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" 20251607Sdim#include "llvm/IR/Intrinsics.h" 21251607Sdim#include "llvm/IR/IRBuilder.h" 22251607Sdim#include "llvm/IR/Module.h" 23251607Sdim#include "llvm/Pass.h" 24251607Sdim#include "llvm/Support/CommandLine.h" 25263509Sdim#include "llvm/Support/NoFolder.h" 26263509Sdim#include "llvm/Support/ValueHandle.h" 27263509Sdim#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 51251607Sdim bool runOnModule(Module &M); 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 77263509Sdimstatic Instruction * 78263509SdimcreateReplacementInstr(ConstantExpr *CE, Instruction *Instr) { 79263509Sdim IRBuilder<true,NoFolder> Builder(Instr); 80263509Sdim unsigned OpCode = CE->getOpcode(); 81263509Sdim switch (OpCode) { 82263509Sdim case Instruction::GetElementPtr: { 83263509Sdim SmallVector<Value *,4> CEOpVec(CE->op_begin(), CE->op_end()); 84263509Sdim ArrayRef<Value *> CEOps(CEOpVec); 85263509Sdim return dyn_cast<Instruction>(Builder.CreateInBoundsGEP(CEOps[0], 86263509Sdim CEOps.slice(1))); 87263509Sdim } 88263509Sdim case Instruction::Add: 89263509Sdim case Instruction::Sub: 90263509Sdim case Instruction::Mul: 91263509Sdim case Instruction::UDiv: 92263509Sdim case Instruction::SDiv: 93263509Sdim case Instruction::FDiv: 94263509Sdim case Instruction::URem: 95263509Sdim case Instruction::SRem: 96263509Sdim case Instruction::FRem: 97263509Sdim case Instruction::Shl: 98263509Sdim case Instruction::LShr: 99263509Sdim case Instruction::AShr: 100263509Sdim case Instruction::And: 101263509Sdim case Instruction::Or: 102263509Sdim case Instruction::Xor: 103263509Sdim return dyn_cast<Instruction>( 104263509Sdim Builder.CreateBinOp((Instruction::BinaryOps)OpCode, 105263509Sdim CE->getOperand(0), CE->getOperand(1), 106263509Sdim CE->getName())); 107263509Sdim case Instruction::Trunc: 108263509Sdim case Instruction::ZExt: 109263509Sdim case Instruction::SExt: 110263509Sdim case Instruction::FPToUI: 111263509Sdim case Instruction::FPToSI: 112263509Sdim case Instruction::UIToFP: 113263509Sdim case Instruction::SIToFP: 114263509Sdim case Instruction::FPTrunc: 115263509Sdim case Instruction::FPExt: 116263509Sdim case Instruction::PtrToInt: 117263509Sdim case Instruction::IntToPtr: 118263509Sdim case Instruction::BitCast: 119263509Sdim return dyn_cast<Instruction>( 120263509Sdim Builder.CreateCast((Instruction::CastOps)OpCode, 121263509Sdim CE->getOperand(0), CE->getType(), 122263509Sdim CE->getName())); 123263509Sdim default: 124263509Sdim llvm_unreachable("Unhandled constant expression!\n"); 125263509Sdim } 126263509Sdim} 127251607Sdim 128263509Sdimstatic bool replaceConstantExprOp(ConstantExpr *CE, Pass *P) { 129263509Sdim do { 130263509Sdim SmallVector<WeakVH,8> WUsers; 131263509Sdim for (Value::use_iterator I = CE->use_begin(), E = CE->use_end(); 132263509Sdim I != E; ++I) 133263509Sdim WUsers.push_back(WeakVH(*I)); 134263509Sdim std::sort(WUsers.begin(), WUsers.end()); 135263509Sdim WUsers.erase(std::unique(WUsers.begin(), WUsers.end()), WUsers.end()); 136263509Sdim while (!WUsers.empty()) 137263509Sdim if (WeakVH WU = WUsers.pop_back_val()) { 138263509Sdim if (PHINode *PN = dyn_cast<PHINode>(WU)) { 139263509Sdim for (int I = 0, E = PN->getNumIncomingValues(); I < E; ++I) 140263509Sdim if (PN->getIncomingValue(I) == CE) { 141263509Sdim BasicBlock *PredBB = PN->getIncomingBlock(I); 142263509Sdim if (PredBB->getTerminator()->getNumSuccessors() > 1) 143263509Sdim PredBB = SplitEdge(PredBB, PN->getParent(), P); 144263509Sdim Instruction *InsertPos = PredBB->getTerminator(); 145263509Sdim Instruction *NewInst = createReplacementInstr(CE, InsertPos); 146263509Sdim PN->setOperand(I, NewInst); 147263509Sdim } 148263509Sdim } else if (Instruction *Instr = dyn_cast<Instruction>(WU)) { 149263509Sdim Instruction *NewInst = createReplacementInstr(CE, Instr); 150263509Sdim Instr->replaceUsesOfWith(CE, NewInst); 151263509Sdim } else { 152263509Sdim ConstantExpr *CExpr = dyn_cast<ConstantExpr>(WU); 153263509Sdim if (!CExpr || !replaceConstantExprOp(CExpr, P)) 154263509Sdim return false; 155263509Sdim } 156263509Sdim } 157263509Sdim } while (CE->hasNUsesOrMore(1)); // We need to check becasue a recursive 158263509Sdim // sibbling may have used 'CE' when createReplacementInstr was called. 159263509Sdim CE->destroyConstant(); 160263509Sdim return true; 161251607Sdim} 162251607Sdim 163263509Sdimstatic bool rewriteNonInstructionUses(GlobalVariable *GV, Pass *P) { 164263509Sdim SmallVector<WeakVH,8> WUsers; 165263509Sdim for (Value::use_iterator I = GV->use_begin(), E = GV->use_end(); I != E; ++I) 166263509Sdim if (!isa<Instruction>(*I)) 167263509Sdim WUsers.push_back(WeakVH(*I)); 168263509Sdim while (!WUsers.empty()) 169263509Sdim if (WeakVH WU = WUsers.pop_back_val()) { 170263509Sdim ConstantExpr *CE = dyn_cast<ConstantExpr>(WU); 171263509Sdim if (!CE || !replaceConstantExprOp(CE, P)) 172263509Sdim return false; 173263509Sdim } 174263509Sdim return true; 175263509Sdim} 176263509Sdim 177251607Sdimstatic bool isZeroLengthArray(Type *Ty) { 178251607Sdim ArrayType *AT = dyn_cast<ArrayType>(Ty); 179251607Sdim return AT && (AT->getNumElements() == 0); 180251607Sdim} 181251607Sdim 182251607Sdimbool XCoreLowerThreadLocal::lowerGlobal(GlobalVariable *GV) { 183251607Sdim Module *M = GV->getParent(); 184251607Sdim LLVMContext &Ctx = M->getContext(); 185251607Sdim if (!GV->isThreadLocal()) 186251607Sdim return false; 187251607Sdim 188251607Sdim // Skip globals that we can't lower and leave it for the backend to error. 189263509Sdim if (!rewriteNonInstructionUses(GV, this) || 190251607Sdim !GV->getType()->isSized() || isZeroLengthArray(GV->getType())) 191251607Sdim return false; 192251607Sdim 193251607Sdim // Create replacement global. 194251607Sdim ArrayType *NewType = createLoweredType(GV->getType()->getElementType()); 195263509Sdim Constant *NewInitializer = 0; 196263509Sdim if (GV->hasInitializer()) 197263509Sdim NewInitializer = createLoweredInitializer(NewType, 198263509Sdim GV->getInitializer()); 199251607Sdim GlobalVariable *NewGV = 200251607Sdim new GlobalVariable(*M, NewType, GV->isConstant(), GV->getLinkage(), 201251607Sdim NewInitializer, "", 0, GlobalVariable::NotThreadLocal, 202251607Sdim GV->getType()->getAddressSpace(), 203251607Sdim GV->isExternallyInitialized()); 204251607Sdim 205251607Sdim // Update uses. 206251607Sdim SmallVector<User *, 16> Users(GV->use_begin(), GV->use_end()); 207251607Sdim for (unsigned I = 0, E = Users.size(); I != E; ++I) { 208251607Sdim User *U = Users[I]; 209251607Sdim Instruction *Inst = cast<Instruction>(U); 210251607Sdim IRBuilder<> Builder(Inst); 211251607Sdim Function *GetID = Intrinsic::getDeclaration(GV->getParent(), 212251607Sdim Intrinsic::xcore_getid); 213251607Sdim Value *ThreadID = Builder.CreateCall(GetID); 214251607Sdim SmallVector<Value *, 2> Indices; 215251607Sdim Indices.push_back(Constant::getNullValue(Type::getInt64Ty(Ctx))); 216251607Sdim Indices.push_back(ThreadID); 217251607Sdim Value *Addr = Builder.CreateInBoundsGEP(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; 231251607Sdim for (Module::global_iterator GVI = M.global_begin(), E = M.global_end(); 232251607Sdim GVI != E; ++GVI) { 233251607Sdim GlobalVariable *GV = GVI; 234251607Sdim if (GV->isThreadLocal()) 235251607Sdim ThreadLocalGlobals.push_back(GV); 236251607Sdim } 237251607Sdim for (unsigned I = 0, E = ThreadLocalGlobals.size(); I != E; ++I) { 238251607Sdim MadeChange |= lowerGlobal(ThreadLocalGlobals[I]); 239251607Sdim } 240251607Sdim return MadeChange; 241251607Sdim} 242