[all-commits] [llvm/llvm-project] 08c115: [DAG] Add computeOverflowForSignedSub/computeOverf...

[Simon Pilgrim via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 08c1150d4c3545949d7c98efaee52d06549d2552
      https://github.com/llvm/llvm-project/commit/08c1150d4c3545949d7c98efaee52d06549d2552
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2023-05-06 (Sat, 06 May 2023)

  Changed paths:
    M llvm/include/llvm/CodeGen/SelectionDAG.h
    M llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
    M llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
    M llvm/test/CodeGen/X86/xaluo.ll

  Log Message:
  -----------
  [DAG] Add computeOverflowForSignedSub/computeOverflowForUnsignedSub/computeOverflowForSub

Match the addition variants (although computeOverflowForUnsignedSub is really just a placeholder), and use this in DAGCombiner::visitSUBO


  Commit: 05a57fd18cb1117127f48ee9f63d42631f5725b9
      https://github.com/llvm/llvm-project/commit/05a57fd18cb1117127f48ee9f63d42631f5725b9
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2023-05-06 (Sat, 06 May 2023)

  Changed paths:
    M llvm/test/CodeGen/X86/combine-sub-ssat.ll
    M llvm/test/CodeGen/X86/combine-sub-usat.ll

  Log Message:
  -----------
  [X86] Add tests showing failure to simplify ssubsat/usubsat to sub


  Commit: 8f82d8ee760360a68de47d75d6a1851dacbdb8ef
      https://github.com/llvm/llvm-project/commit/8f82d8ee760360a68de47d75d6a1851dacbdb8ef
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2023-05-06 (Sat, 06 May 2023)

  Changed paths:
    M llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
    M llvm/test/CodeGen/X86/combine-sub-ssat.ll

  Log Message:
  -----------
  [DAG] visitSUBSAT - fold subsat(x,y) -> sub(x,y) if it never overflows


Compare: https://github.com/llvm/llvm-project/compare/3551e0f34522...8f82d8ee7603