[llvm] [InstCombine] Implement `fcmp (fadd x, 0.0), y` => `fcmp x, y` optimization (PR #88476)

[Yingwei Zheng via llvm-commits]

dtcxzyw wrote:

> Question: Should I also add tests for the case of fcmp (fsub x, 0.0), y? From what I can tell my implementation already covers this case. Is this because somewhere in the code we transform fsub x, 0.0 => fadd x, 0.0?

Yeah, `fsub x, +/-0.0` are not in canonical form. I don't think these tests are necessary.


https://github.com/llvm/llvm-project/pull/88476