[PATCH] D106403: [RISCV] Avoid using x0,x0 vsetvli for vmv.x.s and vfmv.f.s unless we know the sew/lmul ratio is constant.

[Craig Topper via Phabricator via llvm-commits]

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

Since we're changing VTYPE, we may change VLMAX which could
invalidate the previous VL. If we can't tell if it is safe we
should use an AVL of 1 instead of keeping the old VL.

This is a quick fix. A better fix is to thread VL to the pseudo
instruction instead of making up a value. That will require ISD
opcode changes and changes to the C intrinsic interface.

This fixes the issue raised in D106286 <https://reviews.llvm.org/D106286>.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D106403

Files:
  llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp
  llvm/test/CodeGen/RISCV/rvv/extractelt-fp-rv32.ll
  llvm/test/CodeGen/RISCV/rvv/extractelt-fp-rv64.ll
  llvm/test/CodeGen/RISCV/rvv/extractelt-int-rv32.ll
  llvm/test/CodeGen/RISCV/rvv/extractelt-int-rv64.ll
  llvm/test/CodeGen/RISCV/rvv/fixed-vectors-bitcast.ll
  llvm/test/CodeGen/RISCV/rvv/fixed-vectors-fp-bitcast.ll
  llvm/test/CodeGen/RISCV/rvv/fixed-vectors-fp-buildvec.ll
  llvm/test/CodeGen/RISCV/rvv/fixed-vectors-int-shuffles.ll
  llvm/test/CodeGen/RISCV/rvv/fixed-vectors-unaligned.ll
  llvm/test/CodeGen/RISCV/rvv/vfmv.f.s.ll
  llvm/test/CodeGen/RISCV/rvv/vmv.x.s-rv32.ll
  llvm/test/CodeGen/RISCV/rvv/vmv.x.s-rv64.ll
  llvm/test/CodeGen/RISCV/rvv/vsetvli-insert.mir
  llvm/test/CodeGen/RISCV/spill-fpr-scalar.ll
  llvm/test/CodeGen/RISCV/srem-seteq-illegal-types.ll

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D106403.360286.patch
Type: text/x-patch
Size: 65833 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20210720/e8d3b5f1/attachment.bin>