[PATCH] D155929: [RISCV] Use the first element of source as the start value of reduction.

[Yeting Kuo via Phabricator via llvm-commits]

fakepaper56 created this revision.
fakepaper56 added reviewers: craig.topper, reames, frasercrmck, rogfer01, luke.
Herald added subscribers: jobnoorman, VincentWu, 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, arichardson.
Herald added a project: All.
fakepaper56 requested review of this revision.
Herald added subscribers: llvm-commits, wangpc, eopXD, MaskRay.
Herald added a project: LLVM.

Previously when llvm.reduce.* lowered, riscv backend created scalar vector with
netural element as start value. For llvm.reduce.and/or/min/max/fmax/fmin, we
could use the first element of source as the start value. It's benefit for RVV
since we could just use source vector as start vector.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D155929

Files:
  llvm/lib/Target/RISCV/RISCVISelLowering.cpp
  llvm/test/CodeGen/RISCV/double_reduct.ll
  llvm/test/CodeGen/RISCV/rvv/fixed-vectors-reduction-fp.ll
  llvm/test/CodeGen/RISCV/rvv/fixed-vectors-reduction-int-vp.ll
  llvm/test/CodeGen/RISCV/rvv/fixed-vectors-reduction-int.ll
  llvm/test/CodeGen/RISCV/rvv/fold-binary-reduce.ll
  llvm/test/CodeGen/RISCV/rvv/vreductions-fp-sdnode.ll
  llvm/test/CodeGen/RISCV/rvv/vreductions-int-vp.ll
  llvm/test/CodeGen/RISCV/rvv/vreductions-int.ll

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D155929.542829.patch
Type: text/x-patch
Size: 203708 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20230721/8d15bfc4/attachment-0001.bin>