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 // TailDuplication - Eliminate unconditional branches through controlled code
175 // duplication, creating simpler CFG structures.
177 FunctionPass *createTailDuplicationPass();
179 //===----------------------------------------------------------------------===//
181 // JumpThreading - Thread control through mult-pred/multi-succ blocks where some
182 // preds always go to some succ.
184 FunctionPass *createJumpThreadingPass();
186 //===----------------------------------------------------------------------===//
188 // CFGSimplification - Merge basic blocks, eliminate unreachable blocks,
189 // simplify terminator instructions, etc...
191 FunctionPass *createCFGSimplificationPass();
193 //===----------------------------------------------------------------------===//
195 // BreakCriticalEdges - Break all of the critical edges in the CFG by inserting
196 // a dummy basic block. This pass may be "required" by passes that cannot deal
197 // with critical edges. For this usage, a pass must call:
199 // AU.addRequiredID(BreakCriticalEdgesID);
201 // This pass obviously invalidates the CFG, but can update forward dominator
202 // (set, immediate dominators, tree, and frontier) information.
204 FunctionPass *createBreakCriticalEdgesPass();
205 extern const PassInfo *const BreakCriticalEdgesID;
207 //===----------------------------------------------------------------------===//
209 // LoopSimplify - Insert Pre-header blocks into the CFG for every function in
210 // the module. This pass updates dominator information, loop information, and
211 // does not add critical edges to the CFG.
213 // AU.addRequiredID(LoopSimplifyID);
215 Pass *createLoopSimplifyPass();
216 extern const PassInfo *const LoopSimplifyID;
218 //===----------------------------------------------------------------------===//
220 // TailCallElimination - This pass eliminates call instructions to the current
221 // function which occur immediately before return instructions.
223 FunctionPass *createTailCallEliminationPass();
225 //===----------------------------------------------------------------------===//
227 // LowerSwitch - This pass converts SwitchInst instructions into a sequence of
228 // chained binary branch instructions.
230 FunctionPass *createLowerSwitchPass();
231 extern const PassInfo *const LowerSwitchID;
233 //===----------------------------------------------------------------------===//
235 // LowerInvoke - This pass converts invoke and unwind instructions to use sjlj
236 // exception handling mechanisms. Note that after this pass runs the CFG is not
237 // entirely accurate (exceptional control flow edges are not correct anymore) so
238 // only very simple things should be done after the lowerinvoke pass has run
239 // (like generation of native code). This should *NOT* be used as a general
240 // purpose "my LLVM-to-LLVM pass doesn't support the invoke instruction yet"
243 FunctionPass *createLowerInvokePass(const TargetLowering *TLI = 0);
244 extern const PassInfo *const LowerInvokePassID;
246 //===----------------------------------------------------------------------===//
248 // BlockPlacement - This pass reorders basic blocks in order to increase the
249 // number of fall-through conditional branches.
251 FunctionPass *createBlockPlacementPass();
253 //===----------------------------------------------------------------------===//
255 // LCSSA - This pass inserts phi nodes at loop boundaries to simplify other loop
258 Pass *createLCSSAPass();
259 extern const PassInfo *const LCSSAID;
261 //===----------------------------------------------------------------------===//
263 // GVN - This pass performs global value numbering and redundant load
264 // elimination cotemporaneously.
266 FunctionPass *createGVNPass(bool NoLoads = false);
268 //===----------------------------------------------------------------------===//
270 // MemCpyOpt - This pass performs optimizations related to eliminating memcpy
271 // calls and/or combining multiple stores into memset's.
273 FunctionPass *createMemCpyOptPass();
275 //===----------------------------------------------------------------------===//
277 // LoopDeletion - This pass performs DCE of non-infinite loops that it
278 // can prove are dead.
280 Pass *createLoopDeletionPass();
282 //===----------------------------------------------------------------------===//
284 /// createSimplifyLibCallsPass - This pass optimizes specific calls to
285 /// specific well-known (library) functions.
286 FunctionPass *createSimplifyLibCallsPass();
288 //===----------------------------------------------------------------------===//
290 /// createSimplifyHalfPowrLibCallsPass - This is an experimental pass that
291 /// optimizes specific half_pow functions.
292 FunctionPass *createSimplifyHalfPowrLibCallsPass();
294 //===----------------------------------------------------------------------===//
296 // CodeGenPrepare - This pass prepares a function for instruction selection.
298 FunctionPass *createCodeGenPreparePass(const TargetLowering *TLI = 0);
300 //===----------------------------------------------------------------------===//
302 // InstructionNamer - Give any unnamed non-void instructions "tmp" names.
304 FunctionPass *createInstructionNamerPass();
305 extern const PassInfo *const InstructionNamerID;
307 //===----------------------------------------------------------------------===//
309 // SSI - This pass converts instructions to Static Single Information form
312 FunctionPass *createSSIPass();
314 //===----------------------------------------------------------------------===//
316 // SSI - This pass converts every non-void instuction to Static Single
319 FunctionPass *createSSIEverythingPass();
321 //===----------------------------------------------------------------------===//
323 // GEPSplitter - Split complex GEPs into simple ones
325 FunctionPass *createGEPSplitterPass();
327 //===----------------------------------------------------------------------===//
329 // SCCVN - Aggressively eliminate redundant scalar values
331 FunctionPass *createSCCVNPass();
333 //===----------------------------------------------------------------------===//
335 // ABCD - Elimination of Array Bounds Checks on Demand
337 FunctionPass *createABCDPass();
339 } // End llvm namespace