[all-commits] [llvm/llvm-project] d1a566: [RISCV] Disable subregister liveness by default

[Fraser Cormack via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: d1a5669f5e4434d1a556b189088e96a011ec0999
      https://github.com/llvm/llvm-project/commit/d1a5669f5e4434d1a556b189088e96a011ec0999
  Author: Fraser Cormack <fraser at codeplay.com>
  Date:   2022-07-14 (Thu, 14 Jul 2022)

  Changed paths:
    M llvm/lib/Target/RISCV/RISCVSubtarget.cpp
    M llvm/test/CodeGen/RISCV/rvv/extract-subvector.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vector-segN-load.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vector-trunc-vp.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-fp-interleave.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-int-exttrunc.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-int-interleave.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-masked-gather.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-masked-scatter.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-reduction-fp.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-reduction-int.ll
    M llvm/test/CodeGen/RISCV/rvv/insert-subvector.ll
    M llvm/test/CodeGen/RISCV/rvv/rv32-spill-zvlsseg.ll
    M llvm/test/CodeGen/RISCV/rvv/rv64-spill-zvlsseg.ll
    M llvm/test/CodeGen/RISCV/rvv/vfptrunc-vp.ll
    M llvm/test/CodeGen/RISCV/rvv/vloxseg-rv32.ll
    M llvm/test/CodeGen/RISCV/rvv/vloxseg-rv64.ll
    M llvm/test/CodeGen/RISCV/rvv/vlseg-rv32.ll
    M llvm/test/CodeGen/RISCV/rvv/vlseg-rv64.ll
    M llvm/test/CodeGen/RISCV/rvv/vlsegff-rv32-dead.ll
    M llvm/test/CodeGen/RISCV/rvv/vlsegff-rv32.ll
    M llvm/test/CodeGen/RISCV/rvv/vlsegff-rv64-dead.ll
    M llvm/test/CodeGen/RISCV/rvv/vlsegff-rv64.ll
    M llvm/test/CodeGen/RISCV/rvv/vlsseg-rv32.ll
    M llvm/test/CodeGen/RISCV/rvv/vlsseg-rv64.ll
    M llvm/test/CodeGen/RISCV/rvv/vluxseg-rv32.ll
    M llvm/test/CodeGen/RISCV/rvv/vluxseg-rv64.ll
    M llvm/test/CodeGen/RISCV/rvv/vpgather-sdnode.ll
    M llvm/test/CodeGen/RISCV/rvv/vrgatherei16-subreg-liveness.ll
    M llvm/test/CodeGen/RISCV/rvv/vsetvli-insert-crossbb.ll
    M llvm/test/CodeGen/RISCV/rvv/vsoxseg-rv32.ll
    M llvm/test/CodeGen/RISCV/rvv/vsoxseg-rv64.ll
    M llvm/test/CodeGen/RISCV/rvv/vsseg-rv32.ll
    M llvm/test/CodeGen/RISCV/rvv/vsseg-rv64.ll
    M llvm/test/CodeGen/RISCV/rvv/vssseg-rv32.ll
    M llvm/test/CodeGen/RISCV/rvv/vssseg-rv64.ll
    M llvm/test/CodeGen/RISCV/rvv/vsuxseg-rv32.ll
    M llvm/test/CodeGen/RISCV/rvv/vsuxseg-rv64.ll
    M llvm/test/CodeGen/RISCV/rvv/zvlsseg-zero-vl.ll

  Log Message:
  -----------
  [RISCV] Disable subregister liveness by default

We previously enabled subregister liveness by default when compiling
with RVV. This has been shown to cause miscompilations where RVV
register operand constraints are not met. A test was added for this in
D129639 which explains the issue in more detail.

Until this issue is fixed in some way, we should not be enabling
subregister liveness unless the user asks for it.

Reviewed By: craig.topper, rogfer01, kito-cheng

Differential Revision: https://reviews.llvm.org/D129646