From 9f0b95f260d05ab149cb790bc9e5ef16f8777a69 Mon Sep 17 00:00:00 2001 From: Andrew Trick Date: Wed, 9 Jan 2013 03:36:49 +0000 Subject: MIsched: add an ILP window property to machine model. This was an experimental option, but needs to be defined per-target. e.g. PPC A2 needs to aggressively hide latency. I converted some in-order scheduling tests to A2. Hal is working on more test cases. llvm-svn: 171946 --- llvm/lib/CodeGen/MachineScheduler.cpp | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-) (limited to 'llvm/lib/CodeGen/MachineScheduler.cpp') diff --git a/llvm/lib/CodeGen/MachineScheduler.cpp b/llvm/lib/CodeGen/MachineScheduler.cpp index 117b2bdccf3..a32df7805bf 100644 --- a/llvm/lib/CodeGen/MachineScheduler.cpp +++ b/llvm/lib/CodeGen/MachineScheduler.cpp @@ -48,15 +48,6 @@ static cl::opt MISchedCutoff("misched-cutoff", cl::Hidden, static bool ViewMISchedDAGs = false; #endif // NDEBUG -// Threshold to very roughly model an out-of-order processor's instruction -// buffers. If the actual value of this threshold matters much in practice, then -// it can be specified by the machine model. For now, it's an experimental -// tuning knob to determine when and if it matters. -static cl::opt ILPWindow("ilp-window", cl::Hidden, - cl::desc("Allow expected latency to exceed the critical path by N cycles " - "before attempting to balance ILP"), - cl::init(10U)); - // Experimental heuristics static cl::opt EnableLoadCluster("misched-cluster", cl::Hidden, cl::desc("Enable load clustering."), cl::init(true)); @@ -1297,7 +1288,8 @@ void ConvergingScheduler::SchedBoundary::setLatencyPolicy(CandPolicy &Policy) { if (L > RemLatency) RemLatency = L; } - if (RemLatency + ExpectedLatency >= Rem->CriticalPath + ILPWindow + unsigned CriticalPathLimit = Rem->CriticalPath + SchedModel->getILPWindow(); + if (RemLatency + ExpectedLatency >= CriticalPathLimit && RemLatency > Rem->getMaxRemainingCount(SchedModel)) { Policy.ReduceLatency = true; DEBUG(dbgs() << "Increase ILP: " << Available.getName() << '\n'); -- cgit v1.2.3