Target RegisterInfo: devirtualize TargetFrameLowering

Summary:
The target frame lowering's concrete type is always known in RegisterInfo, yet it's only sometimes devirtualized through a static_cast. This change adds an auto-generated static function <Target>GenRegisterInfo::getFrameLowering(const MachineFunction &MF) which does this devirtualization, and uses this function in all targets which can.

This change was suggested by sunfish in D11070 for WebAssembly, I figure that I may as well improve the other targets while I'm here.

Subscribers: sunfish, ted, llvm-commits, jfb

Differential Revision: http://reviews.llvm.org/D11093

llvm-svn: 241921

1 files changed, 3 insertions, 3 deletions

diff --git a/llvm/lib/Target/SystemZ/SystemZRegisterInfo.cpp b/llvm/lib/Target/SystemZ/SystemZRegisterInfo.cpp
index 7cabea962e9..dc7bd25d7ed 100644
--- a/llvm/lib/Target/SystemZ/SystemZRegisterInfo.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZRegisterInfo.cpp
@@ -36,7 +36,7 @@ SystemZRegisterInfo::getCallPreservedMask(const MachineFunction &MF,
 BitVector
 SystemZRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
   BitVector Reserved(getNumRegs());
-  const TargetFrameLowering *TFI = MF.getSubtarget().getFrameLowering();
+  const SystemZFrameLowering *TFI = getFrameLowering(MF);
 
   if (TFI->hasFP(MF)) {
     // R11D is the frame pointer.  Reserve all aliases.
@@ -64,7 +64,7 @@ SystemZRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator MI,
   MachineFunction &MF = *MBB.getParent();
   auto *TII =
       static_cast<const SystemZInstrInfo *>(MF.getSubtarget().getInstrInfo());
-  const TargetFrameLowering *TFI = MF.getSubtarget().getFrameLowering();
+  const SystemZFrameLowering *TFI = getFrameLowering(MF);
   DebugLoc DL = MI->getDebugLoc();
 
   // Decompose the frame index into a base and offset.
@@ -135,6 +135,6 @@ SystemZRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator MI,
 
 unsigned
 SystemZRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
-  const TargetFrameLowering *TFI = MF.getSubtarget().getFrameLowering();
+  const SystemZFrameLowering *TFI = getFrameLowering(MF);
   return TFI->hasFP(MF) ? SystemZ::R11D : SystemZ::R15D;
 }