Enable-ipra: pass of llc

Hi,

I’m trying the pass of llc --enable-ipra with benchmarks SPEC CPU 2017.

I compile this benchmarks with clang -O3, and after, y run llc -O3 -enable-ipra.

However, this pass seems not work. If I count the number of mov operations using -enable-ipra or not, I don’t get a significant difference.

Why doesn’t this pass work?