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;
28 //===----------------------------------------------------------------------===//
30 // ConstantPropagation - A worklist driven constant propagation pass
32 FunctionPass *createConstantPropagationPass();
34 //===----------------------------------------------------------------------===//
36 // SCCP - Sparse conditional constant propagation.
38 FunctionPass *createSCCPPass();
40 //===----------------------------------------------------------------------===//
42 // DeadInstElimination - This pass quickly removes trivially dead instructions
43 // without modifying the CFG of the function. It is a BasicBlockPass, so it
44 // runs efficiently when queued next to other BasicBlockPass's.
46 Pass *createDeadInstEliminationPass();
48 //===----------------------------------------------------------------------===//
50 // DeadCodeElimination - This pass is more powerful than DeadInstElimination,
51 // because it is worklist driven that can potentially revisit instructions when
52 // their other instructions become dead, to eliminate chains of dead
55 FunctionPass *createDeadCodeEliminationPass();
57 //===----------------------------------------------------------------------===//
59 // DeadStoreElimination - This pass deletes stores that are post-dominated by
60 // must-aliased stores and are not loaded used between the stores.
62 FunctionPass *createDeadStoreEliminationPass();
64 //===----------------------------------------------------------------------===//
66 // AggressiveDCE - This pass uses the SSA based Aggressive DCE algorithm. This
67 // algorithm assumes instructions are dead until proven otherwise, which makes
68 // it more successful are removing non-obviously dead instructions.
70 FunctionPass *createAggressiveDCEPass();
72 //===----------------------------------------------------------------------===//
74 // SROA - Replace aggregates or pieces of aggregates with scalar SSA values.
76 FunctionPass *createSROAPass(bool RequiresDomTree = true);
78 //===----------------------------------------------------------------------===//
80 // ScalarReplAggregates - Break up alloca's of aggregates into multiple allocas
83 FunctionPass *createScalarReplAggregatesPass(signed Threshold = -1,
84 bool UseDomTree = true,
85 signed StructMemberThreshold = -1,
86 signed ArrayElementThreshold = -1,
87 signed ScalarLoadThreshold = -1);
89 //===----------------------------------------------------------------------===//
91 // InductionVariableSimplify - Transform induction variables in a program to all
92 // use a single canonical induction variable per loop.
94 Pass *createIndVarSimplifyPass();
96 //===----------------------------------------------------------------------===//
98 // InstructionCombining - Combine instructions to form fewer, simple
99 // instructions. This pass does not modify the CFG, and has a tendency to make
100 // instructions dead, so a subsequent DCE pass is useful.
102 // This pass combines things like:
103 // %Y = add int 1, %X
104 // %Z = add int 1, %Y
106 // %Z = add int 2, %X
108 FunctionPass *createInstructionCombiningPass();
110 //===----------------------------------------------------------------------===//
112 // LICM - This pass is a loop invariant code motion and memory promotion pass.
114 Pass *createLICMPass();
116 //===----------------------------------------------------------------------===//
118 // LoopStrengthReduce - This pass is strength reduces GEP instructions that use
119 // a loop's canonical induction variable as one of their indices.
121 Pass *createLoopStrengthReducePass();
123 Pass *createGlobalMergePass(const TargetMachine *TM = 0);
125 //===----------------------------------------------------------------------===//
127 // LoopUnswitch - This pass is a simple loop unswitching pass.
129 Pass *createLoopUnswitchPass(bool OptimizeForSize = false);
131 //===----------------------------------------------------------------------===//
133 // LoopInstSimplify - This pass simplifies instructions in a loop's body.
135 Pass *createLoopInstSimplifyPass();
137 //===----------------------------------------------------------------------===//
139 // LoopUnroll - This pass is a simple loop unrolling pass.
141 Pass *createLoopUnrollPass(int Threshold = -1, int Count = -1, int AllowPartial = -1);
143 //===----------------------------------------------------------------------===//
145 // LoopRotate - This pass is a simple loop rotating pass.
147 Pass *createLoopRotatePass();
149 //===----------------------------------------------------------------------===//
151 // LoopIdiom - This pass recognizes and replaces idioms in loops.
153 Pass *createLoopIdiomPass();
155 //===----------------------------------------------------------------------===//
157 // PromoteMemoryToRegister - This pass is used to promote memory references to
158 // be register references. A simple example of the transformation performed by
162 // %X = alloca i32, i32 1 ret i32 42
163 // store i32 42, i32 *%X
167 FunctionPass *createPromoteMemoryToRegisterPass();
169 //===----------------------------------------------------------------------===//
171 // DemoteRegisterToMemoryPass - This pass is used to demote registers to memory
172 // references. In basically undoes the PromoteMemoryToRegister pass to make cfg
175 FunctionPass *createDemoteRegisterToMemoryPass();
176 extern char &DemoteRegisterToMemoryID;
178 //===----------------------------------------------------------------------===//
180 // Reassociate - This pass reassociates commutative expressions in an order that
181 // is designed to promote better constant propagation, GCSE, LICM, PRE...
183 // For example: 4 + (x + 5) -> x + (4 + 5)
185 FunctionPass *createReassociatePass();
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 // FlattenCFG - flatten CFG, reduce number of conditional branches by using
204 // parallel-and and parallel-or mode, etc...
206 FunctionPass *createFlattenCFGPass();
208 //===----------------------------------------------------------------------===//
210 // CFG Structurization - Remove irreducible control flow
212 Pass *createStructurizeCFGPass();
214 //===----------------------------------------------------------------------===//
216 // BreakCriticalEdges - Break all of the critical edges in the CFG by inserting
217 // a dummy basic block. This pass may be "required" by passes that cannot deal
218 // with critical edges. For this usage, a pass must call:
220 // AU.addRequiredID(BreakCriticalEdgesID);
222 // This pass obviously invalidates the CFG, but can update forward dominator
223 // (set, immediate dominators, tree, and frontier) information.
225 FunctionPass *createBreakCriticalEdgesPass();
226 extern char &BreakCriticalEdgesID;
228 //===----------------------------------------------------------------------===//
230 // LoopSimplify - Insert Pre-header blocks into the CFG for every function in
231 // the module. This pass updates dominator information, loop information, and
232 // does not add critical edges to the CFG.
234 // AU.addRequiredID(LoopSimplifyID);
236 Pass *createLoopSimplifyPass();
237 extern char &LoopSimplifyID;
239 //===----------------------------------------------------------------------===//
241 // TailCallElimination - This pass eliminates call instructions to the current
242 // function which occur immediately before return instructions.
244 FunctionPass *createTailCallEliminationPass();
246 //===----------------------------------------------------------------------===//
248 // LowerSwitch - This pass converts SwitchInst instructions into a sequence of
249 // chained binary branch instructions.
251 FunctionPass *createLowerSwitchPass();
252 extern char &LowerSwitchID;
254 //===----------------------------------------------------------------------===//
256 // LowerInvoke - This pass converts invoke and unwind instructions to use sjlj
257 // exception handling mechanisms. Note that after this pass runs the CFG is not
258 // entirely accurate (exceptional control flow edges are not correct anymore) so
259 // only very simple things should be done after the lowerinvoke pass has run
260 // (like generation of native code). This should *NOT* be used as a general
261 // purpose "my LLVM-to-LLVM pass doesn't support the invoke instruction yet"
264 FunctionPass *createLowerInvokePass(const TargetMachine *TM = 0,
265 bool useExpensiveEHSupport = false);
266 extern char &LowerInvokePassID;
268 //===----------------------------------------------------------------------===//
270 // BlockPlacement - This pass reorders basic blocks in order to increase the
271 // number of fall-through conditional branches.
273 FunctionPass *createBlockPlacementPass();
275 //===----------------------------------------------------------------------===//
277 // LCSSA - This pass inserts phi nodes at loop boundaries to simplify other loop
280 Pass *createLCSSAPass();
281 extern char &LCSSAID;
283 //===----------------------------------------------------------------------===//
285 // EarlyCSE - This pass performs a simple and fast CSE pass over the dominator
288 FunctionPass *createEarlyCSEPass();
290 //===----------------------------------------------------------------------===//
292 // GVN - This pass performs global value numbering and redundant load
293 // elimination cotemporaneously.
295 FunctionPass *createGVNPass(bool NoLoads = false);
297 //===----------------------------------------------------------------------===//
299 // MemCpyOpt - This pass performs optimizations related to eliminating memcpy
300 // calls and/or combining multiple stores into memset's.
302 FunctionPass *createMemCpyOptPass();
304 //===----------------------------------------------------------------------===//
306 // LoopDeletion - This pass performs DCE of non-infinite loops that it
307 // can prove are dead.
309 Pass *createLoopDeletionPass();
311 //===----------------------------------------------------------------------===//
313 // CodeGenPrepare - This pass prepares a function for instruction selection.
315 FunctionPass *createCodeGenPreparePass(const TargetMachine *TM = 0);
317 //===----------------------------------------------------------------------===//
319 // InstructionNamer - Give any unnamed non-void instructions "tmp" names.
321 FunctionPass *createInstructionNamerPass();
322 extern char &InstructionNamerID;
324 //===----------------------------------------------------------------------===//
326 // Sink - Code Sinking
328 FunctionPass *createSinkingPass();
330 //===----------------------------------------------------------------------===//
332 // LowerAtomic - Lower atomic intrinsics to non-atomic form
334 Pass *createLowerAtomicPass();
336 //===----------------------------------------------------------------------===//
338 // ValuePropagation - Propagate CFG-derived value information
340 Pass *createCorrelatedValuePropagationPass();
342 //===----------------------------------------------------------------------===//
344 // InstructionSimplifier - Remove redundant instructions.
346 FunctionPass *createInstructionSimplifierPass();
347 extern char &InstructionSimplifierID;
350 //===----------------------------------------------------------------------===//
352 // LowerExpectIntrinsics - Removes llvm.expect intrinsics and creates
353 // "block_weights" metadata.
354 FunctionPass *createLowerExpectIntrinsicPass();
357 //===----------------------------------------------------------------------===//
359 // PartiallyInlineLibCalls - Tries to inline the fast path of library
360 // calls such as sqrt.
362 FunctionPass *createPartiallyInlineLibCallsPass();
364 } // End llvm namespace