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/CodeGen/StackProtector.h" 19 #include "llvm/IR/Function.h" 20 #include "llvm/IR/Instructions.h" 21 #include "llvm/Pass.h" 22 #include "llvm/Transforms/Scalar.h" 23 24 using namespace llvm; 25 26 namespace llvm { 27 void initializeHexagonRemoveExtendArgsPass(PassRegistry&); 28 } 29 30 namespace { 31 struct HexagonRemoveExtendArgs : public FunctionPass { 32 public: 33 static char ID; HexagonRemoveExtendArgs__anonae56f8440111::HexagonRemoveExtendArgs34 HexagonRemoveExtendArgs() : FunctionPass(ID) { 35 initializeHexagonRemoveExtendArgsPass(*PassRegistry::getPassRegistry()); 36 } 37 bool runOnFunction(Function &F) override; 38 getPassName__anonae56f8440111::HexagonRemoveExtendArgs39 const char *getPassName() const override { 40 return "Remove sign extends"; 41 } 42 getAnalysisUsage__anonae56f8440111::HexagonRemoveExtendArgs43 void getAnalysisUsage(AnalysisUsage &AU) const override { 44 AU.addRequired<MachineFunctionAnalysis>(); 45 AU.addPreserved<MachineFunctionAnalysis>(); 46 AU.addPreserved<StackProtector>(); 47 FunctionPass::getAnalysisUsage(AU); 48 } 49 }; 50 } 51 52 char HexagonRemoveExtendArgs::ID = 0; 53 54 INITIALIZE_PASS(HexagonRemoveExtendArgs, "reargs", 55 "Remove Sign and Zero Extends for Args", false, false) 56 runOnFunction(Function & F)57bool HexagonRemoveExtendArgs::runOnFunction(Function &F) { 58 unsigned Idx = 1; 59 for (Function::arg_iterator AI = F.arg_begin(), AE = F.arg_end(); AI != AE; 60 ++AI, ++Idx) { 61 if (F.getAttributes().hasAttribute(Idx, Attribute::SExt)) { 62 Argument* Arg = AI; 63 if (!isa<PointerType>(Arg->getType())) { 64 for (auto UI = Arg->user_begin(); UI != Arg->user_end();) { 65 if (isa<SExtInst>(*UI)) { 66 Instruction* I = cast<Instruction>(*UI); 67 SExtInst* SI = new SExtInst(Arg, I->getType()); 68 assert (EVT::getEVT(SI->getType()) == 69 (EVT::getEVT(I->getType()))); 70 ++UI; 71 I->replaceAllUsesWith(SI); 72 Instruction* First = F.getEntryBlock().begin(); 73 SI->insertBefore(First); 74 I->eraseFromParent(); 75 } else { 76 ++UI; 77 } 78 } 79 } 80 } 81 } 82 return true; 83 } 84 85 86 87 FunctionPass* createHexagonRemoveExtendArgs(const HexagonTargetMachine & TM)88llvm::createHexagonRemoveExtendArgs(const HexagonTargetMachine &TM) { 89 return new HexagonRemoveExtendArgs(); 90 } 91