LLVM  14.0.0git
Local.h
Go to the documentation of this file.
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/ADT/STLExtras.h"
19 #include "llvm/ADT/SmallVector.h"
21 #include "llvm/IR/Constant.h"
22 #include "llvm/IR/Constants.h"
23 #include "llvm/IR/DataLayout.h"
24 #include "llvm/IR/Dominators.h"
25 #include "llvm/IR/Operator.h"
26 #include "llvm/IR/Type.h"
27 #include "llvm/IR/User.h"
28 #include "llvm/IR/Value.h"
29 #include "llvm/IR/ValueHandle.h"
30 #include "llvm/Support/Casting.h"
33 #include <cstdint>
34 #include <limits>
35 
36 namespace llvm {
37 
38 class AAResults;
39 class AllocaInst;
40 class AssumptionCache;
41 class BasicBlock;
42 class BranchInst;
43 class CallBase;
44 class CallInst;
45 class DbgDeclareInst;
46 class DbgVariableIntrinsic;
47 class DbgValueInst;
48 class DIBuilder;
49 class DomTreeUpdater;
50 class Function;
51 class Instruction;
52 class InvokeInst;
53 class LoadInst;
54 class MDNode;
55 class MemorySSAUpdater;
56 class PHINode;
57 class StoreInst;
58 class TargetLibraryInfo;
59 class TargetTransformInfo;
60 
61 //===----------------------------------------------------------------------===//
62 // Local constant propagation.
63 //
64 
65 /// If a terminator instruction is predicated on a constant value, convert it
66 /// into an unconditional branch to the constant destination.
67 /// This is a nontrivial operation because the successors of this basic block
68 /// must have their PHI nodes updated.
69 /// Also calls RecursivelyDeleteTriviallyDeadInstructions() on any branch/switch
70 /// conditions and indirectbr addresses this might make dead if
71 /// DeleteDeadConditions is true.
72 bool ConstantFoldTerminator(BasicBlock *BB, bool DeleteDeadConditions = false,
73  const TargetLibraryInfo *TLI = nullptr,
74  DomTreeUpdater *DTU = nullptr);
75 
76 //===----------------------------------------------------------------------===//
77 // Local dead code elimination.
78 //
79 
80 /// Return true if the result produced by the instruction is not used, and the
81 /// instruction will return. Certain side-effecting instructions are also
82 /// considered dead if there are no uses of the instruction.
83 bool isInstructionTriviallyDead(Instruction *I,
84  const TargetLibraryInfo *TLI = nullptr);
85 
86 /// Return true if the result produced by the instruction would have no side
87 /// effects if it was not used. This is equivalent to checking whether
88 /// isInstructionTriviallyDead would be true if the use count was 0.
89 bool wouldInstructionBeTriviallyDead(Instruction *I,
90  const TargetLibraryInfo *TLI = nullptr);
91 
92 /// If the specified value is a trivially dead instruction, delete it.
93 /// If that makes any of its operands trivially dead, delete them too,
94 /// recursively. Return true if any instructions were deleted.
96  Value *V, const TargetLibraryInfo *TLI = nullptr,
97  MemorySSAUpdater *MSSAU = nullptr,
98  std::function<void(Value *)> AboutToDeleteCallback =
99  std::function<void(Value *)>());
100 
101 /// Delete all of the instructions in `DeadInsts`, and all other instructions
102 /// that deleting these in turn causes to be trivially dead.
103 ///
104 /// The initial instructions in the provided vector must all have empty use
105 /// lists and satisfy `isInstructionTriviallyDead`.
106 ///
107 /// `DeadInsts` will be used as scratch storage for this routine and will be
108 /// empty afterward.
110  SmallVectorImpl<WeakTrackingVH> &DeadInsts,
111  const TargetLibraryInfo *TLI = nullptr, MemorySSAUpdater *MSSAU = nullptr,
112  std::function<void(Value *)> AboutToDeleteCallback =
113  std::function<void(Value *)>());
114 
115 /// Same functionality as RecursivelyDeleteTriviallyDeadInstructions, but allow
116 /// instructions that are not trivially dead. These will be ignored.
117 /// Returns true if any changes were made, i.e. any instructions trivially dead
118 /// were found and deleted.
120  SmallVectorImpl<WeakTrackingVH> &DeadInsts,
121  const TargetLibraryInfo *TLI = nullptr, MemorySSAUpdater *MSSAU = nullptr,
122  std::function<void(Value *)> AboutToDeleteCallback =
123  std::function<void(Value *)>());
124 
125 /// If the specified value is an effectively dead PHI node, due to being a
126 /// def-use chain of single-use nodes that either forms a cycle or is terminated
127 /// by a trivially dead instruction, delete it. If that makes any of its
128 /// operands trivially dead, delete them too, recursively. Return true if a
129 /// change was made.
130 bool RecursivelyDeleteDeadPHINode(PHINode *PN,
131  const TargetLibraryInfo *TLI = nullptr,
132  MemorySSAUpdater *MSSAU = nullptr);
133 
134 /// Scan the specified basic block and try to simplify any instructions in it
135 /// and recursively delete dead instructions.
136 ///
137 /// This returns true if it changed the code, note that it can delete
138 /// instructions in other blocks as well in this block.
140  const TargetLibraryInfo *TLI = nullptr);
141 
142 /// Replace all the uses of an SSA value in @llvm.dbg intrinsics with
143 /// undef. This is useful for signaling that a variable, e.g. has been
144 /// found dead and hence it's unavailable at a given program point.
145 /// Returns true if the dbg values have been changed.
146 bool replaceDbgUsesWithUndef(Instruction *I);
147 
148 //===----------------------------------------------------------------------===//
149 // Control Flow Graph Restructuring.
150 //
151 
152 /// BB is a block with one predecessor and its predecessor is known to have one
153 /// successor (BB!). Eliminate the edge between them, moving the instructions in
154 /// the predecessor into BB. This deletes the predecessor block.
155 void MergeBasicBlockIntoOnlyPred(BasicBlock *BB, DomTreeUpdater *DTU = nullptr);
156 
157 /// BB is known to contain an unconditional branch, and contains no instructions
158 /// other than PHI nodes, potential debug intrinsics and the branch. If
159 /// possible, eliminate BB by rewriting all the predecessors to branch to the
160 /// successor block and return true. If we can't transform, return false.
162  DomTreeUpdater *DTU = nullptr);
163 
164 /// Check for and eliminate duplicate PHI nodes in this block. This doesn't try
165 /// to be clever about PHI nodes which differ only in the order of the incoming
166 /// values, but instcombine orders them so it usually won't matter.
168 
169 /// This function is used to do simplification of a CFG. For example, it
170 /// adjusts branches to branches to eliminate the extra hop, it eliminates
171 /// unreachable basic blocks, and does other peephole optimization of the CFG.
172 /// It returns true if a modification was made, possibly deleting the basic
173 /// block that was pointed to. LoopHeaders is an optional input parameter
174 /// providing the set of loop headers that SimplifyCFG should not eliminate.
175 extern cl::opt<bool> RequireAndPreserveDomTree;
176 bool simplifyCFG(BasicBlock *BB, const TargetTransformInfo &TTI,
177  DomTreeUpdater *DTU = nullptr,
178  const SimplifyCFGOptions &Options = {},
179  ArrayRef<WeakVH> LoopHeaders = {});
180 
181 /// This function is used to flatten a CFG. For example, it uses parallel-and
182 /// and parallel-or mode to collapse if-conditions and merge if-regions with
183 /// identical statements.
184 bool FlattenCFG(BasicBlock *BB, AAResults *AA = nullptr);
185 
186 /// If this basic block is ONLY a setcc and a branch, and if a predecessor
187 /// branches to us and one of our successors, fold the setcc into the
188 /// predecessor and use logical operations to pick the right destination.
189 bool FoldBranchToCommonDest(BranchInst *BI, llvm::DomTreeUpdater *DTU = nullptr,
190  MemorySSAUpdater *MSSAU = nullptr,
191  const TargetTransformInfo *TTI = nullptr,
192  unsigned BonusInstThreshold = 1);
193 
194 /// This function takes a virtual register computed by an Instruction and
195 /// replaces it with a slot in the stack frame, allocated via alloca.
196 /// This allows the CFG to be changed around without fear of invalidating the
197 /// SSA information for the value. It returns the pointer to the alloca inserted
198 /// to create a stack slot for X.
199 AllocaInst *DemoteRegToStack(Instruction &X,
200  bool VolatileLoads = false,
201  Instruction *AllocaPoint = nullptr);
202 
203 /// This function takes a virtual register computed by a phi node and replaces
204 /// it with a slot in the stack frame, allocated via alloca. The phi node is
205 /// deleted and it returns the pointer to the alloca inserted.
206 AllocaInst *DemotePHIToStack(PHINode *P, Instruction *AllocaPoint = nullptr);
207 
208 /// Try to ensure that the alignment of \p V is at least \p PrefAlign bytes. If
209 /// the owning object can be modified and has an alignment less than \p
210 /// PrefAlign, it will be increased and \p PrefAlign returned. If the alignment
211 /// cannot be increased, the known alignment of the value is returned.
212 ///
213 /// It is not always possible to modify the alignment of the underlying object,
214 /// so if alignment is important, a more reliable approach is to simply align
215 /// all global variables and allocation instructions to their preferred
216 /// alignment from the beginning.
217 Align getOrEnforceKnownAlignment(Value *V, MaybeAlign PrefAlign,
218  const DataLayout &DL,
219  const Instruction *CxtI = nullptr,
220  AssumptionCache *AC = nullptr,
221  const DominatorTree *DT = nullptr);
222 
223 /// Try to infer an alignment for the specified pointer.
225  const Instruction *CxtI = nullptr,
226  AssumptionCache *AC = nullptr,
227  const DominatorTree *DT = nullptr) {
228  return getOrEnforceKnownAlignment(V, MaybeAlign(), DL, CxtI, AC, DT);
229 }
230 
231 /// Create a call that matches the invoke \p II in terms of arguments,
232 /// attributes, debug information, etc. The call is not placed in a block and it
233 /// will not have a name. The invoke instruction is not removed, nor are the
234 /// uses replaced by the new call.
235 CallInst *createCallMatchingInvoke(InvokeInst *II);
236 
237 /// This function converts the specified invoek into a normall call.
238 void changeToCall(InvokeInst *II, DomTreeUpdater *DTU = nullptr);
239 
240 ///===---------------------------------------------------------------------===//
241 /// Dbg Intrinsic utilities
242 ///
243 
244 /// Inserts a llvm.dbg.value intrinsic before a store to an alloca'd value
245 /// that has an associated llvm.dbg.declare or llvm.dbg.addr intrinsic.
246 void ConvertDebugDeclareToDebugValue(DbgVariableIntrinsic *DII,
247  StoreInst *SI, DIBuilder &Builder);
248 
249 /// Inserts a llvm.dbg.value intrinsic before a load of an alloca'd value
250 /// that has an associated llvm.dbg.declare or llvm.dbg.addr intrinsic.
251 void ConvertDebugDeclareToDebugValue(DbgVariableIntrinsic *DII,
252  LoadInst *LI, DIBuilder &Builder);
253 
254 /// Inserts a llvm.dbg.value intrinsic after a phi that has an associated
255 /// llvm.dbg.declare or llvm.dbg.addr intrinsic.
256 void ConvertDebugDeclareToDebugValue(DbgVariableIntrinsic *DII,
257  PHINode *LI, DIBuilder &Builder);
258 
259 /// Lowers llvm.dbg.declare intrinsics into appropriate set of
260 /// llvm.dbg.value intrinsics.
261 bool LowerDbgDeclare(Function &F);
262 
263 /// Propagate dbg.value intrinsics through the newly inserted PHIs.
265  SmallVectorImpl<PHINode *> &InsertedPHIs);
266 
267 /// Replaces llvm.dbg.declare instruction when the address it
268 /// describes is replaced with a new value. If Deref is true, an
269 /// additional DW_OP_deref is prepended to the expression. If Offset
270 /// is non-zero, a constant displacement is added to the expression
271 /// (between the optional Deref operations). Offset can be negative.
272 bool replaceDbgDeclare(Value *Address, Value *NewAddress, DIBuilder &Builder,
273  uint8_t DIExprFlags, int Offset);
274 
275 /// Replaces multiple llvm.dbg.value instructions when the alloca it describes
276 /// is replaced with a new value. If Offset is non-zero, a constant displacement
277 /// is added to the expression (after the mandatory Deref). Offset can be
278 /// negative. New llvm.dbg.value instructions are inserted at the locations of
279 /// the instructions they replace.
280 void replaceDbgValueForAlloca(AllocaInst *AI, Value *NewAllocaAddress,
281  DIBuilder &Builder, int Offset = 0);
282 
283 /// Assuming the instruction \p I is going to be deleted, attempt to salvage
284 /// debug users of \p I by writing the effect of \p I in a DIExpression. If it
285 /// cannot be salvaged changes its debug uses to undef.
286 void salvageDebugInfo(Instruction &I);
287 
288 
289 /// Implementation of salvageDebugInfo, applying only to instructions in
290 /// \p Insns, rather than all debug users from findDbgUsers( \p I).
291 /// Returns true if any debug users were updated.
292 /// Mark undef if salvaging cannot be completed.
293 void salvageDebugInfoForDbgValues(Instruction &I,
294  ArrayRef<DbgVariableIntrinsic *> Insns);
295 
296 /// Given an instruction \p I and DIExpression \p DIExpr operating on
297 /// it, append the effects of \p I to the DIExpression operand list
298 /// \p Ops, or return \p nullptr if it cannot be salvaged.
299 /// \p CurrentLocOps is the number of SSA values referenced by the
300 /// incoming \p Ops. \return the first non-constant operand
301 /// implicitly referred to by Ops. If \p I references more than one
302 /// non-constant operand, any additional operands are added to
303 /// \p AdditionalValues.
304 ///
305 /// \example
306 ////
307 /// I = add %a, i32 1
308 ///
309 /// Return = %a
310 /// Ops = llvm::dwarf::DW_OP_lit1 llvm::dwarf::DW_OP_add
311 ///
312 /// I = add %a, %b
313 ///
314 /// Return = %a
315 /// Ops = llvm::dwarf::DW_OP_LLVM_arg0 llvm::dwarf::DW_OP_add
316 /// AdditionalValues = %b
317 Value *salvageDebugInfoImpl(Instruction &I, uint64_t CurrentLocOps,
318  SmallVectorImpl<uint64_t> &Ops,
319  SmallVectorImpl<Value *> &AdditionalValues);
320 
321 /// Point debug users of \p From to \p To or salvage them. Use this function
322 /// only when replacing all uses of \p From with \p To, with a guarantee that
323 /// \p From is going to be deleted.
324 ///
325 /// Follow these rules to prevent use-before-def of \p To:
326 /// . If \p To is a linked Instruction, set \p DomPoint to \p To.
327 /// . If \p To is an unlinked Instruction, set \p DomPoint to the Instruction
328 /// \p To will be inserted after.
329 /// . If \p To is not an Instruction (e.g a Constant), the choice of
330 /// \p DomPoint is arbitrary. Pick \p From for simplicity.
331 ///
332 /// If a debug user cannot be preserved without reordering variable updates or
333 /// introducing a use-before-def, it is either salvaged (\ref salvageDebugInfo)
334 /// or deleted. Returns true if any debug users were updated.
335 bool replaceAllDbgUsesWith(Instruction &From, Value &To, Instruction &DomPoint,
336  DominatorTree &DT);
337 
338 /// Remove all instructions from a basic block other than its terminator
339 /// and any present EH pad instructions. Returns a pair where the first element
340 /// is the number of instructions (excluding debug info instrinsics) that have
341 /// been removed, and the second element is the number of debug info intrinsics
342 /// that have been removed.
343 std::pair<unsigned, unsigned>
345 
346 /// Insert an unreachable instruction before the specified
347 /// instruction, making it and the rest of the code in the block dead.
348 unsigned changeToUnreachable(Instruction *I, bool PreserveLCSSA = false,
349  DomTreeUpdater *DTU = nullptr,
350  MemorySSAUpdater *MSSAU = nullptr);
351 
352 /// Convert the CallInst to InvokeInst with the specified unwind edge basic
353 /// block. This also splits the basic block where CI is located, because
354 /// InvokeInst is a terminator instruction. Returns the newly split basic
355 /// block.
357  BasicBlock *UnwindEdge,
358  DomTreeUpdater *DTU = nullptr);
359 
360 /// Replace 'BB's terminator with one that does not have an unwind successor
361 /// block. Rewrites `invoke` to `call`, etc. Updates any PHIs in unwind
362 /// successor.
363 ///
364 /// \param BB Block whose terminator will be replaced. Its terminator must
365 /// have an unwind successor.
366 void removeUnwindEdge(BasicBlock *BB, DomTreeUpdater *DTU = nullptr);
367 
368 /// Remove all blocks that can not be reached from the function's entry.
369 ///
370 /// Returns true if any basic block was removed.
371 bool removeUnreachableBlocks(Function &F, DomTreeUpdater *DTU = nullptr,
372  MemorySSAUpdater *MSSAU = nullptr);
373 
374 /// Combine the metadata of two instructions so that K can replace J. Some
375 /// metadata kinds can only be kept if K does not move, meaning it dominated
376 /// J in the original IR.
377 ///
378 /// Metadata not listed as known via KnownIDs is removed
379 void combineMetadata(Instruction *K, const Instruction *J,
380  ArrayRef<unsigned> KnownIDs, bool DoesKMove);
381 
382 /// Combine the metadata of two instructions so that K can replace J. This
383 /// specifically handles the case of CSE-like transformations. Some
384 /// metadata can only be kept if K dominates J. For this to be correct,
385 /// K cannot be hoisted.
386 ///
387 /// Unknown metadata is removed.
388 void combineMetadataForCSE(Instruction *K, const Instruction *J,
389  bool DoesKMove);
390 
391 /// Copy the metadata from the source instruction to the destination (the
392 /// replacement for the source instruction).
393 void copyMetadataForLoad(LoadInst &Dest, const LoadInst &Source);
394 
395 /// Patch the replacement so that it is not more restrictive than the value
396 /// being replaced. It assumes that the replacement does not get moved from
397 /// its original position.
398 void patchReplacementInstruction(Instruction *I, Value *Repl);
399 
400 // Replace each use of 'From' with 'To', if that use does not belong to basic
401 // block where 'From' is defined. Returns the number of replacements made.
402 unsigned replaceNonLocalUsesWith(Instruction *From, Value *To);
403 
404 /// Replace each use of 'From' with 'To' if that use is dominated by
405 /// the given edge. Returns the number of replacements made.
406 unsigned replaceDominatedUsesWith(Value *From, Value *To, DominatorTree &DT,
407  const BasicBlockEdge &Edge);
408 /// Replace each use of 'From' with 'To' if that use is dominated by
409 /// the end of the given BasicBlock. Returns the number of replacements made.
410 unsigned replaceDominatedUsesWith(Value *From, Value *To, DominatorTree &DT,
411  const BasicBlock *BB);
412 
413 /// Return true if this call calls a gc leaf function.
414 ///
415 /// A leaf function is a function that does not safepoint the thread during its
416 /// execution. During a call or invoke to such a function, the callers stack
417 /// does not have to be made parseable.
418 ///
419 /// Most passes can and should ignore this information, and it is only used
420 /// during lowering by the GC infrastructure.
421 bool callsGCLeafFunction(const CallBase *Call, const TargetLibraryInfo &TLI);
422 
423 /// Copy a nonnull metadata node to a new load instruction.
424 ///
425 /// This handles mapping it to range metadata if the new load is an integer
426 /// load instead of a pointer load.
427 void copyNonnullMetadata(const LoadInst &OldLI, MDNode *N, LoadInst &NewLI);
428 
429 /// Copy a range metadata node to a new load instruction.
430 ///
431 /// This handles mapping it to nonnull metadata if the new load is a pointer
432 /// load instead of an integer load and the range doesn't cover null.
433 void copyRangeMetadata(const DataLayout &DL, const LoadInst &OldLI, MDNode *N,
434  LoadInst &NewLI);
435 
436 /// Remove the debug intrinsic instructions for the given instruction.
437 void dropDebugUsers(Instruction &I);
438 
439 /// Hoist all of the instructions in the \p IfBlock to the dominant block
440 /// \p DomBlock, by moving its instructions to the insertion point \p InsertPt.
441 ///
442 /// The moved instructions receive the insertion point debug location values
443 /// (DILocations) and their debug intrinsic instructions are removed.
444 void hoistAllInstructionsInto(BasicBlock *DomBlock, Instruction *InsertPt,
445  BasicBlock *BB);
446 
447 //===----------------------------------------------------------------------===//
448 // Intrinsic pattern matching
449 //
450 
451 /// Try to match a bswap or bitreverse idiom.
452 ///
453 /// If an idiom is matched, an intrinsic call is inserted before \c I. Any added
454 /// instructions are returned in \c InsertedInsts. They will all have been added
455 /// to a basic block.
456 ///
457 /// A bitreverse idiom normally requires around 2*BW nodes to be searched (where
458 /// BW is the bitwidth of the integer type). A bswap idiom requires anywhere up
459 /// to BW / 4 nodes to be searched, so is significantly faster.
460 ///
461 /// This function returns true on a successful match or false otherwise.
463  Instruction *I, bool MatchBSwaps, bool MatchBitReversals,
464  SmallVectorImpl<Instruction *> &InsertedInsts);
465 
466 //===----------------------------------------------------------------------===//
467 // Sanitizer utilities
468 //
469 
470 /// Given a CallInst, check if it calls a string function known to CodeGen,
471 /// and mark it with NoBuiltin if so. To be used by sanitizers that intend
472 /// to intercept string functions and want to avoid converting them to target
473 /// specific instructions.
475  const TargetLibraryInfo *TLI);
476 
477 //===----------------------------------------------------------------------===//
478 // Transform predicates
479 //
480 
481 /// Given an instruction, is it legal to set operand OpIdx to a non-constant
482 /// value?
483 bool canReplaceOperandWithVariable(const Instruction *I, unsigned OpIdx);
484 
485 //===----------------------------------------------------------------------===//
486 // Value helper functions
487 //
488 
489 /// Invert the given true/false value, possibly reusing an existing copy.
490 Value *invertCondition(Value *Condition);
491 
492 
493 //===----------------------------------------------------------------------===//
494 // Assorted
495 //
496 
497 /// If we can infer one attribute from another on the declaration of a
498 /// function, explicitly materialize the maximal set in the IR.
499 bool inferAttributesFromOthers(Function &F);
500 
501 } // end namespace llvm
502 
503 #endif // LLVM_TRANSFORMS_UTILS_LOCAL_H
llvm::invertCondition
Value * invertCondition(Value *Condition)
Invert the given true/false value, possibly reusing an existing copy.
Definition: Local.cpp:3306
llvm::RecursivelyDeleteTriviallyDeadInstructions
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:511
llvm::combineMetadata
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:2484
llvm
This file implements support for optimizing divisions by a constant.
Definition: AllocatorList.h:23
llvm::ConvertDebugDeclareToDebugValue
void ConvertDebugDeclareToDebugValue(DbgVariableIntrinsic *DII, StoreInst *SI, DIBuilder &Builder)
===------------------------------------------------------------------—===// Dbg Intrinsic utilities
Definition: Local.cpp:1439
llvm::DataLayout
A parsed version of the target data layout string in and methods for querying it.
Definition: DataLayout.h:113
llvm::callsGCLeafFunction
bool callsGCLeafFunction(const CallBase *Call, const TargetLibraryInfo &TLI)
Return true if this call calls a gc leaf function.
Definition: Local.cpp:2712
P
This currently compiles esp xmm0 movsd esp eax eax esp ret We should use not the dag combiner This is because dagcombine2 needs to be able to see through the X86ISD::Wrapper which DAGCombine can t really do The code for turning x load into a single vector load is target independent and should be moved to the dag combiner The code for turning x load into a vector load can only handle a direct load from a global or a direct load from the stack It should be generalized to handle any load from P
Definition: README-SSE.txt:411
llvm::replaceNonLocalUsesWith
unsigned replaceNonLocalUsesWith(Instruction *From, Value *To)
Definition: Local.cpp:2679
llvm::dropDebugUsers
void dropDebugUsers(Instruction &I)
Remove the debug intrinsic instructions for the given instruction.
Definition: Local.cpp:2784
llvm::DominatorTree
Concrete subclass of DominatorTreeBase that is used to compute a normal dominator tree.
Definition: Dominators.h:151
llvm::removeUnreachableBlocks
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:2447
llvm::getOrEnforceKnownAlignment
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:1343
Offset
uint64_t Offset
Definition: ELFObjHandler.cpp:81
Operator.h
STLExtras.h
llvm::combineMetadataForCSE
void combineMetadataForCSE(Instruction *K, const Instruction *J, bool DoesKMove)
Combine the metadata of two instructions so that K can replace J.
Definition: Local.cpp:2565
F
#define F(x, y, z)
Definition: MD5.cpp:56
llvm::RecursivelyDeleteDeadPHINode
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:621
CommandLine.h
llvm::SimplifyInstructionsInBlock
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:701
Constants.h
llvm::DemotePHIToStack
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...
Definition: DemoteRegToStack.cpp:110
llvm::getKnownAlignment
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:224
llvm::canReplaceOperandWithVariable
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:3233
llvm::FoldBranchToCommonDest
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 ...
Definition: SimplifyCFG.cpp:3163
llvm::MaybeAlign
This struct is a compact representation of a valid (power of two) or undefined (0) alignment.
Definition: Alignment.h:109
llvm::inferAttributesFromOthers
bool inferAttributesFromOthers(Function &F)
If we can infer one attribute from another on the declaration of a function, explicitly materialize t...
Definition: Local.cpp:3340
llvm::removeAllNonTerminatorAndEHPadInstructions
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:2085
llvm::Instruction
Definition: Instruction.h:45
Options
const char LLVMTargetMachineRef LLVMPassBuilderOptionsRef Options
Definition: PassBuilderBindings.cpp:48
llvm::copyRangeMetadata
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:2766
llvm::DomTreeUpdater
Definition: DomTreeUpdater.h:28
Align
uint64_t Align
Definition: ELFObjHandler.cpp:83
llvm::Align
This struct is a compact representation of a valid (non-zero power of two) alignment.
Definition: Alignment.h:39
llvm::MCID::Call
@ Call
Definition: MCInstrDesc.h:153
Type.h
X
static GCMetadataPrinterRegistry::Add< ErlangGCPrinter > X("erlang", "erlang-compatible garbage collector")
llvm::wouldInstructionBeTriviallyDead
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:405
llvm::copyNonnullMetadata
void copyNonnullMetadata(const LoadInst &OldLI, MDNode *N, LoadInst &NewLI)
Copy a nonnull metadata node to a new load instruction.
Definition: Local.cpp:2741
llvm::copyMetadataForLoad
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:2578
llvm::removeUnwindEdge
void removeUnwindEdge(BasicBlock *BB, DomTreeUpdater *DTU=nullptr)
Replace 'BB's terminator with one that does not have an unwind successor block.
Definition: Local.cpp:2408
llvm::TryToSimplifyUncondBranchFromEmptyBlock
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:1043
uint64_t
I
#define I(x, y, z)
Definition: MD5.cpp:59
llvm::insertDebugValuesForPHIs
void insertDebugValuesForPHIs(BasicBlock *BB, SmallVectorImpl< PHINode * > &InsertedPHIs)
Propagate dbg.value intrinsics through the newly inserted PHIs.
Definition: Local.cpp:1612
ArrayRef.h
llvm::hoistAllInstructionsInto
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:2791
llvm::salvageDebugInfoForDbgValues
void salvageDebugInfoForDbgValues(Instruction &I, ArrayRef< DbgVariableIntrinsic * > Insns)
Implementation of salvageDebugInfo, applying only to instructions in Insns, rather than all debug use...
Definition: Local.cpp:1732
SI
StandardInstrumentations SI(Debug, VerifyEach)
llvm::ISD::BasicBlock
@ BasicBlock
Various leaf nodes.
Definition: ISDOpcodes.h:71
llvm::TTI
TargetTransformInfo TTI
Definition: TargetTransformInfo.h:163
function
print Print MemDeps of function
Definition: MemDepPrinter.cpp:83
llvm::replaceDominatedUsesWith
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:2694
llvm::replaceAllDbgUsesWith
bool replaceAllDbgUsesWith(Instruction &From, Value &To, Instruction &DomPoint, DominatorTree &DT)
Point debug users of From to To or salvage them.
Definition: Local.cpp:2030
llvm::changeToInvokeAndSplitBasicBlock
BasicBlock * changeToInvokeAndSplitBasicBlock(CallInst *CI, BasicBlock *UnwindEdge, DomTreeUpdater *DTU=nullptr)
Convert the CallInst to InvokeInst with the specified unwind edge basic block.
Definition: Local.cpp:2193
Builder
assume Assume Builder
Definition: AssumeBundleBuilder.cpp:650
llvm::simplifyCFG
bool simplifyCFG(BasicBlock *BB, const TargetTransformInfo &TTI, DomTreeUpdater *DTU=nullptr, const SimplifyCFGOptions &Options={}, ArrayRef< WeakVH > LoopHeaders={})
Definition: SimplifyCFG.cpp:6777
llvm::ReplayInlineScope::Function
@ Function
llvm::Sched::Source
@ Source
Definition: TargetLowering.h:100
llvm::isInstructionTriviallyDead
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
DataLayout.h
llvm::AssumptionCache
A cache of @llvm.assume calls within a function.
Definition: AssumptionCache.h:41
llvm::FlattenCFG
bool FlattenCFG(BasicBlock *BB, AAResults *AA=nullptr)
This function is used to flatten a CFG.
Definition: FlattenCFG.cpp:547
DL
MachineBasicBlock MachineBasicBlock::iterator DebugLoc DL
Definition: AArch64SLSHardening.cpp:76
llvm::recognizeBSwapOrBitReverseIdiom
bool recognizeBSwapOrBitReverseIdiom(Instruction *I, bool MatchBSwaps, bool MatchBitReversals, SmallVectorImpl< Instruction * > &InsertedInsts)
Try to match a bswap or bitreverse idiom.
Definition: Local.cpp:3118
Local.h
llvm::DemoteRegToStack
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 ...
Definition: DemoteRegToStack.cpp:23
llvm::maybeMarkSanitizerLibraryCallNoBuiltin
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:3223
llvm::RequireAndPreserveDomTree
cl::opt< bool > RequireAndPreserveDomTree
This function is used to do simplification of a CFG.
ValueHandle.h
llvm::replaceDbgValueForAlloca
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:1715
llvm::EliminateDuplicatePHINodes
bool EliminateDuplicatePHINodes(BasicBlock *BB)
Check for and eliminate duplicate PHI nodes in this block.
Definition: Local.cpp:1284
Constant.h
llvm::ConstantFoldTerminator
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:128
llvm::salvageDebugInfoImpl
Value * salvageDebugInfoImpl(Instruction &I, uint64_t CurrentLocOps, SmallVectorImpl< uint64_t > &Ops, SmallVectorImpl< Value * > &AdditionalValues)
Definition: Local.cpp:1898
Casting.h
llvm::TargetStackID::Value
Value
Definition: TargetFrameLowering.h:27
llvm::salvageDebugInfo
void salvageDebugInfo(Instruction &I)
Assuming the instruction I is going to be deleted, attempt to salvage debug users of I by writing the...
Definition: Local.cpp:1726
llvm::LowerDbgDeclare
bool LowerDbgDeclare(Function &F)
Lowers llvm.dbg.declare intrinsics into appropriate set of llvm.dbg.value intrinsics.
Definition: Local.cpp:1538
llvm::replaceDbgUsesWithUndef
bool replaceDbgUsesWithUndef(Instruction *I)
Replace all the uses of an SSA value in @llvm.dbg intrinsics with undef.
Definition: Local.cpp:588
SimplifyCFGOptions.h
llvm::changeToUnreachable
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:2109
SmallVector.h
User.h
Dominators.h
N
#define N
llvm::changeToCall
void changeToCall(InvokeInst *II, DomTreeUpdater *DTU=nullptr)
This function converts the specified invoek into a normall call.
Definition: Local.cpp:2174
BB
Common register allocation spilling lr str ldr sxth r3 ldr mla r4 can lr mov lr str ldr sxth r3 mla r4 and then merge mul and lr str ldr sxth r3 mla r4 It also increase the likelihood the store may become dead bb27 Successors according to LLVM BB
Definition: README.txt:39
llvm::createCallMatchingInvoke
CallInst * createCallMatchingInvoke(InvokeInst *II)
Create a call that matches the invoke II in terms of arguments, attributes, debug information,...
Definition: Local.cpp:2148
llvm::patchReplacementInstruction
void patchReplacementInstruction(Instruction *I, Value *Repl)
Patch the replacement so that it is not more restrictive than the value being replaced.
Definition: Local.cpp:2629
llvm::MergeBasicBlockIntoOnlyPred
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:741
From
BlockVerifier::State From
Definition: BlockVerifier.cpp:55
llvm::replaceDbgDeclare
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:1674
Value.h
llvm::RecursivelyDeleteTriviallyDeadInstructionsPermissive
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:526
llvm::Value
LLVM Value Representation.
Definition: Value.h:74