[SystemZ] Post-RA scheduler implementation

Post-RA sched strategy and scheduling instruction annotations for z196, zEC12
and z13.

This scheduler optimizes decoder grouping and balances processor resources
(including side steering the FPd unit instructions).

The SystemZHazardRecognizer keeps track of the scheduling state, which can
be dumped with -debug-only=misched.

Reviers: Ulrich Weigand, Andrew Trick.
https://reviews.llvm.org/D17260

llvm-svn: 284704

1 files changed, 9 insertions, 7 deletions

diff --git a/llvm/lib/Target/SystemZ/SystemZTargetMachine.cpp b/llvm/lib/Target/SystemZ/SystemZTargetMachine.cpp
index ceb79f7e774..4d60ab7e8d4 100644
--- a/llvm/lib/Target/SystemZ/SystemZTargetMachine.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZTargetMachine.cpp
@@ -9,6 +9,7 @@
 
 #include "SystemZTargetMachine.h"
 #include "SystemZTargetTransformInfo.h"
+#include "SystemZMachineScheduler.h"
 #include "llvm/CodeGen/Passes.h"
 #include "llvm/CodeGen/TargetPassConfig.h"
 #include "llvm/Support/TargetRegistry.h"
@@ -17,7 +18,6 @@
 
 using namespace llvm;
 
-extern cl::opt<bool> MISchedPostRA;
 extern "C" void LLVMInitializeSystemZTarget() {
   // Register the target.
   RegisterTargetMachine<SystemZTargetMachine> X(getTheSystemZTarget());
@@ -114,6 +114,12 @@ public:
     return getTM<SystemZTargetMachine>();
   }
 
+  ScheduleDAGInstrs *
+  createPostMachineScheduler(MachineSchedContext *C) const override {
+    return new ScheduleDAGMI(C, make_unique<SystemZPostRASchedStrategy>(C),
+                             /*IsPostRA=*/true);
+  }
+
   void addIRPasses() override;
   bool addInstSelector() override;
   void addPreSched2() override;
@@ -180,12 +186,8 @@ void SystemZPassConfig::addPreEmitPass() {
   // Do final scheduling after all other optimizations, to get an
   // optimal input for the decoder (branch relaxation must happen
   // after block placement).
-  if (getOptLevel() != CodeGenOpt::None) {
-    if (MISchedPostRA)
-      addPass(&PostMachineSchedulerID);
-    else
-      addPass(&PostRASchedulerID);
-  }
+  if (getOptLevel() != CodeGenOpt::None)
+    addPass(&PostMachineSchedulerID);
 }
 
 TargetPassConfig *SystemZTargetMachine::createPassConfig(PassManagerBase &PM) {