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/Constant.h" 11 #include "llvm/GlobalValue.h" 12 #include "llvm/User.h" 13 14 namespace llvm { 15 16 //===----------------------------------------------------------------------===// 17 // User Class 18 //===----------------------------------------------------------------------===// 19 20 void User::anchor() {} 21 22 // replaceUsesOfWith - Replaces all references to the "From" definition with 23 // references to the "To" definition. 24 // 25 void User::replaceUsesOfWith(Value *From, Value *To) { 26 if (From == To) return; // Duh what? 27 28 assert((!isa<Constant>(this) || isa<GlobalValue>(this)) && 29 "Cannot call User::replaceUsesOfWith on a constant!"); 30 31 for (unsigned i = 0, E = getNumOperands(); i != E; ++i) 32 if (getOperand(i) == From) { // Is This operand is pointing to oldval? 33 // The side effects of this setOperand call include linking to 34 // "To", adding "this" to the uses list of To, and 35 // most importantly, removing "this" from the use list of "From". 36 setOperand(i, To); // Fix it now... 37 } 38 } 39 40 //===----------------------------------------------------------------------===// 41 // User allocHungoffUses Implementation 42 //===----------------------------------------------------------------------===// 43 44 Use *User::allocHungoffUses(unsigned N) const { 45 // Allocate the array of Uses, followed by a pointer (with bottom bit set) to 46 // the User. 47 size_t size = N * sizeof(Use) + sizeof(Use::UserRef); 48 Use *Begin = static_cast<Use*>(::operator new(size)); 49 Use *End = Begin + N; 50 (void) new(End) Use::UserRef(const_cast<User*>(this), 1); 51 return Use::initTags(Begin, End); 52 } 53 54 //===----------------------------------------------------------------------===// 55 // User operator new Implementations 56 //===----------------------------------------------------------------------===// 57 58 void *User::operator new(size_t s, unsigned Us) { 59 void *Storage = ::operator new(s + sizeof(Use) * Us); 60 Use *Start = static_cast<Use*>(Storage); 61 Use *End = Start + Us; 62 User *Obj = reinterpret_cast<User*>(End); 63 Obj->OperandList = Start; 64 Obj->NumOperands = Us; 65 Use::initTags(Start, End); 66 return Obj; 67 } 68 69 //===----------------------------------------------------------------------===// 70 // User operator delete Implementation 71 //===----------------------------------------------------------------------===// 72 73 void User::operator delete(void *Usr) { 74 User *Start = static_cast<User*>(Usr); 75 Use *Storage = static_cast<Use*>(Usr) - Start->NumOperands; 76 // If there were hung-off uses, they will have been freed already and 77 // NumOperands reset to 0, so here we just free the User itself. 78 ::operator delete(Storage); 79 } 80 81 } // End llvm namespace 82
