1 //===- HexagonRemoveExtendArgs.cpp - Remove unecessary argument sign extends =// 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 // Pass that removes sign extends for function parameters. These parameters 11 // are already sign extended by the caller per Hexagon's ABI 12 // 13 //===----------------------------------------------------------------------===// 14 15 #include "HexagonTargetMachine.h" 16 #include "llvm/Function.h" 17 #include "llvm/Instructions.h" 18 #include "llvm/Pass.h" 19 #include "llvm/CodeGen/MachineFunctionAnalysis.h" 20 #include "llvm/Transforms/Scalar.h" 21 22 using namespace llvm; 23 namespace { 24 struct HexagonRemoveExtendArgs : public FunctionPass { 25 public: 26 static char ID; 27 HexagonRemoveExtendArgs() : FunctionPass(ID) {} 28 virtual bool runOnFunction(Function &F); 29 30 const char *getPassName() const { 31 return "Remove sign extends"; 32 } 33 34 virtual void getAnalysisUsage(AnalysisUsage &AU) const { 35 AU.addRequired<MachineFunctionAnalysis>(); 36 AU.addPreserved<MachineFunctionAnalysis>(); 37 FunctionPass::getAnalysisUsage(AU); 38 } 39 }; 40 } 41 42 char HexagonRemoveExtendArgs::ID = 0; 43 RegisterPass<HexagonRemoveExtendArgs> X("reargs", 44 "Remove Sign and Zero Extends for Args" 45 ); 46 47 48 49 bool HexagonRemoveExtendArgs::runOnFunction(Function &F) { 50 unsigned Idx = 1; 51 for (Function::arg_iterator AI = F.arg_begin(), AE = F.arg_end(); AI != AE; 52 ++AI, ++Idx) { 53 if (F.paramHasAttr(Idx, Attribute::SExt)) { 54 Argument* Arg = AI; 55 if (!isa<PointerType>(Arg->getType())) { 56 for (Instruction::use_iterator UI = Arg->use_begin(); 57 UI != Arg->use_end();) { 58 if (isa<SExtInst>(*UI)) { 59 Instruction* Use = cast<Instruction>(*UI); 60 SExtInst* SI = new SExtInst(Arg, Use->getType()); 61 assert (EVT::getEVT(SI->getType()) == 62 (EVT::getEVT(Use->getType()))); 63 ++UI; 64 Use->replaceAllUsesWith(SI); 65 Instruction* First = F.getEntryBlock().begin(); 66 SI->insertBefore(First); 67 Use->eraseFromParent(); 68 } else { 69 ++UI; 70 } 71 } 72 } 73 } 74 } 75 return true; 76 } 77 78 79 80 FunctionPass *llvm::createHexagonRemoveExtendOps(HexagonTargetMachine &TM) { 81 return new HexagonRemoveExtendArgs(); 82 } 83
