llvm-mirror/lib/VMCore/User.cpp
Jay Foad db0a7d4143 Simplify User::operator delete().
llvm-svn: 124330
2011-01-26 21:56:10 +00:00

82 lines
3.1 KiB
C++

//===-- User.cpp - Implement the User class -------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/Constant.h"
#include "llvm/GlobalValue.h"
#include "llvm/User.h"
namespace llvm {
//===----------------------------------------------------------------------===//
// User Class
//===----------------------------------------------------------------------===//
// replaceUsesOfWith - Replaces all references to the "From" definition with
// references to the "To" definition.
//
void User::replaceUsesOfWith(Value *From, Value *To) {
if (From == To) return; // Duh what?
assert((!isa<Constant>(this) || isa<GlobalValue>(this)) &&
"Cannot call User::replaceUsesOfWith on a constant!");
for (unsigned i = 0, E = getNumOperands(); i != E; ++i)
if (getOperand(i) == From) { // Is This operand is pointing to oldval?
// The side effects of this setOperand call include linking to
// "To", adding "this" to the uses list of To, and
// most importantly, removing "this" from the use list of "From".
setOperand(i, To); // Fix it now...
}
}
//===----------------------------------------------------------------------===//
// User allocHungoffUses Implementation
//===----------------------------------------------------------------------===//
Use *User::allocHungoffUses(unsigned N) const {
Use *Begin = static_cast<Use*>(::operator new(sizeof(Use) * N
+ sizeof(AugmentedUse)
- sizeof(Use)));
Use *End = Begin + N;
PointerIntPair<User*, 1, unsigned>&
ref(static_cast<AugmentedUse&>(End[-1]).ref);
ref.setPointer(const_cast<User*>(this));
ref.setInt(1);
return Use::initTags(Begin, End);
}
//===----------------------------------------------------------------------===//
// User operator new Implementations
//===----------------------------------------------------------------------===//
void *User::operator new(size_t s, unsigned Us) {
void *Storage = ::operator new(s + sizeof(Use) * Us);
Use *Start = static_cast<Use*>(Storage);
Use *End = Start + Us;
User *Obj = reinterpret_cast<User*>(End);
Obj->OperandList = Start;
Obj->NumOperands = Us;
Use::initTags(Start, End);
return Obj;
}
//===----------------------------------------------------------------------===//
// User operator delete Implementation
//===----------------------------------------------------------------------===//
void User::operator delete(void *Usr) {
User *Start = static_cast<User*>(Usr);
Use *Storage = static_cast<Use*>(Usr) - Start->NumOperands;
// If there were hung-off uses, they will have been freed already and
// NumOperands reset to 0, so here we just free the User itself.
::operator delete(Storage);
}
} // End llvm namespace