misched: ignore debug values during scheduling

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155457 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Andrew Trick 2012-04-24 18:04:34 +00:00
parent 006e1abf76
commit eb45ebbdef

View File

@ -123,6 +123,29 @@ DefaultSchedRegistry("default", "Use the target's default scheduler choice.",
/// default scheduler if the target does not set a default.
static ScheduleDAGInstrs *createConvergingSched(MachineSchedContext *C);
/// Decrement this iterator until reaching the top or a non-debug instr.
static MachineBasicBlock::iterator
priorNonDebug(MachineBasicBlock::iterator I, MachineBasicBlock::iterator Beg) {
assert(I != Beg && "reached the top of the region, cannot decrement");
while (--I != Beg) {
if (!I->isDebugValue())
break;
}
return I;
}
/// If this iterator is a debug value, increment until reaching the End or a
/// non-debug instruction.
static MachineBasicBlock::iterator
nextIfDebug(MachineBasicBlock::iterator I, MachineBasicBlock::iterator End) {
while(I != End) {
if (!I->isDebugValue())
break;
}
return I;
}
/// Top-level MachineScheduler pass driver.
///
/// Visit blocks in function order. Divide each block into scheduling regions
@ -464,7 +487,7 @@ void ScheduleDAGMI::schedule() {
SchedImpl->releaseBottomNode(&(*I));
}
CurrentTop = RegionBegin;
CurrentTop = nextIfDebug(RegionBegin, RegionEnd);
CurrentBottom = RegionEnd;
bool IsTopNode = false;
while (SUnit *SU = SchedImpl->pickNode(IsTopNode)) {
@ -479,7 +502,7 @@ void ScheduleDAGMI::schedule() {
if (IsTopNode) {
assert(SU->isTopReady() && "node still has unscheduled dependencies");
if (&*CurrentTop == MI)
++CurrentTop;
CurrentTop = nextIfDebug(++CurrentTop, CurrentBottom);
else
moveInstruction(MI, CurrentTop);
// Release dependent instructions for scheduling.
@ -487,11 +510,13 @@ void ScheduleDAGMI::schedule() {
}
else {
assert(SU->isBottomReady() && "node still has unscheduled dependencies");
if (&*llvm::prior(CurrentBottom) == MI)
--CurrentBottom;
MachineBasicBlock::iterator priorII =
priorNonDebug(CurrentBottom, CurrentTop);
if (&*priorII == MI)
CurrentBottom = priorII;
else {
if (&*CurrentTop == MI)
CurrentTop = llvm::next(CurrentTop);
CurrentTop = nextIfDebug(++CurrentTop, CurrentBottom);
moveInstruction(MI, CurrentBottom);
CurrentBottom = MI;
}
@ -536,7 +561,7 @@ public:
IsTopNode = true;
}
else {
SU = DAG->getSUnit(llvm::prior(DAG->bottom()));
SU = DAG->getSUnit(priorNonDebug(DAG->bottom(), DAG->top()));
IsTopNode = false;
}
if (SU->isTopReady()) {