[llvm] c7fddf5 - [ARM] Prevent converting virtual register to MCRegister. (#122862)

[via llvm-commits]

Author: Craig Topper
Date: 2025-01-14T10:03:51-08:00
New Revision: c7fddf5f786d4ed726b53096d461b62cf7649b90

URL: https://github.com/llvm/llvm-project/commit/c7fddf5f786d4ed726b53096d461b62cf7649b90
DIFF: https://github.com/llvm/llvm-project/commit/c7fddf5f786d4ed726b53096d461b62cf7649b90.diff

LOG: [ARM] Prevent converting virtual register to MCRegister. (#122862)

MCRegister should only be used for physical reigsters.

Added: 
    

Modified: 
    llvm/lib/Target/ARM/ThumbRegisterInfo.cpp

Removed: 
    


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diff  --git a/llvm/lib/Target/ARM/ThumbRegisterInfo.cpp b/llvm/lib/Target/ARM/ThumbRegisterInfo.cpp
index 381ade5c85a65e..4fe4ed47e0081d 100644
--- a/llvm/lib/Target/ARM/ThumbRegisterInfo.cpp
+++ b/llvm/lib/Target/ARM/ThumbRegisterInfo.cpp
@@ -139,7 +139,7 @@ static void emitThumbRegPlusImmInReg(
     return;
   }
 
-  bool isHigh = !isARMLowRegister(DestReg) ||
+  bool isHigh = DestReg.isVirtual() || !isARMLowRegister(DestReg) ||
                 (BaseReg != 0 && !isARMLowRegister(BaseReg));
   bool isSub = false;
   // Subtract doesn't have high register version. Load the negative value
@@ -153,7 +153,7 @@ static void emitThumbRegPlusImmInReg(
   Register LdReg = DestReg;
   if (DestReg == ARM::SP)
     assert(BaseReg == ARM::SP && "Unexpected!");
-  if (!isARMLowRegister(DestReg) && !DestReg.isVirtual())
+  if (!DestReg.isVirtual() && !isARMLowRegister(DestReg))
     LdReg = MF.getRegInfo().createVirtualRegister(&ARM::tGPRRegClass);
 
   if (NumBytes <= 255 && NumBytes >= 0 && CanChangeCC) {