Fix logic bug in finding retry slot in tally.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@24188 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp
index 0b82a6a..1666f43 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp
@@ -101,15 +101,13 @@
typedef typename std::vector<T>::iterator Iter;
// Tally iterator
- /// SlotsAvailable - Returns the an iterator equal to Begin if all units
- /// are available. Otherwise return an iterator to a better Begin.
- Iter SlotsAvailable(Iter Begin, unsigned N, unsigned ResourceSet,
+ /// SlotsAvailable - Returns true if all units are available.
+ ///
+ bool SlotsAvailable(Iter Begin, unsigned N, unsigned ResourceSet,
unsigned &Resource) {
assert(N && "Must check availability with N != 0");
// Determine end of interval
Iter End = Begin + N;
- // Alternate result
- Iter Better = End;
assert(End <= Tally.end() && "Tally is not large enough for schedule");
// Iterate thru each resource
@@ -126,15 +124,31 @@
if (Interval == Begin) {
// Success
Resource = Res;
- return Begin;
+ return true;
}
- if (Better > Interval) Better = Interval;
}
// No luck
Resource = 0;
- return Better;
+ return false;
}
+
+ /// RetrySlot - Finds a good candidate slot to retry search.
+ Iter RetrySlot(Iter Begin, unsigned N, unsigned ResourceSet) {
+ assert(N && "Must check availability with N != 0");
+ // Determine end of interval
+ Iter End = Begin + N;
+ assert(End <= Tally.end() && "Tally is not large enough for schedule");
+
+ while (Begin != End--) {
+ // Clear units in use
+ ResourceSet &= ~*End;
+ // If no units left then we should go no further
+ if (!ResourceSet) return End + 1;
+ }
+ // Made it all the way through
+ return Begin;
+ }
/// FindAndReserveStages - Return true if the stages can be completed. If
/// so mark as busy.
@@ -146,7 +160,7 @@
unsigned N = Stage->Cycles;
// Check to see if N slots are available, if not fail
unsigned Resource;
- if (SlotsAvailable(Begin, N, Stage->Units, Resource) != Begin) return false;
+ if (!SlotsAvailable(Begin, N, Stage->Units, Resource)) return false;
// Check to see if remaining stages are available, if not fail
if (!FindAndReserveStages(Begin + N, Stage + 1, StageEnd)) return false;
// Reserve resource
@@ -177,9 +191,7 @@
// Try at cursor, if successful return position.
if (FindAndReserveStages(Cursor, StageBegin, StageEnd)) return Cursor;
// Locate a better position
- unsigned Resource;
- Cursor = SlotsAvailable(Cursor + 1, StageBegin->Cycles, StageBegin->Units,
- Resource);
+ Cursor = RetrySlot(Cursor + 1, StageBegin->Cycles, StageBegin->Units);
}
}
@@ -194,7 +206,13 @@
// as busy.
unsigned FindAndReserve(unsigned Slot, InstrStage *StageBegin,
InstrStage *StageEnd) {
- return FindSlots(Tally.begin() + Slot, StageBegin, StageEnd)-Tally.begin();
+ // Where to begin
+ Iter Begin = Tally.begin() + Slot;
+ // Find a free slot
+ Iter Where = FindSlots(Begin, StageBegin, StageEnd);
+ // Distance is slot number
+ unsigned Final = Where - Tally.begin();
+ return Final;
}
};
@@ -718,7 +736,7 @@
/// GatherSchedulingInfo - Get latency and resource information about each node.
///
void SimpleSched::GatherSchedulingInfo() {
-
+ // Get instruction itineraries for the target
const InstrItineraryData InstrItins = TM.getInstrItineraryData();
// For each node
@@ -781,7 +799,7 @@
if (!Group->getDominator()) {
NIIterator NGI = Group->group_begin(), NGE = Group->group_end();
NodeInfo *Dominator = *NGI;
- unsigned Latency = Dominator->Latency;
+ unsigned Latency = 0;
for (NGI++; NGI != NGE; NGI++) {
NodeInfo* NGNI = *NGI;