1251607Sdim//===-- XCoreLowerThreadLocal - Lower thread local variables --------------===// 2251607Sdim// 3251607Sdim// The LLVM Compiler Infrastructure 4251607Sdim// 5251607Sdim// This file is distributed under the University of Illinois Open Source 6251607Sdim// License. See LICENSE.TXT for details. 7251607Sdim// 8251607Sdim//===----------------------------------------------------------------------===// 9251607Sdim/// 10251607Sdim/// \file 11251607Sdim/// \brief This file contains a pass that lowers thread local variables on the 12251607Sdim/// XCore. 13251607Sdim/// 14251607Sdim//===----------------------------------------------------------------------===// 15251607Sdim 16251607Sdim#include "XCore.h" 17251607Sdim#include "llvm/IR/Constants.h" 18251607Sdim#include "llvm/IR/DerivedTypes.h" 19251607Sdim#include "llvm/IR/GlobalVariable.h" 20276479Sdim#include "llvm/IR/IRBuilder.h" 21251607Sdim#include "llvm/IR/Intrinsics.h" 22251607Sdim#include "llvm/IR/Module.h" 23276479Sdim#include "llvm/IR/NoFolder.h" 24276479Sdim#include "llvm/IR/ValueHandle.h" 25251607Sdim#include "llvm/Pass.h" 26251607Sdim#include "llvm/Support/CommandLine.h" 27261991Sdim#include "llvm/Transforms/Utils/BasicBlockUtils.h" 28251607Sdim 29251607Sdim#define DEBUG_TYPE "xcore-lower-thread-local" 30251607Sdim 31251607Sdimusing namespace llvm; 32251607Sdim 33251607Sdimstatic cl::opt<unsigned> MaxThreads( 34251607Sdim "xcore-max-threads", cl::Optional, 35251607Sdim cl::desc("Maximum number of threads (for emulation thread-local storage)"), 36251607Sdim cl::Hidden, cl::value_desc("number"), cl::init(8)); 37251607Sdim 38251607Sdimnamespace { 39251607Sdim /// Lowers thread local variables on the XCore. Each thread local variable is 40251607Sdim /// expanded to an array of n elements indexed by the thread ID where n is the 41251607Sdim /// fixed number hardware threads supported by the device. 42251607Sdim struct XCoreLowerThreadLocal : public ModulePass { 43251607Sdim static char ID; 44251607Sdim 45251607Sdim XCoreLowerThreadLocal() : ModulePass(ID) { 46251607Sdim initializeXCoreLowerThreadLocalPass(*PassRegistry::getPassRegistry()); 47251607Sdim } 48251607Sdim 49251607Sdim bool lowerGlobal(GlobalVariable *GV); 50251607Sdim 51276479Sdim bool runOnModule(Module &M) override; 52251607Sdim }; 53251607Sdim} 54251607Sdim 55251607Sdimchar XCoreLowerThreadLocal::ID = 0; 56251607Sdim 57251607SdimINITIALIZE_PASS(XCoreLowerThreadLocal, "xcore-lower-thread-local", 58251607Sdim "Lower thread local variables", false, false) 59251607Sdim 60251607SdimModulePass *llvm::createXCoreLowerThreadLocalPass() { 61251607Sdim return new XCoreLowerThreadLocal(); 62251607Sdim} 63251607Sdim 64251607Sdimstatic ArrayType *createLoweredType(Type *OriginalType) { 65251607Sdim return ArrayType::get(OriginalType, MaxThreads); 66251607Sdim} 67251607Sdim 68251607Sdimstatic Constant * 69251607SdimcreateLoweredInitializer(ArrayType *NewType, Constant *OriginalInitializer) { 70251607Sdim SmallVector<Constant *, 8> Elements(MaxThreads); 71251607Sdim for (unsigned i = 0; i != MaxThreads; ++i) { 72251607Sdim Elements[i] = OriginalInitializer; 73251607Sdim } 74251607Sdim return ConstantArray::get(NewType, Elements); 75251607Sdim} 76251607Sdim 77261991Sdimstatic Instruction * 78261991SdimcreateReplacementInstr(ConstantExpr *CE, Instruction *Instr) { 79261991Sdim IRBuilder<true,NoFolder> Builder(Instr); 80261991Sdim unsigned OpCode = CE->getOpcode(); 81261991Sdim switch (OpCode) { 82261991Sdim case Instruction::GetElementPtr: { 83261991Sdim SmallVector<Value *,4> CEOpVec(CE->op_begin(), CE->op_end()); 84261991Sdim ArrayRef<Value *> CEOps(CEOpVec); 85288943Sdim return dyn_cast<Instruction>(Builder.CreateInBoundsGEP( 86288943Sdim cast<GEPOperator>(CE)->getSourceElementType(), CEOps[0], 87288943Sdim CEOps.slice(1))); 88261991Sdim } 89261991Sdim case Instruction::Add: 90261991Sdim case Instruction::Sub: 91261991Sdim case Instruction::Mul: 92261991Sdim case Instruction::UDiv: 93261991Sdim case Instruction::SDiv: 94261991Sdim case Instruction::FDiv: 95261991Sdim case Instruction::URem: 96261991Sdim case Instruction::SRem: 97261991Sdim case Instruction::FRem: 98261991Sdim case Instruction::Shl: 99261991Sdim case Instruction::LShr: 100261991Sdim case Instruction::AShr: 101261991Sdim case Instruction::And: 102261991Sdim case Instruction::Or: 103261991Sdim case Instruction::Xor: 104261991Sdim return dyn_cast<Instruction>( 105261991Sdim Builder.CreateBinOp((Instruction::BinaryOps)OpCode, 106261991Sdim CE->getOperand(0), CE->getOperand(1), 107261991Sdim CE->getName())); 108261991Sdim case Instruction::Trunc: 109261991Sdim case Instruction::ZExt: 110261991Sdim case Instruction::SExt: 111261991Sdim case Instruction::FPToUI: 112261991Sdim case Instruction::FPToSI: 113261991Sdim case Instruction::UIToFP: 114261991Sdim case Instruction::SIToFP: 115261991Sdim case Instruction::FPTrunc: 116261991Sdim case Instruction::FPExt: 117261991Sdim case Instruction::PtrToInt: 118261991Sdim case Instruction::IntToPtr: 119261991Sdim case Instruction::BitCast: 120261991Sdim return dyn_cast<Instruction>( 121261991Sdim Builder.CreateCast((Instruction::CastOps)OpCode, 122261991Sdim CE->getOperand(0), CE->getType(), 123261991Sdim CE->getName())); 124261991Sdim default: 125261991Sdim llvm_unreachable("Unhandled constant expression!\n"); 126261991Sdim } 127261991Sdim} 128251607Sdim 129261991Sdimstatic bool replaceConstantExprOp(ConstantExpr *CE, Pass *P) { 130261991Sdim do { 131276479Sdim SmallVector<WeakVH,8> WUsers(CE->user_begin(), CE->user_end()); 132261991Sdim std::sort(WUsers.begin(), WUsers.end()); 133261991Sdim WUsers.erase(std::unique(WUsers.begin(), WUsers.end()), WUsers.end()); 134261991Sdim while (!WUsers.empty()) 135261991Sdim if (WeakVH WU = WUsers.pop_back_val()) { 136261991Sdim if (PHINode *PN = dyn_cast<PHINode>(WU)) { 137261991Sdim for (int I = 0, E = PN->getNumIncomingValues(); I < E; ++I) 138261991Sdim if (PN->getIncomingValue(I) == CE) { 139261991Sdim BasicBlock *PredBB = PN->getIncomingBlock(I); 140261991Sdim if (PredBB->getTerminator()->getNumSuccessors() > 1) 141288943Sdim PredBB = SplitEdge(PredBB, PN->getParent()); 142261991Sdim Instruction *InsertPos = PredBB->getTerminator(); 143261991Sdim Instruction *NewInst = createReplacementInstr(CE, InsertPos); 144261991Sdim PN->setOperand(I, NewInst); 145261991Sdim } 146261991Sdim } else if (Instruction *Instr = dyn_cast<Instruction>(WU)) { 147261991Sdim Instruction *NewInst = createReplacementInstr(CE, Instr); 148261991Sdim Instr->replaceUsesOfWith(CE, NewInst); 149261991Sdim } else { 150261991Sdim ConstantExpr *CExpr = dyn_cast<ConstantExpr>(WU); 151261991Sdim if (!CExpr || !replaceConstantExprOp(CExpr, P)) 152261991Sdim return false; 153261991Sdim } 154261991Sdim } 155276479Sdim } while (CE->hasNUsesOrMore(1)); // We need to check because a recursive 156276479Sdim // sibling may have used 'CE' when createReplacementInstr was called. 157261991Sdim CE->destroyConstant(); 158261991Sdim return true; 159251607Sdim} 160251607Sdim 161261991Sdimstatic bool rewriteNonInstructionUses(GlobalVariable *GV, Pass *P) { 162261991Sdim SmallVector<WeakVH,8> WUsers; 163276479Sdim for (User *U : GV->users()) 164276479Sdim if (!isa<Instruction>(U)) 165276479Sdim WUsers.push_back(WeakVH(U)); 166261991Sdim while (!WUsers.empty()) 167261991Sdim if (WeakVH WU = WUsers.pop_back_val()) { 168261991Sdim ConstantExpr *CE = dyn_cast<ConstantExpr>(WU); 169261991Sdim if (!CE || !replaceConstantExprOp(CE, P)) 170261991Sdim return false; 171261991Sdim } 172261991Sdim return true; 173261991Sdim} 174261991Sdim 175251607Sdimstatic bool isZeroLengthArray(Type *Ty) { 176251607Sdim ArrayType *AT = dyn_cast<ArrayType>(Ty); 177251607Sdim return AT && (AT->getNumElements() == 0); 178251607Sdim} 179251607Sdim 180251607Sdimbool XCoreLowerThreadLocal::lowerGlobal(GlobalVariable *GV) { 181251607Sdim Module *M = GV->getParent(); 182251607Sdim LLVMContext &Ctx = M->getContext(); 183251607Sdim if (!GV->isThreadLocal()) 184251607Sdim return false; 185251607Sdim 186251607Sdim // Skip globals that we can't lower and leave it for the backend to error. 187261991Sdim if (!rewriteNonInstructionUses(GV, this) || 188251607Sdim !GV->getType()->isSized() || isZeroLengthArray(GV->getType())) 189251607Sdim return false; 190251607Sdim 191251607Sdim // Create replacement global. 192251607Sdim ArrayType *NewType = createLoweredType(GV->getType()->getElementType()); 193276479Sdim Constant *NewInitializer = nullptr; 194261991Sdim if (GV->hasInitializer()) 195261991Sdim NewInitializer = createLoweredInitializer(NewType, 196261991Sdim GV->getInitializer()); 197251607Sdim GlobalVariable *NewGV = 198251607Sdim new GlobalVariable(*M, NewType, GV->isConstant(), GV->getLinkage(), 199276479Sdim NewInitializer, "", nullptr, 200276479Sdim GlobalVariable::NotThreadLocal, 201251607Sdim GV->getType()->getAddressSpace(), 202251607Sdim GV->isExternallyInitialized()); 203251607Sdim 204251607Sdim // Update uses. 205276479Sdim SmallVector<User *, 16> Users(GV->user_begin(), GV->user_end()); 206251607Sdim for (unsigned I = 0, E = Users.size(); I != E; ++I) { 207251607Sdim User *U = Users[I]; 208251607Sdim Instruction *Inst = cast<Instruction>(U); 209251607Sdim IRBuilder<> Builder(Inst); 210251607Sdim Function *GetID = Intrinsic::getDeclaration(GV->getParent(), 211251607Sdim Intrinsic::xcore_getid); 212288943Sdim Value *ThreadID = Builder.CreateCall(GetID, {}); 213251607Sdim SmallVector<Value *, 2> Indices; 214251607Sdim Indices.push_back(Constant::getNullValue(Type::getInt64Ty(Ctx))); 215251607Sdim Indices.push_back(ThreadID); 216288943Sdim Value *Addr = 217288943Sdim Builder.CreateInBoundsGEP(NewGV->getValueType(), NewGV, Indices); 218251607Sdim U->replaceUsesOfWith(GV, Addr); 219251607Sdim } 220251607Sdim 221251607Sdim // Remove old global. 222251607Sdim NewGV->takeName(GV); 223251607Sdim GV->eraseFromParent(); 224251607Sdim return true; 225251607Sdim} 226251607Sdim 227251607Sdimbool XCoreLowerThreadLocal::runOnModule(Module &M) { 228251607Sdim // Find thread local globals. 229251607Sdim bool MadeChange = false; 230251607Sdim SmallVector<GlobalVariable *, 16> ThreadLocalGlobals; 231296417Sdim for (GlobalVariable &GV : M.globals()) 232296417Sdim if (GV.isThreadLocal()) 233296417Sdim ThreadLocalGlobals.push_back(&GV); 234251607Sdim for (unsigned I = 0, E = ThreadLocalGlobals.size(); I != E; ++I) { 235251607Sdim MadeChange |= lowerGlobal(ThreadLocalGlobals[I]); 236251607Sdim } 237251607Sdim return MadeChange; 238251607Sdim} 239