[llvm] 2484680 - Add non-null check before accessing pointer (#83459)

[via llvm-commits]

Author: Martin Wehking
Date: 2024-03-07T10:31:34+05:30
New Revision: 248468097faa9739ae66ff6fe1836e529d58455a

URL: https://github.com/llvm/llvm-project/commit/248468097faa9739ae66ff6fe1836e529d58455a
DIFF: https://github.com/llvm/llvm-project/commit/248468097faa9739ae66ff6fe1836e529d58455a.diff

LOG: Add non-null check before accessing pointer (#83459)

Add a check if RC is not null to ensure that a consecutive access is
safe.

A static analyzer flagged this issue since hasVectorRegisters
potentially dereferences RC.

Added: 
    

Modified: 
    llvm/lib/Target/AMDGPU/SIFoldOperands.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/AMDGPU/SIFoldOperands.cpp b/llvm/lib/Target/AMDGPU/SIFoldOperands.cpp
index 634b4aeb30a730..cb448aaafa4c08 100644
--- a/llvm/lib/Target/AMDGPU/SIFoldOperands.cpp
+++ b/llvm/lib/Target/AMDGPU/SIFoldOperands.cpp
@@ -1054,6 +1054,7 @@ void SIFoldOperands::foldOperand(
       // Don't fold if OpToFold doesn't hold an aligned register.
       const TargetRegisterClass *RC =
           TRI->getRegClassForReg(*MRI, OpToFold.getReg());
+      assert(RC);
       if (TRI->hasVectorRegisters(RC) && OpToFold.getSubReg()) {
         unsigned SubReg = OpToFold.getSubReg();
         if (const TargetRegisterClass *SubRC =