1 //===- HexagonRemoveExtendArgs.cpp - Remove unnecessary 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 "Hexagon.h" 16 #include "HexagonTargetMachine.h" 17 #include "llvm/CodeGen/MachineFunctionAnalysis.h" 18 #include "llvm/IR/Function.h" 19 #include "llvm/IR/Instructions.h" 20 #include "llvm/Pass.h" 21 #include "llvm/Transforms/Scalar.h" 22 23 using namespace llvm; 24 25 namespace llvm { 26 void initializeHexagonRemoveExtendArgsPass(PassRegistry&); 27 } 28 29 namespace { 30 struct HexagonRemoveExtendArgs : public FunctionPass { 31 public: 32 static char ID; 33 HexagonRemoveExtendArgs() : FunctionPass(ID) { 34 initializeHexagonRemoveExtendArgsPass(*PassRegistry::getPassRegistry()); 35 } 36 virtual bool runOnFunction(Function &F); 37 38 const char *getPassName() const { 39 return "Remove sign extends"; 40 } 41 42 virtual void getAnalysisUsage(AnalysisUsage &AU) const { 43 AU.addRequired<MachineFunctionAnalysis>(); 44 AU.addPreserved<MachineFunctionAnalysis>(); 45 FunctionPass::getAnalysisUsage(AU); 46 } 47 }; 48 } 49 50 char HexagonRemoveExtendArgs::ID = 0; 51 52 INITIALIZE_PASS(HexagonRemoveExtendArgs, "reargs", 53 "Remove Sign and Zero Extends for Args", false, false) 54 55 bool HexagonRemoveExtendArgs::runOnFunction(Function &F) { 56 unsigned Idx = 1; 57 for (Function::arg_iterator AI = F.arg_begin(), AE = F.arg_end(); AI != AE; 58 ++AI, ++Idx) { 59 if (F.getAttributes().hasAttribute(Idx, Attribute::SExt)) { 60 Argument* Arg = AI; 61 if (!isa<PointerType>(Arg->getType())) { 62 for (Instruction::use_iterator UI = Arg->use_begin(); 63 UI != Arg->use_end();) { 64 if (isa<SExtInst>(*UI)) { 65 Instruction* Use = cast<Instruction>(*UI); 66 SExtInst* SI = new SExtInst(Arg, Use->getType()); 67 assert (EVT::getEVT(SI->getType()) == 68 (EVT::getEVT(Use->getType()))); 69 ++UI; 70 Use->replaceAllUsesWith(SI); 71 Instruction* First = F.getEntryBlock().begin(); 72 SI->insertBefore(First); 73 Use->eraseFromParent(); 74 } else { 75 ++UI; 76 } 77 } 78 } 79 } 80 } 81 return true; 82 } 83 84 85 86 FunctionPass* 87 llvm::createHexagonRemoveExtendArgs(const HexagonTargetMachine &TM) { 88 return new HexagonRemoveExtendArgs(); 89 } 90
