Not sure whether this is generally true. GCC appears to have similar optimizations and I personally find LLVM's code much more intimidating. But it is certainly true that LLVM seems to see more investment. I assume the license may also play a role. For comparison, here is some related code:

https://github.com/gcc-mirror/gcc/blob/master/gcc/tree-chrec... https://github.com/llvm/llvm-project/blob/release/21.x/llvm/...