[all-commits] [llvm/llvm-project] ac603c: [RISCV] Add scalable vector truncate patterns

[Fraser Cormack via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: ac603c8d3850ed0c715c421d79bb5cb014bb21de
      https://github.com/llvm/llvm-project/commit/ac603c8d3850ed0c715c421d79bb5cb014bb21de
  Author: Fraser Cormack <fraser at codeplay.com>
  Date:   2021-01-18 (Mon, 18 Jan 2021)

  Changed paths:
    M llvm/lib/Target/RISCV/RISCVISelLowering.cpp
    M llvm/lib/Target/RISCV/RISCVISelLowering.h
    M llvm/lib/Target/RISCV/RISCVInstrInfoVSDPatterns.td
    A llvm/test/CodeGen/RISCV/rvv/vtruncs-sdnode-rv32.ll
    A llvm/test/CodeGen/RISCV/rvv/vtruncs-sdnode-rv64.ll

  Log Message:
  -----------
  [RISCV] Add scalable vector truncate patterns

Original patch by @rogfer01.

This patch supports vector truncates, which on RVV must be done in a
series of instructions truncating by one power-of-two at a time. This is
done through custom-lowering and a custom node to avoid LLVM
re-combining the split TRUNCATE nodes.

Authored-by: Roger Ferrer Ibanez <rofirrim at gmail.com>
Co-Authored-by: Fraser Cormack <fraser at codeplay.com>

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D94796