Pattern matching for Instruction

Hey, i’m currently working on my own LLVM Backend for a specific architecture. At the moment I’m trying to find patterns in the SelectionDAG and replace them with a target specific instruction using the file.
One of the patterns contains many nodes (like 50) which leads to a huge entry in the file.
My problem is now, that the project build takes forever and freezes at “Built target LLVMCodeGen”.
Is there a better way to replace these patterns in the SelectionDAG and if so, which file/function should I edit?
(the instruction that I’m trying to implement is a complex MAC on a 8x8bit vector btw.)

Thanks in advance.