[FrameLowering] Use MCRegister instead of Register in CalleeSavedInfo. NFC (#128095)

Callee saved registers should always be phyiscal registers. They are
often passed directly to other functions that take MCRegister like
getMinimalPhysRegClass or TargetRegisterClass::contains.

Unfortunately, sometimes the MCRegister is compared to a Register which
gave an ambiguous comparison error when the MCRegister is on the LHS.
Adding a MCRegister==Register comparison operator created more ambiguous
comparison errors elsewhere. These cases were usually comparing against
a base or frame pointer register that is a physical register in a
Register. For those I added an explicit conversion of Register to
MCRegister to fix the error.

1 files changed, 3 insertions, 2 deletions

diff --git a/llvm/lib/Target/AMDGPU/SIFrameLowering.cpp b/llvm/lib/Target/AMDGPU/SIFrameLowering.cpp
index 060db477a59f..ce21f8963fe8 100644
--- a/llvm/lib/Target/AMDGPU/SIFrameLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/SIFrameLowering.cpp
@@ -1719,11 +1719,12 @@ bool SIFrameLowering::assignCalleeSavedSpillSlots(
     NumModifiedRegs++;
 
   for (auto &CS : CSI) {
-    if (CS.getReg() == FramePtrReg && SGPRForFPSaveRestoreCopy) {
+    if (CS.getReg() == FramePtrReg.asMCReg() && SGPRForFPSaveRestoreCopy) {
       CS.setDstReg(SGPRForFPSaveRestoreCopy);
       if (--NumModifiedRegs)
         break;
-    } else if (CS.getReg() == BasePtrReg && SGPRForBPSaveRestoreCopy) {
+    } else if (CS.getReg() == BasePtrReg.asMCReg() &&
+               SGPRForBPSaveRestoreCopy) {
       CS.setDstReg(SGPRForBPSaveRestoreCopy);
       if (--NumModifiedRegs)
         break;