[PATCH] D73659: [GlobalISel] Add new combine to convert G_MUL to G_SHL.

[Amara Emerson via Phabricator via llvm-commits]

aemerson created this revision.
aemerson added reviewers: arsenm, paquette.
aemerson added a project: LLVM.
Herald added subscribers: kerbowa, Petar.Avramovic, volkan, jfb, hiraditya, rovka, nhaehnle, wdng, jvesely.
aemerson added a comment.

@arsenm Matt when I run the update_llc_test_checks script on the llvm/test/CodeGen/AMDGPU/GlobalISel/llvm.amdgcn.update.dpp.ll test, it crashes with a backtrace like this:

  Assertion failed: (Opcode < NumOpcodes && "Invalid opcode!"), function get, file /Users/aemerson/work/oss/co1/src/llvm/include/llvm/MC/MCInstrInfo.h, line 4
  frame #4: 0x00000001000bdef3 llc`llvm::MCInstrInfo::get(this=0x0000000110010248, Opcode=4294967295) const at MCInstrInfo.h:45:5
  frame #5: 0x000000010083b8d7 llc`llvm::SIInstrInfo::getMCOpcodeFromPseudo(this=0x0000000110010240, Opcode=3758) const at SIInstrInfo.h:939:12
  frame #6: 0x00000001008277e3 llc`llvm::SIInstrInfo::getInstSizeInBytes(this=0x0000000110010240, MI=0x000000010f879b28) const at SIInstrInfo.cpp:6067:29
  frame #7: 0x0000000101f9bf44 llc`(anonymous namespace)::BranchRelaxation::computeBlockSize(this=0x000000010f03fb60, MBB=0x000000010f8bbf28) const at BranchRelaxation.cpp:168:18
  frame #8: 0x0000000101f9b7be llc`(anonymous namespace)::BranchRelaxation::scanFunction(this=0x000000010f03fb60) at BranchRelaxation.cpp:158:39
  frame #9: 0x0000000101f9b264 llc`(anonymous namespace)::BranchRelaxation::runOnMachineFunction(this=0x000000010f03fb60, mf=0x000000010f0566f0) at BranchRelaxation.cpp:555:3

I'm replacing a G_MUL with an equivalent G_SHL here, is there an issue with doing this for AMDGPU?


For pow2 constants we should use G_SHL for pattern matching (and perf) purposes later.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D73659

Files:
  llvm/include/llvm/CodeGen/GlobalISel/CombinerHelper.h
  llvm/include/llvm/Target/GlobalISel/Combine.td
  llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
  llvm/test/CodeGen/AArch64/GlobalISel/combine-mul-to-lsl.mir
  llvm/test/CodeGen/AMDGPU/GlobalISel/lds-relocs.ll
  llvm/test/CodeGen/AMDGPU/GlobalISel/llvm.amdgcn.atomic.dec.ll
  llvm/test/CodeGen/AMDGPU/GlobalISel/llvm.amdgcn.atomic.inc.ll
  llvm/test/CodeGen/AMDGPU/GlobalISel/llvm.amdgcn.is.private.ll
  llvm/test/CodeGen/AMDGPU/GlobalISel/llvm.amdgcn.is.shared.ll
  llvm/test/CodeGen/AMDGPU/GlobalISel/llvm.amdgcn.update.dpp.ll
  llvm/test/CodeGen/AMDGPU/GlobalISel/mubuf-global.ll

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D73659.241260.patch
Type: text/x-patch
Size: 105001 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20200129/1226de8d/attachment-0001.bin>