XCore target: fix handling of unsized global arrays in large code model

[oota-llvm.git] / lib / CodeGen / TargetSchedule.cpp

diff --git a/lib/CodeGen/TargetSchedule.cpp b/lib/CodeGen/TargetSchedule.cpp
index 53cd11c5daa633a22db433f226b68cccc63478f9..b0f2ca68884b973920af2071df9bbb09d2a0a751 100644 (file)
--- a/lib/CodeGen/TargetSchedule.cpp
+++ b/lib/CodeGen/TargetSchedule.cpp
@@ -201,13 +201,17 @@ unsigned TargetSchedModel::computeOperandLatency(
     if (UseDesc->NumReadAdvanceEntries == 0)
       return Latency;
     unsigned UseIdx = findUseIdx(UseMI, UseOperIdx);
-    return Latency - STI->getReadAdvanceCycles(UseDesc, UseIdx, WriteID);
+    int Advance = STI->getReadAdvanceCycles(UseDesc, UseIdx, WriteID);
+    if (Advance > 0 && (unsigned)Advance > Latency) // unsigned wrap
+      return 0;
+    return Latency - Advance;
   }
   // If DefIdx does not exist in the model (e.g. implicit defs), then return
   // unit latency (defaultDefLatency may be too conservative).
 #ifndef NDEBUG
   if (SCDesc->isValid() && !DefMI->getOperand(DefOperIdx).isImplicit()
-      && !DefMI->getDesc().OpInfo[DefOperIdx].isOptionalDef()) {
+      && !DefMI->getDesc().OpInfo[DefOperIdx].isOptionalDef()
+      && SchedModel.isComplete()) {
     std::string Err;
     raw_string_ostream ss(Err);
     ss << "DefIdx " << DefIdx << " exceeds machine model writes for "
@@ -221,10 +225,13 @@ unsigned TargetSchedModel::computeOperandLatency(
   return DefMI->isTransient() ? 0 : TII->defaultDefLatency(&SchedModel, DefMI);
 }
 
-unsigned TargetSchedModel::computeInstrLatency(const MachineInstr *MI) const {
+unsigned
+TargetSchedModel::computeInstrLatency(const MachineInstr *MI,
+                                      bool UseDefaultDefLatency) const {
   // For the itinerary model, fall back to the old subtarget hook.
   // Allow subtargets to compute Bundle latencies outside the machine model.
-  if (hasInstrItineraries() || MI->isBundle())
+  if (hasInstrItineraries() || MI->isBundle() ||
+      (!hasInstrSchedModel() && !UseDefaultDefLatency))
     return TII->getInstrLatency(&InstrItins, MI);
 
   if (hasInstrSchedModel()) {