1 //===-- Scalar.h - Scalar Transformations -----------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This header file defines prototypes for accessor functions that expose passes
11 // in the Scalar transformations library.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_TRANSFORMS_SCALAR_H
16 #define LLVM_TRANSFORMS_SCALAR_H
27 class GetElementPtrInst;
33 //===----------------------------------------------------------------------===//
35 // ConstantPropagation - A worklist driven constant propagation pass
37 FunctionPass *createConstantPropagationPass();
39 //===----------------------------------------------------------------------===//
41 // AlignmentFromAssumptions - Use assume intrinsics to set load/store
44 FunctionPass *createAlignmentFromAssumptionsPass();
46 //===----------------------------------------------------------------------===//
48 // SCCP - Sparse conditional constant propagation.
50 FunctionPass *createSCCPPass();
52 //===----------------------------------------------------------------------===//
54 // DeadInstElimination - This pass quickly removes trivially dead instructions
55 // without modifying the CFG of the function. It is a BasicBlockPass, so it
56 // runs efficiently when queued next to other BasicBlockPass's.
58 Pass *createDeadInstEliminationPass();
60 //===----------------------------------------------------------------------===//
62 // DeadCodeElimination - This pass is more powerful than DeadInstElimination,
63 // because it is worklist driven that can potentially revisit instructions when
64 // their other instructions become dead, to eliminate chains of dead
67 FunctionPass *createDeadCodeEliminationPass();
69 //===----------------------------------------------------------------------===//
71 // DeadStoreElimination - This pass deletes stores that are post-dominated by
72 // must-aliased stores and are not loaded used between the stores.
74 FunctionPass *createDeadStoreEliminationPass();
76 //===----------------------------------------------------------------------===//
78 // AggressiveDCE - This pass uses the SSA based Aggressive DCE algorithm. This
79 // algorithm assumes instructions are dead until proven otherwise, which makes
80 // it more successful are removing non-obviously dead instructions.
82 FunctionPass *createAggressiveDCEPass();
85 //===----------------------------------------------------------------------===//
87 // GuardWidening - An optimization over the @llvm.experimental.guard intrinsic
88 // that (optimistically) combines multiple guards into one to have fewer checks
91 FunctionPass *createGuardWideningPass();
94 //===----------------------------------------------------------------------===//
96 // BitTrackingDCE - This pass uses a bit-tracking DCE algorithm in order to
97 // remove computations of dead bits.
99 FunctionPass *createBitTrackingDCEPass();
101 //===----------------------------------------------------------------------===//
103 // SROA - Replace aggregates or pieces of aggregates with scalar SSA values.
105 FunctionPass *createSROAPass();
107 //===----------------------------------------------------------------------===//
109 // InductiveRangeCheckElimination - Transform loops to elide range checks on
110 // linear functions of the induction variable.
112 Pass *createInductiveRangeCheckEliminationPass();
114 //===----------------------------------------------------------------------===//
116 // InductionVariableSimplify - Transform induction variables in a program to all
117 // use a single canonical induction variable per loop.
119 Pass *createIndVarSimplifyPass();
121 //===----------------------------------------------------------------------===//
123 // InstructionCombining - Combine instructions to form fewer, simple
124 // instructions. This pass does not modify the CFG, and has a tendency to make
125 // instructions dead, so a subsequent DCE pass is useful.
127 // This pass combines things like:
128 // %Y = add int 1, %X
129 // %Z = add int 1, %Y
131 // %Z = add int 2, %X
133 FunctionPass *createInstructionCombiningPass(bool ExpensiveCombines = true);
135 //===----------------------------------------------------------------------===//
137 // LICM - This pass is a loop invariant code motion and memory promotion pass.
139 Pass *createLICMPass();
141 //===----------------------------------------------------------------------===//
143 // LoopSink - This pass sinks invariants from preheader to loop body where
144 // frequency is lower than loop preheader.
146 Pass *createLoopSinkPass();
148 //===----------------------------------------------------------------------===//
150 // LoopInterchange - This pass interchanges loops to provide a more
151 // cache-friendly memory access patterns.
153 Pass *createLoopInterchangePass();
155 //===----------------------------------------------------------------------===//
157 // LoopStrengthReduce - This pass is strength reduces GEP instructions that use
158 // a loop's canonical induction variable as one of their indices.
160 Pass *createLoopStrengthReducePass();
162 //===----------------------------------------------------------------------===//
164 // LoopUnswitch - This pass is a simple loop unswitching pass.
166 Pass *createLoopUnswitchPass(bool OptimizeForSize = false);
168 //===----------------------------------------------------------------------===//
170 // LoopInstSimplify - This pass simplifies instructions in a loop's body.
172 Pass *createLoopInstSimplifyPass();
174 //===----------------------------------------------------------------------===//
176 // LoopUnroll - This pass is a simple loop unrolling pass.
178 Pass *createLoopUnrollPass(int Threshold = -1, int Count = -1,
179 int AllowPartial = -1, int Runtime = -1,
180 int UpperBound = -1);
181 // Create an unrolling pass for full unrolling that uses exact trip count only.
182 Pass *createSimpleLoopUnrollPass();
184 //===----------------------------------------------------------------------===//
186 // LoopReroll - This pass is a simple loop rerolling pass.
188 Pass *createLoopRerollPass();
190 //===----------------------------------------------------------------------===//
192 // LoopRotate - This pass is a simple loop rotating pass.
194 Pass *createLoopRotatePass(int MaxHeaderSize = -1);
196 //===----------------------------------------------------------------------===//
198 // LoopIdiom - This pass recognizes and replaces idioms in loops.
200 Pass *createLoopIdiomPass();
202 //===----------------------------------------------------------------------===//
204 // LoopVersioningLICM - This pass is a loop versioning pass for LICM.
206 Pass *createLoopVersioningLICMPass();
208 //===----------------------------------------------------------------------===//
210 // PromoteMemoryToRegister - This pass is used to promote memory references to
211 // be register references. A simple example of the transformation performed by
215 // %X = alloca i32, i32 1 ret i32 42
216 // store i32 42, i32 *%X
220 FunctionPass *createPromoteMemoryToRegisterPass();
222 //===----------------------------------------------------------------------===//
224 // DemoteRegisterToMemoryPass - This pass is used to demote registers to memory
225 // references. In basically undoes the PromoteMemoryToRegister pass to make cfg
228 FunctionPass *createDemoteRegisterToMemoryPass();
229 extern char &DemoteRegisterToMemoryID;
231 //===----------------------------------------------------------------------===//
233 // Reassociate - This pass reassociates commutative expressions in an order that
234 // is designed to promote better constant propagation, GCSE, LICM, PRE...
236 // For example: 4 + (x + 5) -> x + (4 + 5)
238 FunctionPass *createReassociatePass();
240 //===----------------------------------------------------------------------===//
242 // JumpThreading - Thread control through mult-pred/multi-succ blocks where some
243 // preds always go to some succ. Thresholds other than minus one override the
244 // internal BB duplication default threshold.
246 FunctionPass *createJumpThreadingPass(int Threshold = -1);
248 //===----------------------------------------------------------------------===//
250 // CFGSimplification - Merge basic blocks, eliminate unreachable blocks,
251 // simplify terminator instructions, etc...
253 FunctionPass *createCFGSimplificationPass(
254 int Threshold = -1, std::function<bool(const Function &)> Ftor = nullptr);
256 //===----------------------------------------------------------------------===//
258 // FlattenCFG - flatten CFG, reduce number of conditional branches by using
259 // parallel-and and parallel-or mode, etc...
261 FunctionPass *createFlattenCFGPass();
263 //===----------------------------------------------------------------------===//
265 // CFG Structurization - Remove irreducible control flow
268 /// When \p SkipUniformRegions is true the structizer will not structurize
269 /// regions that only contain uniform branches.
270 Pass *createStructurizeCFGPass(bool SkipUniformRegions = false);
272 //===----------------------------------------------------------------------===//
274 // BreakCriticalEdges - Break all of the critical edges in the CFG by inserting
275 // a dummy basic block. This pass may be "required" by passes that cannot deal
276 // with critical edges. For this usage, a pass must call:
278 // AU.addRequiredID(BreakCriticalEdgesID);
280 // This pass obviously invalidates the CFG, but can update forward dominator
281 // (set, immediate dominators, tree, and frontier) information.
283 FunctionPass *createBreakCriticalEdgesPass();
284 extern char &BreakCriticalEdgesID;
286 //===----------------------------------------------------------------------===//
288 // LoopSimplify - Insert Pre-header blocks into the CFG for every function in
289 // the module. This pass updates dominator information, loop information, and
290 // does not add critical edges to the CFG.
292 // AU.addRequiredID(LoopSimplifyID);
294 Pass *createLoopSimplifyPass();
295 extern char &LoopSimplifyID;
297 //===----------------------------------------------------------------------===//
299 // TailCallElimination - This pass eliminates call instructions to the current
300 // function which occur immediately before return instructions.
302 FunctionPass *createTailCallEliminationPass();
304 //===----------------------------------------------------------------------===//
306 // LowerSwitch - This pass converts SwitchInst instructions into a sequence of
307 // chained binary branch instructions.
309 FunctionPass *createLowerSwitchPass();
310 extern char &LowerSwitchID;
312 //===----------------------------------------------------------------------===//
314 // LowerInvoke - This pass removes invoke instructions, converting them to call
317 FunctionPass *createLowerInvokePass();
318 extern char &LowerInvokePassID;
320 //===----------------------------------------------------------------------===//
322 // LCSSA - This pass inserts phi nodes at loop boundaries to simplify other loop
325 Pass *createLCSSAPass();
326 extern char &LCSSAID;
328 //===----------------------------------------------------------------------===//
330 // EarlyCSE - This pass performs a simple and fast CSE pass over the dominator
333 FunctionPass *createEarlyCSEPass(bool UseMemorySSA = false);
335 //===----------------------------------------------------------------------===//
337 // GVNHoist - This pass performs a simple and fast GVN pass over the dominator
338 // tree to hoist common expressions from sibling branches.
340 FunctionPass *createGVNHoistPass();
342 //===----------------------------------------------------------------------===//
344 // MergedLoadStoreMotion - This pass merges loads and stores in diamonds. Loads
345 // are hoisted into the header, while stores sink into the footer.
347 FunctionPass *createMergedLoadStoreMotionPass();
349 //===----------------------------------------------------------------------===//
351 // GVN - This pass performs global value numbering and redundant load
352 // elimination cotemporaneously.
354 FunctionPass *createNewGVNPass();
356 //===----------------------------------------------------------------------===//
358 // MemCpyOpt - This pass performs optimizations related to eliminating memcpy
359 // calls and/or combining multiple stores into memset's.
361 FunctionPass *createMemCpyOptPass();
363 //===----------------------------------------------------------------------===//
365 // LoopDeletion - This pass performs DCE of non-infinite loops that it
366 // can prove are dead.
368 Pass *createLoopDeletionPass();
370 //===----------------------------------------------------------------------===//
372 // ConstantHoisting - This pass prepares a function for expensive constants.
374 FunctionPass *createConstantHoistingPass();
376 //===----------------------------------------------------------------------===//
378 // InstructionNamer - Give any unnamed non-void instructions "tmp" names.
380 FunctionPass *createInstructionNamerPass();
381 extern char &InstructionNamerID;
383 //===----------------------------------------------------------------------===//
385 // Sink - Code Sinking
387 FunctionPass *createSinkingPass();
389 //===----------------------------------------------------------------------===//
391 // LowerAtomic - Lower atomic intrinsics to non-atomic form
393 Pass *createLowerAtomicPass();
395 //===----------------------------------------------------------------------===//
397 // LowerGuardIntrinsic - Lower guard intrinsics to normal control flow.
399 Pass *createLowerGuardIntrinsicPass();
401 //===----------------------------------------------------------------------===//
403 // ValuePropagation - Propagate CFG-derived value information
405 Pass *createCorrelatedValuePropagationPass();
407 //===----------------------------------------------------------------------===//
409 // InstructionSimplifier - Remove redundant instructions.
411 FunctionPass *createInstructionSimplifierPass();
412 extern char &InstructionSimplifierID;
414 //===----------------------------------------------------------------------===//
416 // LowerExpectIntrinsics - Removes llvm.expect intrinsics and creates
417 // "block_weights" metadata.
418 FunctionPass *createLowerExpectIntrinsicPass();
420 //===----------------------------------------------------------------------===//
422 // PartiallyInlineLibCalls - Tries to inline the fast path of library
423 // calls such as sqrt.
425 FunctionPass *createPartiallyInlineLibCallsPass();
427 //===----------------------------------------------------------------------===//
429 // ScalarizerPass - Converts vector operations into scalar operations
431 FunctionPass *createScalarizerPass();
433 //===----------------------------------------------------------------------===//
435 // AddDiscriminators - Add DWARF path discriminators to the IR.
436 FunctionPass *createAddDiscriminatorsPass();
438 //===----------------------------------------------------------------------===//
440 // SeparateConstOffsetFromGEP - Split GEPs for better CSE
443 createSeparateConstOffsetFromGEPPass(const TargetMachine *TM = nullptr,
444 bool LowerGEP = false);
446 //===----------------------------------------------------------------------===//
448 // SpeculativeExecution - Aggressively hoist instructions to enable
449 // speculative execution on targets where branches are expensive.
451 FunctionPass *createSpeculativeExecutionPass();
453 // Same as createSpeculativeExecutionPass, but does nothing unless
454 // TargetTransformInfo::hasBranchDivergence() is true.
455 FunctionPass *createSpeculativeExecutionIfHasBranchDivergencePass();
457 //===----------------------------------------------------------------------===//
459 // LoadCombine - Combine loads into bigger loads.
461 BasicBlockPass *createLoadCombinePass();
463 //===----------------------------------------------------------------------===//
465 // StraightLineStrengthReduce - This pass strength-reduces some certain
466 // instruction patterns in straight-line code.
468 FunctionPass *createStraightLineStrengthReducePass();
470 //===----------------------------------------------------------------------===//
472 // PlaceSafepoints - Rewrite any IR calls to gc.statepoints and insert any
473 // safepoint polls (method entry, backedge) that might be required. This pass
474 // does not generate explicit relocation sequences - that's handled by
475 // RewriteStatepointsForGC which can be run at an arbitrary point in the pass
476 // order following this pass.
478 FunctionPass *createPlaceSafepointsPass();
480 //===----------------------------------------------------------------------===//
482 // RewriteStatepointsForGC - Rewrite any gc.statepoints which do not yet have
483 // explicit relocations to include explicit relocations.
485 ModulePass *createRewriteStatepointsForGCPass();
487 //===----------------------------------------------------------------------===//
489 // StripGCRelocates - Remove GC relocates that have been inserted by
490 // RewriteStatepointsForGC. The resulting IR is incorrect, but this is useful
491 // for manual inspection.
492 FunctionPass *createStripGCRelocatesPass();
494 //===----------------------------------------------------------------------===//
496 // Float2Int - Demote floats to ints where possible.
498 FunctionPass *createFloat2IntPass();
500 //===----------------------------------------------------------------------===//
502 // NaryReassociate - Simplify n-ary operations by reassociation.
504 FunctionPass *createNaryReassociatePass();
506 //===----------------------------------------------------------------------===//
508 // LoopDistribute - Distribute loops.
510 FunctionPass *createLoopDistributePass();
512 //===----------------------------------------------------------------------===//
514 // LoopLoadElimination - Perform loop-aware load elimination.
516 FunctionPass *createLoopLoadEliminationPass();
518 //===----------------------------------------------------------------------===//
520 // LoopSimplifyCFG - This pass performs basic CFG simplification on loops,
521 // primarily to help other loop passes.
523 Pass *createLoopSimplifyCFGPass();
525 //===----------------------------------------------------------------------===//
527 // LoopVersioning - Perform loop multi-versioning.
529 FunctionPass *createLoopVersioningPass();
531 //===----------------------------------------------------------------------===//
533 // LoopDataPrefetch - Perform data prefetching in loops.
535 FunctionPass *createLoopDataPrefetchPass();
537 ///===---------------------------------------------------------------------===//
538 ModulePass *createNameAnonGlobalPass();
540 //===----------------------------------------------------------------------===//
542 // LibCallsShrinkWrap - Shrink-wraps a call to function if the result is not
545 FunctionPass *createLibCallsShrinkWrapPass();
546 } // End llvm namespace