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
18 #include "llvm/ADT/StringRef.h"
24 class GetElementPtrInst;
30 //===----------------------------------------------------------------------===//
32 // ConstantPropagation - A worklist driven constant propagation pass
34 FunctionPass *createConstantPropagationPass();
36 //===----------------------------------------------------------------------===//
38 // SCCP - Sparse conditional constant propagation.
40 FunctionPass *createSCCPPass();
42 //===----------------------------------------------------------------------===//
44 // DeadInstElimination - This pass quickly removes trivially dead instructions
45 // without modifying the CFG of the function. It is a BasicBlockPass, so it
46 // runs efficiently when queued next to other BasicBlockPass's.
48 Pass *createDeadInstEliminationPass();
50 //===----------------------------------------------------------------------===//
52 // DeadCodeElimination - This pass is more powerful than DeadInstElimination,
53 // because it is worklist driven that can potentially revisit instructions when
54 // their other instructions become dead, to eliminate chains of dead
57 FunctionPass *createDeadCodeEliminationPass();
59 //===----------------------------------------------------------------------===//
61 // DeadStoreElimination - This pass deletes stores that are post-dominated by
62 // must-aliased stores and are not loaded used between the stores.
64 FunctionPass *createDeadStoreEliminationPass();
66 //===----------------------------------------------------------------------===//
68 // AggressiveDCE - This pass uses the SSA based Aggressive DCE algorithm. This
69 // algorithm assumes instructions are dead until proven otherwise, which makes
70 // it more successful are removing non-obviously dead instructions.
72 FunctionPass *createAggressiveDCEPass();
74 //===----------------------------------------------------------------------===//
76 // SROA - Replace aggregates or pieces of aggregates with scalar SSA values.
78 FunctionPass *createSROAPass(bool RequiresDomTree = true);
80 //===----------------------------------------------------------------------===//
82 // ScalarReplAggregates - Break up alloca's of aggregates into multiple allocas
85 FunctionPass *createScalarReplAggregatesPass(signed Threshold = -1,
86 bool UseDomTree = true,
87 signed StructMemberThreshold = -1,
88 signed ArrayElementThreshold = -1,
89 signed ScalarLoadThreshold = -1);
91 //===----------------------------------------------------------------------===//
93 // InductionVariableSimplify - Transform induction variables in a program to all
94 // use a single canonical induction variable per loop.
96 Pass *createIndVarSimplifyPass();
98 //===----------------------------------------------------------------------===//
100 // InstructionCombining - Combine instructions to form fewer, simple
101 // instructions. This pass does not modify the CFG, and has a tendency to make
102 // instructions dead, so a subsequent DCE pass is useful.
104 // This pass combines things like:
105 // %Y = add int 1, %X
106 // %Z = add int 1, %Y
108 // %Z = add int 2, %X
110 FunctionPass *createInstructionCombiningPass();
112 //===----------------------------------------------------------------------===//
114 // LICM - This pass is a loop invariant code motion and memory promotion pass.
116 Pass *createLICMPass();
118 //===----------------------------------------------------------------------===//
120 // LoopStrengthReduce - This pass is strength reduces GEP instructions that use
121 // a loop's canonical induction variable as one of their indices.
123 Pass *createLoopStrengthReducePass();
125 Pass *createGlobalMergePass(const TargetMachine *TM = 0);
127 //===----------------------------------------------------------------------===//
129 // LoopUnswitch - This pass is a simple loop unswitching pass.
131 Pass *createLoopUnswitchPass(bool OptimizeForSize = false);
133 //===----------------------------------------------------------------------===//
135 // LoopInstSimplify - This pass simplifies instructions in a loop's body.
137 Pass *createLoopInstSimplifyPass();
139 //===----------------------------------------------------------------------===//
141 // LoopUnroll - This pass is a simple loop unrolling pass.
143 Pass *createLoopUnrollPass(int Threshold = -1, int Count = -1,
144 int AllowPartial = -1, int Runtime = -1);
146 //===----------------------------------------------------------------------===//
148 // LoopRotate - This pass is a simple loop rotating pass.
150 Pass *createLoopRotatePass();
152 //===----------------------------------------------------------------------===//
154 // LoopIdiom - This pass recognizes and replaces idioms in loops.
156 Pass *createLoopIdiomPass();
158 //===----------------------------------------------------------------------===//
160 // PromoteMemoryToRegister - This pass is used to promote memory references to
161 // be register references. A simple example of the transformation performed by
165 // %X = alloca i32, i32 1 ret i32 42
166 // store i32 42, i32 *%X
170 FunctionPass *createPromoteMemoryToRegisterPass();
172 //===----------------------------------------------------------------------===//
174 // DemoteRegisterToMemoryPass - This pass is used to demote registers to memory
175 // references. In basically undoes the PromoteMemoryToRegister pass to make cfg
178 FunctionPass *createDemoteRegisterToMemoryPass();
179 extern char &DemoteRegisterToMemoryID;
181 //===----------------------------------------------------------------------===//
183 // Reassociate - This pass reassociates commutative expressions in an order that
184 // is designed to promote better constant propagation, GCSE, LICM, PRE...
186 // For example: 4 + (x + 5) -> x + (4 + 5)
188 FunctionPass *createReassociatePass();
190 //===----------------------------------------------------------------------===//
192 // JumpThreading - Thread control through mult-pred/multi-succ blocks where some
193 // preds always go to some succ.
195 FunctionPass *createJumpThreadingPass();
197 //===----------------------------------------------------------------------===//
199 // CFGSimplification - Merge basic blocks, eliminate unreachable blocks,
200 // simplify terminator instructions, etc...
202 FunctionPass *createCFGSimplificationPass();
204 //===----------------------------------------------------------------------===//
206 // FlattenCFG - flatten CFG, reduce number of conditional branches by using
207 // parallel-and and parallel-or mode, etc...
209 FunctionPass *createFlattenCFGPass();
211 //===----------------------------------------------------------------------===//
213 // CFG Structurization - Remove irreducible control flow
215 Pass *createStructurizeCFGPass();
217 //===----------------------------------------------------------------------===//
219 // BreakCriticalEdges - Break all of the critical edges in the CFG by inserting
220 // a dummy basic block. This pass may be "required" by passes that cannot deal
221 // with critical edges. For this usage, a pass must call:
223 // AU.addRequiredID(BreakCriticalEdgesID);
225 // This pass obviously invalidates the CFG, but can update forward dominator
226 // (set, immediate dominators, tree, and frontier) information.
228 FunctionPass *createBreakCriticalEdgesPass();
229 extern char &BreakCriticalEdgesID;
231 //===----------------------------------------------------------------------===//
233 // LoopSimplify - Insert Pre-header blocks into the CFG for every function in
234 // the module. This pass updates dominator information, loop information, and
235 // does not add critical edges to the CFG.
237 // AU.addRequiredID(LoopSimplifyID);
239 Pass *createLoopSimplifyPass();
240 extern char &LoopSimplifyID;
242 //===----------------------------------------------------------------------===//
244 // TailCallElimination - This pass eliminates call instructions to the current
245 // function which occur immediately before return instructions.
247 FunctionPass *createTailCallEliminationPass();
249 //===----------------------------------------------------------------------===//
251 // LowerSwitch - This pass converts SwitchInst instructions into a sequence of
252 // chained binary branch instructions.
254 FunctionPass *createLowerSwitchPass();
255 extern char &LowerSwitchID;
257 //===----------------------------------------------------------------------===//
259 // LowerInvoke - This pass converts invoke and unwind instructions to use sjlj
260 // exception handling mechanisms. Note that after this pass runs the CFG is not
261 // entirely accurate (exceptional control flow edges are not correct anymore) so
262 // only very simple things should be done after the lowerinvoke pass has run
263 // (like generation of native code). This should *NOT* be used as a general
264 // purpose "my LLVM-to-LLVM pass doesn't support the invoke instruction yet"
267 FunctionPass *createLowerInvokePass(const TargetMachine *TM = 0,
268 bool useExpensiveEHSupport = false);
269 extern char &LowerInvokePassID;
271 //===----------------------------------------------------------------------===//
273 // LCSSA - This pass inserts phi nodes at loop boundaries to simplify other loop
276 Pass *createLCSSAPass();
277 extern char &LCSSAID;
279 //===----------------------------------------------------------------------===//
281 // EarlyCSE - This pass performs a simple and fast CSE pass over the dominator
284 FunctionPass *createEarlyCSEPass();
286 //===----------------------------------------------------------------------===//
288 // GVN - This pass performs global value numbering and redundant load
289 // elimination cotemporaneously.
291 FunctionPass *createGVNPass(bool NoLoads = false);
293 //===----------------------------------------------------------------------===//
295 // MemCpyOpt - This pass performs optimizations related to eliminating memcpy
296 // calls and/or combining multiple stores into memset's.
298 FunctionPass *createMemCpyOptPass();
300 //===----------------------------------------------------------------------===//
302 // LoopDeletion - This pass performs DCE of non-infinite loops that it
303 // can prove are dead.
305 Pass *createLoopDeletionPass();
307 //===----------------------------------------------------------------------===//
309 // CodeGenPrepare - This pass prepares a function for instruction selection.
311 FunctionPass *createCodeGenPreparePass(const TargetMachine *TM = 0);
313 //===----------------------------------------------------------------------===//
315 // InstructionNamer - Give any unnamed non-void instructions "tmp" names.
317 FunctionPass *createInstructionNamerPass();
318 extern char &InstructionNamerID;
320 //===----------------------------------------------------------------------===//
322 // Sink - Code Sinking
324 FunctionPass *createSinkingPass();
326 //===----------------------------------------------------------------------===//
328 // LowerAtomic - Lower atomic intrinsics to non-atomic form
330 Pass *createLowerAtomicPass();
332 //===----------------------------------------------------------------------===//
334 // ValuePropagation - Propagate CFG-derived value information
336 Pass *createCorrelatedValuePropagationPass();
338 //===----------------------------------------------------------------------===//
340 // InstructionSimplifier - Remove redundant instructions.
342 FunctionPass *createInstructionSimplifierPass();
343 extern char &InstructionSimplifierID;
346 //===----------------------------------------------------------------------===//
348 // LowerExpectIntrinsics - Removes llvm.expect intrinsics and creates
349 // "block_weights" metadata.
350 FunctionPass *createLowerExpectIntrinsicPass();
353 //===----------------------------------------------------------------------===//
355 // PartiallyInlineLibCalls - Tries to inline the fast path of library
356 // calls such as sqrt.
358 FunctionPass *createPartiallyInlineLibCallsPass();
360 //===----------------------------------------------------------------------===//
362 // SampleProfilePass - Loads sample profile data from disk and generates
363 // IR metadata to reflect the profile.
364 FunctionPass *createSampleProfileLoaderPass();
365 FunctionPass *createSampleProfileLoaderPass(StringRef Name);
367 } // End llvm namespace