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
22 class GetElementPtrInst;
27 //===----------------------------------------------------------------------===//
29 // ConstantPropagation - A worklist driven constant propagation pass
31 FunctionPass *createConstantPropagationPass();
33 //===----------------------------------------------------------------------===//
35 // SCCP - Sparse conditional constant propagation.
37 FunctionPass *createSCCPPass();
39 //===----------------------------------------------------------------------===//
41 // DeadInstElimination - This pass quickly removes trivially dead instructions
42 // without modifying the CFG of the function. It is a BasicBlockPass, so it
43 // runs efficiently when queued next to other BasicBlockPass's.
45 Pass *createDeadInstEliminationPass();
47 //===----------------------------------------------------------------------===//
49 // DeadCodeElimination - This pass is more powerful than DeadInstElimination,
50 // because it is worklist driven that can potentially revisit instructions when
51 // their other instructions become dead, to eliminate chains of dead
54 FunctionPass *createDeadCodeEliminationPass();
56 //===----------------------------------------------------------------------===//
58 // DeadStoreElimination - This pass deletes stores that are post-dominated by
59 // must-aliased stores and are not loaded used between the stores.
61 FunctionPass *createDeadStoreEliminationPass();
63 //===----------------------------------------------------------------------===//
65 // AggressiveDCE - This pass uses the SSA based Aggressive DCE algorithm. This
66 // algorithm assumes instructions are dead until proven otherwise, which makes
67 // it more successful are removing non-obviously dead instructions.
69 FunctionPass *createAggressiveDCEPass();
71 //===----------------------------------------------------------------------===//
73 // ScalarReplAggregates - Break up alloca's of aggregates into multiple allocas
76 FunctionPass *createScalarReplAggregatesPass(signed Threshold = -1,
77 bool UseDomTree = true);
79 //===----------------------------------------------------------------------===//
81 // InductionVariableSimplify - Transform induction variables in a program to all
82 // use a single canonical induction variable per loop.
84 Pass *createIndVarSimplifyPass();
86 //===----------------------------------------------------------------------===//
88 // InstructionCombining - Combine instructions to form fewer, simple
89 // instructions. This pass does not modify the CFG, and has a tendency to make
90 // instructions dead, so a subsequent DCE pass is useful.
92 // This pass combines things like:
98 FunctionPass *createInstructionCombiningPass();
100 //===----------------------------------------------------------------------===//
102 // LICM - This pass is a loop invariant code motion and memory promotion pass.
104 Pass *createLICMPass();
106 //===----------------------------------------------------------------------===//
108 // LoopStrengthReduce - This pass is strength reduces GEP instructions that use
109 // a loop's canonical induction variable as one of their indices. It takes an
110 // optional parameter used to consult the target machine whether certain
111 // transformations are profitable.
113 Pass *createLoopStrengthReducePass(const TargetLowering *TLI = 0);
115 //===----------------------------------------------------------------------===//
117 // LoopUnswitch - This pass is a simple loop unswitching pass.
119 Pass *createLoopUnswitchPass(bool OptimizeForSize = false);
121 //===----------------------------------------------------------------------===//
123 // LoopInstSimplify - This pass simplifies instructions in a loop's body.
125 Pass *createLoopInstSimplifyPass();
127 //===----------------------------------------------------------------------===//
129 // LoopUnroll - This pass is a simple loop unrolling pass.
131 Pass *createLoopUnrollPass(int Threshold = -1, int Count = -1, int AllowPartial = -1);
133 //===----------------------------------------------------------------------===//
135 // LoopRotate - This pass is a simple loop rotating pass.
137 Pass *createLoopRotatePass();
139 //===----------------------------------------------------------------------===//
141 // LoopIdiom - This pass recognizes and replaces idioms in loops.
143 Pass *createLoopIdiomPass();
145 //===----------------------------------------------------------------------===//
147 // PromoteMemoryToRegister - This pass is used to promote memory references to
148 // be register references. A simple example of the transformation performed by
152 // %X = alloca i32, i32 1 ret i32 42
153 // store i32 42, i32 *%X
157 FunctionPass *createPromoteMemoryToRegisterPass();
159 //===----------------------------------------------------------------------===//
161 // DemoteRegisterToMemoryPass - This pass is used to demote registers to memory
162 // references. In basically undoes the PromoteMemoryToRegister pass to make cfg
165 FunctionPass *createDemoteRegisterToMemoryPass();
166 extern char &DemoteRegisterToMemoryID;
168 //===----------------------------------------------------------------------===//
170 // Reassociate - This pass reassociates commutative expressions in an order that
171 // is designed to promote better constant propagation, GCSE, LICM, PRE...
173 // For example: 4 + (x + 5) -> x + (4 + 5)
175 FunctionPass *createReassociatePass();
177 //===----------------------------------------------------------------------===//
179 // TailDuplication - Eliminate unconditional branches through controlled code
180 // duplication, creating simpler CFG structures.
182 FunctionPass *createTailDuplicationPass();
184 //===----------------------------------------------------------------------===//
186 // JumpThreading - Thread control through mult-pred/multi-succ blocks where some
187 // preds always go to some succ.
189 FunctionPass *createJumpThreadingPass();
191 //===----------------------------------------------------------------------===//
193 // CFGSimplification - Merge basic blocks, eliminate unreachable blocks,
194 // simplify terminator instructions, etc...
196 FunctionPass *createCFGSimplificationPass();
198 //===----------------------------------------------------------------------===//
200 // BreakCriticalEdges - Break all of the critical edges in the CFG by inserting
201 // a dummy basic block. This pass may be "required" by passes that cannot deal
202 // with critical edges. For this usage, a pass must call:
204 // AU.addRequiredID(BreakCriticalEdgesID);
206 // This pass obviously invalidates the CFG, but can update forward dominator
207 // (set, immediate dominators, tree, and frontier) information.
209 FunctionPass *createBreakCriticalEdgesPass();
210 extern char &BreakCriticalEdgesID;
212 //===----------------------------------------------------------------------===//
214 // LoopSimplify - Insert Pre-header blocks into the CFG for every function in
215 // the module. This pass updates dominator information, loop information, and
216 // does not add critical edges to the CFG.
218 // AU.addRequiredID(LoopSimplifyID);
220 Pass *createLoopSimplifyPass();
221 extern char &LoopSimplifyID;
223 //===----------------------------------------------------------------------===//
225 // TailCallElimination - This pass eliminates call instructions to the current
226 // function which occur immediately before return instructions.
228 FunctionPass *createTailCallEliminationPass();
230 //===----------------------------------------------------------------------===//
232 // LowerSwitch - This pass converts SwitchInst instructions into a sequence of
233 // chained binary branch instructions.
235 FunctionPass *createLowerSwitchPass();
236 extern char &LowerSwitchID;
238 //===----------------------------------------------------------------------===//
240 // LowerInvoke - This pass converts invoke and unwind instructions to use sjlj
241 // exception handling mechanisms. Note that after this pass runs the CFG is not
242 // entirely accurate (exceptional control flow edges are not correct anymore) so
243 // only very simple things should be done after the lowerinvoke pass has run
244 // (like generation of native code). This should *NOT* be used as a general
245 // purpose "my LLVM-to-LLVM pass doesn't support the invoke instruction yet"
248 FunctionPass *createLowerInvokePass(const TargetLowering *TLI = 0);
249 FunctionPass *createLowerInvokePass(const TargetLowering *TLI,
250 bool useExpensiveEHSupport);
251 extern char &LowerInvokePassID;
253 //===----------------------------------------------------------------------===//
255 // BlockPlacement - This pass reorders basic blocks in order to increase the
256 // number of fall-through conditional branches.
258 FunctionPass *createBlockPlacementPass();
260 //===----------------------------------------------------------------------===//
262 // LCSSA - This pass inserts phi nodes at loop boundaries to simplify other loop
265 Pass *createLCSSAPass();
266 extern char &LCSSAID;
268 //===----------------------------------------------------------------------===//
270 // EarlyCSE - This pass performs a simple and fast CSE pass over the dominator
273 FunctionPass *createEarlyCSEPass();
275 //===----------------------------------------------------------------------===//
277 // GVN - This pass performs global value numbering and redundant load
278 // elimination cotemporaneously.
280 FunctionPass *createGVNPass(bool NoLoads = false);
282 //===----------------------------------------------------------------------===//
284 // MemCpyOpt - This pass performs optimizations related to eliminating memcpy
285 // calls and/or combining multiple stores into memset's.
287 FunctionPass *createMemCpyOptPass();
289 //===----------------------------------------------------------------------===//
291 // LoopDeletion - This pass performs DCE of non-infinite loops that it
292 // can prove are dead.
294 Pass *createLoopDeletionPass();
296 //===----------------------------------------------------------------------===//
298 /// createSimplifyLibCallsPass - This pass optimizes specific calls to
299 /// specific well-known (library) functions.
300 FunctionPass *createSimplifyLibCallsPass();
302 //===----------------------------------------------------------------------===//
304 // CodeGenPrepare - This pass prepares a function for instruction selection.
306 FunctionPass *createCodeGenPreparePass(const TargetLowering *TLI = 0);
308 //===----------------------------------------------------------------------===//
310 // InstructionNamer - Give any unnamed non-void instructions "tmp" names.
312 FunctionPass *createInstructionNamerPass();
313 extern char &InstructionNamerID;
315 //===----------------------------------------------------------------------===//
317 // GEPSplitter - Split complex GEPs into simple ones
319 FunctionPass *createGEPSplitterPass();
321 //===----------------------------------------------------------------------===//
323 // Sink - Code Sinking
325 FunctionPass *createSinkingPass();
327 //===----------------------------------------------------------------------===//
329 // LowerAtomic - Lower atomic intrinsics to non-atomic form
331 Pass *createLowerAtomicPass();
333 //===----------------------------------------------------------------------===//
335 // ValuePropagation - Propagate CFG-derived value information
337 Pass *createCorrelatedValuePropagationPass();
339 //===----------------------------------------------------------------------===//
341 // ObjCARCExpand - ObjC ARC preliminary simplifications.
343 Pass *createObjCARCExpandPass();
345 //===----------------------------------------------------------------------===//
347 // ObjCARCContract - Late ObjC ARC cleanups.
349 Pass *createObjCARCContractPass();
351 //===----------------------------------------------------------------------===//
353 // ObjCARCOpt - ObjC ARC optimization.
355 Pass *createObjCARCOptPass();
357 //===----------------------------------------------------------------------===//
359 // InstructionSimplifier - Remove redundant instructions.
361 FunctionPass *createInstructionSimplifierPass();
362 extern char &InstructionSimplifierID;
365 //===----------------------------------------------------------------------===//
367 // LowerExpectIntriniscs - Removes llvm.expect intrinsics and creates
368 // "block_weights" metadata.
369 FunctionPass *createLowerExpectIntrinsicPass();
372 } // End llvm namespace