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
anchor()21 void User::anchor() {}
22
23 // replaceUsesOfWith - Replaces all references to the "From" definition with
24 // references to the "To" definition.
25 //
replaceUsesOfWith(Value * From,Value * To)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
allocHungoffUses(unsigned N) const45 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
operator new(size_t s,unsigned Us)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
operator delete(void * Usr)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
~Operator()86 Operator::~Operator() {
87 llvm_unreachable("should never destroy an Operator");
88 }
89
90 } // End llvm namespace
91