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);
78 //===----------------------------------------------------------------------===//
80 // InductionVariableSimplify - Transform induction variables in a program to all
81 // use a single canonical induction variable per loop.
83 Pass *createIndVarSimplifyPass();
85 //===----------------------------------------------------------------------===//
87 // InstructionCombining - Combine instructions to form fewer, simple
88 // instructions. This pass does not modify the CFG, and has a tendency to make
89 // instructions dead, so a subsequent DCE pass is useful.
91 // This pass combines things like:
97 FunctionPass *createInstructionCombiningPass();
99 //===----------------------------------------------------------------------===//
101 // LICM - This pass is a loop invariant code motion and memory promotion pass.
103 Pass *createLICMPass();
105 //===----------------------------------------------------------------------===//
107 // LoopStrengthReduce - This pass is strength reduces GEP instructions that use
108 // a loop's canonical induction variable as one of their indices. It takes an
109 // optional parameter used to consult the target machine whether certain
110 // transformations are profitable.
112 Pass *createLoopStrengthReducePass(const TargetLowering *TLI = 0);
114 //===----------------------------------------------------------------------===//
116 // LoopUnswitch - This pass is a simple loop unswitching pass.
118 Pass *createLoopUnswitchPass(bool OptimizeForSize = false);
120 //===----------------------------------------------------------------------===//
122 // LoopUnroll - This pass is a simple loop unrolling pass.
124 Pass *createLoopUnrollPass();
126 //===----------------------------------------------------------------------===//
128 // LoopRotate - This pass is a simple loop rotating pass.
130 Pass *createLoopRotatePass();
132 //===----------------------------------------------------------------------===//
134 // LoopIndexSplit - This pass divides loop's iteration range by spliting loop
135 // such that each individual loop is executed efficiently.
137 Pass *createLoopIndexSplitPass();
139 //===----------------------------------------------------------------------===//
141 // PromoteMemoryToRegister - This pass is used to promote memory references to
142 // be register references. A simple example of the transformation performed by
146 // %X = alloca i32, i32 1 ret i32 42
147 // store i32 42, i32 *%X
151 FunctionPass *createPromoteMemoryToRegisterPass();
152 extern const PassInfo *const PromoteMemoryToRegisterID;
154 //===----------------------------------------------------------------------===//
156 // DemoteRegisterToMemoryPass - This pass is used to demote registers to memory
157 // references. In basically undoes the PromoteMemoryToRegister pass to make cfg
160 FunctionPass *createDemoteRegisterToMemoryPass();
161 extern const PassInfo *const DemoteRegisterToMemoryID;
163 //===----------------------------------------------------------------------===//
165 // Reassociate - This pass reassociates commutative expressions in an order that
166 // is designed to promote better constant propagation, GCSE, LICM, PRE...
168 // For example: 4 + (x + 5) -> x + (4 + 5)
170 FunctionPass *createReassociatePass();
172 //===----------------------------------------------------------------------===//
174 // CondPropagationPass - This pass propagates information about conditional
175 // expressions through the program, allowing it to eliminate conditional
176 // branches in some cases.
178 FunctionPass *createCondPropagationPass();
180 //===----------------------------------------------------------------------===//
182 // TailDuplication - Eliminate unconditional branches through controlled code
183 // duplication, creating simpler CFG structures.
185 FunctionPass *createTailDuplicationPass();
187 //===----------------------------------------------------------------------===//
189 // JumpThreading - Thread control through mult-pred/multi-succ blocks where some
190 // preds always go to some succ.
192 FunctionPass *createJumpThreadingPass();
194 //===----------------------------------------------------------------------===//
196 // CFGSimplification - Merge basic blocks, eliminate unreachable blocks,
197 // simplify terminator instructions, etc...
199 FunctionPass *createCFGSimplificationPass();
201 //===----------------------------------------------------------------------===//
203 // BreakCriticalEdges - Break all of the critical edges in the CFG by inserting
204 // a dummy basic block. This pass may be "required" by passes that cannot deal
205 // with critical edges. For this usage, a pass must call:
207 // AU.addRequiredID(BreakCriticalEdgesID);
209 // This pass obviously invalidates the CFG, but can update forward dominator
210 // (set, immediate dominators, tree, and frontier) information.
212 FunctionPass *createBreakCriticalEdgesPass();
213 extern const PassInfo *const BreakCriticalEdgesID;
215 //===----------------------------------------------------------------------===//
217 // LoopSimplify - Insert Pre-header blocks into the CFG for every function in
218 // the module. This pass updates dominator information, loop information, and
219 // does not add critical edges to the CFG.
221 // AU.addRequiredID(LoopSimplifyID);
223 Pass *createLoopSimplifyPass();
224 extern const PassInfo *const LoopSimplifyID;
226 //===----------------------------------------------------------------------===//
228 // LowerAllocations - Turn free instructions into @free calls.
230 // AU.addRequiredID(LowerAllocationsID);
232 Pass *createLowerAllocationsPass();
233 extern const PassInfo *const LowerAllocationsID;
235 //===----------------------------------------------------------------------===//
237 // TailCallElimination - This pass eliminates call instructions to the current
238 // function which occur immediately before return instructions.
240 FunctionPass *createTailCallEliminationPass();
242 //===----------------------------------------------------------------------===//
244 // LowerSwitch - This pass converts SwitchInst instructions into a sequence of
245 // chained binary branch instructions.
247 FunctionPass *createLowerSwitchPass();
248 extern const PassInfo *const LowerSwitchID;
250 //===----------------------------------------------------------------------===//
252 // LowerInvoke - This pass converts invoke and unwind instructions to use sjlj
253 // exception handling mechanisms. Note that after this pass runs the CFG is not
254 // entirely accurate (exceptional control flow edges are not correct anymore) so
255 // only very simple things should be done after the lowerinvoke pass has run
256 // (like generation of native code). This should *NOT* be used as a general
257 // purpose "my LLVM-to-LLVM pass doesn't support the invoke instruction yet"
260 FunctionPass *createLowerInvokePass(const TargetLowering *TLI = 0);
261 extern const PassInfo *const LowerInvokePassID;
263 //===----------------------------------------------------------------------===//
265 // BlockPlacement - This pass reorders basic blocks in order to increase the
266 // number of fall-through conditional branches.
268 FunctionPass *createBlockPlacementPass();
270 //===----------------------------------------------------------------------===//
272 // LCSSA - This pass inserts phi nodes at loop boundaries to simplify other loop
275 Pass *createLCSSAPass();
276 extern const PassInfo *const LCSSAID;
278 //===----------------------------------------------------------------------===//
280 // GVN - This pass performs global value numbering and redundant load
281 // elimination cotemporaneously.
283 FunctionPass *createGVNPass();
285 //===----------------------------------------------------------------------===//
287 // MemCpyOpt - This pass performs optimizations related to eliminating memcpy
288 // calls and/or combining multiple stores into memset's.
290 FunctionPass *createMemCpyOptPass();
292 //===----------------------------------------------------------------------===//
294 // LoopDeletion - This pass performs DCE of non-infinite loops that it
295 // can prove are dead.
297 Pass *createLoopDeletionPass();
299 //===----------------------------------------------------------------------===//
301 /// createSimplifyLibCallsPass - This pass optimizes specific calls to
302 /// specific well-known (library) functions.
303 FunctionPass *createSimplifyLibCallsPass();
305 //===----------------------------------------------------------------------===//
307 /// createSimplifyHalfPowrLibCallsPass - This is an experimental pass that
308 /// optimizes specific half_pow functions.
309 FunctionPass *createSimplifyHalfPowrLibCallsPass();
311 //===----------------------------------------------------------------------===//
313 // CodeGenPrepare - This pass prepares a function for instruction selection.
315 FunctionPass *createCodeGenPreparePass(const TargetLowering *TLI = 0);
317 //===----------------------------------------------------------------------===//
319 // CodeGenLICM - This pass performs late LICM; hoisting constants out of loops.
321 Pass *createCodeGenLICMPass();
323 //===----------------------------------------------------------------------===//
325 // InstructionNamer - Give any unnamed non-void instructions "tmp" names.
327 FunctionPass *createInstructionNamerPass();
328 extern const PassInfo *const InstructionNamerID;
330 //===----------------------------------------------------------------------===//
332 // SSI - This pass converts instructions to Static Single Information form
335 FunctionPass *createSSIPass();
337 //===----------------------------------------------------------------------===//
339 // SSI - This pass converts every non-void instuction to Static Single
342 FunctionPass *createSSIEverythingPass();
344 //===----------------------------------------------------------------------===//
346 // GEPSplitter - Split complex GEPs into simple ones
348 FunctionPass *createGEPSplitterPass();
350 } // End llvm namespace