[PATCH] D45486: [X86][Atom] Convert Atom scheduler model to SchedRW (PR32431)

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added inline comments.


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Comment at: test/CodeGen/X86/sse2-schedule.ll:10709
-; ATOM-NEXT:    paddw %xmm0, %xmm1 # sched: [1:0.50]
-; ATOM-NEXT:    movdqa %xmm1, %xmm0 # sched: [1:0.50]
 ; ATOM-NEXT:    retq # sched: [79:39.50]
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RKSimon wrote:
> craig.topper wrote:
> > Any idea why the paddw wasn't commuted before to make the movdqa unnecessary?
> Sorry, no - with the patch MachineCSE is performing the commute.
Both with/without the patch MachineCSE the paddw is being commutated twice (there and back again....). Without the patch I'm then seeing one more commutations coming from TwoAddressInstructionPass, and that leaves us with the movdqa.


Repository:
  rL LLVM

https://reviews.llvm.org/D45486