[llvm-commits] [llvm] r83159 - in /llvm/trunk: include/llvm/CodeGen/ScheduleDAG.h lib/CodeGen/PostRASchedulerList.cpp lib/CodeGen/ScheduleDAG.cpp lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp lib/CodeGen/SelectionDAG/ScheduleDAGList.cpp lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp

Reid Kleckner reid at kleckner.net
Wed Sep 30 13:15:39 PDT 2009


Author: rnk
Date: Wed Sep 30 15:15:38 2009
New Revision: 83159

URL: http://llvm.org/viewvc/llvm-project?rev=83159&view=rev
Log:
Fix integer overflow in instruction scheduling.  This can happen if we have
basic blocks that are so long that their size overflows a short.

Also assert that overflow does not happen in the future, as requested by Evan.

This fixes PR4401.

Modified:
    llvm/trunk/include/llvm/CodeGen/ScheduleDAG.h
    llvm/trunk/lib/CodeGen/PostRASchedulerList.cpp
    llvm/trunk/lib/CodeGen/ScheduleDAG.cpp
    llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp
    llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGList.cpp
    llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp

Modified: llvm/trunk/include/llvm/CodeGen/ScheduleDAG.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/ScheduleDAG.h?rev=83159&r1=83158&r2=83159&view=diff

==============================================================================
--- llvm/trunk/include/llvm/CodeGen/ScheduleDAG.h (original)
+++ llvm/trunk/include/llvm/CodeGen/ScheduleDAG.h Wed Sep 30 15:15:38 2009
@@ -243,10 +243,10 @@
     unsigned NodeNum;                   // Entry # of node in the node vector.
     unsigned NodeQueueId;               // Queue id of node.
     unsigned short Latency;             // Node latency.
-    short NumPreds;                     // # of SDep::Data preds.
-    short NumSuccs;                     // # of SDep::Data sucss.
-    short NumPredsLeft;                 // # of preds not scheduled.
-    short NumSuccsLeft;                 // # of succs not scheduled.
+    unsigned NumPreds;                  // # of SDep::Data preds.
+    unsigned NumSuccs;                  // # of SDep::Data sucss.
+    unsigned NumPredsLeft;              // # of preds not scheduled.
+    unsigned NumSuccsLeft;              // # of succs not scheduled.
     bool isTwoAddress     : 1;          // Is a two-address instruction.
     bool isCommutable     : 1;          // Is a commutable instruction.
     bool hasPhysRegDefs   : 1;          // Has physreg defs that are being used.

Modified: llvm/trunk/lib/CodeGen/PostRASchedulerList.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/PostRASchedulerList.cpp?rev=83159&r1=83158&r2=83159&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/PostRASchedulerList.cpp (original)
+++ llvm/trunk/lib/CodeGen/PostRASchedulerList.cpp Wed Sep 30 15:15:38 2009
@@ -972,17 +972,17 @@
 /// the PendingQueue if the count reaches zero. Also update its cycle bound.
 void SchedulePostRATDList::ReleaseSucc(SUnit *SU, SDep *SuccEdge) {
   SUnit *SuccSU = SuccEdge->getSUnit();
-  --SuccSU->NumPredsLeft;
-  
+
 #ifndef NDEBUG
-  if (SuccSU->NumPredsLeft < 0) {
+  if (SuccSU->NumPredsLeft == 0) {
     errs() << "*** Scheduling failed! ***\n";
     SuccSU->dump(this);
     errs() << " has been released too many times!\n";
     llvm_unreachable(0);
   }
 #endif
-  
+  --SuccSU->NumPredsLeft;
+
   // Compute how many cycles it will be before this actually becomes
   // available.  This is the max of the start time of all predecessors plus
   // their latencies.

Modified: llvm/trunk/lib/CodeGen/ScheduleDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/ScheduleDAG.cpp?rev=83159&r1=83158&r2=83159&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/ScheduleDAG.cpp (original)
+++ llvm/trunk/lib/CodeGen/ScheduleDAG.cpp Wed Sep 30 15:15:38 2009
@@ -82,13 +82,19 @@
   SUnit *N = D.getSUnit();
   // Update the bookkeeping.
   if (D.getKind() == SDep::Data) {
+    assert(NumPreds < UINT_MAX && "NumPreds will overflow!");
+    assert(N->NumSuccs < UINT_MAX && "NumSuccs will overflow!");
     ++NumPreds;
     ++N->NumSuccs;
   }
-  if (!N->isScheduled)
+  if (!N->isScheduled) {
+    assert(NumPredsLeft < UINT_MAX && "NumPredsLeft will overflow!");
     ++NumPredsLeft;
-  if (!isScheduled)
+  }
+  if (!isScheduled) {
+    assert(N->NumSuccsLeft < UINT_MAX && "NumSuccsLeft will overflow!");
     ++N->NumSuccsLeft;
+  }
   Preds.push_back(D);
   N->Succs.push_back(P);
   if (P.getLatency() != 0) {
@@ -121,13 +127,19 @@
       Preds.erase(I);
       // Update the bookkeeping.
       if (P.getKind() == SDep::Data) {
+        assert(NumPreds > 0 && "NumPreds will underflow!");
+        assert(N->NumSuccs > 0 && "NumSuccs will underflow!");
         --NumPreds;
         --N->NumSuccs;
       }
-      if (!N->isScheduled)
+      if (!N->isScheduled) {
+        assert(NumPredsLeft > 0 && "NumPredsLeft will underflow!");
         --NumPredsLeft;
-      if (!isScheduled)
+      }
+      if (!isScheduled) {
+        assert(N->NumSuccsLeft > 0 && "NumSuccsLeft will underflow!");
         --N->NumSuccsLeft;
+      }
       if (P.getLatency() != 0) {
         this->setDepthDirty();
         N->setHeightDirty();

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp?rev=83159&r1=83158&r2=83159&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp Wed Sep 30 15:15:38 2009
@@ -134,17 +134,17 @@
 /// the AvailableQueue if the count reaches zero. Also update its cycle bound.
 void ScheduleDAGFast::ReleasePred(SUnit *SU, SDep *PredEdge) {
   SUnit *PredSU = PredEdge->getSUnit();
-  --PredSU->NumSuccsLeft;
-  
+
 #ifndef NDEBUG
-  if (PredSU->NumSuccsLeft < 0) {
+  if (PredSU->NumSuccsLeft == 0) {
     errs() << "*** Scheduling failed! ***\n";
     PredSU->dump(this);
     errs() << " has been released too many times!\n";
     llvm_unreachable(0);
   }
 #endif
-  
+  --PredSU->NumSuccsLeft;
+
   // If all the node's successors are scheduled, this node is ready
   // to be scheduled. Ignore the special EntrySU node.
   if (PredSU->NumSuccsLeft == 0 && PredSU != &EntrySU) {

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGList.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGList.cpp?rev=83159&r1=83158&r2=83159&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGList.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGList.cpp Wed Sep 30 15:15:38 2009
@@ -108,17 +108,17 @@
 /// the PendingQueue if the count reaches zero. Also update its cycle bound.
 void ScheduleDAGList::ReleaseSucc(SUnit *SU, const SDep &D) {
   SUnit *SuccSU = D.getSUnit();
-  --SuccSU->NumPredsLeft;
-  
+
 #ifndef NDEBUG
-  if (SuccSU->NumPredsLeft < 0) {
+  if (SuccSU->NumPredsLeft == 0) {
     errs() << "*** Scheduling failed! ***\n";
     SuccSU->dump(this);
     errs() << " has been released too many times!\n";
     llvm_unreachable(0);
   }
 #endif
-  
+  --SuccSU->NumPredsLeft;
+
   SuccSU->setDepthToAtLeast(SU->getDepth() + D.getLatency());
   
   // If all the node's predecessors are scheduled, this node is ready

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp?rev=83159&r1=83158&r2=83159&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp Wed Sep 30 15:15:38 2009
@@ -278,6 +278,7 @@
       AvailableQueue->remove(PredSU);
   }
 
+  assert(PredSU->NumSuccsLeft < UINT_MAX && "NumSuccsLeft will overflow!");
   ++PredSU->NumSuccsLeft;
 }
 
@@ -824,17 +825,17 @@
 /// the AvailableQueue if the count reaches zero. Also update its cycle bound.
 void ScheduleDAGRRList::ReleaseSucc(SUnit *SU, const SDep *SuccEdge) {
   SUnit *SuccSU = SuccEdge->getSUnit();
-  --SuccSU->NumPredsLeft;
-  
+
 #ifndef NDEBUG
-  if (SuccSU->NumPredsLeft < 0) {
+  if (SuccSU->NumPredsLeft == 0) {
     errs() << "*** Scheduling failed! ***\n";
     SuccSU->dump(this);
     errs() << " has been released too many times!\n";
     llvm_unreachable(0);
   }
 #endif
-  
+  --SuccSU->NumPredsLeft;
+
   // If all the node's predecessors are scheduled, this node is ready
   // to be scheduled. Ignore the special ExitSU node.
   if (SuccSU->NumPredsLeft == 0 && SuccSU != &ExitSU) {





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