Scalar.h revision b0db161f5b85c4a31046d2271d9e270991b53a15
1//===-- Scalar.h - Scalar Transformations -----------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This header file defines prototypes for accessor functions that expose passes 11// in the Scalar transformations library. 12// 13//===----------------------------------------------------------------------===// 14 15#ifndef LLVM_TRANSFORMS_SCALAR_H 16#define LLVM_TRANSFORMS_SCALAR_H 17 18namespace llvm { 19 20class FunctionPass; 21class Pass; 22class GetElementPtrInst; 23class PassInfo; 24class TerminatorInst; 25class TargetLowering; 26 27//===----------------------------------------------------------------------===// 28// 29// ConstantPropagation - A worklist driven constant propagation pass 30// 31FunctionPass *createConstantPropagationPass(); 32 33//===----------------------------------------------------------------------===// 34// 35// SCCP - Sparse conditional constant propagation. 36// 37FunctionPass *createSCCPPass(); 38 39//===----------------------------------------------------------------------===// 40// 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. 44// 45Pass *createDeadInstEliminationPass(); 46 47//===----------------------------------------------------------------------===// 48// 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 52// computations. 53// 54FunctionPass *createDeadCodeEliminationPass(); 55 56//===----------------------------------------------------------------------===// 57// 58// DeadStoreElimination - This pass deletes stores that are post-dominated by 59// must-aliased stores and are not loaded used between the stores. 60// 61FunctionPass *createDeadStoreEliminationPass(); 62 63//===----------------------------------------------------------------------===// 64// 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. 68// 69FunctionPass *createAggressiveDCEPass(); 70 71//===----------------------------------------------------------------------===// 72// 73// ScalarReplAggregates - Break up alloca's of aggregates into multiple allocas 74// if possible. 75// 76FunctionPass *createScalarReplAggregatesPass(signed Threshold = -1); 77 78//===----------------------------------------------------------------------===// 79// 80// InductionVariableSimplify - Transform induction variables in a program to all 81// use a single canonical induction variable per loop. 82// 83Pass *createIndVarSimplifyPass(); 84 85//===----------------------------------------------------------------------===// 86// 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. 90// 91// This pass combines things like: 92// %Y = add int 1, %X 93// %Z = add int 1, %Y 94// into: 95// %Z = add int 2, %X 96// 97FunctionPass *createInstructionCombiningPass(); 98 99//===----------------------------------------------------------------------===// 100// 101// LICM - This pass is a loop invariant code motion and memory promotion pass. 102// 103Pass *createLICMPass(); 104 105//===----------------------------------------------------------------------===// 106// 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. 111// 112Pass *createLoopStrengthReducePass(const TargetLowering *TLI = 0); 113 114//===----------------------------------------------------------------------===// 115// 116// LoopUnswitch - This pass is a simple loop unswitching pass. 117// 118Pass *createLoopUnswitchPass(bool OptimizeForSize = false); 119 120//===----------------------------------------------------------------------===// 121// 122// LoopUnroll - This pass is a simple loop unrolling pass. 123// 124Pass *createLoopUnrollPass(); 125 126//===----------------------------------------------------------------------===// 127// 128// LoopRotate - This pass is a simple loop rotating pass. 129// 130Pass *createLoopRotatePass(); 131 132//===----------------------------------------------------------------------===// 133// 134// LoopIdiom - This pass recognizes and replaces idioms in loops. 135// 136Pass *createLoopIdiomPass(); 137 138//===----------------------------------------------------------------------===// 139// 140// PromoteMemoryToRegister - This pass is used to promote memory references to 141// be register references. A simple example of the transformation performed by 142// this pass is: 143// 144// FROM CODE TO CODE 145// %X = alloca i32, i32 1 ret i32 42 146// store i32 42, i32 *%X 147// %Y = load i32* %X 148// ret i32 %Y 149// 150FunctionPass *createPromoteMemoryToRegisterPass(); 151 152//===----------------------------------------------------------------------===// 153// 154// DemoteRegisterToMemoryPass - This pass is used to demote registers to memory 155// references. In basically undoes the PromoteMemoryToRegister pass to make cfg 156// hacking easier. 157// 158FunctionPass *createDemoteRegisterToMemoryPass(); 159extern char &DemoteRegisterToMemoryID; 160 161//===----------------------------------------------------------------------===// 162// 163// Reassociate - This pass reassociates commutative expressions in an order that 164// is designed to promote better constant propagation, GCSE, LICM, PRE... 165// 166// For example: 4 + (x + 5) -> x + (4 + 5) 167// 168FunctionPass *createReassociatePass(); 169 170//===----------------------------------------------------------------------===// 171// 172// TailDuplication - Eliminate unconditional branches through controlled code 173// duplication, creating simpler CFG structures. 174// 175FunctionPass *createTailDuplicationPass(); 176 177//===----------------------------------------------------------------------===// 178// 179// JumpThreading - Thread control through mult-pred/multi-succ blocks where some 180// preds always go to some succ. 181// 182FunctionPass *createJumpThreadingPass(); 183 184//===----------------------------------------------------------------------===// 185// 186// CFGSimplification - Merge basic blocks, eliminate unreachable blocks, 187// simplify terminator instructions, etc... 188// 189FunctionPass *createCFGSimplificationPass(); 190 191//===----------------------------------------------------------------------===// 192// 193// BreakCriticalEdges - Break all of the critical edges in the CFG by inserting 194// a dummy basic block. This pass may be "required" by passes that cannot deal 195// with critical edges. For this usage, a pass must call: 196// 197// AU.addRequiredID(BreakCriticalEdgesID); 198// 199// This pass obviously invalidates the CFG, but can update forward dominator 200// (set, immediate dominators, tree, and frontier) information. 201// 202FunctionPass *createBreakCriticalEdgesPass(); 203extern char &BreakCriticalEdgesID; 204 205//===----------------------------------------------------------------------===// 206// 207// LoopSimplify - Insert Pre-header blocks into the CFG for every function in 208// the module. This pass updates dominator information, loop information, and 209// does not add critical edges to the CFG. 210// 211// AU.addRequiredID(LoopSimplifyID); 212// 213Pass *createLoopSimplifyPass(); 214extern char &LoopSimplifyID; 215 216//===----------------------------------------------------------------------===// 217// 218// TailCallElimination - This pass eliminates call instructions to the current 219// function which occur immediately before return instructions. 220// 221FunctionPass *createTailCallEliminationPass(); 222 223//===----------------------------------------------------------------------===// 224// 225// LowerSwitch - This pass converts SwitchInst instructions into a sequence of 226// chained binary branch instructions. 227// 228FunctionPass *createLowerSwitchPass(); 229extern char &LowerSwitchID; 230 231//===----------------------------------------------------------------------===// 232// 233// LowerInvoke - This pass converts invoke and unwind instructions to use sjlj 234// exception handling mechanisms. Note that after this pass runs the CFG is not 235// entirely accurate (exceptional control flow edges are not correct anymore) so 236// only very simple things should be done after the lowerinvoke pass has run 237// (like generation of native code). This should *NOT* be used as a general 238// purpose "my LLVM-to-LLVM pass doesn't support the invoke instruction yet" 239// lowering pass. 240// 241FunctionPass *createLowerInvokePass(const TargetLowering *TLI = 0); 242FunctionPass *createLowerInvokePass(const TargetLowering *TLI, 243 bool useExpensiveEHSupport); 244extern char &LowerInvokePassID; 245 246//===----------------------------------------------------------------------===// 247// 248// BlockPlacement - This pass reorders basic blocks in order to increase the 249// number of fall-through conditional branches. 250// 251FunctionPass *createBlockPlacementPass(); 252 253//===----------------------------------------------------------------------===// 254// 255// LCSSA - This pass inserts phi nodes at loop boundaries to simplify other loop 256// optimizations. 257// 258Pass *createLCSSAPass(); 259extern char &LCSSAID; 260 261//===----------------------------------------------------------------------===// 262// 263// GVN - This pass performs global value numbering and redundant load 264// elimination cotemporaneously. 265// 266FunctionPass *createGVNPass(bool NoLoads = false); 267 268//===----------------------------------------------------------------------===// 269// 270// MemCpyOpt - This pass performs optimizations related to eliminating memcpy 271// calls and/or combining multiple stores into memset's. 272// 273FunctionPass *createMemCpyOptPass(); 274 275//===----------------------------------------------------------------------===// 276// 277// LoopDeletion - This pass performs DCE of non-infinite loops that it 278// can prove are dead. 279// 280Pass *createLoopDeletionPass(); 281 282//===----------------------------------------------------------------------===// 283// 284/// createSimplifyLibCallsPass - This pass optimizes specific calls to 285/// specific well-known (library) functions. 286FunctionPass *createSimplifyLibCallsPass(); 287 288//===----------------------------------------------------------------------===// 289// 290/// createSimplifyHalfPowrLibCallsPass - This is an experimental pass that 291/// optimizes specific half_pow functions. 292FunctionPass *createSimplifyHalfPowrLibCallsPass(); 293 294//===----------------------------------------------------------------------===// 295// 296// CodeGenPrepare - This pass prepares a function for instruction selection. 297// 298FunctionPass *createCodeGenPreparePass(const TargetLowering *TLI = 0); 299 300//===----------------------------------------------------------------------===// 301// 302// InstructionNamer - Give any unnamed non-void instructions "tmp" names. 303// 304FunctionPass *createInstructionNamerPass(); 305extern char &InstructionNamerID; 306 307//===----------------------------------------------------------------------===// 308// 309// GEPSplitter - Split complex GEPs into simple ones 310// 311FunctionPass *createGEPSplitterPass(); 312 313//===----------------------------------------------------------------------===// 314// 315// Sink - Code Sinking 316// 317FunctionPass *createSinkingPass(); 318 319//===----------------------------------------------------------------------===// 320// 321// LowerAtomic - Lower atomic intrinsics to non-atomic form 322// 323Pass *createLowerAtomicPass(); 324 325//===----------------------------------------------------------------------===// 326// 327// ValuePropagation - Propagate CFG-derived value information 328// 329Pass *createCorrelatedValuePropagationPass(); 330 331//===----------------------------------------------------------------------===// 332// 333// InstructionSimplifier - Remove redundant instructions. 334// 335FunctionPass *createInstructionSimplifierPass(); 336extern char &InstructionSimplifierID; 337 338} // End llvm namespace 339 340#endif 341