| File: | lib/Transforms/Scalar/LoopRerollPass.cpp |
| Warning: | line 471, column 18 Called C++ object pointer is null |
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| 1 | //===- LoopReroll.cpp - Loop rerolling pass -------------------------------===// | |||
| 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 pass implements a simple loop reroller. | |||
| 11 | // | |||
| 12 | //===----------------------------------------------------------------------===// | |||
| 13 | ||||
| 14 | #include "llvm/ADT/APInt.h" | |||
| 15 | #include "llvm/ADT/BitVector.h" | |||
| 16 | #include "llvm/ADT/DenseMap.h" | |||
| 17 | #include "llvm/ADT/DenseSet.h" | |||
| 18 | #include "llvm/ADT/MapVector.h" | |||
| 19 | #include "llvm/ADT/STLExtras.h" | |||
| 20 | #include "llvm/ADT/SmallPtrSet.h" | |||
| 21 | #include "llvm/ADT/SmallVector.h" | |||
| 22 | #include "llvm/ADT/Statistic.h" | |||
| 23 | #include "llvm/Analysis/AliasAnalysis.h" | |||
| 24 | #include "llvm/Analysis/AliasSetTracker.h" | |||
| 25 | #include "llvm/Analysis/LoopInfo.h" | |||
| 26 | #include "llvm/Analysis/LoopPass.h" | |||
| 27 | #include "llvm/Analysis/ScalarEvolution.h" | |||
| 28 | #include "llvm/Analysis/ScalarEvolutionExpander.h" | |||
| 29 | #include "llvm/Analysis/ScalarEvolutionExpressions.h" | |||
| 30 | #include "llvm/Analysis/TargetLibraryInfo.h" | |||
| 31 | #include "llvm/Transforms/Utils/Local.h" | |||
| 32 | #include "llvm/Analysis/ValueTracking.h" | |||
| 33 | #include "llvm/IR/BasicBlock.h" | |||
| 34 | #include "llvm/IR/Constants.h" | |||
| 35 | #include "llvm/IR/DataLayout.h" | |||
| 36 | #include "llvm/IR/DerivedTypes.h" | |||
| 37 | #include "llvm/IR/Dominators.h" | |||
| 38 | #include "llvm/IR/IRBuilder.h" | |||
| 39 | #include "llvm/IR/InstrTypes.h" | |||
| 40 | #include "llvm/IR/Instruction.h" | |||
| 41 | #include "llvm/IR/Instructions.h" | |||
| 42 | #include "llvm/IR/IntrinsicInst.h" | |||
| 43 | #include "llvm/IR/Intrinsics.h" | |||
| 44 | #include "llvm/IR/Module.h" | |||
| 45 | #include "llvm/IR/Type.h" | |||
| 46 | #include "llvm/IR/Use.h" | |||
| 47 | #include "llvm/IR/User.h" | |||
| 48 | #include "llvm/IR/Value.h" | |||
| 49 | #include "llvm/Pass.h" | |||
| 50 | #include "llvm/Support/Casting.h" | |||
| 51 | #include "llvm/Support/CommandLine.h" | |||
| 52 | #include "llvm/Support/Debug.h" | |||
| 53 | #include "llvm/Support/raw_ostream.h" | |||
| 54 | #include "llvm/Transforms/Scalar.h" | |||
| 55 | #include "llvm/Transforms/Utils.h" | |||
| 56 | #include "llvm/Transforms/Utils/BasicBlockUtils.h" | |||
| 57 | #include "llvm/Transforms/Utils/LoopUtils.h" | |||
| 58 | #include <cassert> | |||
| 59 | #include <cstddef> | |||
| 60 | #include <cstdint> | |||
| 61 | #include <cstdlib> | |||
| 62 | #include <iterator> | |||
| 63 | #include <map> | |||
| 64 | #include <utility> | |||
| 65 | ||||
| 66 | using namespace llvm; | |||
| 67 | ||||
| 68 | #define DEBUG_TYPE"loop-reroll" "loop-reroll" | |||
| 69 | ||||
| 70 | STATISTIC(NumRerolledLoops, "Number of rerolled loops")static llvm::Statistic NumRerolledLoops = {"loop-reroll", "NumRerolledLoops" , "Number of rerolled loops", {0}, {false}}; | |||
| 71 | ||||
| 72 | static cl::opt<unsigned> | |||
| 73 | NumToleratedFailedMatches("reroll-num-tolerated-failed-matches", cl::init(400), | |||
| 74 | cl::Hidden, | |||
| 75 | cl::desc("The maximum number of failures to tolerate" | |||
| 76 | " during fuzzy matching. (default: 400)")); | |||
| 77 | ||||
| 78 | // This loop re-rolling transformation aims to transform loops like this: | |||
| 79 | // | |||
| 80 | // int foo(int a); | |||
| 81 | // void bar(int *x) { | |||
| 82 | // for (int i = 0; i < 500; i += 3) { | |||
| 83 | // foo(i); | |||
| 84 | // foo(i+1); | |||
| 85 | // foo(i+2); | |||
| 86 | // } | |||
| 87 | // } | |||
| 88 | // | |||
| 89 | // into a loop like this: | |||
| 90 | // | |||
| 91 | // void bar(int *x) { | |||
| 92 | // for (int i = 0; i < 500; ++i) | |||
| 93 | // foo(i); | |||
| 94 | // } | |||
| 95 | // | |||
| 96 | // It does this by looking for loops that, besides the latch code, are composed | |||
| 97 | // of isomorphic DAGs of instructions, with each DAG rooted at some increment | |||
| 98 | // to the induction variable, and where each DAG is isomorphic to the DAG | |||
| 99 | // rooted at the induction variable (excepting the sub-DAGs which root the | |||
| 100 | // other induction-variable increments). In other words, we're looking for loop | |||
| 101 | // bodies of the form: | |||
| 102 | // | |||
| 103 | // %iv = phi [ (preheader, ...), (body, %iv.next) ] | |||
| 104 | // f(%iv) | |||
| 105 | // %iv.1 = add %iv, 1 <-- a root increment | |||
| 106 | // f(%iv.1) | |||
| 107 | // %iv.2 = add %iv, 2 <-- a root increment | |||
| 108 | // f(%iv.2) | |||
| 109 | // %iv.scale_m_1 = add %iv, scale-1 <-- a root increment | |||
| 110 | // f(%iv.scale_m_1) | |||
| 111 | // ... | |||
| 112 | // %iv.next = add %iv, scale | |||
| 113 | // %cmp = icmp(%iv, ...) | |||
| 114 | // br %cmp, header, exit | |||
| 115 | // | |||
| 116 | // where each f(i) is a set of instructions that, collectively, are a function | |||
| 117 | // only of i (and other loop-invariant values). | |||
| 118 | // | |||
| 119 | // As a special case, we can also reroll loops like this: | |||
| 120 | // | |||
| 121 | // int foo(int); | |||
| 122 | // void bar(int *x) { | |||
| 123 | // for (int i = 0; i < 500; ++i) { | |||
| 124 | // x[3*i] = foo(0); | |||
| 125 | // x[3*i+1] = foo(0); | |||
| 126 | // x[3*i+2] = foo(0); | |||
| 127 | // } | |||
| 128 | // } | |||
| 129 | // | |||
| 130 | // into this: | |||
| 131 | // | |||
| 132 | // void bar(int *x) { | |||
| 133 | // for (int i = 0; i < 1500; ++i) | |||
| 134 | // x[i] = foo(0); | |||
| 135 | // } | |||
| 136 | // | |||
| 137 | // in which case, we're looking for inputs like this: | |||
| 138 | // | |||
| 139 | // %iv = phi [ (preheader, ...), (body, %iv.next) ] | |||
| 140 | // %scaled.iv = mul %iv, scale | |||
| 141 | // f(%scaled.iv) | |||
| 142 | // %scaled.iv.1 = add %scaled.iv, 1 | |||
| 143 | // f(%scaled.iv.1) | |||
| 144 | // %scaled.iv.2 = add %scaled.iv, 2 | |||
| 145 | // f(%scaled.iv.2) | |||
| 146 | // %scaled.iv.scale_m_1 = add %scaled.iv, scale-1 | |||
| 147 | // f(%scaled.iv.scale_m_1) | |||
| 148 | // ... | |||
| 149 | // %iv.next = add %iv, 1 | |||
| 150 | // %cmp = icmp(%iv, ...) | |||
| 151 | // br %cmp, header, exit | |||
| 152 | ||||
| 153 | namespace { | |||
| 154 | ||||
| 155 | enum IterationLimits { | |||
| 156 | /// The maximum number of iterations that we'll try and reroll. | |||
| 157 | IL_MaxRerollIterations = 32, | |||
| 158 | /// The bitvector index used by loop induction variables and other | |||
| 159 | /// instructions that belong to all iterations. | |||
| 160 | IL_All, | |||
| 161 | IL_End | |||
| 162 | }; | |||
| 163 | ||||
| 164 | class LoopReroll : public LoopPass { | |||
| 165 | public: | |||
| 166 | static char ID; // Pass ID, replacement for typeid | |||
| 167 | ||||
| 168 | LoopReroll() : LoopPass(ID) { | |||
| 169 | initializeLoopRerollPass(*PassRegistry::getPassRegistry()); | |||
| 170 | } | |||
| 171 | ||||
| 172 | bool runOnLoop(Loop *L, LPPassManager &LPM) override; | |||
| 173 | ||||
| 174 | void getAnalysisUsage(AnalysisUsage &AU) const override { | |||
| 175 | AU.addRequired<TargetLibraryInfoWrapperPass>(); | |||
| 176 | getLoopAnalysisUsage(AU); | |||
| 177 | } | |||
| 178 | ||||
| 179 | protected: | |||
| 180 | AliasAnalysis *AA; | |||
| 181 | LoopInfo *LI; | |||
| 182 | ScalarEvolution *SE; | |||
| 183 | TargetLibraryInfo *TLI; | |||
| 184 | DominatorTree *DT; | |||
| 185 | bool PreserveLCSSA; | |||
| 186 | ||||
| 187 | using SmallInstructionVector = SmallVector<Instruction *, 16>; | |||
| 188 | using SmallInstructionSet = SmallPtrSet<Instruction *, 16>; | |||
| 189 | ||||
| 190 | // Map between induction variable and its increment | |||
| 191 | DenseMap<Instruction *, int64_t> IVToIncMap; | |||
| 192 | ||||
| 193 | // For loop with multiple induction variable, remember the one used only to | |||
| 194 | // control the loop. | |||
| 195 | Instruction *LoopControlIV; | |||
| 196 | ||||
| 197 | // A chain of isomorphic instructions, identified by a single-use PHI | |||
| 198 | // representing a reduction. Only the last value may be used outside the | |||
| 199 | // loop. | |||
| 200 | struct SimpleLoopReduction { | |||
| 201 | SimpleLoopReduction(Instruction *P, Loop *L) : Instructions(1, P) { | |||
| 202 | assert(isa<PHINode>(P) && "First reduction instruction must be a PHI")(static_cast <bool> (isa<PHINode>(P) && "First reduction instruction must be a PHI" ) ? void (0) : __assert_fail ("isa<PHINode>(P) && \"First reduction instruction must be a PHI\"" , "/build/llvm-toolchain-snapshot-7~svn338205/lib/Transforms/Scalar/LoopRerollPass.cpp" , 202, __extension__ __PRETTY_FUNCTION__)); | |||
| 203 | add(L); | |||
| 204 | } | |||
| 205 | ||||
| 206 | bool valid() const { | |||
| 207 | return Valid; | |||
| 208 | } | |||
| 209 | ||||
| 210 | Instruction *getPHI() const { | |||
| 211 | assert(Valid && "Using invalid reduction")(static_cast <bool> (Valid && "Using invalid reduction" ) ? void (0) : __assert_fail ("Valid && \"Using invalid reduction\"" , "/build/llvm-toolchain-snapshot-7~svn338205/lib/Transforms/Scalar/LoopRerollPass.cpp" , 211, __extension__ __PRETTY_FUNCTION__)); | |||
| 212 | return Instructions.front(); | |||
| 213 | } | |||
| 214 | ||||
| 215 | Instruction *getReducedValue() const { | |||
| 216 | assert(Valid && "Using invalid reduction")(static_cast <bool> (Valid && "Using invalid reduction" ) ? void (0) : __assert_fail ("Valid && \"Using invalid reduction\"" , "/build/llvm-toolchain-snapshot-7~svn338205/lib/Transforms/Scalar/LoopRerollPass.cpp" , 216, __extension__ __PRETTY_FUNCTION__)); | |||
| 217 | return Instructions.back(); | |||
| 218 | } | |||
| 219 | ||||
| 220 | Instruction *get(size_t i) const { | |||
| 221 | assert(Valid && "Using invalid reduction")(static_cast <bool> (Valid && "Using invalid reduction" ) ? void (0) : __assert_fail ("Valid && \"Using invalid reduction\"" , "/build/llvm-toolchain-snapshot-7~svn338205/lib/Transforms/Scalar/LoopRerollPass.cpp" , 221, __extension__ __PRETTY_FUNCTION__)); | |||
| 222 | return Instructions[i+1]; | |||
| 223 | } | |||
| 224 | ||||
| 225 | Instruction *operator [] (size_t i) const { return get(i); } | |||
| 226 | ||||
| 227 | // The size, ignoring the initial PHI. | |||
| 228 | size_t size() const { | |||
| 229 | assert(Valid && "Using invalid reduction")(static_cast <bool> (Valid && "Using invalid reduction" ) ? void (0) : __assert_fail ("Valid && \"Using invalid reduction\"" , "/build/llvm-toolchain-snapshot-7~svn338205/lib/Transforms/Scalar/LoopRerollPass.cpp" , 229, __extension__ __PRETTY_FUNCTION__)); | |||
| 230 | return Instructions.size()-1; | |||
| 231 | } | |||
| 232 | ||||
| 233 | using iterator = SmallInstructionVector::iterator; | |||
| 234 | using const_iterator = SmallInstructionVector::const_iterator; | |||
| 235 | ||||
| 236 | iterator begin() { | |||
| 237 | assert(Valid && "Using invalid reduction")(static_cast <bool> (Valid && "Using invalid reduction" ) ? void (0) : __assert_fail ("Valid && \"Using invalid reduction\"" , "/build/llvm-toolchain-snapshot-7~svn338205/lib/Transforms/Scalar/LoopRerollPass.cpp" , 237, __extension__ __PRETTY_FUNCTION__)); | |||
| 238 | return std::next(Instructions.begin()); | |||
| 239 | } | |||
| 240 | ||||
| 241 | const_iterator begin() const { | |||
| 242 | assert(Valid && "Using invalid reduction")(static_cast <bool> (Valid && "Using invalid reduction" ) ? void (0) : __assert_fail ("Valid && \"Using invalid reduction\"" , "/build/llvm-toolchain-snapshot-7~svn338205/lib/Transforms/Scalar/LoopRerollPass.cpp" , 242, __extension__ __PRETTY_FUNCTION__)); | |||
| 243 | return std::next(Instructions.begin()); | |||
| 244 | } | |||
| 245 | ||||
| 246 | iterator end() { return Instructions.end(); } | |||
| 247 | const_iterator end() const { return Instructions.end(); } | |||
| 248 | ||||
| 249 | protected: | |||
| 250 | bool Valid = false; | |||
| 251 | SmallInstructionVector Instructions; | |||
| 252 | ||||
| 253 | void add(Loop *L); | |||
| 254 | }; | |||
| 255 | ||||
| 256 | // The set of all reductions, and state tracking of possible reductions | |||
| 257 | // during loop instruction processing. | |||
| 258 | struct ReductionTracker { | |||
| 259 | using SmallReductionVector = SmallVector<SimpleLoopReduction, 16>; | |||
| 260 | ||||
| 261 | // Add a new possible reduction. | |||
| 262 | void addSLR(SimpleLoopReduction &SLR) { PossibleReds.push_back(SLR); } | |||
| 263 | ||||
| 264 | // Setup to track possible reductions corresponding to the provided | |||
| 265 | // rerolling scale. Only reductions with a number of non-PHI instructions | |||
| 266 | // that is divisible by the scale are considered. Three instructions sets | |||
| 267 | // are filled in: | |||
| 268 | // - A set of all possible instructions in eligible reductions. | |||
| 269 | // - A set of all PHIs in eligible reductions | |||
| 270 | // - A set of all reduced values (last instructions) in eligible | |||
| 271 | // reductions. | |||
| 272 | void restrictToScale(uint64_t Scale, | |||
| 273 | SmallInstructionSet &PossibleRedSet, | |||
| 274 | SmallInstructionSet &PossibleRedPHISet, | |||
| 275 | SmallInstructionSet &PossibleRedLastSet) { | |||
| 276 | PossibleRedIdx.clear(); | |||
| 277 | PossibleRedIter.clear(); | |||
| 278 | Reds.clear(); | |||
| 279 | ||||
| 280 | for (unsigned i = 0, e = PossibleReds.size(); i != e; ++i) | |||
| 281 | if (PossibleReds[i].size() % Scale == 0) { | |||
| 282 | PossibleRedLastSet.insert(PossibleReds[i].getReducedValue()); | |||
| 283 | PossibleRedPHISet.insert(PossibleReds[i].getPHI()); | |||
| 284 | ||||
| 285 | PossibleRedSet.insert(PossibleReds[i].getPHI()); | |||
| 286 | PossibleRedIdx[PossibleReds[i].getPHI()] = i; | |||
| 287 | for (Instruction *J : PossibleReds[i]) { | |||
| 288 | PossibleRedSet.insert(J); | |||
| 289 | PossibleRedIdx[J] = i; | |||
| 290 | } | |||
| 291 | } | |||
| 292 | } | |||
| 293 | ||||
| 294 | // The functions below are used while processing the loop instructions. | |||
| 295 | ||||
| 296 | // Are the two instructions both from reductions, and furthermore, from | |||
| 297 | // the same reduction? | |||
| 298 | bool isPairInSame(Instruction *J1, Instruction *J2) { | |||
| 299 | DenseMap<Instruction *, int>::iterator J1I = PossibleRedIdx.find(J1); | |||
| 300 | if (J1I != PossibleRedIdx.end()) { | |||
| 301 | DenseMap<Instruction *, int>::iterator J2I = PossibleRedIdx.find(J2); | |||
| 302 | if (J2I != PossibleRedIdx.end() && J1I->second == J2I->second) | |||
| 303 | return true; | |||
| 304 | } | |||
| 305 | ||||
| 306 | return false; | |||
| 307 | } | |||
| 308 | ||||
| 309 | // The two provided instructions, the first from the base iteration, and | |||
| 310 | // the second from iteration i, form a matched pair. If these are part of | |||
| 311 | // a reduction, record that fact. | |||
| 312 | void recordPair(Instruction *J1, Instruction *J2, unsigned i) { | |||
| 313 | if (PossibleRedIdx.count(J1)) { | |||
| 314 | assert(PossibleRedIdx.count(J2) &&(static_cast <bool> (PossibleRedIdx.count(J2) && "Recording reduction vs. non-reduction instruction?") ? void (0) : __assert_fail ("PossibleRedIdx.count(J2) && \"Recording reduction vs. non-reduction instruction?\"" , "/build/llvm-toolchain-snapshot-7~svn338205/lib/Transforms/Scalar/LoopRerollPass.cpp" , 315, __extension__ __PRETTY_FUNCTION__)) | |||
| 315 | "Recording reduction vs. non-reduction instruction?")(static_cast <bool> (PossibleRedIdx.count(J2) && "Recording reduction vs. non-reduction instruction?") ? void (0) : __assert_fail ("PossibleRedIdx.count(J2) && \"Recording reduction vs. non-reduction instruction?\"" , "/build/llvm-toolchain-snapshot-7~svn338205/lib/Transforms/Scalar/LoopRerollPass.cpp" , 315, __extension__ __PRETTY_FUNCTION__)); | |||
| 316 | ||||
| 317 | PossibleRedIter[J1] = 0; | |||
| 318 | PossibleRedIter[J2] = i; | |||
| 319 | ||||
| 320 | int Idx = PossibleRedIdx[J1]; | |||
| 321 | assert(Idx == PossibleRedIdx[J2] &&(static_cast <bool> (Idx == PossibleRedIdx[J2] && "Recording pair from different reductions?") ? void (0) : __assert_fail ("Idx == PossibleRedIdx[J2] && \"Recording pair from different reductions?\"" , "/build/llvm-toolchain-snapshot-7~svn338205/lib/Transforms/Scalar/LoopRerollPass.cpp" , 322, __extension__ __PRETTY_FUNCTION__)) | |||
| 322 | "Recording pair from different reductions?")(static_cast <bool> (Idx == PossibleRedIdx[J2] && "Recording pair from different reductions?") ? void (0) : __assert_fail ("Idx == PossibleRedIdx[J2] && \"Recording pair from different reductions?\"" , "/build/llvm-toolchain-snapshot-7~svn338205/lib/Transforms/Scalar/LoopRerollPass.cpp" , 322, __extension__ __PRETTY_FUNCTION__)); | |||
| 323 | Reds.insert(Idx); | |||
| 324 | } | |||
| 325 | } | |||
| 326 | ||||
| 327 | // The functions below can be called after we've finished processing all | |||
| 328 | // instructions in the loop, and we know which reductions were selected. | |||
| 329 | ||||
| 330 | bool validateSelected(); | |||
| 331 | void replaceSelected(); | |||
| 332 | ||||
| 333 | protected: | |||
| 334 | // The vector of all possible reductions (for any scale). | |||
| 335 | SmallReductionVector PossibleReds; | |||
| 336 | ||||
| 337 | DenseMap<Instruction *, int> PossibleRedIdx; | |||
| 338 | DenseMap<Instruction *, int> PossibleRedIter; | |||
| 339 | DenseSet<int> Reds; | |||
| 340 | }; | |||
| 341 | ||||
| 342 | // A DAGRootSet models an induction variable being used in a rerollable | |||
| 343 | // loop. For example, | |||
| 344 | // | |||
| 345 | // x[i*3+0] = y1 | |||
| 346 | // x[i*3+1] = y2 | |||
| 347 | // x[i*3+2] = y3 | |||
| 348 | // | |||
| 349 | // Base instruction -> i*3 | |||
| 350 | // +---+----+ | |||
| 351 | // / | \ | |||
| 352 | // ST[y1] +1 +2 <-- Roots | |||
| 353 | // | | | |||
| 354 | // ST[y2] ST[y3] | |||
| 355 | // | |||
| 356 | // There may be multiple DAGRoots, for example: | |||
| 357 | // | |||
| 358 | // x[i*2+0] = ... (1) | |||
| 359 | // x[i*2+1] = ... (1) | |||
| 360 | // x[i*2+4] = ... (2) | |||
| 361 | // x[i*2+5] = ... (2) | |||
| 362 | // x[(i+1234)*2+5678] = ... (3) | |||
| 363 | // x[(i+1234)*2+5679] = ... (3) | |||
| 364 | // | |||
| 365 | // The loop will be rerolled by adding a new loop induction variable, | |||
| 366 | // one for the Base instruction in each DAGRootSet. | |||
| 367 | // | |||
| 368 | struct DAGRootSet { | |||
| 369 | Instruction *BaseInst; | |||
| 370 | SmallInstructionVector Roots; | |||
| 371 | ||||
| 372 | // The instructions between IV and BaseInst (but not including BaseInst). | |||
| 373 | SmallInstructionSet SubsumedInsts; | |||
| 374 | }; | |||
| 375 | ||||
| 376 | // The set of all DAG roots, and state tracking of all roots | |||
| 377 | // for a particular induction variable. | |||
| 378 | struct DAGRootTracker { | |||
| 379 | DAGRootTracker(LoopReroll *Parent, Loop *L, Instruction *IV, | |||
| 380 | ScalarEvolution *SE, AliasAnalysis *AA, | |||
| 381 | TargetLibraryInfo *TLI, DominatorTree *DT, LoopInfo *LI, | |||
| 382 | bool PreserveLCSSA, | |||
| 383 | DenseMap<Instruction *, int64_t> &IncrMap, | |||
| 384 | Instruction *LoopCtrlIV) | |||
| 385 | : Parent(Parent), L(L), SE(SE), AA(AA), TLI(TLI), DT(DT), LI(LI), | |||
| 386 | PreserveLCSSA(PreserveLCSSA), IV(IV), IVToIncMap(IncrMap), | |||
| 387 | LoopControlIV(LoopCtrlIV) {} | |||
| 388 | ||||
| 389 | /// Stage 1: Find all the DAG roots for the induction variable. | |||
| 390 | bool findRoots(); | |||
| 391 | ||||
| 392 | /// Stage 2: Validate if the found roots are valid. | |||
| 393 | bool validate(ReductionTracker &Reductions); | |||
| 394 | ||||
| 395 | /// Stage 3: Assuming validate() returned true, perform the | |||
| 396 | /// replacement. | |||
| 397 | /// @param BackedgeTakenCount The backedge-taken count of L. | |||
| 398 | void replace(const SCEV *BackedgeTakenCount); | |||
| 399 | ||||
| 400 | protected: | |||
| 401 | using UsesTy = MapVector<Instruction *, BitVector>; | |||
| 402 | ||||
| 403 | void findRootsRecursive(Instruction *IVU, | |||
| 404 | SmallInstructionSet SubsumedInsts); | |||
| 405 | bool findRootsBase(Instruction *IVU, SmallInstructionSet SubsumedInsts); | |||
| 406 | bool collectPossibleRoots(Instruction *Base, | |||
| 407 | std::map<int64_t,Instruction*> &Roots); | |||
| 408 | bool validateRootSet(DAGRootSet &DRS); | |||
| 409 | ||||
| 410 | bool collectUsedInstructions(SmallInstructionSet &PossibleRedSet); | |||
| 411 | void collectInLoopUserSet(const SmallInstructionVector &Roots, | |||
| 412 | const SmallInstructionSet &Exclude, | |||
| 413 | const SmallInstructionSet &Final, | |||
| 414 | DenseSet<Instruction *> &Users); | |||
| 415 | void collectInLoopUserSet(Instruction *Root, | |||
| 416 | const SmallInstructionSet &Exclude, | |||
| 417 | const SmallInstructionSet &Final, | |||
| 418 | DenseSet<Instruction *> &Users); | |||
| 419 | ||||
| 420 | UsesTy::iterator nextInstr(int Val, UsesTy &In, | |||
| 421 | const SmallInstructionSet &Exclude, | |||
| 422 | UsesTy::iterator *StartI=nullptr); | |||
| 423 | bool isBaseInst(Instruction *I); | |||
| 424 | bool isRootInst(Instruction *I); | |||
| 425 | bool instrDependsOn(Instruction *I, | |||
| 426 | UsesTy::iterator Start, | |||
| 427 | UsesTy::iterator End); | |||
| 428 | void replaceIV(DAGRootSet &DRS, const SCEV *Start, const SCEV *IncrExpr); | |||
| 429 | ||||
| 430 | LoopReroll *Parent; | |||
| 431 | ||||
| 432 | // Members of Parent, replicated here for brevity. | |||
| 433 | Loop *L; | |||
| 434 | ScalarEvolution *SE; | |||
| 435 | AliasAnalysis *AA; | |||
| 436 | TargetLibraryInfo *TLI; | |||
| 437 | DominatorTree *DT; | |||
| 438 | LoopInfo *LI; | |||
| 439 | bool PreserveLCSSA; | |||
| 440 | ||||
| 441 | // The loop induction variable. | |||
| 442 | Instruction *IV; | |||
| 443 | ||||
| 444 | // Loop step amount. | |||
| 445 | int64_t Inc; | |||
| 446 | ||||
| 447 | // Loop reroll count; if Inc == 1, this records the scaling applied | |||
| 448 | // to the indvar: a[i*2+0] = ...; a[i*2+1] = ... ; | |||
| 449 | // If Inc is not 1, Scale = Inc. | |||
| 450 | uint64_t Scale; | |||
| 451 | ||||
| 452 | // The roots themselves. | |||
| 453 | SmallVector<DAGRootSet,16> RootSets; | |||
| 454 | ||||
| 455 | // All increment instructions for IV. | |||
| 456 | SmallInstructionVector LoopIncs; | |||
| 457 | ||||
| 458 | // Map of all instructions in the loop (in order) to the iterations | |||
| 459 | // they are used in (or specially, IL_All for instructions | |||
| 460 | // used in the loop increment mechanism). | |||
| 461 | UsesTy Uses; | |||
| 462 | ||||
| 463 | // Map between induction variable and its increment | |||
| 464 | DenseMap<Instruction *, int64_t> &IVToIncMap; | |||
| 465 | ||||
| 466 | Instruction *LoopControlIV; | |||
| 467 | }; | |||
| 468 | ||||
| 469 | // Check if it is a compare-like instruction whose user is a branch | |||
| 470 | bool isCompareUsedByBranch(Instruction *I) { | |||
| 471 | auto *TI = I->getParent()->getTerminator(); | |||
| ||||
| 472 | if (!isa<BranchInst>(TI) || !isa<CmpInst>(I)) | |||
| 473 | return false; | |||
| 474 | return I->hasOneUse() && TI->getOperand(0) == I; | |||
| 475 | }; | |||
| 476 | ||||
| 477 | bool isLoopControlIV(Loop *L, Instruction *IV); | |||
| 478 | void collectPossibleIVs(Loop *L, SmallInstructionVector &PossibleIVs); | |||
| 479 | void collectPossibleReductions(Loop *L, | |||
| 480 | ReductionTracker &Reductions); | |||
| 481 | bool reroll(Instruction *IV, Loop *L, BasicBlock *Header, | |||
| 482 | const SCEV *BackedgeTakenCount, ReductionTracker &Reductions); | |||
| 483 | }; | |||
| 484 | ||||
| 485 | } // end anonymous namespace | |||
| 486 | ||||
| 487 | char LoopReroll::ID = 0; | |||
| 488 | ||||
| 489 | INITIALIZE_PASS_BEGIN(LoopReroll, "loop-reroll", "Reroll loops", false, false)static void *initializeLoopRerollPassOnce(PassRegistry &Registry ) { | |||
| 490 | INITIALIZE_PASS_DEPENDENCY(LoopPass)initializeLoopPassPass(Registry); | |||
| 491 | INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)initializeTargetLibraryInfoWrapperPassPass(Registry); | |||
| 492 | INITIALIZE_PASS_END(LoopReroll, "loop-reroll", "Reroll loops", false, false)PassInfo *PI = new PassInfo( "Reroll loops", "loop-reroll", & LoopReroll::ID, PassInfo::NormalCtor_t(callDefaultCtor<LoopReroll >), false, false); Registry.registerPass(*PI, true); return PI; } static llvm::once_flag InitializeLoopRerollPassFlag; void llvm::initializeLoopRerollPass(PassRegistry &Registry) { llvm::call_once(InitializeLoopRerollPassFlag, initializeLoopRerollPassOnce , std::ref(Registry)); } | |||
| 493 | ||||
| 494 | Pass *llvm::createLoopRerollPass() { | |||
| 495 | return new LoopReroll; | |||
| 496 | } | |||
| 497 | ||||
| 498 | // Returns true if the provided instruction is used outside the given loop. | |||
| 499 | // This operates like Instruction::isUsedOutsideOfBlock, but considers PHIs in | |||
| 500 | // non-loop blocks to be outside the loop. | |||
| 501 | static bool hasUsesOutsideLoop(Instruction *I, Loop *L) { | |||
| 502 | for (User *U : I->users()) { | |||
| 503 | if (!L->contains(cast<Instruction>(U))) | |||
| 504 | return true; | |||
| 505 | } | |||
| 506 | return false; | |||
| 507 | } | |||
| 508 | ||||
| 509 | // Check if an IV is only used to control the loop. There are two cases: | |||
| 510 | // 1. It only has one use which is loop increment, and the increment is only | |||
| 511 | // used by comparison and the PHI (could has sext with nsw in between), and the | |||
| 512 | // comparison is only used by branch. | |||
| 513 | // 2. It is used by loop increment and the comparison, the loop increment is | |||
| 514 | // only used by the PHI, and the comparison is used only by the branch. | |||
| 515 | bool LoopReroll::isLoopControlIV(Loop *L, Instruction *IV) { | |||
| 516 | unsigned IVUses = IV->getNumUses(); | |||
| 517 | if (IVUses != 2 && IVUses != 1) | |||
| 518 | return false; | |||
| 519 | ||||
| 520 | for (auto *User : IV->users()) { | |||
| 521 | int32_t IncOrCmpUses = User->getNumUses(); | |||
| 522 | bool IsCompInst = isCompareUsedByBranch(cast<Instruction>(User)); | |||
| 523 | ||||
| 524 | // User can only have one or two uses. | |||
| 525 | if (IncOrCmpUses != 2 && IncOrCmpUses != 1) | |||
| 526 | return false; | |||
| 527 | ||||
| 528 | // Case 1 | |||
| 529 | if (IVUses == 1) { | |||
| 530 | // The only user must be the loop increment. | |||
| 531 | // The loop increment must have two uses. | |||
| 532 | if (IsCompInst || IncOrCmpUses != 2) | |||
| 533 | return false; | |||
| 534 | } | |||
| 535 | ||||
| 536 | // Case 2 | |||
| 537 | if (IVUses == 2 && IncOrCmpUses != 1) | |||
| 538 | return false; | |||
| 539 | ||||
| 540 | // The users of the IV must be a binary operation or a comparison | |||
| 541 | if (auto *BO = dyn_cast<BinaryOperator>(User)) { | |||
| 542 | if (BO->getOpcode() == Instruction::Add) { | |||
| 543 | // Loop Increment | |||
| 544 | // User of Loop Increment should be either PHI or CMP | |||
| 545 | for (auto *UU : User->users()) { | |||
| 546 | if (PHINode *PN = dyn_cast<PHINode>(UU)) { | |||
| 547 | if (PN != IV) | |||
| 548 | return false; | |||
| 549 | } | |||
| 550 | // Must be a CMP or an ext (of a value with nsw) then CMP | |||
| 551 | else { | |||
| 552 | Instruction *UUser = dyn_cast<Instruction>(UU); | |||
| 553 | // Skip SExt if we are extending an nsw value | |||
| 554 | // TODO: Allow ZExt too | |||
| 555 | if (BO->hasNoSignedWrap() && UUser && UUser->hasOneUse() && | |||
| 556 | isa<SExtInst>(UUser)) | |||
| 557 | UUser = dyn_cast<Instruction>(*(UUser->user_begin())); | |||
| 558 | if (!isCompareUsedByBranch(UUser)) | |||
| 559 | return false; | |||
| 560 | } | |||
| 561 | } | |||
| 562 | } else | |||
| 563 | return false; | |||
| 564 | // Compare : can only have one use, and must be branch | |||
| 565 | } else if (!IsCompInst) | |||
| 566 | return false; | |||
| 567 | } | |||
| 568 | return true; | |||
| 569 | } | |||
| 570 | ||||
| 571 | // Collect the list of loop induction variables with respect to which it might | |||
| 572 | // be possible to reroll the loop. | |||
| 573 | void LoopReroll::collectPossibleIVs(Loop *L, | |||
| 574 | SmallInstructionVector &PossibleIVs) { | |||
| 575 | BasicBlock *Header = L->getHeader(); | |||
| 576 | for (BasicBlock::iterator I = Header->begin(), | |||
| 577 | IE = Header->getFirstInsertionPt(); I != IE; ++I) { | |||
| 578 | if (!isa<PHINode>(I)) | |||
| 579 | continue; | |||
| 580 | if (!I->getType()->isIntegerTy() && !I->getType()->isPointerTy()) | |||
| 581 | continue; | |||
| 582 | ||||
| 583 | if (const SCEVAddRecExpr *PHISCEV = | |||
| 584 | dyn_cast<SCEVAddRecExpr>(SE->getSCEV(&*I))) { | |||
| 585 | if (PHISCEV->getLoop() != L) | |||
| 586 | continue; | |||
| 587 | if (!PHISCEV->isAffine()) | |||
| 588 | continue; | |||
| 589 | auto IncSCEV = dyn_cast<SCEVConstant>(PHISCEV->getStepRecurrence(*SE)); | |||
| 590 | if (IncSCEV) { | |||
| 591 | IVToIncMap[&*I] = IncSCEV->getValue()->getSExtValue(); | |||
| 592 | LLVM_DEBUG(dbgs() << "LRR: Possible IV: " << *I << " = " << *PHISCEVdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Possible IV: " << *I << " = " << *PHISCEV << "\n"; } } while (false) | |||
| 593 | << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Possible IV: " << *I << " = " << *PHISCEV << "\n"; } } while (false); | |||
| 594 | ||||
| 595 | if (isLoopControlIV(L, &*I)) { | |||
| 596 | assert(!LoopControlIV && "Found two loop control only IV")(static_cast <bool> (!LoopControlIV && "Found two loop control only IV" ) ? void (0) : __assert_fail ("!LoopControlIV && \"Found two loop control only IV\"" , "/build/llvm-toolchain-snapshot-7~svn338205/lib/Transforms/Scalar/LoopRerollPass.cpp" , 596, __extension__ __PRETTY_FUNCTION__)); | |||
| 597 | LoopControlIV = &(*I); | |||
| 598 | LLVM_DEBUG(dbgs() << "LRR: Possible loop control only IV: " << *Ido { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Possible loop control only IV: " << *I << " = " << *PHISCEV << "\n"; } } while (false) | |||
| 599 | << " = " << *PHISCEV << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Possible loop control only IV: " << *I << " = " << *PHISCEV << "\n"; } } while (false); | |||
| 600 | } else | |||
| 601 | PossibleIVs.push_back(&*I); | |||
| 602 | } | |||
| 603 | } | |||
| 604 | } | |||
| 605 | } | |||
| 606 | ||||
| 607 | // Add the remainder of the reduction-variable chain to the instruction vector | |||
| 608 | // (the initial PHINode has already been added). If successful, the object is | |||
| 609 | // marked as valid. | |||
| 610 | void LoopReroll::SimpleLoopReduction::add(Loop *L) { | |||
| 611 | assert(!Valid && "Cannot add to an already-valid chain")(static_cast <bool> (!Valid && "Cannot add to an already-valid chain" ) ? void (0) : __assert_fail ("!Valid && \"Cannot add to an already-valid chain\"" , "/build/llvm-toolchain-snapshot-7~svn338205/lib/Transforms/Scalar/LoopRerollPass.cpp" , 611, __extension__ __PRETTY_FUNCTION__)); | |||
| 612 | ||||
| 613 | // The reduction variable must be a chain of single-use instructions | |||
| 614 | // (including the PHI), except for the last value (which is used by the PHI | |||
| 615 | // and also outside the loop). | |||
| 616 | Instruction *C = Instructions.front(); | |||
| 617 | if (C->user_empty()) | |||
| 618 | return; | |||
| 619 | ||||
| 620 | do { | |||
| 621 | C = cast<Instruction>(*C->user_begin()); | |||
| 622 | if (C->hasOneUse()) { | |||
| 623 | if (!C->isBinaryOp()) | |||
| 624 | return; | |||
| 625 | ||||
| 626 | if (!(isa<PHINode>(Instructions.back()) || | |||
| 627 | C->isSameOperationAs(Instructions.back()))) | |||
| 628 | return; | |||
| 629 | ||||
| 630 | Instructions.push_back(C); | |||
| 631 | } | |||
| 632 | } while (C->hasOneUse()); | |||
| 633 | ||||
| 634 | if (Instructions.size() < 2 || | |||
| 635 | !C->isSameOperationAs(Instructions.back()) || | |||
| 636 | C->use_empty()) | |||
| 637 | return; | |||
| 638 | ||||
| 639 | // C is now the (potential) last instruction in the reduction chain. | |||
| 640 | for (User *U : C->users()) { | |||
| 641 | // The only in-loop user can be the initial PHI. | |||
| 642 | if (L->contains(cast<Instruction>(U))) | |||
| 643 | if (cast<Instruction>(U) != Instructions.front()) | |||
| 644 | return; | |||
| 645 | } | |||
| 646 | ||||
| 647 | Instructions.push_back(C); | |||
| 648 | Valid = true; | |||
| 649 | } | |||
| 650 | ||||
| 651 | // Collect the vector of possible reduction variables. | |||
| 652 | void LoopReroll::collectPossibleReductions(Loop *L, | |||
| 653 | ReductionTracker &Reductions) { | |||
| 654 | BasicBlock *Header = L->getHeader(); | |||
| 655 | for (BasicBlock::iterator I = Header->begin(), | |||
| 656 | IE = Header->getFirstInsertionPt(); I != IE; ++I) { | |||
| 657 | if (!isa<PHINode>(I)) | |||
| 658 | continue; | |||
| 659 | if (!I->getType()->isSingleValueType()) | |||
| 660 | continue; | |||
| 661 | ||||
| 662 | SimpleLoopReduction SLR(&*I, L); | |||
| 663 | if (!SLR.valid()) | |||
| 664 | continue; | |||
| 665 | ||||
| 666 | LLVM_DEBUG(dbgs() << "LRR: Possible reduction: " << *I << " (with "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Possible reduction: " << *I << " (with " << SLR.size() << " chained instructions)\n" ; } } while (false) | |||
| 667 | << SLR.size() << " chained instructions)\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Possible reduction: " << *I << " (with " << SLR.size() << " chained instructions)\n" ; } } while (false); | |||
| 668 | Reductions.addSLR(SLR); | |||
| 669 | } | |||
| 670 | } | |||
| 671 | ||||
| 672 | // Collect the set of all users of the provided root instruction. This set of | |||
| 673 | // users contains not only the direct users of the root instruction, but also | |||
| 674 | // all users of those users, and so on. There are two exceptions: | |||
| 675 | // | |||
| 676 | // 1. Instructions in the set of excluded instructions are never added to the | |||
| 677 | // use set (even if they are users). This is used, for example, to exclude | |||
| 678 | // including root increments in the use set of the primary IV. | |||
| 679 | // | |||
| 680 | // 2. Instructions in the set of final instructions are added to the use set | |||
| 681 | // if they are users, but their users are not added. This is used, for | |||
| 682 | // example, to prevent a reduction update from forcing all later reduction | |||
| 683 | // updates into the use set. | |||
| 684 | void LoopReroll::DAGRootTracker::collectInLoopUserSet( | |||
| 685 | Instruction *Root, const SmallInstructionSet &Exclude, | |||
| 686 | const SmallInstructionSet &Final, | |||
| 687 | DenseSet<Instruction *> &Users) { | |||
| 688 | SmallInstructionVector Queue(1, Root); | |||
| 689 | while (!Queue.empty()) { | |||
| 690 | Instruction *I = Queue.pop_back_val(); | |||
| 691 | if (!Users.insert(I).second) | |||
| 692 | continue; | |||
| 693 | ||||
| 694 | if (!Final.count(I)) | |||
| 695 | for (Use &U : I->uses()) { | |||
| 696 | Instruction *User = cast<Instruction>(U.getUser()); | |||
| 697 | if (PHINode *PN = dyn_cast<PHINode>(User)) { | |||
| 698 | // Ignore "wrap-around" uses to PHIs of this loop's header. | |||
| 699 | if (PN->getIncomingBlock(U) == L->getHeader()) | |||
| 700 | continue; | |||
| 701 | } | |||
| 702 | ||||
| 703 | if (L->contains(User) && !Exclude.count(User)) { | |||
| 704 | Queue.push_back(User); | |||
| 705 | } | |||
| 706 | } | |||
| 707 | ||||
| 708 | // We also want to collect single-user "feeder" values. | |||
| 709 | for (User::op_iterator OI = I->op_begin(), | |||
| 710 | OIE = I->op_end(); OI != OIE; ++OI) { | |||
| 711 | if (Instruction *Op = dyn_cast<Instruction>(*OI)) | |||
| 712 | if (Op->hasOneUse() && L->contains(Op) && !Exclude.count(Op) && | |||
| 713 | !Final.count(Op)) | |||
| 714 | Queue.push_back(Op); | |||
| 715 | } | |||
| 716 | } | |||
| 717 | } | |||
| 718 | ||||
| 719 | // Collect all of the users of all of the provided root instructions (combined | |||
| 720 | // into a single set). | |||
| 721 | void LoopReroll::DAGRootTracker::collectInLoopUserSet( | |||
| 722 | const SmallInstructionVector &Roots, | |||
| 723 | const SmallInstructionSet &Exclude, | |||
| 724 | const SmallInstructionSet &Final, | |||
| 725 | DenseSet<Instruction *> &Users) { | |||
| 726 | for (Instruction *Root : Roots) | |||
| 727 | collectInLoopUserSet(Root, Exclude, Final, Users); | |||
| 728 | } | |||
| 729 | ||||
| 730 | static bool isUnorderedLoadStore(Instruction *I) { | |||
| 731 | if (LoadInst *LI = dyn_cast<LoadInst>(I)) | |||
| 732 | return LI->isUnordered(); | |||
| 733 | if (StoreInst *SI = dyn_cast<StoreInst>(I)) | |||
| 734 | return SI->isUnordered(); | |||
| 735 | if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(I)) | |||
| 736 | return !MI->isVolatile(); | |||
| 737 | return false; | |||
| 738 | } | |||
| 739 | ||||
| 740 | /// Return true if IVU is a "simple" arithmetic operation. | |||
| 741 | /// This is used for narrowing the search space for DAGRoots; only arithmetic | |||
| 742 | /// and GEPs can be part of a DAGRoot. | |||
| 743 | static bool isSimpleArithmeticOp(User *IVU) { | |||
| 744 | if (Instruction *I = dyn_cast<Instruction>(IVU)) { | |||
| 745 | switch (I->getOpcode()) { | |||
| 746 | default: return false; | |||
| 747 | case Instruction::Add: | |||
| 748 | case Instruction::Sub: | |||
| 749 | case Instruction::Mul: | |||
| 750 | case Instruction::Shl: | |||
| 751 | case Instruction::AShr: | |||
| 752 | case Instruction::LShr: | |||
| 753 | case Instruction::GetElementPtr: | |||
| 754 | case Instruction::Trunc: | |||
| 755 | case Instruction::ZExt: | |||
| 756 | case Instruction::SExt: | |||
| 757 | return true; | |||
| 758 | } | |||
| 759 | } | |||
| 760 | return false; | |||
| 761 | } | |||
| 762 | ||||
| 763 | static bool isLoopIncrement(User *U, Instruction *IV) { | |||
| 764 | BinaryOperator *BO = dyn_cast<BinaryOperator>(U); | |||
| 765 | ||||
| 766 | if ((BO && BO->getOpcode() != Instruction::Add) || | |||
| 767 | (!BO && !isa<GetElementPtrInst>(U))) | |||
| 768 | return false; | |||
| 769 | ||||
| 770 | for (auto *UU : U->users()) { | |||
| 771 | PHINode *PN = dyn_cast<PHINode>(UU); | |||
| 772 | if (PN && PN == IV) | |||
| 773 | return true; | |||
| 774 | } | |||
| 775 | return false; | |||
| 776 | } | |||
| 777 | ||||
| 778 | bool LoopReroll::DAGRootTracker:: | |||
| 779 | collectPossibleRoots(Instruction *Base, std::map<int64_t,Instruction*> &Roots) { | |||
| 780 | SmallInstructionVector BaseUsers; | |||
| 781 | ||||
| 782 | for (auto *I : Base->users()) { | |||
| 783 | ConstantInt *CI = nullptr; | |||
| 784 | ||||
| 785 | if (isLoopIncrement(I, IV)) { | |||
| 786 | LoopIncs.push_back(cast<Instruction>(I)); | |||
| 787 | continue; | |||
| 788 | } | |||
| 789 | ||||
| 790 | // The root nodes must be either GEPs, ORs or ADDs. | |||
| 791 | if (auto *BO = dyn_cast<BinaryOperator>(I)) { | |||
| 792 | if (BO->getOpcode() == Instruction::Add || | |||
| 793 | BO->getOpcode() == Instruction::Or) | |||
| 794 | CI = dyn_cast<ConstantInt>(BO->getOperand(1)); | |||
| 795 | } else if (auto *GEP = dyn_cast<GetElementPtrInst>(I)) { | |||
| 796 | Value *LastOperand = GEP->getOperand(GEP->getNumOperands()-1); | |||
| 797 | CI = dyn_cast<ConstantInt>(LastOperand); | |||
| 798 | } | |||
| 799 | ||||
| 800 | if (!CI) { | |||
| 801 | if (Instruction *II = dyn_cast<Instruction>(I)) { | |||
| 802 | BaseUsers.push_back(II); | |||
| 803 | continue; | |||
| 804 | } else { | |||
| 805 | LLVM_DEBUG(dbgs() << "LRR: Aborting due to non-instruction: " << *Ido { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Aborting due to non-instruction: " << *I << "\n"; } } while (false) | |||
| 806 | << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Aborting due to non-instruction: " << *I << "\n"; } } while (false); | |||
| 807 | return false; | |||
| 808 | } | |||
| 809 | } | |||
| 810 | ||||
| 811 | int64_t V = std::abs(CI->getValue().getSExtValue()); | |||
| 812 | if (Roots.find(V) != Roots.end()) | |||
| 813 | // No duplicates, please. | |||
| 814 | return false; | |||
| 815 | ||||
| 816 | Roots[V] = cast<Instruction>(I); | |||
| 817 | } | |||
| 818 | ||||
| 819 | // Make sure we have at least two roots. | |||
| 820 | if (Roots.empty() || (Roots.size() == 1 && BaseUsers.empty())) | |||
| 821 | return false; | |||
| 822 | ||||
| 823 | // If we found non-loop-inc, non-root users of Base, assume they are | |||
| 824 | // for the zeroth root index. This is because "add %a, 0" gets optimized | |||
| 825 | // away. | |||
| 826 | if (BaseUsers.size()) { | |||
| 827 | if (Roots.find(0) != Roots.end()) { | |||
| 828 | LLVM_DEBUG(dbgs() << "LRR: Multiple roots found for base - aborting!\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Multiple roots found for base - aborting!\n" ; } } while (false); | |||
| 829 | return false; | |||
| 830 | } | |||
| 831 | Roots[0] = Base; | |||
| 832 | } | |||
| 833 | ||||
| 834 | // Calculate the number of users of the base, or lowest indexed, iteration. | |||
| 835 | unsigned NumBaseUses = BaseUsers.size(); | |||
| 836 | if (NumBaseUses == 0) | |||
| 837 | NumBaseUses = Roots.begin()->second->getNumUses(); | |||
| 838 | ||||
| 839 | // Check that every node has the same number of users. | |||
| 840 | for (auto &KV : Roots) { | |||
| 841 | if (KV.first == 0) | |||
| 842 | continue; | |||
| 843 | if (!KV.second->hasNUses(NumBaseUses)) { | |||
| 844 | LLVM_DEBUG(dbgs() << "LRR: Aborting - Root and Base #users not the same: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Aborting - Root and Base #users not the same: " << "#Base=" << NumBaseUses << ", #Root=" << KV.second->getNumUses() << "\n"; } } while (false) | |||
| 845 | << "#Base=" << NumBaseUsesdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Aborting - Root and Base #users not the same: " << "#Base=" << NumBaseUses << ", #Root=" << KV.second->getNumUses() << "\n"; } } while (false) | |||
| 846 | << ", #Root=" << KV.second->getNumUses() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Aborting - Root and Base #users not the same: " << "#Base=" << NumBaseUses << ", #Root=" << KV.second->getNumUses() << "\n"; } } while (false); | |||
| 847 | return false; | |||
| 848 | } | |||
| 849 | } | |||
| 850 | ||||
| 851 | return true; | |||
| 852 | } | |||
| 853 | ||||
| 854 | void LoopReroll::DAGRootTracker:: | |||
| 855 | findRootsRecursive(Instruction *I, SmallInstructionSet SubsumedInsts) { | |||
| 856 | // Does the user look like it could be part of a root set? | |||
| 857 | // All its users must be simple arithmetic ops. | |||
| 858 | if (I->hasNUsesOrMore(IL_MaxRerollIterations + 1)) | |||
| 859 | return; | |||
| 860 | ||||
| 861 | if (I != IV && findRootsBase(I, SubsumedInsts)) | |||
| 862 | return; | |||
| 863 | ||||
| 864 | SubsumedInsts.insert(I); | |||
| 865 | ||||
| 866 | for (User *V : I->users()) { | |||
| 867 | Instruction *I = cast<Instruction>(V); | |||
| 868 | if (is_contained(LoopIncs, I)) | |||
| 869 | continue; | |||
| 870 | ||||
| 871 | if (!isSimpleArithmeticOp(I)) | |||
| 872 | continue; | |||
| 873 | ||||
| 874 | // The recursive call makes a copy of SubsumedInsts. | |||
| 875 | findRootsRecursive(I, SubsumedInsts); | |||
| 876 | } | |||
| 877 | } | |||
| 878 | ||||
| 879 | bool LoopReroll::DAGRootTracker::validateRootSet(DAGRootSet &DRS) { | |||
| 880 | if (DRS.Roots.empty()) | |||
| 881 | return false; | |||
| 882 | ||||
| 883 | // Consider a DAGRootSet with N-1 roots (so N different values including | |||
| 884 | // BaseInst). | |||
| 885 | // Define d = Roots[0] - BaseInst, which should be the same as | |||
| 886 | // Roots[I] - Roots[I-1] for all I in [1..N). | |||
| 887 | // Define D = BaseInst@J - BaseInst@J-1, where "@J" means the value at the | |||
| 888 | // loop iteration J. | |||
| 889 | // | |||
| 890 | // Now, For the loop iterations to be consecutive: | |||
| 891 | // D = d * N | |||
| 892 | const auto *ADR = dyn_cast<SCEVAddRecExpr>(SE->getSCEV(DRS.BaseInst)); | |||
| 893 | if (!ADR) | |||
| 894 | return false; | |||
| 895 | unsigned N = DRS.Roots.size() + 1; | |||
| 896 | const SCEV *StepSCEV = SE->getMinusSCEV(SE->getSCEV(DRS.Roots[0]), ADR); | |||
| 897 | const SCEV *ScaleSCEV = SE->getConstant(StepSCEV->getType(), N); | |||
| 898 | if (ADR->getStepRecurrence(*SE) != SE->getMulExpr(StepSCEV, ScaleSCEV)) | |||
| 899 | return false; | |||
| 900 | ||||
| 901 | return true; | |||
| 902 | } | |||
| 903 | ||||
| 904 | bool LoopReroll::DAGRootTracker:: | |||
| 905 | findRootsBase(Instruction *IVU, SmallInstructionSet SubsumedInsts) { | |||
| 906 | // The base of a RootSet must be an AddRec, so it can be erased. | |||
| 907 | const auto *IVU_ADR = dyn_cast<SCEVAddRecExpr>(SE->getSCEV(IVU)); | |||
| 908 | if (!IVU_ADR || IVU_ADR->getLoop() != L) | |||
| 909 | return false; | |||
| 910 | ||||
| 911 | std::map<int64_t, Instruction*> V; | |||
| 912 | if (!collectPossibleRoots(IVU, V)) | |||
| 913 | return false; | |||
| 914 | ||||
| 915 | // If we didn't get a root for index zero, then IVU must be | |||
| 916 | // subsumed. | |||
| 917 | if (V.find(0) == V.end()) | |||
| 918 | SubsumedInsts.insert(IVU); | |||
| 919 | ||||
| 920 | // Partition the vector into monotonically increasing indexes. | |||
| 921 | DAGRootSet DRS; | |||
| 922 | DRS.BaseInst = nullptr; | |||
| 923 | ||||
| 924 | SmallVector<DAGRootSet, 16> PotentialRootSets; | |||
| 925 | ||||
| 926 | for (auto &KV : V) { | |||
| 927 | if (!DRS.BaseInst) { | |||
| 928 | DRS.BaseInst = KV.second; | |||
| 929 | DRS.SubsumedInsts = SubsumedInsts; | |||
| 930 | } else if (DRS.Roots.empty()) { | |||
| 931 | DRS.Roots.push_back(KV.second); | |||
| 932 | } else if (V.find(KV.first - 1) != V.end()) { | |||
| 933 | DRS.Roots.push_back(KV.second); | |||
| 934 | } else { | |||
| 935 | // Linear sequence terminated. | |||
| 936 | if (!validateRootSet(DRS)) | |||
| 937 | return false; | |||
| 938 | ||||
| 939 | // Construct a new DAGRootSet with the next sequence. | |||
| 940 | PotentialRootSets.push_back(DRS); | |||
| 941 | DRS.BaseInst = KV.second; | |||
| 942 | DRS.Roots.clear(); | |||
| 943 | } | |||
| 944 | } | |||
| 945 | ||||
| 946 | if (!validateRootSet(DRS)) | |||
| 947 | return false; | |||
| 948 | ||||
| 949 | PotentialRootSets.push_back(DRS); | |||
| 950 | ||||
| 951 | RootSets.append(PotentialRootSets.begin(), PotentialRootSets.end()); | |||
| 952 | ||||
| 953 | return true; | |||
| 954 | } | |||
| 955 | ||||
| 956 | bool LoopReroll::DAGRootTracker::findRoots() { | |||
| 957 | Inc = IVToIncMap[IV]; | |||
| 958 | ||||
| 959 | assert(RootSets.empty() && "Unclean state!")(static_cast <bool> (RootSets.empty() && "Unclean state!" ) ? void (0) : __assert_fail ("RootSets.empty() && \"Unclean state!\"" , "/build/llvm-toolchain-snapshot-7~svn338205/lib/Transforms/Scalar/LoopRerollPass.cpp" , 959, __extension__ __PRETTY_FUNCTION__)); | |||
| 960 | if (std::abs(Inc) == 1) { | |||
| 961 | for (auto *IVU : IV->users()) { | |||
| 962 | if (isLoopIncrement(IVU, IV)) | |||
| 963 | LoopIncs.push_back(cast<Instruction>(IVU)); | |||
| 964 | } | |||
| 965 | findRootsRecursive(IV, SmallInstructionSet()); | |||
| 966 | LoopIncs.push_back(IV); | |||
| 967 | } else { | |||
| 968 | if (!findRootsBase(IV, SmallInstructionSet())) | |||
| 969 | return false; | |||
| 970 | } | |||
| 971 | ||||
| 972 | // Ensure all sets have the same size. | |||
| 973 | if (RootSets.empty()) { | |||
| 974 | LLVM_DEBUG(dbgs() << "LRR: Aborting because no root sets found!\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Aborting because no root sets found!\n" ; } } while (false); | |||
| 975 | return false; | |||
| 976 | } | |||
| 977 | for (auto &V : RootSets) { | |||
| 978 | if (V.Roots.empty() || V.Roots.size() != RootSets[0].Roots.size()) { | |||
| 979 | LLVM_DEBUG(do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Aborting because not all root sets have the same size\n" ; } } while (false) | |||
| 980 | dbgs()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Aborting because not all root sets have the same size\n" ; } } while (false) | |||
| 981 | << "LRR: Aborting because not all root sets have the same size\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Aborting because not all root sets have the same size\n" ; } } while (false); | |||
| 982 | return false; | |||
| 983 | } | |||
| 984 | } | |||
| 985 | ||||
| 986 | Scale = RootSets[0].Roots.size() + 1; | |||
| 987 | ||||
| 988 | if (Scale > IL_MaxRerollIterations) { | |||
| 989 | LLVM_DEBUG(dbgs() << "LRR: Aborting - too many iterations found. "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Aborting - too many iterations found. " << "#Found=" << Scale << ", #Max=" << IL_MaxRerollIterations << "\n"; } } while (false) | |||
| 990 | << "#Found=" << Scaledo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Aborting - too many iterations found. " << "#Found=" << Scale << ", #Max=" << IL_MaxRerollIterations << "\n"; } } while (false) | |||
| 991 | << ", #Max=" << IL_MaxRerollIterations << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Aborting - too many iterations found. " << "#Found=" << Scale << ", #Max=" << IL_MaxRerollIterations << "\n"; } } while (false); | |||
| 992 | return false; | |||
| 993 | } | |||
| 994 | ||||
| 995 | LLVM_DEBUG(dbgs() << "LRR: Successfully found roots: Scale=" << Scaledo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Successfully found roots: Scale=" << Scale << "\n"; } } while (false) | |||
| 996 | << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Successfully found roots: Scale=" << Scale << "\n"; } } while (false); | |||
| 997 | ||||
| 998 | return true; | |||
| 999 | } | |||
| 1000 | ||||
| 1001 | bool LoopReroll::DAGRootTracker::collectUsedInstructions(SmallInstructionSet &PossibleRedSet) { | |||
| 1002 | // Populate the MapVector with all instructions in the block, in order first, | |||
| 1003 | // so we can iterate over the contents later in perfect order. | |||
| 1004 | for (auto &I : *L->getHeader()) { | |||
| 1005 | Uses[&I].resize(IL_End); | |||
| 1006 | } | |||
| 1007 | ||||
| 1008 | SmallInstructionSet Exclude; | |||
| 1009 | for (auto &DRS : RootSets) { | |||
| 1010 | Exclude.insert(DRS.Roots.begin(), DRS.Roots.end()); | |||
| 1011 | Exclude.insert(DRS.SubsumedInsts.begin(), DRS.SubsumedInsts.end()); | |||
| 1012 | Exclude.insert(DRS.BaseInst); | |||
| 1013 | } | |||
| 1014 | Exclude.insert(LoopIncs.begin(), LoopIncs.end()); | |||
| 1015 | ||||
| 1016 | for (auto &DRS : RootSets) { | |||
| 1017 | DenseSet<Instruction*> VBase; | |||
| 1018 | collectInLoopUserSet(DRS.BaseInst, Exclude, PossibleRedSet, VBase); | |||
| 1019 | for (auto *I : VBase) { | |||
| 1020 | Uses[I].set(0); | |||
| 1021 | } | |||
| 1022 | ||||
| 1023 | unsigned Idx = 1; | |||
| 1024 | for (auto *Root : DRS.Roots) { | |||
| 1025 | DenseSet<Instruction*> V; | |||
| 1026 | collectInLoopUserSet(Root, Exclude, PossibleRedSet, V); | |||
| 1027 | ||||
| 1028 | // While we're here, check the use sets are the same size. | |||
| 1029 | if (V.size() != VBase.size()) { | |||
| 1030 | LLVM_DEBUG(dbgs() << "LRR: Aborting - use sets are different sizes\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Aborting - use sets are different sizes\n" ; } } while (false); | |||
| 1031 | return false; | |||
| 1032 | } | |||
| 1033 | ||||
| 1034 | for (auto *I : V) { | |||
| 1035 | Uses[I].set(Idx); | |||
| 1036 | } | |||
| 1037 | ++Idx; | |||
| 1038 | } | |||
| 1039 | ||||
| 1040 | // Make sure our subsumed instructions are remembered too. | |||
| 1041 | for (auto *I : DRS.SubsumedInsts) { | |||
| 1042 | Uses[I].set(IL_All); | |||
| 1043 | } | |||
| 1044 | } | |||
| 1045 | ||||
| 1046 | // Make sure the loop increments are also accounted for. | |||
| 1047 | ||||
| 1048 | Exclude.clear(); | |||
| 1049 | for (auto &DRS : RootSets) { | |||
| 1050 | Exclude.insert(DRS.Roots.begin(), DRS.Roots.end()); | |||
| 1051 | Exclude.insert(DRS.SubsumedInsts.begin(), DRS.SubsumedInsts.end()); | |||
| 1052 | Exclude.insert(DRS.BaseInst); | |||
| 1053 | } | |||
| 1054 | ||||
| 1055 | DenseSet<Instruction*> V; | |||
| 1056 | collectInLoopUserSet(LoopIncs, Exclude, PossibleRedSet, V); | |||
| 1057 | for (auto *I : V) { | |||
| 1058 | Uses[I].set(IL_All); | |||
| 1059 | } | |||
| 1060 | ||||
| 1061 | return true; | |||
| 1062 | } | |||
| 1063 | ||||
| 1064 | /// Get the next instruction in "In" that is a member of set Val. | |||
| 1065 | /// Start searching from StartI, and do not return anything in Exclude. | |||
| 1066 | /// If StartI is not given, start from In.begin(). | |||
| 1067 | LoopReroll::DAGRootTracker::UsesTy::iterator | |||
| 1068 | LoopReroll::DAGRootTracker::nextInstr(int Val, UsesTy &In, | |||
| 1069 | const SmallInstructionSet &Exclude, | |||
| 1070 | UsesTy::iterator *StartI) { | |||
| 1071 | UsesTy::iterator I = StartI ? *StartI : In.begin(); | |||
| 1072 | while (I != In.end() && (I->second.test(Val) == 0 || | |||
| 1073 | Exclude.count(I->first) != 0)) | |||
| 1074 | ++I; | |||
| 1075 | return I; | |||
| 1076 | } | |||
| 1077 | ||||
| 1078 | bool LoopReroll::DAGRootTracker::isBaseInst(Instruction *I) { | |||
| 1079 | for (auto &DRS : RootSets) { | |||
| 1080 | if (DRS.BaseInst == I) | |||
| 1081 | return true; | |||
| 1082 | } | |||
| 1083 | return false; | |||
| 1084 | } | |||
| 1085 | ||||
| 1086 | bool LoopReroll::DAGRootTracker::isRootInst(Instruction *I) { | |||
| 1087 | for (auto &DRS : RootSets) { | |||
| 1088 | if (is_contained(DRS.Roots, I)) | |||
| 1089 | return true; | |||
| 1090 | } | |||
| 1091 | return false; | |||
| 1092 | } | |||
| 1093 | ||||
| 1094 | /// Return true if instruction I depends on any instruction between | |||
| 1095 | /// Start and End. | |||
| 1096 | bool LoopReroll::DAGRootTracker::instrDependsOn(Instruction *I, | |||
| 1097 | UsesTy::iterator Start, | |||
| 1098 | UsesTy::iterator End) { | |||
| 1099 | for (auto *U : I->users()) { | |||
| 1100 | for (auto It = Start; It != End; ++It) | |||
| 1101 | if (U == It->first) | |||
| 1102 | return true; | |||
| 1103 | } | |||
| 1104 | return false; | |||
| 1105 | } | |||
| 1106 | ||||
| 1107 | static bool isIgnorableInst(const Instruction *I) { | |||
| 1108 | if (isa<DbgInfoIntrinsic>(I)) | |||
| 1109 | return true; | |||
| 1110 | const IntrinsicInst* II = dyn_cast<IntrinsicInst>(I); | |||
| 1111 | if (!II) | |||
| 1112 | return false; | |||
| 1113 | switch (II->getIntrinsicID()) { | |||
| 1114 | default: | |||
| 1115 | return false; | |||
| 1116 | case Intrinsic::annotation: | |||
| 1117 | case Intrinsic::ptr_annotation: | |||
| 1118 | case Intrinsic::var_annotation: | |||
| 1119 | // TODO: the following intrinsics may also be whitelisted: | |||
| 1120 | // lifetime_start, lifetime_end, invariant_start, invariant_end | |||
| 1121 | return true; | |||
| 1122 | } | |||
| 1123 | return false; | |||
| 1124 | } | |||
| 1125 | ||||
| 1126 | bool LoopReroll::DAGRootTracker::validate(ReductionTracker &Reductions) { | |||
| 1127 | // We now need to check for equivalence of the use graph of each root with | |||
| 1128 | // that of the primary induction variable (excluding the roots). Our goal | |||
| 1129 | // here is not to solve the full graph isomorphism problem, but rather to | |||
| 1130 | // catch common cases without a lot of work. As a result, we will assume | |||
| 1131 | // that the relative order of the instructions in each unrolled iteration | |||
| 1132 | // is the same (although we will not make an assumption about how the | |||
| 1133 | // different iterations are intermixed). Note that while the order must be | |||
| 1134 | // the same, the instructions may not be in the same basic block. | |||
| 1135 | ||||
| 1136 | // An array of just the possible reductions for this scale factor. When we | |||
| 1137 | // collect the set of all users of some root instructions, these reduction | |||
| 1138 | // instructions are treated as 'final' (their uses are not considered). | |||
| 1139 | // This is important because we don't want the root use set to search down | |||
| 1140 | // the reduction chain. | |||
| 1141 | SmallInstructionSet PossibleRedSet; | |||
| 1142 | SmallInstructionSet PossibleRedLastSet; | |||
| 1143 | SmallInstructionSet PossibleRedPHISet; | |||
| 1144 | Reductions.restrictToScale(Scale, PossibleRedSet, | |||
| 1145 | PossibleRedPHISet, PossibleRedLastSet); | |||
| 1146 | ||||
| 1147 | // Populate "Uses" with where each instruction is used. | |||
| 1148 | if (!collectUsedInstructions(PossibleRedSet)) | |||
| 1149 | return false; | |||
| 1150 | ||||
| 1151 | // Make sure we mark the reduction PHIs as used in all iterations. | |||
| 1152 | for (auto *I : PossibleRedPHISet) { | |||
| 1153 | Uses[I].set(IL_All); | |||
| 1154 | } | |||
| 1155 | ||||
| 1156 | // Make sure we mark loop-control-only PHIs as used in all iterations. See | |||
| 1157 | // comment above LoopReroll::isLoopControlIV for more information. | |||
| 1158 | BasicBlock *Header = L->getHeader(); | |||
| 1159 | if (LoopControlIV && LoopControlIV != IV) { | |||
| 1160 | for (auto *U : LoopControlIV->users()) { | |||
| 1161 | Instruction *IVUser = dyn_cast<Instruction>(U); | |||
| 1162 | // IVUser could be loop increment or compare | |||
| 1163 | Uses[IVUser].set(IL_All); | |||
| 1164 | for (auto *UU : IVUser->users()) { | |||
| 1165 | Instruction *UUser = dyn_cast<Instruction>(UU); | |||
| 1166 | // UUser could be compare, PHI or branch | |||
| 1167 | Uses[UUser].set(IL_All); | |||
| 1168 | // Skip SExt | |||
| 1169 | if (isa<SExtInst>(UUser)) { | |||
| 1170 | UUser = dyn_cast<Instruction>(*(UUser->user_begin())); | |||
| 1171 | Uses[UUser].set(IL_All); | |||
| 1172 | } | |||
| 1173 | // Is UUser a compare instruction? | |||
| 1174 | if (UU->hasOneUse()) { | |||
| 1175 | Instruction *BI = dyn_cast<BranchInst>(*UUser->user_begin()); | |||
| 1176 | if (BI == cast<BranchInst>(Header->getTerminator())) | |||
| 1177 | Uses[BI].set(IL_All); | |||
| 1178 | } | |||
| 1179 | } | |||
| 1180 | } | |||
| 1181 | } | |||
| 1182 | ||||
| 1183 | // Make sure all instructions in the loop are in one and only one | |||
| 1184 | // set. | |||
| 1185 | for (auto &KV : Uses) { | |||
| 1186 | if (KV.second.count() != 1 && !isIgnorableInst(KV.first)) { | |||
| 1187 | LLVM_DEBUG(do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Aborting - instruction is not used in 1 iteration: " << *KV.first << " (#uses=" << KV.second.count () << ")\n"; } } while (false) | |||
| 1188 | dbgs() << "LRR: Aborting - instruction is not used in 1 iteration: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Aborting - instruction is not used in 1 iteration: " << *KV.first << " (#uses=" << KV.second.count () << ")\n"; } } while (false) | |||
| 1189 | << *KV.first << " (#uses=" << KV.second.count() << ")\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Aborting - instruction is not used in 1 iteration: " << *KV.first << " (#uses=" << KV.second.count () << ")\n"; } } while (false); | |||
| 1190 | return false; | |||
| 1191 | } | |||
| 1192 | } | |||
| 1193 | ||||
| 1194 | LLVM_DEBUG(for (auto &KVdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { for (auto &KV : Uses) { dbgs() << "LRR: " << KV.second.find_first() << "\t" << *KV.first << "\n"; }; } } while (false) | |||
| 1195 | : Uses) {do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { for (auto &KV : Uses) { dbgs() << "LRR: " << KV.second.find_first() << "\t" << *KV.first << "\n"; }; } } while (false) | |||
| 1196 | dbgs() << "LRR: " << KV.second.find_first() << "\t" << *KV.first << "\n";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { for (auto &KV : Uses) { dbgs() << "LRR: " << KV.second.find_first() << "\t" << *KV.first << "\n"; }; } } while (false) | |||
| 1197 | })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { for (auto &KV : Uses) { dbgs() << "LRR: " << KV.second.find_first() << "\t" << *KV.first << "\n"; }; } } while (false); | |||
| 1198 | ||||
| 1199 | for (unsigned Iter = 1; Iter < Scale; ++Iter) { | |||
| 1200 | // In addition to regular aliasing information, we need to look for | |||
| 1201 | // instructions from later (future) iterations that have side effects | |||
| 1202 | // preventing us from reordering them past other instructions with side | |||
| 1203 | // effects. | |||
| 1204 | bool FutureSideEffects = false; | |||
| 1205 | AliasSetTracker AST(*AA); | |||
| 1206 | // The map between instructions in f(%iv.(i+1)) and f(%iv). | |||
| 1207 | DenseMap<Value *, Value *> BaseMap; | |||
| 1208 | ||||
| 1209 | // Compare iteration Iter to the base. | |||
| 1210 | SmallInstructionSet Visited; | |||
| 1211 | auto BaseIt = nextInstr(0, Uses, Visited); | |||
| 1212 | auto RootIt = nextInstr(Iter, Uses, Visited); | |||
| 1213 | auto LastRootIt = Uses.begin(); | |||
| 1214 | ||||
| 1215 | while (BaseIt != Uses.end() && RootIt != Uses.end()) { | |||
| 1216 | Instruction *BaseInst = BaseIt->first; | |||
| 1217 | Instruction *RootInst = RootIt->first; | |||
| 1218 | ||||
| 1219 | // Skip over the IV or root instructions; only match their users. | |||
| 1220 | bool Continue = false; | |||
| 1221 | if (isBaseInst(BaseInst)) { | |||
| 1222 | Visited.insert(BaseInst); | |||
| 1223 | BaseIt = nextInstr(0, Uses, Visited); | |||
| 1224 | Continue = true; | |||
| 1225 | } | |||
| 1226 | if (isRootInst(RootInst)) { | |||
| 1227 | LastRootIt = RootIt; | |||
| 1228 | Visited.insert(RootInst); | |||
| 1229 | RootIt = nextInstr(Iter, Uses, Visited); | |||
| 1230 | Continue = true; | |||
| 1231 | } | |||
| 1232 | if (Continue) continue; | |||
| 1233 | ||||
| 1234 | if (!BaseInst->isSameOperationAs(RootInst)) { | |||
| 1235 | // Last chance saloon. We don't try and solve the full isomorphism | |||
| 1236 | // problem, but try and at least catch the case where two instructions | |||
| 1237 | // *of different types* are round the wrong way. We won't be able to | |||
| 1238 | // efficiently tell, given two ADD instructions, which way around we | |||
| 1239 | // should match them, but given an ADD and a SUB, we can at least infer | |||
| 1240 | // which one is which. | |||
| 1241 | // | |||
| 1242 | // This should allow us to deal with a greater subset of the isomorphism | |||
| 1243 | // problem. It does however change a linear algorithm into a quadratic | |||
| 1244 | // one, so limit the number of probes we do. | |||
| 1245 | auto TryIt = RootIt; | |||
| 1246 | unsigned N = NumToleratedFailedMatches; | |||
| 1247 | while (TryIt != Uses.end() && | |||
| 1248 | !BaseInst->isSameOperationAs(TryIt->first) && | |||
| 1249 | N--) { | |||
| 1250 | ++TryIt; | |||
| 1251 | TryIt = nextInstr(Iter, Uses, Visited, &TryIt); | |||
| 1252 | } | |||
| 1253 | ||||
| 1254 | if (TryIt == Uses.end() || TryIt == RootIt || | |||
| 1255 | instrDependsOn(TryIt->first, RootIt, TryIt)) { | |||
| 1256 | LLVM_DEBUG(dbgs() << "LRR: iteration root match failed at "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: iteration root match failed at " << *BaseInst << " vs. " << *RootInst << "\n"; } } while (false) | |||
| 1257 | << *BaseInst << " vs. " << *RootInst << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: iteration root match failed at " << *BaseInst << " vs. " << *RootInst << "\n"; } } while (false); | |||
| 1258 | return false; | |||
| 1259 | } | |||
| 1260 | ||||
| 1261 | RootIt = TryIt; | |||
| 1262 | RootInst = TryIt->first; | |||
| 1263 | } | |||
| 1264 | ||||
| 1265 | // All instructions between the last root and this root | |||
| 1266 | // may belong to some other iteration. If they belong to a | |||
| 1267 | // future iteration, then they're dangerous to alias with. | |||
| 1268 | // | |||
| 1269 | // Note that because we allow a limited amount of flexibility in the order | |||
| 1270 | // that we visit nodes, LastRootIt might be *before* RootIt, in which | |||
| 1271 | // case we've already checked this set of instructions so we shouldn't | |||
| 1272 | // do anything. | |||
| 1273 | for (; LastRootIt < RootIt; ++LastRootIt) { | |||
| 1274 | Instruction *I = LastRootIt->first; | |||
| 1275 | if (LastRootIt->second.find_first() < (int)Iter) | |||
| 1276 | continue; | |||
| 1277 | if (I->mayWriteToMemory()) | |||
| 1278 | AST.add(I); | |||
| 1279 | // Note: This is specifically guarded by a check on isa<PHINode>, | |||
| 1280 | // which while a valid (somewhat arbitrary) micro-optimization, is | |||
| 1281 | // needed because otherwise isSafeToSpeculativelyExecute returns | |||
| 1282 | // false on PHI nodes. | |||
| 1283 | if (!isa<PHINode>(I) && !isUnorderedLoadStore(I) && | |||
| 1284 | !isSafeToSpeculativelyExecute(I)) | |||
| 1285 | // Intervening instructions cause side effects. | |||
| 1286 | FutureSideEffects = true; | |||
| 1287 | } | |||
| 1288 | ||||
| 1289 | // Make sure that this instruction, which is in the use set of this | |||
| 1290 | // root instruction, does not also belong to the base set or the set of | |||
| 1291 | // some other root instruction. | |||
| 1292 | if (RootIt->second.count() > 1) { | |||
| 1293 | LLVM_DEBUG(dbgs() << "LRR: iteration root match failed at " << *BaseInstdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: iteration root match failed at " << *BaseInst << " vs. " << *RootInst << " (prev. case overlap)\n"; } } while (false) | |||
| 1294 | << " vs. " << *RootInst << " (prev. case overlap)\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: iteration root match failed at " << *BaseInst << " vs. " << *RootInst << " (prev. case overlap)\n"; } } while (false); | |||
| 1295 | return false; | |||
| 1296 | } | |||
| 1297 | ||||
| 1298 | // Make sure that we don't alias with any instruction in the alias set | |||
| 1299 | // tracker. If we do, then we depend on a future iteration, and we | |||
| 1300 | // can't reroll. | |||
| 1301 | if (RootInst->mayReadFromMemory()) | |||
| 1302 | for (auto &K : AST) { | |||
| 1303 | if (K.aliasesUnknownInst(RootInst, *AA)) { | |||
| 1304 | LLVM_DEBUG(dbgs() << "LRR: iteration root match failed at "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: iteration root match failed at " << *BaseInst << " vs. " << *RootInst << " (depends on future store)\n"; } } while (false) | |||
| 1305 | << *BaseInst << " vs. " << *RootInstdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: iteration root match failed at " << *BaseInst << " vs. " << *RootInst << " (depends on future store)\n"; } } while (false) | |||
| 1306 | << " (depends on future store)\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: iteration root match failed at " << *BaseInst << " vs. " << *RootInst << " (depends on future store)\n"; } } while (false); | |||
| 1307 | return false; | |||
| 1308 | } | |||
| 1309 | } | |||
| 1310 | ||||
| 1311 | // If we've past an instruction from a future iteration that may have | |||
| 1312 | // side effects, and this instruction might also, then we can't reorder | |||
| 1313 | // them, and this matching fails. As an exception, we allow the alias | |||
| 1314 | // set tracker to handle regular (unordered) load/store dependencies. | |||
| 1315 | if (FutureSideEffects && ((!isUnorderedLoadStore(BaseInst) && | |||
| 1316 | !isSafeToSpeculativelyExecute(BaseInst)) || | |||
| 1317 | (!isUnorderedLoadStore(RootInst) && | |||
| 1318 | !isSafeToSpeculativelyExecute(RootInst)))) { | |||
| 1319 | LLVM_DEBUG(dbgs() << "LRR: iteration root match failed at " << *BaseInstdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: iteration root match failed at " << *BaseInst << " vs. " << *RootInst << " (side effects prevent reordering)\n"; } } while (false) | |||
| 1320 | << " vs. " << *RootInstdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: iteration root match failed at " << *BaseInst << " vs. " << *RootInst << " (side effects prevent reordering)\n"; } } while (false) | |||
| 1321 | << " (side effects prevent reordering)\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: iteration root match failed at " << *BaseInst << " vs. " << *RootInst << " (side effects prevent reordering)\n"; } } while (false); | |||
| 1322 | return false; | |||
| 1323 | } | |||
| 1324 | ||||
| 1325 | // For instructions that are part of a reduction, if the operation is | |||
| 1326 | // associative, then don't bother matching the operands (because we | |||
| 1327 | // already know that the instructions are isomorphic, and the order | |||
| 1328 | // within the iteration does not matter). For non-associative reductions, | |||
| 1329 | // we do need to match the operands, because we need to reject | |||
| 1330 | // out-of-order instructions within an iteration! | |||
| 1331 | // For example (assume floating-point addition), we need to reject this: | |||
| 1332 | // x += a[i]; x += b[i]; | |||
| 1333 | // x += a[i+1]; x += b[i+1]; | |||
| 1334 | // x += b[i+2]; x += a[i+2]; | |||
| 1335 | bool InReduction = Reductions.isPairInSame(BaseInst, RootInst); | |||
| 1336 | ||||
| 1337 | if (!(InReduction && BaseInst->isAssociative())) { | |||
| 1338 | bool Swapped = false, SomeOpMatched = false; | |||
| 1339 | for (unsigned j = 0; j < BaseInst->getNumOperands(); ++j) { | |||
| 1340 | Value *Op2 = RootInst->getOperand(j); | |||
| 1341 | ||||
| 1342 | // If this is part of a reduction (and the operation is not | |||
| 1343 | // associatve), then we match all operands, but not those that are | |||
| 1344 | // part of the reduction. | |||
| 1345 | if (InReduction) | |||
| 1346 | if (Instruction *Op2I = dyn_cast<Instruction>(Op2)) | |||
| 1347 | if (Reductions.isPairInSame(RootInst, Op2I)) | |||
| 1348 | continue; | |||
| 1349 | ||||
| 1350 | DenseMap<Value *, Value *>::iterator BMI = BaseMap.find(Op2); | |||
| 1351 | if (BMI != BaseMap.end()) { | |||
| 1352 | Op2 = BMI->second; | |||
| 1353 | } else { | |||
| 1354 | for (auto &DRS : RootSets) { | |||
| 1355 | if (DRS.Roots[Iter-1] == (Instruction*) Op2) { | |||
| 1356 | Op2 = DRS.BaseInst; | |||
| 1357 | break; | |||
| 1358 | } | |||
| 1359 | } | |||
| 1360 | } | |||
| 1361 | ||||
| 1362 | if (BaseInst->getOperand(Swapped ? unsigned(!j) : j) != Op2) { | |||
| 1363 | // If we've not already decided to swap the matched operands, and | |||
| 1364 | // we've not already matched our first operand (note that we could | |||
| 1365 | // have skipped matching the first operand because it is part of a | |||
| 1366 | // reduction above), and the instruction is commutative, then try | |||
| 1367 | // the swapped match. | |||
| 1368 | if (!Swapped && BaseInst->isCommutative() && !SomeOpMatched && | |||
| 1369 | BaseInst->getOperand(!j) == Op2) { | |||
| 1370 | Swapped = true; | |||
| 1371 | } else { | |||
| 1372 | LLVM_DEBUG(dbgs()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: iteration root match failed at " << *BaseInst << " vs. " << *RootInst << " (operand " << j << ")\n"; } } while (false) | |||
| 1373 | << "LRR: iteration root match failed at " << *BaseInstdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: iteration root match failed at " << *BaseInst << " vs. " << *RootInst << " (operand " << j << ")\n"; } } while (false) | |||
| 1374 | << " vs. " << *RootInst << " (operand " << j << ")\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: iteration root match failed at " << *BaseInst << " vs. " << *RootInst << " (operand " << j << ")\n"; } } while (false); | |||
| 1375 | return false; | |||
| 1376 | } | |||
| 1377 | } | |||
| 1378 | ||||
| 1379 | SomeOpMatched = true; | |||
| 1380 | } | |||
| 1381 | } | |||
| 1382 | ||||
| 1383 | if ((!PossibleRedLastSet.count(BaseInst) && | |||
| 1384 | hasUsesOutsideLoop(BaseInst, L)) || | |||
| 1385 | (!PossibleRedLastSet.count(RootInst) && | |||
| 1386 | hasUsesOutsideLoop(RootInst, L))) { | |||
| 1387 | LLVM_DEBUG(dbgs() << "LRR: iteration root match failed at " << *BaseInstdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: iteration root match failed at " << *BaseInst << " vs. " << *RootInst << " (uses outside loop)\n"; } } while (false) | |||
| 1388 | << " vs. " << *RootInst << " (uses outside loop)\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: iteration root match failed at " << *BaseInst << " vs. " << *RootInst << " (uses outside loop)\n"; } } while (false); | |||
| 1389 | return false; | |||
| 1390 | } | |||
| 1391 | ||||
| 1392 | Reductions.recordPair(BaseInst, RootInst, Iter); | |||
| 1393 | BaseMap.insert(std::make_pair(RootInst, BaseInst)); | |||
| 1394 | ||||
| 1395 | LastRootIt = RootIt; | |||
| 1396 | Visited.insert(BaseInst); | |||
| 1397 | Visited.insert(RootInst); | |||
| 1398 | BaseIt = nextInstr(0, Uses, Visited); | |||
| 1399 | RootIt = nextInstr(Iter, Uses, Visited); | |||
| 1400 | } | |||
| 1401 | assert(BaseIt == Uses.end() && RootIt == Uses.end() &&(static_cast <bool> (BaseIt == Uses.end() && RootIt == Uses.end() && "Mismatched set sizes!") ? void (0) : __assert_fail ("BaseIt == Uses.end() && RootIt == Uses.end() && \"Mismatched set sizes!\"" , "/build/llvm-toolchain-snapshot-7~svn338205/lib/Transforms/Scalar/LoopRerollPass.cpp" , 1402, __extension__ __PRETTY_FUNCTION__)) | |||
| 1402 | "Mismatched set sizes!")(static_cast <bool> (BaseIt == Uses.end() && RootIt == Uses.end() && "Mismatched set sizes!") ? void (0) : __assert_fail ("BaseIt == Uses.end() && RootIt == Uses.end() && \"Mismatched set sizes!\"" , "/build/llvm-toolchain-snapshot-7~svn338205/lib/Transforms/Scalar/LoopRerollPass.cpp" , 1402, __extension__ __PRETTY_FUNCTION__)); | |||
| 1403 | } | |||
| 1404 | ||||
| 1405 | LLVM_DEBUG(dbgs() << "LRR: Matched all iteration increments for " << *IVdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Matched all iteration increments for " << *IV << "\n"; } } while (false) | |||
| 1406 | << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Matched all iteration increments for " << *IV << "\n"; } } while (false); | |||
| 1407 | ||||
| 1408 | return true; | |||
| 1409 | } | |||
| 1410 | ||||
| 1411 | void LoopReroll::DAGRootTracker::replace(const SCEV *BackedgeTakenCount) { | |||
| 1412 | BasicBlock *Header = L->getHeader(); | |||
| 1413 | ||||
| 1414 | // Compute the start and increment for each BaseInst before we start erasing | |||
| 1415 | // instructions. | |||
| 1416 | SmallVector<const SCEV *, 8> StartExprs; | |||
| 1417 | SmallVector<const SCEV *, 8> IncrExprs; | |||
| 1418 | for (auto &DRS : RootSets) { | |||
| 1419 | const SCEVAddRecExpr *IVSCEV = | |||
| 1420 | cast<SCEVAddRecExpr>(SE->getSCEV(DRS.BaseInst)); | |||
| 1421 | StartExprs.push_back(IVSCEV->getStart()); | |||
| 1422 | IncrExprs.push_back(SE->getMinusSCEV(SE->getSCEV(DRS.Roots[0]), IVSCEV)); | |||
| 1423 | } | |||
| 1424 | ||||
| 1425 | // Remove instructions associated with non-base iterations. | |||
| 1426 | for (BasicBlock::reverse_iterator J = Header->rbegin(), JE = Header->rend(); | |||
| 1427 | J != JE;) { | |||
| 1428 | unsigned I = Uses[&*J].find_first(); | |||
| 1429 | if (I > 0 && I < IL_All) { | |||
| 1430 | LLVM_DEBUG(dbgs() << "LRR: removing: " << *J << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: removing: " << *J << "\n"; } } while (false); | |||
| 1431 | J++->eraseFromParent(); | |||
| 1432 | continue; | |||
| 1433 | } | |||
| 1434 | ||||
| 1435 | ++J; | |||
| 1436 | } | |||
| 1437 | ||||
| 1438 | // Rewrite each BaseInst using SCEV. | |||
| 1439 | for (size_t i = 0, e = RootSets.size(); i != e; ++i) | |||
| 1440 | // Insert the new induction variable. | |||
| 1441 | replaceIV(RootSets[i], StartExprs[i], IncrExprs[i]); | |||
| 1442 | ||||
| 1443 | { // Limit the lifetime of SCEVExpander. | |||
| 1444 | BranchInst *BI = cast<BranchInst>(Header->getTerminator()); | |||
| 1445 | const DataLayout &DL = Header->getModule()->getDataLayout(); | |||
| 1446 | SCEVExpander Expander(*SE, DL, "reroll"); | |||
| 1447 | auto Zero = SE->getZero(BackedgeTakenCount->getType()); | |||
| 1448 | auto One = SE->getOne(BackedgeTakenCount->getType()); | |||
| 1449 | auto NewIVSCEV = SE->getAddRecExpr(Zero, One, L, SCEV::FlagAnyWrap); | |||
| 1450 | Value *NewIV = | |||
| 1451 | Expander.expandCodeFor(NewIVSCEV, BackedgeTakenCount->getType(), | |||
| 1452 | Header->getFirstNonPHIOrDbg()); | |||
| 1453 | // FIXME: This arithmetic can overflow. | |||
| 1454 | auto TripCount = SE->getAddExpr(BackedgeTakenCount, One); | |||
| 1455 | auto ScaledTripCount = SE->getMulExpr( | |||
| 1456 | TripCount, SE->getConstant(BackedgeTakenCount->getType(), Scale)); | |||
| 1457 | auto ScaledBECount = SE->getMinusSCEV(ScaledTripCount, One); | |||
| 1458 | Value *TakenCount = | |||
| 1459 | Expander.expandCodeFor(ScaledBECount, BackedgeTakenCount->getType(), | |||
| 1460 | Header->getFirstNonPHIOrDbg()); | |||
| 1461 | Value *Cond = | |||
| 1462 | new ICmpInst(BI, CmpInst::ICMP_EQ, NewIV, TakenCount, "exitcond"); | |||
| 1463 | BI->setCondition(Cond); | |||
| 1464 | ||||
| 1465 | if (BI->getSuccessor(1) != Header) | |||
| 1466 | BI->swapSuccessors(); | |||
| 1467 | } | |||
| 1468 | ||||
| 1469 | SimplifyInstructionsInBlock(Header, TLI); | |||
| 1470 | DeleteDeadPHIs(Header, TLI); | |||
| 1471 | } | |||
| 1472 | ||||
| 1473 | void LoopReroll::DAGRootTracker::replaceIV(DAGRootSet &DRS, | |||
| 1474 | const SCEV *Start, | |||
| 1475 | const SCEV *IncrExpr) { | |||
| 1476 | BasicBlock *Header = L->getHeader(); | |||
| 1477 | Instruction *Inst = DRS.BaseInst; | |||
| 1478 | ||||
| 1479 | const SCEV *NewIVSCEV = | |||
| 1480 | SE->getAddRecExpr(Start, IncrExpr, L, SCEV::FlagAnyWrap); | |||
| 1481 | ||||
| 1482 | { // Limit the lifetime of SCEVExpander. | |||
| 1483 | const DataLayout &DL = Header->getModule()->getDataLayout(); | |||
| 1484 | SCEVExpander Expander(*SE, DL, "reroll"); | |||
| 1485 | Value *NewIV = Expander.expandCodeFor(NewIVSCEV, Inst->getType(), | |||
| 1486 | Header->getFirstNonPHIOrDbg()); | |||
| 1487 | ||||
| 1488 | for (auto &KV : Uses) | |||
| 1489 | if (KV.second.find_first() == 0) | |||
| 1490 | KV.first->replaceUsesOfWith(Inst, NewIV); | |||
| 1491 | } | |||
| 1492 | } | |||
| 1493 | ||||
| 1494 | // Validate the selected reductions. All iterations must have an isomorphic | |||
| 1495 | // part of the reduction chain and, for non-associative reductions, the chain | |||
| 1496 | // entries must appear in order. | |||
| 1497 | bool LoopReroll::ReductionTracker::validateSelected() { | |||
| 1498 | // For a non-associative reduction, the chain entries must appear in order. | |||
| 1499 | for (int i : Reds) { | |||
| 1500 | int PrevIter = 0, BaseCount = 0, Count = 0; | |||
| 1501 | for (Instruction *J : PossibleReds[i]) { | |||
| 1502 | // Note that all instructions in the chain must have been found because | |||
| 1503 | // all instructions in the function must have been assigned to some | |||
| 1504 | // iteration. | |||
| 1505 | int Iter = PossibleRedIter[J]; | |||
| 1506 | if (Iter != PrevIter && Iter != PrevIter + 1 && | |||
| 1507 | !PossibleReds[i].getReducedValue()->isAssociative()) { | |||
| 1508 | LLVM_DEBUG(dbgs() << "LRR: Out-of-order non-associative reduction: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Out-of-order non-associative reduction: " << J << "\n"; } } while (false) | |||
| 1509 | << J << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Out-of-order non-associative reduction: " << J << "\n"; } } while (false); | |||
| 1510 | return false; | |||
| 1511 | } | |||
| 1512 | ||||
| 1513 | if (Iter != PrevIter) { | |||
| 1514 | if (Count != BaseCount) { | |||
| 1515 | LLVM_DEBUG(dbgs()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Iteration " << PrevIter << " reduction use count " << Count << " is not equal to the base use count " << BaseCount << "\n"; } } while (false) | |||
| 1516 | << "LRR: Iteration " << PrevIter << " reduction use count "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Iteration " << PrevIter << " reduction use count " << Count << " is not equal to the base use count " << BaseCount << "\n"; } } while (false) | |||
| 1517 | << Count << " is not equal to the base use count "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Iteration " << PrevIter << " reduction use count " << Count << " is not equal to the base use count " << BaseCount << "\n"; } } while (false) | |||
| 1518 | << BaseCount << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Iteration " << PrevIter << " reduction use count " << Count << " is not equal to the base use count " << BaseCount << "\n"; } } while (false); | |||
| 1519 | return false; | |||
| 1520 | } | |||
| 1521 | ||||
| 1522 | Count = 0; | |||
| 1523 | } | |||
| 1524 | ||||
| 1525 | ++Count; | |||
| 1526 | if (Iter == 0) | |||
| 1527 | ++BaseCount; | |||
| 1528 | ||||
| 1529 | PrevIter = Iter; | |||
| 1530 | } | |||
| 1531 | } | |||
| 1532 | ||||
| 1533 | return true; | |||
| 1534 | } | |||
| 1535 | ||||
| 1536 | // For all selected reductions, remove all parts except those in the first | |||
| 1537 | // iteration (and the PHI). Replace outside uses of the reduced value with uses | |||
| 1538 | // of the first-iteration reduced value (in other words, reroll the selected | |||
| 1539 | // reductions). | |||
| 1540 | void LoopReroll::ReductionTracker::replaceSelected() { | |||
| 1541 | // Fixup reductions to refer to the last instruction associated with the | |||
| 1542 | // first iteration (not the last). | |||
| 1543 | for (int i : Reds) { | |||
| 1544 | int j = 0; | |||
| 1545 | for (int e = PossibleReds[i].size(); j != e; ++j) | |||
| 1546 | if (PossibleRedIter[PossibleReds[i][j]] != 0) { | |||
| 1547 | --j; | |||
| 1548 | break; | |||
| 1549 | } | |||
| 1550 | ||||
| 1551 | // Replace users with the new end-of-chain value. | |||
| 1552 | SmallInstructionVector Users; | |||
| 1553 | for (User *U : PossibleReds[i].getReducedValue()->users()) { | |||
| 1554 | Users.push_back(cast<Instruction>(U)); | |||
| 1555 | } | |||
| 1556 | ||||
| 1557 | for (Instruction *User : Users) | |||
| 1558 | User->replaceUsesOfWith(PossibleReds[i].getReducedValue(), | |||
| 1559 | PossibleReds[i][j]); | |||
| 1560 | } | |||
| 1561 | } | |||
| 1562 | ||||
| 1563 | // Reroll the provided loop with respect to the provided induction variable. | |||
| 1564 | // Generally, we're looking for a loop like this: | |||
| 1565 | // | |||
| 1566 | // %iv = phi [ (preheader, ...), (body, %iv.next) ] | |||
| 1567 | // f(%iv) | |||
| 1568 | // %iv.1 = add %iv, 1 <-- a root increment | |||
| 1569 | // f(%iv.1) | |||
| 1570 | // %iv.2 = add %iv, 2 <-- a root increment | |||
| 1571 | // f(%iv.2) | |||
| 1572 | // %iv.scale_m_1 = add %iv, scale-1 <-- a root increment | |||
| 1573 | // f(%iv.scale_m_1) | |||
| 1574 | // ... | |||
| 1575 | // %iv.next = add %iv, scale | |||
| 1576 | // %cmp = icmp(%iv, ...) | |||
| 1577 | // br %cmp, header, exit | |||
| 1578 | // | |||
| 1579 | // Notably, we do not require that f(%iv), f(%iv.1), etc. be isolated groups of | |||
| 1580 | // instructions. In other words, the instructions in f(%iv), f(%iv.1), etc. can | |||
| 1581 | // be intermixed with eachother. The restriction imposed by this algorithm is | |||
| 1582 | // that the relative order of the isomorphic instructions in f(%iv), f(%iv.1), | |||
| 1583 | // etc. be the same. | |||
| 1584 | // | |||
| 1585 | // First, we collect the use set of %iv, excluding the other increment roots. | |||
| 1586 | // This gives us f(%iv). Then we iterate over the loop instructions (scale-1) | |||
| 1587 | // times, having collected the use set of f(%iv.(i+1)), during which we: | |||
| 1588 | // - Ensure that the next unmatched instruction in f(%iv) is isomorphic to | |||
| 1589 | // the next unmatched instruction in f(%iv.(i+1)). | |||
| 1590 | // - Ensure that both matched instructions don't have any external users | |||
| 1591 | // (with the exception of last-in-chain reduction instructions). | |||
| 1592 | // - Track the (aliasing) write set, and other side effects, of all | |||
| 1593 | // instructions that belong to future iterations that come before the matched | |||
| 1594 | // instructions. If the matched instructions read from that write set, then | |||
| 1595 | // f(%iv) or f(%iv.(i+1)) has some dependency on instructions in | |||
| 1596 | // f(%iv.(j+1)) for some j > i, and we cannot reroll the loop. Similarly, | |||
| 1597 | // if any of these future instructions had side effects (could not be | |||
| 1598 | // speculatively executed), and so do the matched instructions, when we | |||
| 1599 | // cannot reorder those side-effect-producing instructions, and rerolling | |||
| 1600 | // fails. | |||
| 1601 | // | |||
| 1602 | // Finally, we make sure that all loop instructions are either loop increment | |||
| 1603 | // roots, belong to simple latch code, parts of validated reductions, part of | |||
| 1604 | // f(%iv) or part of some f(%iv.i). If all of that is true (and all reductions | |||
| 1605 | // have been validated), then we reroll the loop. | |||
| 1606 | bool LoopReroll::reroll(Instruction *IV, Loop *L, BasicBlock *Header, | |||
| 1607 | const SCEV *BackedgeTakenCount, | |||
| 1608 | ReductionTracker &Reductions) { | |||
| 1609 | DAGRootTracker DAGRoots(this, L, IV, SE, AA, TLI, DT, LI, PreserveLCSSA, | |||
| 1610 | IVToIncMap, LoopControlIV); | |||
| 1611 | ||||
| 1612 | if (!DAGRoots.findRoots()) | |||
| 1613 | return false; | |||
| 1614 | LLVM_DEBUG(dbgs() << "LRR: Found all root induction increments for: " << *IVdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Found all root induction increments for: " << *IV << "\n"; } } while (false) | |||
| 1615 | << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: Found all root induction increments for: " << *IV << "\n"; } } while (false); | |||
| 1616 | ||||
| 1617 | if (!DAGRoots.validate(Reductions)) | |||
| 1618 | return false; | |||
| 1619 | if (!Reductions.validateSelected()) | |||
| 1620 | return false; | |||
| 1621 | // At this point, we've validated the rerolling, and we're committed to | |||
| 1622 | // making changes! | |||
| 1623 | ||||
| 1624 | Reductions.replaceSelected(); | |||
| 1625 | DAGRoots.replace(BackedgeTakenCount); | |||
| 1626 | ||||
| 1627 | ++NumRerolledLoops; | |||
| 1628 | return true; | |||
| 1629 | } | |||
| 1630 | ||||
| 1631 | bool LoopReroll::runOnLoop(Loop *L, LPPassManager &LPM) { | |||
| 1632 | if (skipLoop(L)) | |||
| ||||
| 1633 | return false; | |||
| 1634 | ||||
| 1635 | AA = &getAnalysis<AAResultsWrapperPass>().getAAResults(); | |||
| 1636 | LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo(); | |||
| 1637 | SE = &getAnalysis<ScalarEvolutionWrapperPass>().getSE(); | |||
| 1638 | TLI = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI(); | |||
| 1639 | DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree(); | |||
| 1640 | PreserveLCSSA = mustPreserveAnalysisID(LCSSAID); | |||
| 1641 | ||||
| 1642 | BasicBlock *Header = L->getHeader(); | |||
| 1643 | LLVM_DEBUG(dbgs() << "LRR: F[" << Header->getParent()->getName() << "] Loop %"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: F[" << Header-> getParent()->getName() << "] Loop %" << Header ->getName() << " (" << L->getNumBlocks() << " block(s))\n"; } } while (false) | |||
| 1644 | << Header->getName() << " (" << L->getNumBlocks()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: F[" << Header-> getParent()->getName() << "] Loop %" << Header ->getName() << " (" << L->getNumBlocks() << " block(s))\n"; } } while (false) | |||
| 1645 | << " block(s))\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: F[" << Header-> getParent()->getName() << "] Loop %" << Header ->getName() << " (" << L->getNumBlocks() << " block(s))\n"; } } while (false); | |||
| 1646 | ||||
| 1647 | // For now, we'll handle only single BB loops. | |||
| 1648 | if (L->getNumBlocks() > 1) | |||
| 1649 | return false; | |||
| 1650 | ||||
| 1651 | if (!SE->hasLoopInvariantBackedgeTakenCount(L)) | |||
| 1652 | return false; | |||
| 1653 | ||||
| 1654 | const SCEV *BackedgeTakenCount = SE->getBackedgeTakenCount(L); | |||
| 1655 | LLVM_DEBUG(dbgs() << "\n Before Reroll:\n" << *(L->getHeader()) << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "\n Before Reroll:\n" << *(L->getHeader()) << "\n"; } } while (false); | |||
| 1656 | LLVM_DEBUG(dbgs() << "LRR: backedge-taken count = " << *BackedgeTakenCountdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: backedge-taken count = " << *BackedgeTakenCount << "\n"; } } while (false ) | |||
| 1657 | << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: backedge-taken count = " << *BackedgeTakenCount << "\n"; } } while (false ); | |||
| 1658 | ||||
| 1659 | // First, we need to find the induction variable with respect to which we can | |||
| 1660 | // reroll (there may be several possible options). | |||
| 1661 | SmallInstructionVector PossibleIVs; | |||
| 1662 | IVToIncMap.clear(); | |||
| 1663 | LoopControlIV = nullptr; | |||
| 1664 | collectPossibleIVs(L, PossibleIVs); | |||
| 1665 | ||||
| 1666 | if (PossibleIVs.empty()) { | |||
| 1667 | LLVM_DEBUG(dbgs() << "LRR: No possible IVs found\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "LRR: No possible IVs found\n" ; } } while (false); | |||
| 1668 | return false; | |||
| 1669 | } | |||
| 1670 | ||||
| 1671 | ReductionTracker Reductions; | |||
| 1672 | collectPossibleReductions(L, Reductions); | |||
| 1673 | bool Changed = false; | |||
| 1674 | ||||
| 1675 | // For each possible IV, collect the associated possible set of 'root' nodes | |||
| 1676 | // (i+1, i+2, etc.). | |||
| 1677 | for (Instruction *PossibleIV : PossibleIVs) | |||
| 1678 | if (reroll(PossibleIV, L, Header, BackedgeTakenCount, Reductions)) { | |||
| 1679 | Changed = true; | |||
| 1680 | break; | |||
| 1681 | } | |||
| 1682 | LLVM_DEBUG(dbgs() << "\n After Reroll:\n" << *(L->getHeader()) << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("loop-reroll")) { dbgs() << "\n After Reroll:\n" << *(L->getHeader()) << "\n"; } } while (false); | |||
| 1683 | ||||
| 1684 | // Trip count of L has changed so SE must be re-evaluated. | |||
| 1685 | if (Changed) | |||
| 1686 | SE->forgetLoop(L); | |||
| 1687 | ||||
| 1688 | return Changed; | |||
| 1689 | } |
| 1 | //===- llvm/Support/Casting.h - Allow flexible, checked, casts --*- 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 file defines the isa<X>(), cast<X>(), dyn_cast<X>(), cast_or_null<X>(), |
| 11 | // and dyn_cast_or_null<X>() templates. |
| 12 | // |
| 13 | //===----------------------------------------------------------------------===// |
| 14 | |
| 15 | #ifndef LLVM_SUPPORT_CASTING_H |
| 16 | #define LLVM_SUPPORT_CASTING_H |
| 17 | |
| 18 | #include "llvm/Support/Compiler.h" |
| 19 | #include "llvm/Support/type_traits.h" |
| 20 | #include <cassert> |
| 21 | #include <memory> |
| 22 | #include <type_traits> |
| 23 | |
| 24 | namespace llvm { |
| 25 | |
| 26 | //===----------------------------------------------------------------------===// |
| 27 | // isa<x> Support Templates |
| 28 | //===----------------------------------------------------------------------===// |
| 29 | |
| 30 | // Define a template that can be specialized by smart pointers to reflect the |
| 31 | // fact that they are automatically dereferenced, and are not involved with the |
| 32 | // template selection process... the default implementation is a noop. |
| 33 | // |
| 34 | template<typename From> struct simplify_type { |
| 35 | using SimpleType = From; // The real type this represents... |
| 36 | |
| 37 | // An accessor to get the real value... |
| 38 | static SimpleType &getSimplifiedValue(From &Val) { return Val; } |
| 39 | }; |
| 40 | |
| 41 | template<typename From> struct simplify_type<const From> { |
| 42 | using NonConstSimpleType = typename simplify_type<From>::SimpleType; |
| 43 | using SimpleType = |
| 44 | typename add_const_past_pointer<NonConstSimpleType>::type; |
| 45 | using RetType = |
| 46 | typename add_lvalue_reference_if_not_pointer<SimpleType>::type; |
| 47 | |
| 48 | static RetType getSimplifiedValue(const From& Val) { |
| 49 | return simplify_type<From>::getSimplifiedValue(const_cast<From&>(Val)); |
| 50 | } |
| 51 | }; |
| 52 | |
| 53 | // The core of the implementation of isa<X> is here; To and From should be |
| 54 | // the names of classes. This template can be specialized to customize the |
| 55 | // implementation of isa<> without rewriting it from scratch. |
| 56 | template <typename To, typename From, typename Enabler = void> |
| 57 | struct isa_impl { |
| 58 | static inline bool doit(const From &Val) { |
| 59 | return To::classof(&Val); |
| 60 | } |
| 61 | }; |
| 62 | |
| 63 | /// Always allow upcasts, and perform no dynamic check for them. |
| 64 | template <typename To, typename From> |
| 65 | struct isa_impl< |
| 66 | To, From, typename std::enable_if<std::is_base_of<To, From>::value>::type> { |
| 67 | static inline bool doit(const From &) { return true; } |
| 68 | }; |
| 69 | |
| 70 | template <typename To, typename From> struct isa_impl_cl { |
| 71 | static inline bool doit(const From &Val) { |
| 72 | return isa_impl<To, From>::doit(Val); |
| 73 | } |
| 74 | }; |
| 75 | |
| 76 | template <typename To, typename From> struct isa_impl_cl<To, const From> { |
| 77 | static inline bool doit(const From &Val) { |
| 78 | return isa_impl<To, From>::doit(Val); |
| 79 | } |
| 80 | }; |
| 81 | |
| 82 | template <typename To, typename From> |
| 83 | struct isa_impl_cl<To, const std::unique_ptr<From>> { |
| 84 | static inline bool doit(const std::unique_ptr<From> &Val) { |
| 85 | assert(Val && "isa<> used on a null pointer")(static_cast <bool> (Val && "isa<> used on a null pointer" ) ? void (0) : __assert_fail ("Val && \"isa<> used on a null pointer\"" , "/build/llvm-toolchain-snapshot-7~svn338205/include/llvm/Support/Casting.h" , 85, __extension__ __PRETTY_FUNCTION__)); |
| 86 | return isa_impl_cl<To, From>::doit(*Val); |
| 87 | } |
| 88 | }; |
| 89 | |
| 90 | template <typename To, typename From> struct isa_impl_cl<To, From*> { |
| 91 | static inline bool doit(const From *Val) { |
| 92 | assert(Val && "isa<> used on a null pointer")(static_cast <bool> (Val && "isa<> used on a null pointer" ) ? void (0) : __assert_fail ("Val && \"isa<> used on a null pointer\"" , "/build/llvm-toolchain-snapshot-7~svn338205/include/llvm/Support/Casting.h" , 92, __extension__ __PRETTY_FUNCTION__)); |
| 93 | return isa_impl<To, From>::doit(*Val); |
| 94 | } |
| 95 | }; |
| 96 | |
| 97 | template <typename To, typename From> struct isa_impl_cl<To, From*const> { |
| 98 | static inline bool doit(const From *Val) { |
| 99 | assert(Val && "isa<> used on a null pointer")(static_cast <bool> (Val && "isa<> used on a null pointer" ) ? void (0) : __assert_fail ("Val && \"isa<> used on a null pointer\"" , "/build/llvm-toolchain-snapshot-7~svn338205/include/llvm/Support/Casting.h" , 99, __extension__ __PRETTY_FUNCTION__)); |
| 100 | return isa_impl<To, From>::doit(*Val); |
| 101 | } |
| 102 | }; |
| 103 | |
| 104 | template <typename To, typename From> struct isa_impl_cl<To, const From*> { |
| 105 | static inline bool doit(const From *Val) { |
| 106 | assert(Val && "isa<> used on a null pointer")(static_cast <bool> (Val && "isa<> used on a null pointer" ) ? void (0) : __assert_fail ("Val && \"isa<> used on a null pointer\"" , "/build/llvm-toolchain-snapshot-7~svn338205/include/llvm/Support/Casting.h" , 106, __extension__ __PRETTY_FUNCTION__)); |
| 107 | return isa_impl<To, From>::doit(*Val); |
| 108 | } |
| 109 | }; |
| 110 | |
| 111 | template <typename To, typename From> struct isa_impl_cl<To, const From*const> { |
| 112 | static inline bool doit(const From *Val) { |
| 113 | assert(Val && "isa<> used on a null pointer")(static_cast <bool> (Val && "isa<> used on a null pointer" ) ? void (0) : __assert_fail ("Val && \"isa<> used on a null pointer\"" , "/build/llvm-toolchain-snapshot-7~svn338205/include/llvm/Support/Casting.h" , 113, __extension__ __PRETTY_FUNCTION__)); |
| 114 | return isa_impl<To, From>::doit(*Val); |
| 115 | } |
| 116 | }; |
| 117 | |
| 118 | template<typename To, typename From, typename SimpleFrom> |
| 119 | struct isa_impl_wrap { |
| 120 | // When From != SimplifiedType, we can simplify the type some more by using |
| 121 | // the simplify_type template. |
| 122 | static bool doit(const From &Val) { |
| 123 | return isa_impl_wrap<To, SimpleFrom, |
| 124 | typename simplify_type<SimpleFrom>::SimpleType>::doit( |
| 125 | simplify_type<const From>::getSimplifiedValue(Val)); |
| 126 | } |
| 127 | }; |
| 128 | |
| 129 | template<typename To, typename FromTy> |
| 130 | struct isa_impl_wrap<To, FromTy, FromTy> { |
| 131 | // When From == SimpleType, we are as simple as we are going to get. |
| 132 | static bool doit(const FromTy &Val) { |
| 133 | return isa_impl_cl<To,FromTy>::doit(Val); |
| 134 | } |
| 135 | }; |
| 136 | |
| 137 | // isa<X> - Return true if the parameter to the template is an instance of the |
| 138 | // template type argument. Used like this: |
| 139 | // |
| 140 | // if (isa<Type>(myVal)) { ... } |
| 141 | // |
| 142 | template <class X, class Y> LLVM_NODISCARD[[clang::warn_unused_result]] inline bool isa(const Y &Val) { |
| 143 | return isa_impl_wrap<X, const Y, |
| 144 | typename simplify_type<const Y>::SimpleType>::doit(Val); |
| 145 | } |
| 146 | |
| 147 | //===----------------------------------------------------------------------===// |
| 148 | // cast<x> Support Templates |
| 149 | //===----------------------------------------------------------------------===// |
| 150 | |
| 151 | template<class To, class From> struct cast_retty; |
| 152 | |
| 153 | // Calculate what type the 'cast' function should return, based on a requested |
| 154 | // type of To and a source type of From. |
| 155 | template<class To, class From> struct cast_retty_impl { |
| 156 | using ret_type = To &; // Normal case, return Ty& |
| 157 | }; |
| 158 | template<class To, class From> struct cast_retty_impl<To, const From> { |
| 159 | using ret_type = const To &; // Normal case, return Ty& |
| 160 | }; |
| 161 | |
| 162 | template<class To, class From> struct cast_retty_impl<To, From*> { |
| 163 | using ret_type = To *; // Pointer arg case, return Ty* |
| 164 | }; |
| 165 | |
| 166 | template<class To, class From> struct cast_retty_impl<To, const From*> { |
| 167 | using ret_type = const To *; // Constant pointer arg case, return const Ty* |
| 168 | }; |
| 169 | |
| 170 | template<class To, class From> struct cast_retty_impl<To, const From*const> { |
| 171 | using ret_type = const To *; // Constant pointer arg case, return const Ty* |
| 172 | }; |
| 173 | |
| 174 | template <class To, class From> |
| 175 | struct cast_retty_impl<To, std::unique_ptr<From>> { |
| 176 | private: |
| 177 | using PointerType = typename cast_retty_impl<To, From *>::ret_type; |
| 178 | using ResultType = typename std::remove_pointer<PointerType>::type; |
| 179 | |
| 180 | public: |
| 181 | using ret_type = std::unique_ptr<ResultType>; |
| 182 | }; |
| 183 | |
| 184 | template<class To, class From, class SimpleFrom> |
| 185 | struct cast_retty_wrap { |
| 186 | // When the simplified type and the from type are not the same, use the type |
| 187 | // simplifier to reduce the type, then reuse cast_retty_impl to get the |
| 188 | // resultant type. |
| 189 | using ret_type = typename cast_retty<To, SimpleFrom>::ret_type; |
| 190 | }; |
| 191 | |
| 192 | template<class To, class FromTy> |
| 193 | struct cast_retty_wrap<To, FromTy, FromTy> { |
| 194 | // When the simplified type is equal to the from type, use it directly. |
| 195 | using ret_type = typename cast_retty_impl<To,FromTy>::ret_type; |
| 196 | }; |
| 197 | |
| 198 | template<class To, class From> |
| 199 | struct cast_retty { |
| 200 | using ret_type = typename cast_retty_wrap< |
| 201 | To, From, typename simplify_type<From>::SimpleType>::ret_type; |
| 202 | }; |
| 203 | |
| 204 | // Ensure the non-simple values are converted using the simplify_type template |
| 205 | // that may be specialized by smart pointers... |
| 206 | // |
| 207 | template<class To, class From, class SimpleFrom> struct cast_convert_val { |
| 208 | // This is not a simple type, use the template to simplify it... |
| 209 | static typename cast_retty<To, From>::ret_type doit(From &Val) { |
| 210 | return cast_convert_val<To, SimpleFrom, |
| 211 | typename simplify_type<SimpleFrom>::SimpleType>::doit( |
| 212 | simplify_type<From>::getSimplifiedValue(Val)); |
| 213 | } |
| 214 | }; |
| 215 | |
| 216 | template<class To, class FromTy> struct cast_convert_val<To,FromTy,FromTy> { |
| 217 | // This _is_ a simple type, just cast it. |
| 218 | static typename cast_retty<To, FromTy>::ret_type doit(const FromTy &Val) { |
| 219 | typename cast_retty<To, FromTy>::ret_type Res2 |
| 220 | = (typename cast_retty<To, FromTy>::ret_type)const_cast<FromTy&>(Val); |
| 221 | return Res2; |
| 222 | } |
| 223 | }; |
| 224 | |
| 225 | template <class X> struct is_simple_type { |
| 226 | static const bool value = |
| 227 | std::is_same<X, typename simplify_type<X>::SimpleType>::value; |
| 228 | }; |
| 229 | |
| 230 | // cast<X> - Return the argument parameter cast to the specified type. This |
| 231 | // casting operator asserts that the type is correct, so it does not return null |
| 232 | // on failure. It does not allow a null argument (use cast_or_null for that). |
| 233 | // It is typically used like this: |
| 234 | // |
| 235 | // cast<Instruction>(myVal)->getParent() |
| 236 | // |
| 237 | template <class X, class Y> |
| 238 | inline typename std::enable_if<!is_simple_type<Y>::value, |
| 239 | typename cast_retty<X, const Y>::ret_type>::type |
| 240 | cast(const Y &Val) { |
| 241 | assert(isa<X>(Val) && "cast<Ty>() argument of incompatible type!")(static_cast <bool> (isa<X>(Val) && "cast<Ty>() argument of incompatible type!" ) ? void (0) : __assert_fail ("isa<X>(Val) && \"cast<Ty>() argument of incompatible type!\"" , "/build/llvm-toolchain-snapshot-7~svn338205/include/llvm/Support/Casting.h" , 241, __extension__ __PRETTY_FUNCTION__)); |
| 242 | return cast_convert_val< |
| 243 | X, const Y, typename simplify_type<const Y>::SimpleType>::doit(Val); |
| 244 | } |
| 245 | |
| 246 | template <class X, class Y> |
| 247 | inline typename cast_retty<X, Y>::ret_type cast(Y &Val) { |
| 248 | assert(isa<X>(Val) && "cast<Ty>() argument of incompatible type!")(static_cast <bool> (isa<X>(Val) && "cast<Ty>() argument of incompatible type!" ) ? void (0) : __assert_fail ("isa<X>(Val) && \"cast<Ty>() argument of incompatible type!\"" , "/build/llvm-toolchain-snapshot-7~svn338205/include/llvm/Support/Casting.h" , 248, __extension__ __PRETTY_FUNCTION__)); |
| 249 | return cast_convert_val<X, Y, |
| 250 | typename simplify_type<Y>::SimpleType>::doit(Val); |
| 251 | } |
| 252 | |
| 253 | template <class X, class Y> |
| 254 | inline typename cast_retty<X, Y *>::ret_type cast(Y *Val) { |
| 255 | assert(isa<X>(Val) && "cast<Ty>() argument of incompatible type!")(static_cast <bool> (isa<X>(Val) && "cast<Ty>() argument of incompatible type!" ) ? void (0) : __assert_fail ("isa<X>(Val) && \"cast<Ty>() argument of incompatible type!\"" , "/build/llvm-toolchain-snapshot-7~svn338205/include/llvm/Support/Casting.h" , 255, __extension__ __PRETTY_FUNCTION__)); |
| 256 | return cast_convert_val<X, Y*, |
| 257 | typename simplify_type<Y*>::SimpleType>::doit(Val); |
| 258 | } |
| 259 | |
| 260 | template <class X, class Y> |
| 261 | inline typename cast_retty<X, std::unique_ptr<Y>>::ret_type |
| 262 | cast(std::unique_ptr<Y> &&Val) { |
| 263 | assert(isa<X>(Val.get()) && "cast<Ty>() argument of incompatible type!")(static_cast <bool> (isa<X>(Val.get()) && "cast<Ty>() argument of incompatible type!") ? void (0 ) : __assert_fail ("isa<X>(Val.get()) && \"cast<Ty>() argument of incompatible type!\"" , "/build/llvm-toolchain-snapshot-7~svn338205/include/llvm/Support/Casting.h" , 263, __extension__ __PRETTY_FUNCTION__)); |
| 264 | using ret_type = typename cast_retty<X, std::unique_ptr<Y>>::ret_type; |
| 265 | return ret_type( |
| 266 | cast_convert_val<X, Y *, typename simplify_type<Y *>::SimpleType>::doit( |
| 267 | Val.release())); |
| 268 | } |
| 269 | |
| 270 | // cast_or_null<X> - Functionally identical to cast, except that a null value is |
| 271 | // accepted. |
| 272 | // |
| 273 | template <class X, class Y> |
| 274 | LLVM_NODISCARD[[clang::warn_unused_result]] inline |
| 275 | typename std::enable_if<!is_simple_type<Y>::value, |
| 276 | typename cast_retty<X, const Y>::ret_type>::type |
| 277 | cast_or_null(const Y &Val) { |
| 278 | if (!Val) |
| 279 | return nullptr; |
| 280 | assert(isa<X>(Val) && "cast_or_null<Ty>() argument of incompatible type!")(static_cast <bool> (isa<X>(Val) && "cast_or_null<Ty>() argument of incompatible type!" ) ? void (0) : __assert_fail ("isa<X>(Val) && \"cast_or_null<Ty>() argument of incompatible type!\"" , "/build/llvm-toolchain-snapshot-7~svn338205/include/llvm/Support/Casting.h" , 280, __extension__ __PRETTY_FUNCTION__)); |
| 281 | return cast<X>(Val); |
| 282 | } |
| 283 | |
| 284 | template <class X, class Y> |
| 285 | LLVM_NODISCARD[[clang::warn_unused_result]] inline |
| 286 | typename std::enable_if<!is_simple_type<Y>::value, |
| 287 | typename cast_retty<X, Y>::ret_type>::type |
| 288 | cast_or_null(Y &Val) { |
| 289 | if (!Val) |
| 290 | return nullptr; |
| 291 | assert(isa<X>(Val) && "cast_or_null<Ty>() argument of incompatible type!")(static_cast <bool> (isa<X>(Val) && "cast_or_null<Ty>() argument of incompatible type!" ) ? void (0) : __assert_fail ("isa<X>(Val) && \"cast_or_null<Ty>() argument of incompatible type!\"" , "/build/llvm-toolchain-snapshot-7~svn338205/include/llvm/Support/Casting.h" , 291, __extension__ __PRETTY_FUNCTION__)); |
| 292 | return cast<X>(Val); |
| 293 | } |
| 294 | |
| 295 | template <class X, class Y> |
| 296 | LLVM_NODISCARD[[clang::warn_unused_result]] inline typename cast_retty<X, Y *>::ret_type |
| 297 | cast_or_null(Y *Val) { |
| 298 | if (!Val) return nullptr; |
| 299 | assert(isa<X>(Val) && "cast_or_null<Ty>() argument of incompatible type!")(static_cast <bool> (isa<X>(Val) && "cast_or_null<Ty>() argument of incompatible type!" ) ? void (0) : __assert_fail ("isa<X>(Val) && \"cast_or_null<Ty>() argument of incompatible type!\"" , "/build/llvm-toolchain-snapshot-7~svn338205/include/llvm/Support/Casting.h" , 299, __extension__ __PRETTY_FUNCTION__)); |
| 300 | return cast<X>(Val); |
| 301 | } |
| 302 | |
| 303 | template <class X, class Y> |
| 304 | inline typename cast_retty<X, std::unique_ptr<Y>>::ret_type |
| 305 | cast_or_null(std::unique_ptr<Y> &&Val) { |
| 306 | if (!Val) |
| 307 | return nullptr; |
| 308 | return cast<X>(std::move(Val)); |
| 309 | } |
| 310 | |
| 311 | // dyn_cast<X> - Return the argument parameter cast to the specified type. This |
| 312 | // casting operator returns null if the argument is of the wrong type, so it can |
| 313 | // be used to test for a type as well as cast if successful. This should be |
| 314 | // used in the context of an if statement like this: |
| 315 | // |
| 316 | // if (const Instruction *I = dyn_cast<Instruction>(myVal)) { ... } |
| 317 | // |
| 318 | |
| 319 | template <class X, class Y> |
| 320 | LLVM_NODISCARD[[clang::warn_unused_result]] inline |
| 321 | typename std::enable_if<!is_simple_type<Y>::value, |
| 322 | typename cast_retty<X, const Y>::ret_type>::type |
| 323 | dyn_cast(const Y &Val) { |
| 324 | return isa<X>(Val) ? cast<X>(Val) : nullptr; |
| 325 | } |
| 326 | |
| 327 | template <class X, class Y> |
| 328 | LLVM_NODISCARD[[clang::warn_unused_result]] inline typename cast_retty<X, Y>::ret_type dyn_cast(Y &Val) { |
| 329 | return isa<X>(Val) ? cast<X>(Val) : nullptr; |
| 330 | } |
| 331 | |
| 332 | template <class X, class Y> |
| 333 | LLVM_NODISCARD[[clang::warn_unused_result]] inline typename cast_retty<X, Y *>::ret_type dyn_cast(Y *Val) { |
| 334 | return isa<X>(Val) ? cast<X>(Val) : nullptr; |
| 335 | } |
| 336 | |
| 337 | // dyn_cast_or_null<X> - Functionally identical to dyn_cast, except that a null |
| 338 | // value is accepted. |
| 339 | // |
| 340 | template <class X, class Y> |
| 341 | LLVM_NODISCARD[[clang::warn_unused_result]] inline |
| 342 | typename std::enable_if<!is_simple_type<Y>::value, |
| 343 | typename cast_retty<X, const Y>::ret_type>::type |
| 344 | dyn_cast_or_null(const Y &Val) { |
| 345 | return (Val && isa<X>(Val)) ? cast<X>(Val) : nullptr; |
| 346 | } |
| 347 | |
| 348 | template <class X, class Y> |
| 349 | LLVM_NODISCARD[[clang::warn_unused_result]] inline |
| 350 | typename std::enable_if<!is_simple_type<Y>::value, |
| 351 | typename cast_retty<X, Y>::ret_type>::type |
| 352 | dyn_cast_or_null(Y &Val) { |
| 353 | return (Val && isa<X>(Val)) ? cast<X>(Val) : nullptr; |
| 354 | } |
| 355 | |
| 356 | template <class X, class Y> |
| 357 | LLVM_NODISCARD[[clang::warn_unused_result]] inline typename cast_retty<X, Y *>::ret_type |
| 358 | dyn_cast_or_null(Y *Val) { |
| 359 | return (Val && isa<X>(Val)) ? cast<X>(Val) : nullptr; |
| 360 | } |
| 361 | |
| 362 | // unique_dyn_cast<X> - Given a unique_ptr<Y>, try to return a unique_ptr<X>, |
| 363 | // taking ownership of the input pointer iff isa<X>(Val) is true. If the |
| 364 | // cast is successful, From refers to nullptr on exit and the casted value |
| 365 | // is returned. If the cast is unsuccessful, the function returns nullptr |
| 366 | // and From is unchanged. |
| 367 | template <class X, class Y> |
| 368 | LLVM_NODISCARD[[clang::warn_unused_result]] inline auto unique_dyn_cast(std::unique_ptr<Y> &Val) |
| 369 | -> decltype(cast<X>(Val)) { |
| 370 | if (!isa<X>(Val)) |
| 371 | return nullptr; |
| 372 | return cast<X>(std::move(Val)); |
| 373 | } |
| 374 | |
| 375 | template <class X, class Y> |
| 376 | LLVM_NODISCARD[[clang::warn_unused_result]] inline auto unique_dyn_cast(std::unique_ptr<Y> &&Val) |
| 377 | -> decltype(cast<X>(Val)) { |
| 378 | return unique_dyn_cast<X, Y>(Val); |
| 379 | } |
| 380 | |
| 381 | // dyn_cast_or_null<X> - Functionally identical to unique_dyn_cast, except that |
| 382 | // a null value is accepted. |
| 383 | template <class X, class Y> |
| 384 | LLVM_NODISCARD[[clang::warn_unused_result]] inline auto unique_dyn_cast_or_null(std::unique_ptr<Y> &Val) |
| 385 | -> decltype(cast<X>(Val)) { |
| 386 | if (!Val) |
| 387 | return nullptr; |
| 388 | return unique_dyn_cast<X, Y>(Val); |
| 389 | } |
| 390 | |
| 391 | template <class X, class Y> |
| 392 | LLVM_NODISCARD[[clang::warn_unused_result]] inline auto unique_dyn_cast_or_null(std::unique_ptr<Y> &&Val) |
| 393 | -> decltype(cast<X>(Val)) { |
| 394 | return unique_dyn_cast_or_null<X, Y>(Val); |
| 395 | } |
| 396 | |
| 397 | } // end namespace llvm |
| 398 | |
| 399 | #endif // LLVM_SUPPORT_CASTING_H |