[llvm] [GlobalIsel] Combine logic of floating point compares (PR #81886)

[Nikita Popov via llvm-commits]

Thorsten =?utf-8?q?Schütt?= <schuett at gmail.com>
Message-ID:
In-Reply-To: <llvm.org/llvm/llvm-project/pull/81886 at github.com>


nikic wrote:

> Is there a motivating real use case for this? My concern is if we're implementing IR InstCombines in the combiner purely for symmetry we add compile time cost for little benefit.

For DAGCombine, the general policy is that it should only contain combines that are either target-dependent, or arise during legalization/lowering. Everything else should be handled (only) in InstCombine instead. I'd expect GlobalISel to follow the same approach...

https://github.com/llvm/llvm-project/pull/81886