Allow the -enable-misched command line option to control the post-ra MI scheduler as well.

[mcrosier]

Summary

I'm also fine with creating a new option (e.g., -enable-postra-misched) that controls only the post-ra mi scheduler.

Also, I have a yet-to-be-submitted patch that requires this change to prevent a lit test from regressing.

Chad

[mcrosier]

I decided to go ahead an commit a fix in r258364, which adds a new command line option -enable-post-misched. This was necessary for D16369 and I decided this type of change didn't really warrant the review (or it could be addressed in post-commit review).

lib/CodeGen/MachineScheduler.cpp

bool MachineScheduler::runOnMachineFunction(MachineFunction &mf) {
 
   DEBUG(LIS->dump());
   if (VerifyScheduling)
     MF->verify(this, "After machine scheduling.");
   return true;
 }
 
 bool PostMachineScheduler::runOnMachineFunction(MachineFunction &mf) {
+  if (EnableMachineSched.getNumOccurrences()) {
+    if (!EnableMachineSched)
+      return false;
+  } else {
     if (skipOptnoneFunction(*mf.getFunction()))
       return false;
-
     if (!mf.getSubtarget().enablePostRAScheduler()) {
       DEBUG(dbgs() << "Subtarget disables post-MI-sched.\n");
       return false;
     }
+  }
   DEBUG(dbgs() << "Before post-MI-sched:\n"; mf.print(dbgs()));
 
   // Initialize the context of the pass.
   MF = &mf;
   PassConfig = &getAnalysis<TargetPassConfig>();
 
   if (VerifyScheduling)
     MF->verify(this, "Before post machine scheduling.");