Simplify the allocation and freeing of Users' operand lists, now that

every BranchInst has a fixed number of operands.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123027 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jay Foad 2011-01-07 20:29:02 +00:00
parent 43eaadeea5
commit 8e3914d12e
5 changed files with 4 additions and 69 deletions

View File

@ -2068,22 +2068,20 @@ protected:
virtual BranchInst *clone_impl() const;
public:
static BranchInst *Create(BasicBlock *IfTrue, Instruction *InsertBefore = 0) {
return new(1, true) BranchInst(IfTrue, InsertBefore);
return new(1) BranchInst(IfTrue, InsertBefore);
}
static BranchInst *Create(BasicBlock *IfTrue, BasicBlock *IfFalse,
Value *Cond, Instruction *InsertBefore = 0) {
return new(3) BranchInst(IfTrue, IfFalse, Cond, InsertBefore);
}
static BranchInst *Create(BasicBlock *IfTrue, BasicBlock *InsertAtEnd) {
return new(1, true) BranchInst(IfTrue, InsertAtEnd);
return new(1) BranchInst(IfTrue, InsertAtEnd);
}
static BranchInst *Create(BasicBlock *IfTrue, BasicBlock *IfFalse,
Value *Cond, BasicBlock *InsertAtEnd) {
return new(3) BranchInst(IfTrue, IfFalse, Cond, InsertAtEnd);
}
~BranchInst();
/// Transparently provide more efficient getOperand methods.
DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);

View File

@ -112,8 +112,6 @@ public:
/// a User changes.
static void zap(Use *Start, const Use *Stop, bool del = false);
/// getPrefix - Return deletable pointer if appropriate
Use *getPrefix();
private:
const Use* getImpliedUser() const;
static Use *initTags(Use *Start, Use *Stop, ptrdiff_t Done = 0);

View File

@ -61,7 +61,6 @@ protected:
unsigned NumOperands;
void *operator new(size_t s, unsigned Us);
void *operator new(size_t s, unsigned Us, bool Prefix);
User(const Type *ty, unsigned vty, Use *OpList, unsigned NumOps)
: Value(ty, vty), OperandList(OpList), NumOperands(NumOps) {}
Use *allocHungoffUses(unsigned) const;
@ -74,7 +73,6 @@ protected:
}
public:
~User() {
if ((intptr_t(OperandList) & 1) == 0)
Use::zap(OperandList, OperandList + NumOperands);
}
/// operator delete - free memory allocated for User and Use objects

View File

@ -730,31 +730,6 @@ BranchInst::BranchInst(const BranchInst &BI) :
SubclassOptionalData = BI.SubclassOptionalData;
}
Use* Use::getPrefix() {
PointerIntPair<Use**, 2, PrevPtrTag> &PotentialPrefix(this[-1].Prev);
if (PotentialPrefix.getOpaqueValue())
return 0;
return reinterpret_cast<Use*>((char*)&PotentialPrefix + 1);
}
BranchInst::~BranchInst() {
if (NumOperands == 1) {
if (Use *Prefix = OperandList->getPrefix()) {
Op<-1>() = 0;
//
// mark OperandList to have a special value for scrutiny
// by baseclass destructors and operator delete
OperandList = Prefix;
} else {
NumOperands = 3;
OperandList = op_begin();
}
}
}
BasicBlock *BranchInst::getSuccessorV(unsigned idx) const {
return getSuccessor(idx);
}
@ -3329,8 +3304,7 @@ ReturnInst *ReturnInst::clone_impl() const {
}
BranchInst *BranchInst::clone_impl() const {
unsigned Ops(getNumOperands());
return new(Ops, Ops == 1) BranchInst(*this);
return new(getNumOperands()) BranchInst(*this);
}
SwitchInst *SwitchInst::clone_impl() const {

View File

@ -191,31 +191,6 @@ void *User::operator new(size_t s, unsigned Us) {
return Obj;
}
/// Prefixed allocation - just before the first Use, allocate a NULL pointer.
/// The destructor can detect its presence and readjust the OperandList
/// for deletition.
///
void *User::operator new(size_t s, unsigned Us, bool Prefix) {
// currently prefixed allocation only admissible for
// unconditional branch instructions
if (!Prefix)
return operator new(s, Us);
assert(Us == 1 && "Other than one Use allocated?");
typedef PointerIntPair<void*, 2, Use::PrevPtrTag> TaggedPrefix;
void *Raw = ::operator new(s + sizeof(TaggedPrefix) + sizeof(Use) * Us);
TaggedPrefix *Pre = static_cast<TaggedPrefix*>(Raw);
Pre->setFromOpaqueValue(0);
void *Storage = Pre + 1; // skip over prefix
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
//===----------------------------------------------------------------------===//
@ -230,14 +205,6 @@ void User::operator delete(void *Usr) {
return;
}
//
// check for the flag whether the destructor has detected a prefixed
// allocation, in which case we remove the flag and delete starting
// at OperandList
if (reinterpret_cast<intptr_t>(Start->OperandList) & 1) {
::operator delete(reinterpret_cast<char*>(Start->OperandList) - 1);
return;
}
//
// in all other cases just delete the nullary User (covers hung-off
// uses also
::operator delete(Usr);