User.cpp revision 280031
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 15namespace llvm { 16 17//===----------------------------------------------------------------------===// 18// User Class 19//===----------------------------------------------------------------------===// 20 21void User::anchor() {} 22 23void User::replaceUsesOfWith(Value *From, Value *To) { 24 if (From == To) return; // Duh what? 25 26 assert((!isa<Constant>(this) || isa<GlobalValue>(this)) && 27 "Cannot call User::replaceUsesOfWith on a constant!"); 28 29 for (unsigned i = 0, E = getNumOperands(); i != E; ++i) 30 if (getOperand(i) == From) { // Is This operand is pointing to oldval? 31 // The side effects of this setOperand call include linking to 32 // "To", adding "this" to the uses list of To, and 33 // most importantly, removing "this" from the use list of "From". 34 setOperand(i, To); // Fix it now... 35 } 36} 37 38//===----------------------------------------------------------------------===// 39// User allocHungoffUses Implementation 40//===----------------------------------------------------------------------===// 41 42Use *User::allocHungoffUses(unsigned N) const { 43 // Allocate the array of Uses, followed by a pointer (with bottom bit set) to 44 // the User. 45 size_t size = N * sizeof(Use) + sizeof(Use::UserRef); 46 Use *Begin = static_cast<Use*>(::operator new(size)); 47 Use *End = Begin + N; 48 (void) new(End) Use::UserRef(const_cast<User*>(this), 1); 49 return Use::initTags(Begin, End); 50} 51 52//===----------------------------------------------------------------------===// 53// User operator new Implementations 54//===----------------------------------------------------------------------===// 55 56void *User::operator new(size_t s, unsigned Us) { 57 void *Storage = ::operator new(s + sizeof(Use) * Us); 58 Use *Start = static_cast<Use*>(Storage); 59 Use *End = Start + Us; 60 User *Obj = reinterpret_cast<User*>(End); 61 Obj->OperandList = Start; 62 Obj->NumOperands = Us; 63 Use::initTags(Start, End); 64 return Obj; 65} 66 67//===----------------------------------------------------------------------===// 68// User operator delete Implementation 69//===----------------------------------------------------------------------===// 70 71void User::operator delete(void *Usr) { 72 User *Start = static_cast<User*>(Usr); 73 Use *Storage = static_cast<Use*>(Usr) - Start->NumOperands; 74 // If there were hung-off uses, they will have been freed already and 75 // NumOperands reset to 0, so here we just free the User itself. 76 ::operator delete(Storage); 77} 78 79//===----------------------------------------------------------------------===// 80// Operator Class 81//===----------------------------------------------------------------------===// 82 83Operator::~Operator() { 84 llvm_unreachable("should never destroy an Operator"); 85} 86 87} // End llvm namespace 88