commit 5632722cab2184da3610bfec5d9ca00b8d46a815
author Andrew Trick <atrick@apple.com> Fri Jun 27 04:57:05 2014 +0000
committer Andrew Trick <atrick@apple.com> Fri Jun 27 04:57:05 2014 +0000
tree e0e08ff02f824190a3e4b4e6b6501c7c889e90c5
parent f6ae844eea7fafcdce8cb313fb8fed6ad5be193b

MachineScheduler: add some book-keeping to fix an assert.

Fixe for Bug 20057 - Assertion failied in llvm::SUnit* llvm::SchedBoundary::pickOnlyChoice(): Assertion `i <= (HazardRec->getMaxLookAhead() + MaxObservedStall) && "permanent hazard"'

Thanks to Chad for the test case.

llvm-svn: 211865

llvm/lib/CodeGen/MachineScheduler.cpp

diff --git a/llvm/lib/CodeGen/MachineScheduler.cpp b/llvm/lib/CodeGen/MachineScheduler.cpp
index 0baf2a6..b37f689 100644
--- a/llvm/lib/CodeGen/MachineScheduler.cpp
+++ b/llvm/lib/CodeGen/MachineScheduler.cpp
@@ -1687,8 +1687,14 @@
     for (TargetSchedModel::ProcResIter
            PI = SchedModel->getWriteProcResBegin(SC),
            PE = SchedModel->getWriteProcResEnd(SC); PI != PE; ++PI) {
-      if (getNextResourceCycle(PI->ProcResourceIdx, PI->Cycles) > CurrCycle)
+      unsigned NRCycle = getNextResourceCycle(PI->ProcResourceIdx, PI->Cycles);
+      if (NRCycle > CurrCycle) {
+        MaxObservedStall = std::max(NRCycle - CurrCycle, MaxObservedStall);
+        DEBUG(dbgs() << "  SU(" << SU->NodeNum << ") "
+              << SchedModel->getResourceName(PI->ProcResourceIdx)
+              << "=" << NRCycle << "c\n");
         return true;
+      }
     }
   }
   return false;