU=nullptr)
Insert an unreachable instruction before the specified instruction, making it and the rest of the cod...
Definition: Local.cpp:2244
bool replaceAllDbgUsesWith(Instruction &From, Value &To, Instruction &DomPoint, DominatorTree &DT)
Point debug users of From to To or salvage them.
Definition: Local.cpp:2165
Value * salvageDebugInfoImpl(Instruction &I, uint64_t CurrentLocOps, SmallVectorImpl< uint64_t > &Ops, SmallVectorImpl< Value * > &AdditionalValues)
Definition: Local.cpp:2033
void combineMetadataForCSE(Instruction *K, const Instruction *J, bool DoesKMove)
Combine the metadata of two instructions so that K can replace J.
Definition: Local.cpp:2734
void dropDebugUsers(Instruction &I)
Remove the debug intrinsic instructions for the given instruction.
Definition: Local.cpp:2960
TargetTransformInfo TTI
void MergeBasicBlockIntoOnlyPred(BasicBlock *BB, DomTreeUpdater *DTU=nullptr)
BB is a block with one predecessor and its predecessor is known to have one successor (BB!...
Definition: Local.cpp:765
bool replaceDbgUsesWithUndef(Instruction *I)
Replace all the uses of an SSA value in @llvm.dbg intrinsics with undef.
Definition: Local.cpp:614
void hoistAllInstructionsInto(BasicBlock *DomBlock, Instruction *InsertPt, BasicBlock *BB)
Hoist all of the instructions in the IfBlock to the dominant block DomBlock, by moving its instructio...
Definition: Local.cpp:2967
void copyRangeMetadata(const DataLayout &DL, const LoadInst &OldLI, MDNode *N, LoadInst &NewLI)
Copy a range metadata node to a new load instruction.
Definition: Local.cpp:2937
void copyNonnullMetadata(const LoadInst &OldLI, MDNode *N, LoadInst &NewLI)
Copy a nonnull metadata node to a new load instruction.
Definition: Local.cpp:2912
bool canReplaceOperandWithVariable(const Instruction *I, unsigned OpIdx)
Given an instruction, is it legal to set operand OpIdx to a non-constant value?
Definition: Local.cpp:3404
void replaceDbgValueForAlloca(AllocaInst *AI, Value *NewAllocaAddress, DIBuilder &Builder, int Offset=0)
Replaces multiple llvm.dbg.value instructions when the alloca it describes is replaced with a new val...
Definition: Local.cpp:1808
bool RecursivelyDeleteTriviallyDeadInstructionsPermissive(SmallVectorImpl< WeakTrackingVH > &DeadInsts, const TargetLibraryInfo *TLI=nullptr, MemorySSAUpdater *MSSAU=nullptr, std::function< void(Value *)> AboutToDeleteCallback=std::function< void(Value *)>())
Same functionality as RecursivelyDeleteTriviallyDeadInstructions, but allow instructions that are not...
Definition: Local.cpp:552
bool simplifyCFG(BasicBlock *BB, const TargetTransformInfo &TTI, DomTreeUpdater *DTU=nullptr, const SimplifyCFGOptions &Options={}, ArrayRef< WeakVH > LoopHeaders={})
bool RecursivelyDeleteDeadPHINode(PHINode *PN, const TargetLibraryInfo *TLI=nullptr, MemorySSAUpdater *MSSAU=nullptr)
If the specified value is an effectively dead PHI node, due to being a def-use chain of single-use no...
Definition: Local.cpp:645
bool inferAttributesFromOthers(Function &F)
If we can infer one attribute from another on the declaration of a function, explicitly materialize t...
Definition: Local.cpp:3511
Value * invertCondition(Value *Condition)
Invert the given true/false value, possibly reusing an existing copy.
Definition: Local.cpp:3477
void maybeMarkSanitizerLibraryCallNoBuiltin(CallInst *CI, const TargetLibraryInfo *TLI)
Given a CallInst, check if it calls a string function known to CodeGen, and mark it with NoBuiltin if...
Definition: Local.cpp:3394
bool removeUnreachableBlocks(Function &F, DomTreeUpdater *DTU=nullptr, MemorySSAUpdater *MSSAU=nullptr)
Remove all blocks that can not be reached from the function's entry.
Definition: Local.cpp:2608
bool EliminateDuplicatePHINodes(BasicBlock *BB)
Check for and eliminate duplicate PHI nodes in this block.
Definition: Local.cpp:1374
AllocaInst * DemoteRegToStack(Instruction &X, bool VolatileLoads=false, Instruction *AllocaPoint=nullptr)
This function takes a virtual register computed by an Instruction and replaces it with a slot in the ...
bool callsGCLeafFunction(const CallBase *Call, const TargetLibraryInfo &TLI)
Return true if this call calls a gc leaf function.
Definition: Local.cpp:2883
bool replaceDbgDeclare(Value *Address, Value *NewAddress, DIBuilder &Builder, uint8_t DIExprFlags, int Offset)
Replaces llvm.dbg.declare instruction when the address it describes is replaced with a new value.
Definition: Local.cpp:1767
AllocaInst * DemotePHIToStack(PHINode *P, Instruction *AllocaPoint=nullptr)
This function takes a virtual register computed by a phi node and replaces it with a slot in the stac...
#define N
This struct is a compact representation of a valid (non-zero power of two) alignment.
Definition: Alignment.h:39
This struct is a compact representation of a valid (power of two) or undefined (0) alignment.
Definition: Alignment.h:117