[PATCH] D98683: [RISCV] Improve i32 UADDSAT/USUBSAT on RV64.

[Craig Topper via Phabricator via llvm-commits]

craig.topper created this revision.
craig.topper added reviewers: asb, luismarques, frasercrmck.
Herald added subscribers: StephenFan, vkmr, evandro, apazos, sameer.abuasal, s.egerton, Jim, benna, psnobl, jocewei, PkmX, the_o, brucehoult, MartinMosbeck, rogfer01, edward-jones, zzheng, jrtc27, shiva0217, kito-cheng, niosHD, sabuasal, simoncook, johnrusso, rbar, hiraditya.
craig.topper requested review of this revision.
Herald added a subscriber: MaskRay.
Herald added a project: LLVM.

The default promotion uses zero extends that become shifts. We
cam use sign extend instead which is better for RISCV.

I've used two different implementations based on whether we
have minu/maxu instructions.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D98683

Files:
  llvm/lib/Target/RISCV/RISCVISelLowering.cpp
  llvm/test/CodeGen/RISCV/uadd_sat.ll
  llvm/test/CodeGen/RISCV/uadd_sat_plus.ll
  llvm/test/CodeGen/RISCV/usub_sat.ll
  llvm/test/CodeGen/RISCV/usub_sat_plus.ll

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D98683.330892.patch
Type: text/x-patch
Size: 7132 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20210316/c948e1df/attachment.bin>