Changes in directory llvm/lib/CodeGen/SelectionDAG:
ScheduleDAG.cpp updated: 1.90 -> 1.91
ScheduleDAGRRList.cpp updated: 1.3 -> 1.4
---
Log message:
Fixing 2006-05-01-SchedCausingSpills.ll; some clean up
---
Diffs of the changes: (+69 -15)
ScheduleDAG.cpp | 12 ++++----
ScheduleDAGRRList.cpp | 72 +++++++++++++++++++++++++++++++++++++++++++-------
2 files changed, 69 insertions(+), 15 deletions(-)
Index: llvm/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp
diff -u llvm/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp:1.90
llvm/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp:1.91
--- llvm/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp:1.90 Fri May 12 01:33:48 2006
+++ llvm/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp Sat May 13 03:22:24 2006
@@ -171,26 +171,26 @@
return;
}
-static void CalculateDepths(SUnit *SU, unsigned Depth, unsigned Max) {
- if (Depth > SU->Depth) {
+static void CalculateDepths(SUnit *SU, unsigned Depth) {
+ if (SU->Depth == 0 || Depth > SU->Depth) {
SU->Depth = Depth;
for (std::set<std::pair<SUnit*, bool> >::iterator I = SU->Succs.begin(),
E = SU->Succs.end(); I != E; ++I)
- CalculateDepths(I->first, Depth+1, Max);
+ CalculateDepths(I->first, Depth+1);
}
}
void ScheduleDAG::CalculateDepths() {
SUnit *Entry = SUnitMap[DAG.getEntryNode().Val];
- ::CalculateDepths(Entry, 0U, SUnits.size());
+ ::CalculateDepths(Entry, 0U);
for (unsigned i = 0, e = SUnits.size(); i != e; ++i)
if (SUnits[i].Preds.size() == 0 && &SUnits[i] != Entry) {
- ::CalculateDepths(&SUnits[i], 0U, SUnits.size());
+ ::CalculateDepths(&SUnits[i], 0U);
}
}
static void CalculateHeights(SUnit *SU, unsigned Height) {
- if (Height > SU->Height) {
+ if (SU->Height == 0 || Height > SU->Height) {
SU->Height = Height;
for (std::set<std::pair<SUnit*, bool> >::iterator I = SU->Preds.begin(),
E = SU->Preds.end(); I != E; ++I)
Index: llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
diff -u llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp:1.3
llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp:1.4
--- llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp:1.3 Fri May 12
01:33:48 2006
+++ llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp Sat May 13 03:22:24 2006
@@ -82,6 +82,8 @@
// Build scheduling units.
BuildSchedUnits();
+ DEBUG(for (unsigned su = 0, e = SUnits.size(); su != e; ++su)
+ SUnits[su].dumpAll(&DAG));
CalculateDepths();
CalculateHeights();
@@ -531,6 +533,40 @@
};
}
+static bool isFloater(const SUnit *SU) {
+ if (SU->Node->isTargetOpcode()) {
+ if (SU->NumPreds == 0)
+ return true;
+ if (SU->NumPreds == 1) {
+ for (std::set<std::pair<SUnit*, bool> >::iterator I = SU->Preds.begin(),
+ E = SU->Preds.end(); I != E; ++I) {
+ if (I->second) continue;
+
+ SUnit *PredSU = I->first;
+ unsigned Opc = PredSU->Node->getOpcode();
+ if (Opc != ISD::EntryToken && Opc != ISD::TokenFactor &&
+ Opc != ISD::CopyFromReg && Opc != ISD::CopyToReg)
+ return false;
+ }
+ return true;
+ }
+ }
+ return false;
+}
+
+static bool isSimpleFloaterUse(const SUnit *SU) {
+ unsigned NumOps = 0;
+ for (std::set<std::pair<SUnit*, bool> >::iterator I = SU->Preds.begin(),
+ E = SU->Preds.end(); I != E; ++I) {
+ if (I->second) continue;
+ if (++NumOps > 1)
+ return false;
+ if (!isFloater(I->first))
+ return false;
+ }
+ return true;
+}
+
// Bottom up
bool bu_ls_rr_sort::operator()(const SUnit *left, const SUnit *right) const {
unsigned LeftNum = left->NodeNum;
@@ -539,27 +575,43 @@
bool RIsTarget = right->Node->isTargetOpcode();
int LPriority = SPQ->getSethiUllmanNumber(LeftNum);
int RPriority = SPQ->getSethiUllmanNumber(RightNum);
- bool LIsFloater = LIsTarget && (LPriority == 1 || LPriority == 0);
- bool RIsFloater = RIsTarget && (RPriority == 1 || RPriority == 0);
int LBonus = 0;
int RBonus = 0;
// Schedule floaters (e.g. load from some constant address) and those nodes
// with a single predecessor each first. They maintain / reduce register
// pressure.
- if (LIsFloater)
+ if (isFloater(left) || isSimpleFloaterUse(left))
LBonus += 2;
- if (RIsFloater)
+ if (isFloater(right) || isSimpleFloaterUse(right))
RBonus += 2;
+ // Special tie breaker: if two nodes share a operand, the one that use it
+ // as a def&use operand is preferred.
+ if (LIsTarget && RIsTarget) {
+ if (left->isTwoAddress && !right->isTwoAddress) {
+ SDNode *DUNode = left->Node->getOperand(0).Val;
+ if (DUNode->isOperand(right->Node))
+ LBonus += 2;
+ }
+ if (!left->isTwoAddress && right->isTwoAddress) {
+ SDNode *DUNode = right->Node->getOperand(0).Val;
+ if (DUNode->isOperand(left->Node))
+ RBonus += 2;
+ }
+ }
+
if (LPriority+LBonus < RPriority+RBonus)
return true;
else if (LPriority+LBonus == RPriority+RBonus)
- if (left->NumPredsLeft > right->NumPredsLeft)
+ if (left->Height > right->Height)
return true;
- else if (left->NumPredsLeft+LBonus == right->NumPredsLeft+RBonus)
- if (left->CycleBound > right->CycleBound)
+ else if (left->Height == right->Height)
+ if (left->Depth < right->Depth)
return true;
+ else if (left->Depth == right->Depth)
+ if (left->CycleBound > right->CycleBound)
+ return true;
return false;
}
@@ -634,7 +686,7 @@
if (SuccSU != SU &&
(!canClobber(SuccSU, DUSU) ||
(SchedCommuteNodes && !SU->isCommutable &&
SuccSU->isCommutable))){
- if (SuccSU->Depth <= SU->Depth+2 && !isReachable(SuccSU, SU)) {
+ if (SuccSU->Depth == SU->Depth && !isReachable(SuccSU, SU)) {
DEBUG(std::cerr << "Adding an edge from SU # " << SU->NodeNum
<< " to SU #" << SuccSU->NodeNum << "\n");
if (SU->Preds.insert(std::make_pair(SuccSU, true)).second)
@@ -665,9 +717,11 @@
// Give it a small SethiUllman number so it will be scheduled right before
its
// predecessors that it doesn't lengthen their live ranges.
SethiUllmanNumber = INT_MIN + 10;
+ // FIXME: remove this else if? It seems to reduce register spills but often
+ // ends up increasing runtime. Need to investigate.
else if (SU->NumPredsLeft == 0 &&
(Opc != ISD::CopyFromReg || isCopyFromLiveIn(SU)))
- SethiUllmanNumber = 1;
+ SethiUllmanNumber = INT_MAX - 10;
else {
int Extra = 0;
for (std::set<std::pair<SUnit*, bool> >::const_iterator
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