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 // SROA - Replace aggregates or pieces of aggregates with scalar SSA values.
75 FunctionPass *createSROAPass(bool RequiresDomTree = true);
77 //===----------------------------------------------------------------------===//
79 // ScalarReplAggregates - Break up alloca's of aggregates into multiple allocas
82 FunctionPass *createScalarReplAggregatesPass(signed Threshold = -1,
83 bool UseDomTree = true,
84 signed StructMemberThreshold = -1,
85 signed ArrayElementThreshold = -1,
86 signed ScalarLoadThreshold = -1);
88 //===----------------------------------------------------------------------===//
90 // InductionVariableSimplify - Transform induction variables in a program to all
91 // use a single canonical induction variable per loop.
93 Pass *createIndVarSimplifyPass();
95 //===----------------------------------------------------------------------===//
97 // InstructionCombining - Combine instructions to form fewer, simple
98 // instructions. This pass does not modify the CFG, and has a tendency to make
99 // instructions dead, so a subsequent DCE pass is useful.
101 // This pass combines things like:
102 // %Y = add int 1, %X
103 // %Z = add int 1, %Y
105 // %Z = add int 2, %X
107 FunctionPass *createInstructionCombiningPass();
109 //===----------------------------------------------------------------------===//
111 // LICM - This pass is a loop invariant code motion and memory promotion pass.
113 Pass *createLICMPass();
115 //===----------------------------------------------------------------------===//
117 // LoopStrengthReduce - This pass is strength reduces GEP instructions that use
118 // a loop's canonical induction variable as one of their indices. It takes an
119 // optional parameter used to consult the target machine whether certain
120 // transformations are profitable.
122 Pass *createLoopStrengthReducePass();
124 Pass *createGlobalMergePass(const TargetLowering *TLI = 0);
126 //===----------------------------------------------------------------------===//
128 // LoopUnswitch - This pass is a simple loop unswitching pass.
130 Pass *createLoopUnswitchPass(bool OptimizeForSize = false);
132 //===----------------------------------------------------------------------===//
134 // LoopInstSimplify - This pass simplifies instructions in a loop's body.
136 Pass *createLoopInstSimplifyPass();
138 //===----------------------------------------------------------------------===//
140 // LoopUnroll - This pass is a simple loop unrolling pass.
142 Pass *createLoopUnrollPass(int Threshold = -1, int Count = -1, int AllowPartial = -1);
144 //===----------------------------------------------------------------------===//
146 // LoopRotate - This pass is a simple loop rotating pass.
148 Pass *createLoopRotatePass();
150 //===----------------------------------------------------------------------===//
152 // LoopIdiom - This pass recognizes and replaces idioms in loops.
154 Pass *createLoopIdiomPass();
156 //===----------------------------------------------------------------------===//
158 // PromoteMemoryToRegister - This pass is used to promote memory references to
159 // be register references. A simple example of the transformation performed by
163 // %X = alloca i32, i32 1 ret i32 42
164 // store i32 42, i32 *%X
168 FunctionPass *createPromoteMemoryToRegisterPass();
170 //===----------------------------------------------------------------------===//
172 // DemoteRegisterToMemoryPass - This pass is used to demote registers to memory
173 // references. In basically undoes the PromoteMemoryToRegister pass to make cfg
176 FunctionPass *createDemoteRegisterToMemoryPass();
177 extern char &DemoteRegisterToMemoryID;
179 //===----------------------------------------------------------------------===//
181 // Reassociate - This pass reassociates commutative expressions in an order that
182 // is designed to promote better constant propagation, GCSE, LICM, PRE...
184 // For example: 4 + (x + 5) -> x + (4 + 5)
186 FunctionPass *createReassociatePass();
188 //===----------------------------------------------------------------------===//
190 // JumpThreading - Thread control through mult-pred/multi-succ blocks where some
191 // preds always go to some succ.
193 FunctionPass *createJumpThreadingPass();
195 //===----------------------------------------------------------------------===//
197 // CFGSimplification - Merge basic blocks, eliminate unreachable blocks,
198 // simplify terminator instructions, etc...
200 FunctionPass *createCFGSimplificationPass();
202 //===----------------------------------------------------------------------===//
204 // BreakCriticalEdges - Break all of the critical edges in the CFG by inserting
205 // a dummy basic block. This pass may be "required" by passes that cannot deal
206 // with critical edges. For this usage, a pass must call:
208 // AU.addRequiredID(BreakCriticalEdgesID);
210 // This pass obviously invalidates the CFG, but can update forward dominator
211 // (set, immediate dominators, tree, and frontier) information.
213 FunctionPass *createBreakCriticalEdgesPass();
214 extern char &BreakCriticalEdgesID;
216 //===----------------------------------------------------------------------===//
218 // LoopSimplify - Insert Pre-header blocks into the CFG for every function in
219 // the module. This pass updates dominator information, loop information, and
220 // does not add critical edges to the CFG.
222 // AU.addRequiredID(LoopSimplifyID);
224 Pass *createLoopSimplifyPass();
225 extern char &LoopSimplifyID;
227 //===----------------------------------------------------------------------===//
229 // TailCallElimination - This pass eliminates call instructions to the current
230 // function which occur immediately before return instructions.
232 FunctionPass *createTailCallEliminationPass();
234 //===----------------------------------------------------------------------===//
236 // LowerSwitch - This pass converts SwitchInst instructions into a sequence of
237 // chained binary branch instructions.
239 FunctionPass *createLowerSwitchPass();
240 extern char &LowerSwitchID;
242 //===----------------------------------------------------------------------===//
244 // LowerInvoke - This pass converts invoke and unwind instructions to use sjlj
245 // exception handling mechanisms. Note that after this pass runs the CFG is not
246 // entirely accurate (exceptional control flow edges are not correct anymore) so
247 // only very simple things should be done after the lowerinvoke pass has run
248 // (like generation of native code). This should *NOT* be used as a general
249 // purpose "my LLVM-to-LLVM pass doesn't support the invoke instruction yet"
252 FunctionPass *createLowerInvokePass();
253 FunctionPass *createLowerInvokePass(bool useExpensiveEHSupport);
254 extern char &LowerInvokePassID;
256 //===----------------------------------------------------------------------===//
258 // BlockPlacement - This pass reorders basic blocks in order to increase the
259 // number of fall-through conditional branches.
261 FunctionPass *createBlockPlacementPass();
263 //===----------------------------------------------------------------------===//
265 // LCSSA - This pass inserts phi nodes at loop boundaries to simplify other loop
268 Pass *createLCSSAPass();
269 extern char &LCSSAID;
271 //===----------------------------------------------------------------------===//
273 // EarlyCSE - This pass performs a simple and fast CSE pass over the dominator
276 FunctionPass *createEarlyCSEPass();
278 //===----------------------------------------------------------------------===//
280 // GVN - This pass performs global value numbering and redundant load
281 // elimination cotemporaneously.
283 FunctionPass *createGVNPass(bool NoLoads = false);
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 // CodeGenPrepare - This pass prepares a function for instruction selection.
309 FunctionPass *createCodeGenPreparePass(const TargetLowering *TLI = 0);
311 //===----------------------------------------------------------------------===//
313 // InstructionNamer - Give any unnamed non-void instructions "tmp" names.
315 FunctionPass *createInstructionNamerPass();
316 extern char &InstructionNamerID;
318 //===----------------------------------------------------------------------===//
320 // Sink - Code Sinking
322 FunctionPass *createSinkingPass();
324 //===----------------------------------------------------------------------===//
326 // LowerAtomic - Lower atomic intrinsics to non-atomic form
328 Pass *createLowerAtomicPass();
330 //===----------------------------------------------------------------------===//
332 // ValuePropagation - Propagate CFG-derived value information
334 Pass *createCorrelatedValuePropagationPass();
336 //===----------------------------------------------------------------------===//
338 // ObjCARCAPElim - ObjC ARC autorelease pool elimination.
340 Pass *createObjCARCAPElimPass();
342 //===----------------------------------------------------------------------===//
344 // ObjCARCExpand - ObjC ARC preliminary simplifications.
346 Pass *createObjCARCExpandPass();
348 //===----------------------------------------------------------------------===//
350 // ObjCARCContract - Late ObjC ARC cleanups.
352 Pass *createObjCARCContractPass();
354 //===----------------------------------------------------------------------===//
356 // ObjCARCOpt - ObjC ARC optimization.
358 Pass *createObjCARCOptPass();
360 //===----------------------------------------------------------------------===//
362 // InstructionSimplifier - Remove redundant instructions.
364 FunctionPass *createInstructionSimplifierPass();
365 extern char &InstructionSimplifierID;
368 //===----------------------------------------------------------------------===//
370 // LowerExpectIntriniscs - Removes llvm.expect intrinsics and creates
371 // "block_weights" metadata.
372 FunctionPass *createLowerExpectIntrinsicPass();
375 } // End llvm namespace