Added TargetPassConfig. The first little step toward configuring codegen passes.

Allows command line overrides to be centralized in LLVMTargetMachine.cpp.
LLVMTargetMachine can intercept common passes and give precedence to command line overrides.
Allows adding "internal" target configuration options without touching TargetOptions.
Encapsulates the PassManager.
Provides a good point to initialize all CodeGen passes so that Pass ID's can be used in APIs.
Allows modifying the target configuration hooks without rebuilding the world.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149672 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMTargetMachine.cpp b/lib/Target/ARM/ARMTargetMachine.cpp
index 9d6f9bd..cfe4558 100644
--- a/lib/Target/ARM/ARMTargetMachine.cpp
+++ b/lib/Target/ARM/ARMTargetMachine.cpp
@@ -107,33 +107,62 @@
               : (ARMFrameLowering*)new Thumb1FrameLowering(Subtarget)) {
 }
 
-bool ARMBaseTargetMachine::addPreISel(PassManagerBase &PM) {
-  if (getOptLevel() != CodeGenOpt::None && EnableGlobalMerge)
-    PM.add(createGlobalMergePass(getTargetLowering()));
+namespace {
+/// ARM Code Generator Pass Configuration Options.
+class ARMPassConfig : public TargetPassConfig {
+public:
+  ARMPassConfig(ARMBaseTargetMachine *TM, PassManagerBase &PM,
+                bool DisableVerifyFlag)
+    : TargetPassConfig(TM, PM, DisableVerifyFlag) {}
+
+  ARMBaseTargetMachine &getARMTargetMachine() const {
+    return getTM<ARMBaseTargetMachine>();
+  }
+
+  const ARMSubtarget &getARMSubtarget() const {
+    return *getARMTargetMachine().getSubtargetImpl();
+  }
+
+  virtual bool addPreISel();
+  virtual bool addInstSelector();
+  virtual bool addPreRegAlloc();
+  virtual bool addPreSched2();
+  virtual bool addPreEmitPass();
+};
+} // namespace
+
+TargetPassConfig *ARMBaseTargetMachine::createPassConfig(PassManagerBase &PM,
+                                                         bool DisableVerify) {
+  return new ARMPassConfig(this, PM, DisableVerify);
+}
+
+bool ARMPassConfig::addPreISel() {
+  if (TM->getOptLevel() != CodeGenOpt::None && EnableGlobalMerge)
+    PM.add(createGlobalMergePass(TM->getTargetLowering()));
 
   return false;
 }
 
-bool ARMBaseTargetMachine::addInstSelector(PassManagerBase &PM) {
-  PM.add(createARMISelDag(*this, getOptLevel()));
+bool ARMPassConfig::addInstSelector() {
+  PM.add(createARMISelDag(getARMTargetMachine(), getOptLevel()));
   return false;
 }
 
-bool ARMBaseTargetMachine::addPreRegAlloc(PassManagerBase &PM) {
+bool ARMPassConfig::addPreRegAlloc() {
   // FIXME: temporarily disabling load / store optimization pass for Thumb1.
-  if (getOptLevel() != CodeGenOpt::None && !Subtarget.isThumb1Only())
+  if (getOptLevel() != CodeGenOpt::None && !getARMSubtarget().isThumb1Only())
     PM.add(createARMLoadStoreOptimizationPass(true));
-  if (getOptLevel() != CodeGenOpt::None && Subtarget.isCortexA9())
+  if (getOptLevel() != CodeGenOpt::None && getARMSubtarget().isCortexA9())
     PM.add(createMLxExpansionPass());
   return true;
 }
 
-bool ARMBaseTargetMachine::addPreSched2(PassManagerBase &PM) {
+bool ARMPassConfig::addPreSched2() {
   // FIXME: temporarily disabling load / store optimization pass for Thumb1.
   if (getOptLevel() != CodeGenOpt::None) {
-    if (!Subtarget.isThumb1Only())
+    if (!getARMSubtarget().isThumb1Only())
       PM.add(createARMLoadStoreOptimizationPass());
-    if (Subtarget.hasNEON())
+    if (getARMSubtarget().hasNEON())
       PM.add(createExecutionDependencyFixPass(&ARM::DPRRegClass));
   }
 
@@ -142,18 +171,18 @@
   PM.add(createARMExpandPseudoPass());
 
   if (getOptLevel() != CodeGenOpt::None) {
-    if (!Subtarget.isThumb1Only())
+    if (!getARMSubtarget().isThumb1Only())
       PM.add(createIfConverterPass());
   }
-  if (Subtarget.isThumb2())
+  if (getARMSubtarget().isThumb2())
     PM.add(createThumb2ITBlockPass());
 
   return true;
 }
 
-bool ARMBaseTargetMachine::addPreEmitPass(PassManagerBase &PM) {
-  if (Subtarget.isThumb2()) {
-    if (!Subtarget.prefers32BitThumb())
+bool ARMPassConfig::addPreEmitPass() {
+  if (getARMSubtarget().isThumb2()) {
+    if (!getARMSubtarget().prefers32BitThumb())
       PM.add(createThumb2SizeReductionPass());
 
     // Constant island pass work on unbundled instructions.
@@ -165,8 +194,7 @@
   return true;
 }
 
-bool ARMBaseTargetMachine::addCodeEmitter(PassManagerBase &PM,
-                                          JITCodeEmitter &JCE) {
+bool ARMBaseTargetMachine::addCodeEmitter(PassManagerBase &PM, JITCodeEmitter &JCE) {
   // Machine code emitter pass for ARM.
   PM.add(createARMJITCodeEmitterPass(*this, JCE));
   return false;