Remove -post-RA-schedule flag and add a TargetSubtarget method to enable post-register-allocation scheduling. By default it is off. For ARM, enable/disable with -mattr=+/-postrasched. Enable by default for cortex-a8.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83122 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 7 insertions, 9 deletions

diff --git a/lib/CodeGen/LLVMTargetMachine.cpp b/lib/CodeGen/LLVMTargetMachine.cpp
index 64e28fb764..a38d8ccab7 100644
--- a/lib/CodeGen/LLVMTargetMachine.cpp
+++ b/lib/CodeGen/LLVMTargetMachine.cpp
@@ -45,14 +45,6 @@ static cl::opt<bool> VerifyMachineCode("verify-machineinstrs", cl::Hidden,
     cl::desc("Verify generated machine code"),
     cl::init(getenv("LLVM_VERIFY_MACHINEINSTRS")!=NULL));
 
-// This is not enabled by default due to 1) high compile time cost, 2) it's not
-// beneficial to all targets. The plan is to let targets decide whether this
-// is enabled.
-static cl::opt<bool>
-EnablePostRAScheduler("post-RA-scheduler",
-                       cl::desc("Enable scheduling after register allocation"),
-                       cl::init(false));
-
 // Enable or disable FastISel. Both options are needed, because
 // FastISel is enabled by default with -fast, and we wish to be
 // able to enable or disable fast-isel independently from -O0.
@@ -326,7 +318,7 @@ bool LLVMTargetMachine::addCommonCodeGenPasses(PassManagerBase &PM,
   printAndVerify(PM);
 
   // Second pass scheduler.
-  if (OptLevel != CodeGenOpt::None && EnablePostRAScheduler) {
+  if (OptLevel != CodeGenOpt::None) {
     PM.add(createPostRAScheduler());
     printAndVerify(PM);
   }
diff --git a/lib/CodeGen/PostRASchedulerList.cpp b/lib/CodeGen/PostRASchedulerList.cpp
index 9d75b25b82..42954eac4f 100644
--- a/lib/CodeGen/PostRASchedulerList.cpp
+++ b/lib/CodeGen/PostRASchedulerList.cpp
@@ -34,6 +34,7 @@
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetInstrInfo.h"
 #include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/Target/TargetSubtarget.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
@@ -209,6 +210,11 @@ static bool isSchedulingBoundary(const MachineInstr *MI,
 }
 
 bool PostRAScheduler::runOnMachineFunction(MachineFunction &Fn) {
+  // Check that post-RA scheduling is enabled for this function
+  const TargetSubtarget &ST = Fn.getTarget().getSubtarget<TargetSubtarget>();
+  if (!ST.enablePostRAScheduler())
+    return true;
+
   DEBUG(errs() << "PostRAScheduler\n");
 
   const MachineLoopInfo &MLI = getAnalysis<MachineLoopInfo>();