enable PPC register scavenging by default (update tests and remove some FIXMEs)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145819 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCFrameLowering.cpp b/lib/Target/PowerPC/PPCFrameLowering.cpp
index ec4231e..e9a4290 100644
--- a/lib/Target/PowerPC/PPCFrameLowering.cpp
+++ b/lib/Target/PowerPC/PPCFrameLowering.cpp
@@ -772,7 +772,7 @@
   // FIXME: doesn't detect whether or not we need to spill vXX, which requires
   //        r0 for now.
 
-  if (RegInfo->requiresRegisterScavenging(MF)) // FIXME (64-bit): Enable.
+  if (RegInfo->requiresRegisterScavenging(MF))
     if (needsFP(MF) || spillsCR(MF)) {
       const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
       const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
diff --git a/lib/Target/PowerPC/PPCInstrInfo.cpp b/lib/Target/PowerPC/PPCInstrInfo.cpp
index cdb15a1..f28d07c 100644
--- a/lib/Target/PowerPC/PPCInstrInfo.cpp
+++ b/lib/Target/PowerPC/PPCInstrInfo.cpp
@@ -33,8 +33,8 @@
 #include "PPCGenInstrInfo.inc"
 
 namespace llvm {
-extern cl::opt<bool> EnablePPC32RS;  // FIXME (64-bit): See PPCRegisterInfo.cpp.
-extern cl::opt<bool> EnablePPC64RS;  // FIXME (64-bit): See PPCRegisterInfo.cpp.
+extern cl::opt<bool> DisablePPC32RS;
+extern cl::opt<bool> DisablePPC64RS;
 }
 
 using namespace llvm;
@@ -345,6 +345,7 @@
     BuildMI(MBB, I, DL, MCID, DestReg).addReg(SrcReg, getKillRegState(KillSrc));
 }
 
+// This function returns true if a CR spill is necessary and false otherwise.
 bool
 PPCInstrInfo::StoreRegToStackSlot(MachineFunction &MF,
                                   unsigned SrcReg, bool isKill,
@@ -395,9 +396,8 @@
                                                getKillRegState(isKill)),
                                        FrameIdx));
   } else if (PPC::CRRCRegisterClass->hasSubClassEq(RC)) {
-    if ((EnablePPC32RS && !TM.getSubtargetImpl()->isPPC64()) ||
-        (EnablePPC64RS && TM.getSubtargetImpl()->isPPC64())) {
-      // FIXME (64-bit): Enable
+    if ((!DisablePPC32RS && !TM.getSubtargetImpl()->isPPC64()) ||
+        (!DisablePPC64RS && TM.getSubtargetImpl()->isPPC64())) {
       NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::SPILL_CR))
                                          .addReg(SrcReg,
                                                  getKillRegState(isKill)),
diff --git a/lib/Target/PowerPC/PPCRegisterInfo.cpp b/lib/Target/PowerPC/PPCRegisterInfo.cpp
index 4cfa115..5268133 100644
--- a/lib/Target/PowerPC/PPCRegisterInfo.cpp
+++ b/lib/Target/PowerPC/PPCRegisterInfo.cpp
@@ -46,15 +46,14 @@
 #define GET_REGINFO_TARGET_DESC
 #include "PPCGenRegisterInfo.inc"
 
-// FIXME (64-bit): Eventually enable by default.
 namespace llvm {
-cl::opt<bool> EnablePPC32RS("enable-ppc32-regscavenger",
+cl::opt<bool> DisablePPC32RS("disable-ppc32-regscavenger",
                                    cl::init(false),
-                                   cl::desc("Enable PPC32 register scavenger"),
+                                   cl::desc("Disable PPC32 register scavenger"),
                                    cl::Hidden);
-cl::opt<bool> EnablePPC64RS("enable-ppc64-regscavenger",
+cl::opt<bool> DisablePPC64RS("disable-ppc64-regscavenger",
                                    cl::init(false),
-                                   cl::desc("Enable PPC64 register scavenger"),
+                                   cl::desc("Disable PPC64 register scavenger"),
                                    cl::Hidden);
 }
 
@@ -63,8 +62,8 @@
 // FIXME (64-bit): Should be inlined.
 bool
 PPCRegisterInfo::requiresRegisterScavenging(const MachineFunction &) const {
-  return ((EnablePPC32RS && !Subtarget.isPPC64()) ||
-          (EnablePPC64RS && Subtarget.isPPC64()));
+  return ((!DisablePPC32RS && !Subtarget.isPPC64()) ||
+          (!DisablePPC64RS && Subtarget.isPPC64()));
 }
 
 PPCRegisterInfo::PPCRegisterInfo(const PPCSubtarget &ST,
@@ -231,9 +230,6 @@
     Reserved.set(PPC::R13);
     Reserved.set(PPC::R31);
 
-    if (!requiresRegisterScavenging(MF))
-      Reserved.set(PPC::R0);    // FIXME (64-bit): Remove
-
     Reserved.set(PPC::X0);
     Reserved.set(PPC::X1);
     Reserved.set(PPC::X13);
@@ -544,7 +540,7 @@
   }
 
   // Special case for pseudo-op SPILL_CR.
-  if (requiresRegisterScavenging(MF)) // FIXME (64-bit): Enable by default.
+  if (requiresRegisterScavenging(MF))
     if (OpC == PPC::SPILL_CR) {
       lowerCRSpilling(II, FrameIndex, SPAdj, RS);
       return;