Summary:
"X % C == 0" is optimized to "X & C-1 == 0" (where C is a power-of-two)
However, "X % Y" can also be represented as "X - (X / Y) * Y" so if I rewrite the initial expression:
"X - (X / C) * C == 0" it's not currently optimized to "X & C-1 == 0", see godbolt: https://godbolt.org/z/KzuXUj
This is my first contribution to LLVM so I hope I didn't mess things up
Reviewers: lebedev.ri, spatel
Reviewed By: lebedev.ri
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D79369
EgorBo