LivePhysRegs: Rework constructor + documentation; NFC

- Take reference instead of pointer to a TRI that cannot be nullptr.
- Improve documentation comments.

llvm-svn: 304038

1 files changed, 5 insertions, 5 deletions

diff --git a/llvm/lib/Target/ARM/Thumb1FrameLowering.cpp b/llvm/lib/Target/ARM/Thumb1FrameLowering.cpp
index 1a17d4e33e4..f917c35b9ce 100644
--- a/llvm/lib/Target/ARM/Thumb1FrameLowering.cpp
+++ b/llvm/lib/Target/ARM/Thumb1FrameLowering.cpp
@@ -535,14 +535,14 @@ bool Thumb1FrameLowering::emitPopSpecialFixUp(MachineBasicBlock &MBB,
 
   // Look for a temporary register to use.
   // First, compute the liveness information.
-  LivePhysRegs UsedRegs(STI.getRegisterInfo());
+  const TargetRegisterInfo &TRI = *STI.getRegisterInfo();
+  LivePhysRegs UsedRegs(TRI);
   UsedRegs.addLiveOuts(MBB);
   // The semantic of pristines changed recently and now,
   // the callee-saved registers that are touched in the function
   // are not part of the pristines set anymore.
   // Add those callee-saved now.
-  const TargetRegisterInfo *TRI = STI.getRegisterInfo();
-  const MCPhysReg *CSRegs = TRI->getCalleeSavedRegs(&MF);
+  const MCPhysReg *CSRegs = TRI.getCalleeSavedRegs(&MF);
   for (unsigned i = 0; CSRegs[i]; ++i)
     UsedRegs.addReg(CSRegs[i]);
 
@@ -561,12 +561,12 @@ bool Thumb1FrameLowering::emitPopSpecialFixUp(MachineBasicBlock &MBB,
   // And some temporary register, just in case.
   unsigned TemporaryReg = 0;
   BitVector PopFriendly =
-      TRI->getAllocatableSet(MF, TRI->getRegClass(ARM::tGPRRegClassID));
+      TRI.getAllocatableSet(MF, TRI.getRegClass(ARM::tGPRRegClassID));
   assert(PopFriendly.any() && "No allocatable pop-friendly register?!");
   // Rebuild the GPRs from the high registers because they are removed
   // form the GPR reg class for thumb1.
   BitVector GPRsNoLRSP =
-      TRI->getAllocatableSet(MF, TRI->getRegClass(ARM::hGPRRegClassID));
+      TRI.getAllocatableSet(MF, TRI.getRegClass(ARM::hGPRRegClassID));
   GPRsNoLRSP |= PopFriendly;
   GPRsNoLRSP.reset(ARM::LR);
   GPRsNoLRSP.reset(ARM::SP);