[PATCH] D98133: [SelectionDAG] Add computeKnownBits support for ISD::USUBSAT.

[Craig Topper via Phabricator via llvm-commits]

craig.topper created this revision.
craig.topper added reviewers: RKSimon, spatel, lebedev.ri.
Herald added subscribers: frasercrmck, ecnelises, kerbowa, luismarques, apazos, sameer.abuasal, pengfei, s.egerton, Jim, jocewei, PkmX, the_o, brucehoult, MartinMosbeck, rogfer01, edward-jones, zzheng, jrtc27, niosHD, sabuasal, simoncook, johnrusso, rbar, asb, hiraditya, nhaehnle, jvesely.
craig.topper requested review of this revision.
Herald added a subscriber: MaskRay.
Herald added a project: LLVM.

The result of ISD::USUBSAT will never be larger than the LHS. We
can use this to put a bound on the number of leading zeros.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D98133

Files:
  llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
  llvm/test/CodeGen/AMDGPU/usubsat.ll
  llvm/test/CodeGen/ARM/usub_sat.ll
  llvm/test/CodeGen/ARM/usub_sat_plus.ll
  llvm/test/CodeGen/RISCV/usub_sat.ll
  llvm/test/CodeGen/X86/combine-sub-usat.ll
  llvm/test/CodeGen/X86/usub_sat.ll
  llvm/test/CodeGen/X86/usub_sat_plus.ll

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D98133.328829.patch
Type: text/x-patch
Size: 17751 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20210307/5b8fa2b6/attachment.bin>