[PATCH] [MachineScheduler] Check pending instructions when an instruction is scheduled

Pending instructions that may have been blocked from being available by the HazardRecognizer may no longer may not be blocked any more when an instruction is scheduled; pending instructions should be re-checked in this case.

This is primarily aimed at VLIW targets with large parallelism and esoteric constraints.

No testcase as no in-tree targets have this behavior.

Differential revision: https://reviews.llvm.org/D60861

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358743 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/MachineScheduler.cpp b/lib/CodeGen/MachineScheduler.cpp
index dc2e1f94a244614d05fe0153075fe95e3b94ae1d..d56ea43437ba7739b4fc93327e66a8363960325a 100644 (file)
--- a/lib/CodeGen/MachineScheduler.cpp
+++ b/lib/CodeGen/MachineScheduler.cpp
@@ -2159,6 +2159,8 @@ void SchedBoundary::bumpNode(SUnit *SU) {
       HazardRec->Reset();
     }
     HazardRec->EmitInstruction(SU);
+    // Scheduling an instruction may have made pending instructions available.
+    CheckPending = true;
   }
   // checkHazard should prevent scheduling multiple instructions per cycle that
   // exceed the issue width.