turn this conditional into something humans might actually

be able to understand ;-)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79311 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2009-08-18 04:30:35 +00:00
parent 2c785880ea
commit a006d4e60d

View File

@ -128,14 +128,31 @@ MachineBasicBlock::iterator MachineBasicBlock::getFirstTerminator() {
return I;
}
bool
MachineBasicBlock::isOnlyReachableByFallthrough() const {
return !isLandingPad() &&
!pred_empty() &&
next(pred_begin()) == pred_end() &&
(*pred_begin())->isLayoutSuccessor(this) &&
((*pred_begin())->empty() ||
!(*pred_begin())->back().getDesc().isBarrier());
bool MachineBasicBlock::isOnlyReachableByFallthrough() const {
// If this is a landing pad, it isn't a fall through. If it has no preds,
// then nothing falls through to it.
if (isLandingPad() || pred_empty())
return false;
// If there isn't exactly one predecessor, it can't be a fall through.
const_pred_iterator PI = pred_begin(), PI2 = PI;
++PI;
if (PI != pred_end())
return false;
// The predecessor has to be immediately before this block.
const MachineBasicBlock *Pred = *PI;
if (!Pred->isLayoutSuccessor(this))
return false;
// If the block is completely empty, then it definitely does fall through.
if (Pred->empty())
return true;
// Otherwise, check the last instruction.
const MachineInstr &LastInst = Pred->back();
return LastInst.getDesc().isBarrier();
}
void MachineBasicBlock::dump() const {