[AArch64] Add patterns to replace fsub fmul with fma fneg.
Summary:
This patch adds MachineCombiner patterns for transforming
(fsub (fmul x y) z) into (fma x y (fneg z)). This has a lower
latency on micro architectures where fneg is cheap.
Patch based on work by George Steed.
Reviewers: rengolin, joelkevinjones, joel_k_jones, evandro, efriedma
Reviewed By: evandro
Subscribers: aemerson, javed.absar, llvm-commits, kristof.beyls
Differential Revision: https://reviews.llvm.org/D40306
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319980 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed