LLVMValueRef LLVM_General_BuildAtomicCmpXchg(
LLVMBuilderRef b,
LLVMValueRef ptr,
LLVMValueRef cmp,
LLVMValueRef n,
LLVMBool v,
LLVMAtomicOrdering lao,
LLVMSynchronizationScope lss,
const char *name
) {
AtomicCmpXchgInst *a = unwrap(b)->CreateAtomicCmpXchg(
unwrap(ptr), unwrap(cmp), unwrap(n), unwrap(lao), unwrap(lss)
);
a->setVolatile(v);
a->setName(name);
return wrap(a);
}
static InstTransResult doCmpxchgRM(InstPtr ip, BasicBlock *&b,
Value *dstAddr,
const MCOperand &srcReg)
{
NASSERT(dstAddr != NULL);
NASSERT(srcReg.isReg());
Value *acc;
switch(width) {
case 8:
acc = R_READ<width>(b, X86::AL);
break;
case 16:
acc = R_READ<width>(b, X86::AX);
break;
case 32:
acc = R_READ<width>(b, X86::EAX);
break;
default:
throw TErr(__LINE__, __FILE__, "Width not supported");
}
//Value *mem_v = M_READ<width>(ip, b, dstAddr);
Value *m_addr = NULL;
unsigned addrspace = ip->get_addr_space();
if( dstAddr->getType()->isPointerTy() == false ) {
llvm::Type *ptrTy =
Type::getIntNPtrTy(b->getContext(), width, addrspace);
m_addr = new llvm::IntToPtrInst(dstAddr, ptrTy, "", b);
}
else if( dstAddr->getType() != Type::getIntNPtrTy(
b->getContext(), width, addrspace) )
{
//we need to bitcast the pointer value to a pointer type of the appropriate width
m_addr = CastInst::CreatePointerCast(dstAddr,
Type::getIntNPtrTy(b->getContext(), width, addrspace), "", b);
} else {
m_addr = dstAddr;
}
Value *srcReg_v = R_READ<width>(b, srcReg.getReg());
AtomicCmpXchgInst *cmpx = new AtomicCmpXchgInst(
m_addr,
acc,
srcReg_v,
llvm::SequentiallyConsistent,
llvm::SequentiallyConsistent,
llvm::CrossThread,
b);
cmpx->setVolatile(true);
Value *cmpx_val = ExtractValueInst::Create(cmpx, 0, "cmpxchg_cmpx_val", b);
Value *was_eq = ExtractValueInst::Create(cmpx, 1, "cmpxchg_was_eq", b);
doCmpVV<width>(ip, b, acc, cmpx_val);
F_WRITE(b, ZF, was_eq);
Value *new_acc = SelectInst::Create(was_eq, acc, cmpx_val, "", b);
switch(width) {
case 8:
R_WRITE<width>(b, X86::AL, new_acc);
break;
case 16:
R_WRITE<width>(b, X86::AX, new_acc);
break;
case 32:
R_WRITE<width>(b, X86::EAX, new_acc);
break;
default:
throw TErr(__LINE__, __FILE__, "Width not supported");
}
return ContinueBlock;
}
static InstTransResult doCmpxchgRM(InstPtr ip, BasicBlock *&b,
Value *dstAddr,
const MCOperand &srcReg)
{
NASSERT(dstAddr != NULL);
NASSERT(srcReg.isReg());
Function *F = b->getParent();
BasicBlock *AccEQDest =
BasicBlock::Create(b->getContext(), "AccEQDest", F);
BasicBlock *AccNEDest =
BasicBlock::Create(b->getContext(), "AccNEDest", F);
BasicBlock *done =
BasicBlock::Create(b->getContext(), "done", F);
Value *acc;
switch(width) {
case 8:
acc = R_READ<width>(b, X86::AL);
break;
case 16:
acc = R_READ<width>(b, X86::AX);
break;
case 32:
acc = R_READ<width>(b, X86::EAX);
break;
default:
throw TErr(__LINE__, __FILE__, "Width not supported");
}
//Value *mem_v = M_READ<width>(ip, b, dstAddr);
Value *m_addr = NULL;
unsigned addrspace = ip->get_addr_space();
if( dstAddr->getType()->isPointerTy() == false ) {
llvm::Type *ptrTy =
Type::getIntNPtrTy(b->getContext(), width, addrspace);
m_addr = new llvm::IntToPtrInst(dstAddr, ptrTy, "", b);
}
else if( dstAddr->getType() != Type::getIntNPtrTy(
b->getContext(), width, addrspace) )
{
//we need to bitcast the pointer value to a pointer type of the appropriate width
m_addr = CastInst::CreatePointerCast(dstAddr,
Type::getIntNPtrTy(b->getContext(), width, addrspace), "", b);
} else {
m_addr = dstAddr;
}
Value *srcReg_v = R_READ<width>(b, srcReg.getReg());
AtomicCmpXchgInst *cmpx = new AtomicCmpXchgInst(
m_addr,
acc,
srcReg_v,
llvm::SequentiallyConsistent,
llvm::CrossThread,
b);
cmpx->setVolatile(true);
// needed for flags settings
doCmpVV<width>(ip, b, acc, cmpx);
Value *Cmp = new ICmpInst(*b, CmpInst::ICMP_EQ, cmpx, acc);
BranchInst::Create(AccEQDest, AccNEDest, Cmp, b);
// Acc == Dst
F_SET(AccEQDest, "ZF");
//M_WRITE<width>(ip, AccEQDest, dstAddr, srcReg_v);
BranchInst::Create(done, AccEQDest);
// Acc != Dst
F_CLEAR(AccNEDest, "ZF");
switch(width) {
case 8:
R_WRITE<width>(AccNEDest, X86::AL, cmpx);
break;
case 16:
R_WRITE<width>(AccNEDest, X86::AX, cmpx);
break;
case 32:
R_WRITE<width>(AccNEDest, X86::EAX, cmpx);
break;
default:
throw TErr(__LINE__, __FILE__, "Width not supported");
}
BranchInst::Create(done, AccNEDest);
b = done;
return ContinueBlock;
}