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 17 //===----------------------------------------------------------------------===// 18 // User Class 19 //===----------------------------------------------------------------------===// 20 21 void User::anchor() {} 22 23 // replaceUsesOfWith - Replaces all references to the "From" definition with 24 // references to the "To" definition. 25 // 26 void User::replaceUsesOfWith(Value *From, Value *To) { 27 if (From == To) return; // Duh what? 28 29 assert((!isa<Constant>(this) || isa<GlobalValue>(this)) && 30 "Cannot call User::replaceUsesOfWith on a constant!"); 31 32 for (unsigned i = 0, E = getNumOperands(); i != E; ++i) 33 if (getOperand(i) == From) { // Is This operand is pointing to oldval? 34 // The side effects of this setOperand call include linking to 35 // "To", adding "this" to the uses list of To, and 36 // most importantly, removing "this" from the use list of "From". 37 setOperand(i, To); // Fix it now... 38 } 39 } 40 41 //===----------------------------------------------------------------------===// 42 // User allocHungoffUses Implementation 43 //===----------------------------------------------------------------------===// 44 45 Use *User::allocHungoffUses(unsigned N) const { 46 // Allocate the array of Uses, followed by a pointer (with bottom bit set) to 47 // the User. 48 size_t size = N * sizeof(Use) + sizeof(Use::UserRef); 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 return Use::initTags(Begin, End); 53 } 54 55 //===----------------------------------------------------------------------===// 56 // User operator new Implementations 57 //===----------------------------------------------------------------------===// 58 59 void *User::operator new(size_t s, unsigned Us) { 60 void *Storage = ::operator new(s + sizeof(Use) * Us); 61 Use *Start = static_cast<Use*>(Storage); 62 Use *End = Start + Us; 63 User *Obj = reinterpret_cast<User*>(End); 64 Obj->OperandList = Start; 65 Obj->NumOperands = Us; 66 Use::initTags(Start, End); 67 return Obj; 68 } 69 70 //===----------------------------------------------------------------------===// 71 // User operator delete Implementation 72 //===----------------------------------------------------------------------===// 73 74 void User::operator delete(void *Usr) { 75 User *Start = static_cast<User*>(Usr); 76 Use *Storage = static_cast<Use*>(Usr) - Start->NumOperands; 77 // If there were hung-off uses, they will have been freed already and 78 // NumOperands reset to 0, so here we just free the User itself. 79 ::operator delete(Storage); 80 } 81 82 //===----------------------------------------------------------------------===// 83 // Operator Class 84 //===----------------------------------------------------------------------===// 85 86 Operator::~Operator() { 87 llvm_unreachable("should never destroy an Operator"); 88 } 89 90 } // End llvm namespace 91
