Depends on D152879.
Specification PR: riscv-non-isa/rvv-intrinsic-doc#226
This patch adds variant of `vfadd` that models the rounding mode control.
The added variant has suffix `_rm` appended to differentiate from the
existing ones that does not alternate `frm` and uses whatever is inside.
The value `7` is used to indicate no rounding mode change. Reusing the
semantic from the rounding mode encoding for scalar floating-point
instructions.
Additional data member `HasFRMRoundModeOp` is added so we can append
`_rm` suffix for the fadd variants that models rounding mode control.
Additional data member `IsRVVFixedPoint` is added so we can define
pseudo instructions with rounding mode operand and distinguish the
instructions between fixed-point and floating-point.
Reviewed By: craig.topper, kito-cheng
Differential Revision: https://reviews.llvm.org/D152996
Depends on D151395.
This is the 2nd patch of the patch-set. For the cover letter of the
patch-set, please checkout D151395. This patch originates from
D121376.
This commit models vxrm by adding an immediate operand into intrinsics
and machine instructions of RVV fixed-point instruction `vaadd`,
`vaaddu`, `vasub`, and `vasubu`. This commit only covers intrinsics of
the four instructions, the proceeding patches of the patch-set will do
the same to other RVV fixed-point instructions.
The current naiive approach is to have a write to vxrm inserted before
every fixed-point instruction. This is done by the new added pass
`RISCVInsertReadWriteCSR`. The reason to name the pass in a more general
term is because we will also model rounding mode for the RVV floating-
point instructions. The approach will be improved in the future,
implementing partial redundancy elimination algorithms to it.
The original LLVM intrinsics and machine instructions, take `vaadd` as
an example, does not model the rounding mode is not removed in this
patch. That is, `int.riscv.vaadd.*` co-exists with
`int.riscv.vaadd.rm.*` after this patch. The next patch will add C
intrinsics of vaadd with an additional operand that models the control
of the rounding mode, in this patch, `int.riscv.vaadd.rm.*` will
replace `int.riscv.vaadd.*`.
Authored-by: ShihPo Hung <shihpo.hung@sifive.com>
Co-Authored-by: eop Chen <eop.chen@sifive.com>
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D151396
