1 //===-- Value.cpp - Implement the Value class -----------------------------===//
3 // This file implements the Value and User classes.
5 //===----------------------------------------------------------------------===//
7 #include "llvm/InstrTypes.h"
8 #include "llvm/SymbolTable.h"
9 #include "llvm/DerivedTypes.h"
10 #include "Support/LeakDetector.h"
13 //===----------------------------------------------------------------------===//
15 //===----------------------------------------------------------------------===//
17 static inline const Type *checkType(const Type *Ty) {
18 assert(Ty && "Value defined with a null type: Error!");
22 Value::Value(const Type *ty, ValueTy vty, const std::string &name)
23 : Name(name), Ty(checkType(ty), this) {
28 #ifndef NDEBUG // Only in -g mode...
29 // Check to make sure that there are no uses of this value that are still
30 // around when the value is destroyed. If there are, then we have a dangling
31 // reference and something is wrong. This code is here to print out what is
32 // still being referenced. The value in question should be printed as
35 if (Uses.begin() != Uses.end()) {
36 std::cerr << "While deleting: " << Ty << "%" << Name << "\n";
37 for (use_const_iterator I = Uses.begin(); I != Uses.end(); ++I)
38 std::cerr << "Use still stuck around after Def is destroyed:"
42 assert(Uses.begin() == Uses.end());
44 // There should be no uses of this object anymore, remove it.
45 LeakDetector::removeGarbageObject(this);
48 void Value::replaceAllUsesWith(Value *D) {
49 assert(D && "Value::replaceAllUsesWith(<null>) is invalid!");
50 assert(D != this && "V->replaceAllUsesWith(V) is NOT valid!");
51 assert(D->getType() == getType() &&
52 "replaceAllUses of value with new value of different type!");
53 while (!Uses.empty()) {
54 User *Use = Uses.back();
56 unsigned NumUses = Uses.size();
58 Use->replaceUsesOfWith(this, D);
60 #ifndef NDEBUG // only in -g mode...
61 if (Uses.size() == NumUses)
62 std::cerr << "Use: " << *Use << "replace with: " << *D;
64 assert(Uses.size() != NumUses && "Didn't remove definition!");
68 // refineAbstractType - This function is implemented because we use
69 // potentially abstract types, and these types may be resolved to more
70 // concrete types after we are constructed. For the value class, we simply
71 // change Ty to point to the right type. :)
73 void Value::refineAbstractType(const DerivedType *OldTy, const Type *NewTy) {
74 assert(Ty.get() == OldTy && "Can't refine anything but my type!");
75 if (OldTy == NewTy && !OldTy->isAbstract())
76 Ty.removeUserFromConcrete();
80 void Value::killUse(User *U) {
84 // Scan backwards through the uses list looking for the user. We do this
85 // because vectors like to be accessed on the end. This is incredibly
86 // important from a performance perspective.
87 for (i = Uses.size()-1; Uses[i] != U; --i)
90 assert(i < Uses.size() && "Use not in uses list!!");
91 Uses.erase(Uses.begin()+i);
94 User *Value::use_remove(use_iterator &I) {
95 assert(I != Uses.end() && "Trying to remove the end of the use list!!!");
101 //===----------------------------------------------------------------------===//
103 //===----------------------------------------------------------------------===//
105 User::User(const Type *Ty, ValueTy vty, const std::string &name)
106 : Value(Ty, vty, name) {
109 // replaceUsesOfWith - Replaces all references to the "From" definition with
110 // references to the "To" definition.
112 void User::replaceUsesOfWith(Value *From, Value *To) {
113 if (From == To) return; // Duh what?
115 for (unsigned i = 0, E = getNumOperands(); i != E; ++i)
116 if (getOperand(i) == From) { // Is This operand is pointing to oldval?
117 // The side effects of this setOperand call include linking to
118 // "To", adding "this" to the uses list of To, and
119 // most importantly, removing "this" from the use list of "From".
120 setOperand(i, To); // Fix it now...