[llvm] 2ff635d - CodeGen: Stop checking for physregs in constrainRegClass (#161795)

[via llvm-commits]

Author: Matt Arsenault
Date: 2025-10-03T21:20:59+09:00
New Revision: 2ff635dde236308073bd50ec11490c604492e438

URL: https://github.com/llvm/llvm-project/commit/2ff635dde236308073bd50ec11490c604492e438
DIFF: https://github.com/llvm/llvm-project/commit/2ff635dde236308073bd50ec11490c604492e438.diff

LOG: CodeGen: Stop checking for physregs in constrainRegClass (#161795)

It's nonsensical to call this function on a physical register.

Added: 
    

Modified: 
    llvm/lib/CodeGen/MachineRegisterInfo.cpp

Removed: 
    


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diff  --git a/llvm/lib/CodeGen/MachineRegisterInfo.cpp b/llvm/lib/CodeGen/MachineRegisterInfo.cpp
index abb3f3e612000..ae284f3ae2929 100644
--- a/llvm/lib/CodeGen/MachineRegisterInfo.cpp
+++ b/llvm/lib/CodeGen/MachineRegisterInfo.cpp
@@ -83,8 +83,6 @@ constrainRegClass(MachineRegisterInfo &MRI, Register Reg,
 
 const TargetRegisterClass *MachineRegisterInfo::constrainRegClass(
     Register Reg, const TargetRegisterClass *RC, unsigned MinNumRegs) {
-  if (Reg.isPhysical())
-    return nullptr;
   return ::constrainRegClass(*this, Reg, getRegClass(Reg), RC, MinNumRegs);
 }