mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-23 02:29:18 +00:00
Teach if-converter to avoid removing BBs whose addresses are takne. rdar://13782395
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181160 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
parent
acc47c738d
commit
9a28cc14a9
@ -1039,6 +1039,10 @@ bool IfConverter::IfConvertSimple(BBInfo &BBI, IfcvtKind Kind) {
|
||||
return false;
|
||||
}
|
||||
|
||||
if (CvtBBI->BB->hasAddressTaken())
|
||||
// Conservatively abort if-conversion if BB's address is taken.
|
||||
return false;
|
||||
|
||||
if (Kind == ICSimpleFalse)
|
||||
if (TII->ReverseBranchCondition(Cond))
|
||||
llvm_unreachable("Unable to reverse branch condition!");
|
||||
@ -1116,6 +1120,10 @@ bool IfConverter::IfConvertTriangle(BBInfo &BBI, IfcvtKind Kind) {
|
||||
return false;
|
||||
}
|
||||
|
||||
if (CvtBBI->BB->hasAddressTaken())
|
||||
// Conservatively abort if-conversion if BB's address is taken.
|
||||
return false;
|
||||
|
||||
if (Kind == ICTriangleFalse || Kind == ICTriangleFRev)
|
||||
if (TII->ReverseBranchCondition(Cond))
|
||||
llvm_unreachable("Unable to reverse branch condition!");
|
||||
@ -1184,7 +1192,8 @@ bool IfConverter::IfConvertTriangle(BBInfo &BBI, IfcvtKind Kind) {
|
||||
// block. By not merging them, we make it possible to iteratively
|
||||
// ifcvt the blocks.
|
||||
if (!HasEarlyExit &&
|
||||
NextBBI->BB->pred_size() == 1 && !NextBBI->HasFallThrough) {
|
||||
NextBBI->BB->pred_size() == 1 && !NextBBI->HasFallThrough &&
|
||||
!NextBBI->BB->hasAddressTaken()) {
|
||||
MergeBlocks(BBI, *NextBBI);
|
||||
FalseBBDead = true;
|
||||
} else {
|
||||
@ -1234,6 +1243,10 @@ bool IfConverter::IfConvertDiamond(BBInfo &BBI, IfcvtKind Kind,
|
||||
return false;
|
||||
}
|
||||
|
||||
if (TrueBBI.BB->hasAddressTaken() || FalseBBI.BB->hasAddressTaken())
|
||||
// Conservatively abort if-conversion if either BB has its address taken.
|
||||
return false;
|
||||
|
||||
// Put the predicated instructions from the 'true' block before the
|
||||
// instructions from the 'false' block, unless the true block would clobber
|
||||
// the predicate, in which case, do the opposite.
|
||||
@ -1382,7 +1395,8 @@ bool IfConverter::IfConvertDiamond(BBInfo &BBI, IfcvtKind Kind,
|
||||
// tail, add a unconditional branch to it.
|
||||
if (TailBB) {
|
||||
BBInfo &TailBBI = BBAnalysis[TailBB->getNumber()];
|
||||
bool CanMergeTail = !TailBBI.HasFallThrough;
|
||||
bool CanMergeTail = !TailBBI.HasFallThrough &&
|
||||
!TailBBI.BB->hasAddressTaken();
|
||||
// There may still be a fall-through edge from BBI1 or BBI2 to TailBB;
|
||||
// check if there are any other predecessors besides those.
|
||||
unsigned NumPreds = TailBB->pred_size();
|
||||
@ -1551,6 +1565,9 @@ void IfConverter::CopyAndPredicateBlock(BBInfo &ToBBI, BBInfo &FromBBI,
|
||||
/// i.e., when FromBBI's branch is being moved, add those successor edges to
|
||||
/// ToBBI.
|
||||
void IfConverter::MergeBlocks(BBInfo &ToBBI, BBInfo &FromBBI, bool AddEdges) {
|
||||
assert(!FromBBI.BB->hasAddressTaken() &&
|
||||
"Removing a BB whose address is taken!");
|
||||
|
||||
ToBBI.BB->splice(ToBBI.BB->end(),
|
||||
FromBBI.BB, FromBBI.BB->begin(), FromBBI.BB->end());
|
||||
|
||||
|
Loading…
Reference in New Issue
Block a user