6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-01-14 00:32:55 +00:00
Code Issues Projects Releases Wiki Activity

ScheduleDAG: Added isBoundaryNode to conveniently detect a common corner case.

Browse Source 
This fixes DAG subtree analysis at the boundary.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173427 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Andrew Trick 2013-01-25 06:52:30 +00:00
parent 988d06b0e5
commit a5a73ad159
2 changed files with 31 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
include/llvm/CodeGen/ScheduleDAG.h
View File

@ -258,6 +258,8 @@ namespace llvm {
/// SUnit - Scheduling unit. This is a node in the scheduling DAG.
class SUnit {
private:
enum { BoundaryID = ~0u };
SDNode *Node; // Representative node.
MachineInstr *Instr; // Alternatively, a MachineInstr.
public:
@ -343,7 +345,7 @@ namespace llvm {
/// SUnit - Construct a placeholder SUnit.
SUnit()
: Node(0), Instr(0), OrigNode(0), SchedClass(0), NodeNum(~0u),
: Node(0), Instr(0), OrigNode(0), SchedClass(0), NodeNum(BoundaryID),
NodeQueueId(0), NumPreds(0), NumSuccs(0), NumPredsLeft(0),
NumSuccsLeft(0), WeakPredsLeft(0), WeakSuccsLeft(0), NumRegDefsLeft(0),
Latency(0), isVRegCycle(false), isCall(false), isCallOp(false),
@ -354,6 +356,15 @@ namespace llvm {
isDepthCurrent(false), isHeightCurrent(false), Depth(0), Height(0),
TopReadyCycle(0), BotReadyCycle(0), CopyDstRC(NULL), CopySrcRC(NULL) {}
/// \brief Boundary nodes are placeholders for the boundary of the
/// scheduling region.
///
/// BoundaryNodes can have DAG edges, including Data edges, but they do not
/// correspond to schedulable entities (e.g. instructions) and do not have a
/// valid ID. Consequently, always check for boundary nodes before accessing
/// an assoicative data structure keyed on node ID.
bool isBoundaryNode() const { return NodeNum == BoundaryID; };
/// setNode - Assign the representative SDNode for this SUnit.
/// This may be used during pre-regalloc scheduling.
void setNode(SDNode *N) {

26
lib/CodeGen/ScheduleDAGInstrs.cpp
View File

@ -1078,9 +1078,17 @@ public:
joinPredSubtree(*PI, SU, /*CheckLimit=*/false);
// Either link or merge the TreeData entry from the child to the parent.
if (R.DFSNodeData[PredNum].SubtreeID == PredNum)
RootSet[PredNum].ParentNodeID = SU->NodeNum;
else {
if (R.DFSNodeData[PredNum].SubtreeID == PredNum) {
// If the predecessor's parent is invalid, this is a tree edge and the
// current node is the parent.
if (RootSet[PredNum].ParentNodeID == SchedDFSResult::InvalidSubtreeID)
RootSet[PredNum].ParentNodeID = SU->NodeNum;
}
else if (RootSet.count(PredNum)) {
// The predecessor is not a root, but is still in the root set. This
// must be the new parent that it was just joined to. Note that
// RootSet[PredNum].ParentNodeID may either be invalid or may still be
// set to the original parent.
RData.SubInstrCount += RootSet[PredNum].SubInstrCount;
RootSet.erase(PredNum);
}
@ -1115,8 +1123,10 @@ public:
if (RI->ParentNodeID != SchedDFSResult::InvalidSubtreeID)
R.DFSTreeData[TreeID].ParentTreeID = SubtreeClasses[RI->ParentNodeID];
R.DFSTreeData[TreeID].SubInstrCount = RI->SubInstrCount;
assert(RI->SubInstrCount <= R.DFSNodeData[RI->NodeID].InstrCount &&
"Bad SubInstrCount");
// Note that SubInstrCount may be greater than InstrCount if we joined
// subtrees across a cross edge. InstrCount will be attributed to the
// original parent, while SubInstrCount will be attributed to the joined
// parent.
}
R.SubtreeConnections.resize(SubtreeClasses.getNumClasses());
R.SubtreeConnectLevels.resize(SubtreeClasses.getNumClasses());
@ -1221,7 +1231,7 @@ public:
static bool hasDataSucc(const SUnit *SU) {
for (SUnit::const_succ_iterator
SI = SU->Succs.begin(), SE = SU->Succs.end(); SI != SE; ++SI) {
if (SI->getKind() == SDep::Data)
if (SI->getKind() == SDep::Data && !SI->getSUnit()->isBoundaryNode())
return true;
}
return false;
@ -1249,8 +1259,10 @@ void SchedDFSResult::compute(ArrayRef<SUnit> SUnits) {
const SDep &PredDep = *DFS.getPred();
DFS.advance();
// Ignore non-data edges.
if (PredDep.getKind() != SDep::Data)
if (PredDep.getKind() != SDep::Data
|| PredDep.getSUnit()->isBoundaryNode()) {
continue;
}
// An already visited edge is a cross edge, assuming an acyclic DAG.
if (Impl.isVisited(PredDep.getSUnit())) {
Impl.visitCrossEdge(PredDep, DFS.getCurr());