search for: operation_fus

...; cmpq %rbx, %r14 > jne .LBB0_1 > > LLVM can perform compare-jump fusion, it already does in certain cases, but > not in the case above. We can remove the cmp above if we were to perform > the following transformation: Do you mean branch-fusion (https://en.wikichip.org/wiki/macro-operation_fusion)? Is there any more limitation why these two or not fused? > -----Original Message----- > From: llvm-dev [mailto:llvm-dev-bounces at lists.llvm.org] On Behalf Of via llvm- > dev > Sent: Wednesday, April 4, 2018 3:30 AM > To: llvm-dev at lists.llvm.org > Subject: [llvm-dev] SC...

I am attempting to implement a minor loop strength reduction optimization for targets that support compare and jump fusion, specifically TTI::canMacroFuseCmp(). My approach might be wrong; however, I am soliciting the idea for feedback, so that I can implement this correctly. My plan is to add a Supplemental LSR formula to LoopStrengthReduce.cpp that optimizes the following case, but perhaps