1 //===-- User.cpp - Implement the User class -------------------------------===// 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 #include "llvm/IR/User.h" 11 #include "llvm/IR/Constant.h" 12 #include "llvm/IR/GlobalValue.h" 13 #include "llvm/IR/Operator.h" 14 15 namespace llvm { 16 class BasicBlock; 17 18 //===----------------------------------------------------------------------===// 19 // User Class 20 //===----------------------------------------------------------------------===// 21 22 void User::anchor() {} 23 24 void User::replaceUsesOfWith(Value *From, Value *To) { 25 if (From == To) return; // Duh what? 26 27 assert((!isa<Constant>(this) || isa<GlobalValue>(this)) && 28 "Cannot call User::replaceUsesOfWith on a constant!"); 29 30 for (unsigned i = 0, E = getNumOperands(); i != E; ++i) 31 if (getOperand(i) == From) { // Is This operand is pointing to oldval? 32 // The side effects of this setOperand call include linking to 33 // "To", adding "this" to the uses list of To, and 34 // most importantly, removing "this" from the use list of "From". 35 setOperand(i, To); // Fix it now... 36 } 37 } 38 39 //===----------------------------------------------------------------------===// 40 // User allocHungoffUses Implementation 41 //===----------------------------------------------------------------------===// 42 43 void User::allocHungoffUses(unsigned N, bool IsPhi) { 44 // Allocate the array of Uses, followed by a pointer (with bottom bit set) to 45 // the User. 46 size_t size = N * sizeof(Use) + sizeof(Use::UserRef); 47 if (IsPhi) 48 size += N * sizeof(BasicBlock *); 49 Use *Begin = static_cast<Use*>(::operator new(size)); 50 Use *End = Begin + N; 51 (void) new(End) Use::UserRef(const_cast<User*>(this), 1); 52 OperandList = Use::initTags(Begin, End); 53 // Tag this operand list as being a hung off. 54 HasHungOffUses = true; 55 } 56 57 void User::growHungoffUses(unsigned NewNumUses, bool IsPhi) { 58 assert(HasHungOffUses && "realloc must have hung off uses"); 59 60 unsigned OldNumUses = getNumOperands(); 61 62 // We don't support shrinking the number of uses. We wouldn't have enough 63 // space to copy the old uses in to the new space. 64 assert(NewNumUses > OldNumUses && "realloc must grow num uses"); 65 66 Use *OldOps = OperandList; 67 allocHungoffUses(NewNumUses, IsPhi); 68 Use *NewOps = OperandList; 69 70 // Now copy from the old operands list to the new one. 71 std::copy(OldOps, OldOps + OldNumUses, NewOps); 72 73 // If this is a Phi, then we need to copy the BB pointers too. 74 if (IsPhi) { 75 auto *OldPtr = 76 reinterpret_cast<char *>(OldOps + OldNumUses) + sizeof(Use::UserRef); 77 auto *NewPtr = 78 reinterpret_cast<char *>(NewOps + NewNumUses) + sizeof(Use::UserRef); 79 std::copy(OldPtr, OldPtr + (OldNumUses * sizeof(BasicBlock *)), NewPtr); 80 } 81 Use::zap(OldOps, OldOps + OldNumUses, true); 82 } 83 84 //===----------------------------------------------------------------------===// 85 // User operator new Implementations 86 //===----------------------------------------------------------------------===// 87 88 void *User::operator new(size_t s, unsigned Us) { 89 void *Storage = ::operator new(s + sizeof(Use) * Us); 90 Use *Start = static_cast<Use*>(Storage); 91 Use *End = Start + Us; 92 User *Obj = reinterpret_cast<User*>(End); 93 Obj->OperandList = Start; 94 Obj->HasHungOffUses = false; 95 Obj->NumOperands = Us; 96 Use::initTags(Start, End); 97 return Obj; 98 } 99 100 //===----------------------------------------------------------------------===// 101 // User operator delete Implementation 102 //===----------------------------------------------------------------------===// 103 104 void User::operator delete(void *Usr) { 105 User *Start = static_cast<User*>(Usr); 106 Use *Storage = static_cast<Use*>(Usr) - Start->NumOperands; 107 // If there were hung-off uses, they will have been freed already and 108 // NumOperands reset to 0, so here we just free the User itself. 109 ::operator delete(Storage); 110 } 111 112 //===----------------------------------------------------------------------===// 113 // Operator Class 114 //===----------------------------------------------------------------------===// 115 116 Operator::~Operator() { 117 llvm_unreachable("should never destroy an Operator"); 118 } 119 120 } // End llvm namespace 121