Various bits of framework needed for precise machine-level selection

DAG scheduling during isel. Most new functionality is currently
guarded by -enable-sched-cycles and -enable-sched-hazard.

Added InstrItineraryData::IssueWidth field, currently derived from
ARM itineraries, but could be initialized differently on other targets.

Added ScheduleHazardRecognizer::MaxLookAhead to indicate whether it is
active, and if so how many cycles of state it holds.

Added SchedulingPriorityQueue::HasReadyFilter to allowing gating entry
into the scheduler's available queue.

ScoreboardHazardRecognizer now accesses the ScheduleDAG in order to
get information about it's SUnits, provides RecedeCycle for bottom-up
scheduling, correctly computes scoreboard depth, tracks IssueCount, and
considers potential stall cycles when checking for hazards.

ScheduleDAGRRList now models machine cycles and hazards (under
flags). It tracks MinAvailableCycle, drives the hazard recognizer and
priority queue's ready filter, manages a new PendingQueue, properly
accounts for stall cycles, etc.

llvm-svn: 122541

1 files changed, 6 insertions, 5 deletions

diff --git a/llvm/lib/Target/ARM/ARMHazardRecognizer.h b/llvm/lib/Target/ARM/ARMHazardRecognizer.h
index 9473bc52072..2bc218d8566 100644
--- a/llvm/lib/Target/ARM/ARMHazardRecognizer.h
+++ b/llvm/lib/Target/ARM/ARMHazardRecognizer.h
@@ -29,7 +29,7 @@ class ARMHazardRecognizer : public ScoreboardHazardRecognizer {
   const ARMSubtarget &STI;
 
   MachineInstr *LastMI;
-  unsigned Stalls;
+  unsigned FpMLxStalls;
   unsigned ITBlockSize;  // No. of MIs in current IT block yet to be scheduled.
   MachineInstr *ITBlockMIs[4];
 
@@ -37,11 +37,12 @@ public:
   ARMHazardRecognizer(const InstrItineraryData *ItinData,
                       const ARMBaseInstrInfo &tii,
                       const ARMBaseRegisterInfo &tri,
-                      const ARMSubtarget &sti) :
-    ScoreboardHazardRecognizer(ItinData), TII(tii), TRI(tri), STI(sti),
-    LastMI(0), ITBlockSize(0) {}
+                      const ARMSubtarget &sti,
+                      const ScheduleDAG *DAG) :
+    ScoreboardHazardRecognizer(ItinData, DAG, "post-RA-sched"), TII(tii),
+    TRI(tri), STI(sti), LastMI(0), ITBlockSize(0) {}
 
-  virtual HazardType getHazardType(SUnit *SU);
+  virtual HazardType getHazardType(SUnit *SU, int Stalls);
   virtual void Reset();
   virtual void EmitInstruction(SUnit *SU);
   virtual void AdvanceCycle();