[PATCH] D28448: InstCombine: Do unsafe math combine of fadd + fmuladd + fmul

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added a comment.

In https://reviews.llvm.org/D28448#673662, @hfinkel wrote:

> Under what circumstances do we create a 'fast' fmuladd. Maybe we should canonicalize a 'fast' fmuladd into a 'fast' mul and a 'fast' add instead?


Clang emits this for a * b  + c with  -ffast-math -ffp-contract=on


https://reviews.llvm.org/D28448