PPC should always use the register scavenger for CR spilling

This removes the -disable-ppc[32|64]-regscavenger options; the code
that uses the register scavenger has been working well (and has been the default)
for some time, and we don't need options to enable the old (broken) CR spilling code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176865 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 17 insertions, 58 deletions

diff --git a/lib/Target/PowerPC/PPCRegisterInfo.cpp b/lib/Target/PowerPC/PPCRegisterInfo.cpp
index df245cc655..fd79de1387 100644
--- a/lib/Target/PowerPC/PPCRegisterInfo.cpp
+++ b/lib/Target/PowerPC/PPCRegisterInfo.cpp
@@ -46,26 +46,8 @@
 #define GET_REGINFO_TARGET_DESC
 #include "PPCGenRegisterInfo.inc"
 
-namespace llvm {
-cl::opt<bool> DisablePPC32RS("disable-ppc32-regscavenger",
-                                   cl::init(false),
-                                   cl::desc("Disable PPC32 register scavenger"),
-                                   cl::Hidden);
-cl::opt<bool> DisablePPC64RS("disable-ppc64-regscavenger",
-                                   cl::init(false),
-                                   cl::desc("Disable PPC64 register scavenger"),
-                                   cl::Hidden);
-}
-
 using namespace llvm;
 
-// FIXME (64-bit): Should be inlined.
-bool
-PPCRegisterInfo::requiresRegisterScavenging(const MachineFunction &) const {
-  return ((!DisablePPC32RS && !Subtarget.isPPC64()) ||
-          (!DisablePPC64RS && Subtarget.isPPC64()));
-}
-
 PPCRegisterInfo::PPCRegisterInfo(const PPCSubtarget &ST,
                                  const TargetInstrInfo &tii)
   : PPCGenRegisterInfo(ST.isPPC64() ? PPC::LR8 : PPC::LR,
@@ -273,26 +255,16 @@ void PPCRegisterInfo::lowerDynamicAlloc(MachineBasicBlock::iterator II,
   const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
   const TargetRegisterClass *RC = LP64 ? G8RC : GPRC;
 
-  // FIXME (64-bit): Use "findScratchRegister"
-  unsigned Reg;
-  if (requiresRegisterScavenging(MF))
-    Reg = findScratchRegister(II, RS, RC, SPAdj);
-  else
-    Reg = PPC::R0;
+  unsigned Reg = findScratchRegister(II, RS, RC, SPAdj);
   
   if (MaxAlign < TargetAlign && isInt<16>(FrameSize)) {
     BuildMI(MBB, II, dl, TII.get(PPC::ADDI), Reg)
       .addReg(PPC::R31)
       .addImm(FrameSize);
   } else if (LP64) {
-    if (requiresRegisterScavenging(MF)) // FIXME (64-bit): Use "true" part.
-      BuildMI(MBB, II, dl, TII.get(PPC::LD), Reg)
-        .addImm(0)
-        .addReg(PPC::X1);
-    else
-      BuildMI(MBB, II, dl, TII.get(PPC::LD), PPC::X0)
-        .addImm(0)
-        .addReg(PPC::X1);
+    BuildMI(MBB, II, dl, TII.get(PPC::LD), Reg)
+      .addImm(0)
+      .addReg(PPC::X1);
   } else {
     BuildMI(MBB, II, dl, TII.get(PPC::LWZ), Reg)
       .addImm(0)
@@ -302,17 +274,10 @@ void PPCRegisterInfo::lowerDynamicAlloc(MachineBasicBlock::iterator II,
   // Grow the stack and update the stack pointer link, then determine the
   // address of new allocated space.
   if (LP64) {
-    if (requiresRegisterScavenging(MF)) // FIXME (64-bit): Use "true" part.
-      BuildMI(MBB, II, dl, TII.get(PPC::STDUX), PPC::X1)
-        .addReg(Reg, RegState::Kill)
-        .addReg(PPC::X1)
-        .addReg(MI.getOperand(1).getReg());
-    else
-      BuildMI(MBB, II, dl, TII.get(PPC::STDUX), PPC::X1)
-        .addReg(PPC::X0, RegState::Kill)
-        .addReg(PPC::X1)
-        .addReg(MI.getOperand(1).getReg());
-
+    BuildMI(MBB, II, dl, TII.get(PPC::STDUX), PPC::X1)
+      .addReg(Reg, RegState::Kill)
+      .addReg(PPC::X1)
+      .addReg(MI.getOperand(1).getReg());
     if (!MI.getOperand(1).isKill())
       BuildMI(MBB, II, dl, TII.get(PPC::ADDI8), MI.getOperand(0).getReg())
         .addReg(PPC::X1)
@@ -499,14 +464,12 @@ PPCRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
   }
 
   // Special case for pseudo-ops SPILL_CR and RESTORE_CR.
-  if (requiresRegisterScavenging(MF)) {
-    if (OpC == PPC::SPILL_CR) {
-      lowerCRSpilling(II, FrameIndex, SPAdj, RS);
-      return;
-    } else if (OpC == PPC::RESTORE_CR) {
-      lowerCRRestore(II, FrameIndex, SPAdj, RS);
-      return;
-    }
+  if (OpC == PPC::SPILL_CR) {
+    lowerCRSpilling(II, FrameIndex, SPAdj, RS);
+    return;
+  } else if (OpC == PPC::RESTORE_CR) {
+    lowerCRRestore(II, FrameIndex, SPAdj, RS);
+    return;
   }
 
   // Replace the FrameIndex with base register with GPR1 (SP) or GPR31 (FP).
@@ -563,13 +526,9 @@ PPCRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
   // The offset doesn't fit into a single register, scavenge one to build the
   // offset in.
 
-  unsigned SReg;
-  if (requiresRegisterScavenging(MF)) {
-    const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
-    const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
-    SReg = findScratchRegister(II, RS, is64Bit ? G8RC : GPRC, SPAdj);
-  } else
-    SReg = is64Bit ? PPC::X0 : PPC::R0;
+  const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
+  const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
+  unsigned SReg = findScratchRegister(II, RS, is64Bit ? G8RC : GPRC, SPAdj);
 
   // Insert a set of rA with the full offset value before the ld, st, or add
   BuildMI(MBB, II, dl, TII.get(is64Bit ? PPC::LIS8 : PPC::LIS), SReg)