[all-commits] [llvm/llvm-project] 2df932: [RISCV] Stop performFP_TO_INTCombine from folding ...

[Craig Topper via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 2df9328fe3a0575fa415964a3c3544b0912b168e
      https://github.com/llvm/llvm-project/commit/2df9328fe3a0575fa415964a3c3544b0912b168e
  Author: Craig Topper <craig.topper at sifive.com>
  Date:   2023-08-10 (Thu, 10 Aug 2023)

  Changed paths:
    M llvm/lib/Target/RISCV/RISCVISelLowering.cpp
    M llvm/test/CodeGen/RISCV/rvv/double-round-conv.ll
    M llvm/test/CodeGen/RISCV/rvv/float-round-conv.ll
    M llvm/test/CodeGen/RISCV/rvv/half-round-conv.ll

  Log Message:
  -----------
  [RISCV] Stop performFP_TO_INTCombine from folding with ISD::FRINT.

FRINT was added to matchRoundingOp after this function was written.
So FRINT was not tested originally.

For vectors, folding this causes us to create a CSR swap that tries
to write 7 to FRM. This is an illegal value and will cause the CSR
write to fail.

While this might be a legal fold we could do, I'm disabling it for
now so we can backport to LLVM 17 with the least risk.

Differential Revision: https://reviews.llvm.org/D157583