llvm-6502/lib/IR/User.cpp

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//===-- 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/IR/User.h"
#include "llvm/IR/Constant.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/Operator.h"
namespace llvm {
class BasicBlock;
//===----------------------------------------------------------------------===//
// User Class
//===----------------------------------------------------------------------===//
void User::anchor() {}
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
//===----------------------------------------------------------------------===//
void User::allocHungoffUses(unsigned N, bool IsPhi) {
assert(HasHungOffUses && "alloc must have hung off uses");
static_assert(AlignOf<Use>::Alignment >= AlignOf<Use::UserRef>::Alignment,
"Alignment is insufficient for 'hung-off-uses' pieces");
static_assert(AlignOf<Use::UserRef>::Alignment >=
AlignOf<BasicBlock *>::Alignment,
"Alignment is insufficient for 'hung-off-uses' pieces");
// Allocate the array of Uses, followed by a pointer (with bottom bit set) to
// the User.
size_t size = N * sizeof(Use) + sizeof(Use::UserRef);
if (IsPhi)
size += N * sizeof(BasicBlock *);
Use *Begin = static_cast<Use*>(::operator new(size));
Use *End = Begin + N;
(void) new(End) Use::UserRef(const_cast<User*>(this), 1);
setOperandList(Use::initTags(Begin, End));
}
void User::growHungoffUses(unsigned NewNumUses, bool IsPhi) {
assert(HasHungOffUses && "realloc must have hung off uses");
unsigned OldNumUses = getNumOperands();
// We don't support shrinking the number of uses. We wouldn't have enough
// space to copy the old uses in to the new space.
assert(NewNumUses > OldNumUses && "realloc must grow num uses");
Use *OldOps = getOperandList();
allocHungoffUses(NewNumUses, IsPhi);
Use *NewOps = getOperandList();
// Now copy from the old operands list to the new one.
std::copy(OldOps, OldOps + OldNumUses, NewOps);
// If this is a Phi, then we need to copy the BB pointers too.
if (IsPhi) {
auto *OldPtr =
reinterpret_cast<char *>(OldOps + OldNumUses) + sizeof(Use::UserRef);
auto *NewPtr =
reinterpret_cast<char *>(NewOps + NewNumUses) + sizeof(Use::UserRef);
std::copy(OldPtr, OldPtr + (OldNumUses * sizeof(BasicBlock *)), NewPtr);
}
Use::zap(OldOps, OldOps + OldNumUses, true);
}
//===----------------------------------------------------------------------===//
// User operator new Implementations
//===----------------------------------------------------------------------===//
void *User::operator new(size_t Size, unsigned Us) {
assert(Us < (1u << NumUserOperandsBits) && "Too many operands");
void *Storage = ::operator new(Size + sizeof(Use) * Us);
Use *Start = static_cast<Use*>(Storage);
Use *End = Start + Us;
User *Obj = reinterpret_cast<User*>(End);
Obj->NumUserOperands = Us;
Obj->HasHungOffUses = false;
Use::initTags(Start, End);
return Obj;
}
void *User::operator new(size_t Size) {
// Allocate space for a single Use*
void *Storage = ::operator new(Size + sizeof(Use *));
Use **HungOffOperandList = static_cast<Use **>(Storage);
User *Obj = reinterpret_cast<User *>(HungOffOperandList + 1);
Obj->NumUserOperands = 0;
Obj->HasHungOffUses = true;
*HungOffOperandList = nullptr;
return Obj;
}
//===----------------------------------------------------------------------===//
// User operator delete Implementation
//===----------------------------------------------------------------------===//
void User::operator delete(void *Usr) {
// Hung off uses use a single Use* before the User, while other subclasses
// use a Use[] allocated prior to the user.
User *Obj = static_cast<User *>(Usr);
if (Obj->HasHungOffUses) {
Use **HungOffOperandList = static_cast<Use **>(Usr) - 1;
// drop the hung off uses.
Use::zap(*HungOffOperandList, *HungOffOperandList + Obj->NumUserOperands,
/* Delete */ true);
::operator delete(HungOffOperandList);
} else {
Use *Storage = static_cast<Use *>(Usr) - Obj->NumUserOperands;
Use::zap(Storage, Storage + Obj->NumUserOperands,
/* Delete */ false);
::operator delete(Storage);
}
}
//===----------------------------------------------------------------------===//
// Operator Class
//===----------------------------------------------------------------------===//
Operator::~Operator() {
llvm_unreachable("should never destroy an Operator");
}
} // End llvm namespace