Re: [PATCH V5 0/3] RISC-V: Add an experimental vector calling convention

[Kito Cheng <kito.cheng@gmail.com>]

Pushed to trunk with few testcase modifications, e.g. adding { target
{ riscv_vector } } to dg-run and adding -march / -mabi for compile
tests.

On Tue, Sep 5, 2023 at 4:18 PM Kito Cheng <kito.cheng@gmail.com> wrote:
>
> Thanks for fixing the issue! I guess I could find time tonight to do
> the final round review and test :P then we could land this patch this
> week.
>
> On Tue, Sep 5, 2023 at 3:45 PM Lehua Ding <lehua.ding@rivai.ai> wrote:
> >
> > V5 change: Rebase and fix vsetvl testcase fail by change
> > `(unspec [...] UNSPEC_CALLEE_CC)` to `(use (unspec [...] UNSPEC_CALLEE_CC))`.
> > This change makes single_set function re-think call_insn as a
> > single set pattern.
> >
> > Hi RISC-V folks,
> >
> > This patch implement the proposal of RISC-V vector calling convention[1] and
> > this feature can be enabled by `--param=riscv-vector-abi` option. Currently,
> > all vector type arguments and return values are pass by reference. With this
> > patch, these arguments and return values can pass through vector registers.
> > Currently only vector types defined in the RISC-V Vector Extension Intrinsic Document[2]
> > are supported. GNU-ext vector types are unsupported for now since the
> > corresponding proposal was not presented.
> >
> > The proposal introduce a new calling convention variant, functions which follow
> > this variant need follow the bellow vector register convention.
> >
> > | Name    | ABI Mnemonic | Meaning                      | Preserved across calls?
> > =================================================================================
> > | v0      |              | Argument register            | No
> > | v1-v7   |              | Callee-saved registers       | Yes
> > | v8-v23  |              | Argument registers           | No
> > | v24-v31 |              | Callee-saved registers       | Yes
> >
> > If a functions follow this vector calling convention, then the function symbole
> > must be annotated with .variant_cc directive[3] (used to indicate that it is a
> > calling convention variant).
> >
> > This implementation split into three parts, each part corresponds to a sub-patch.
> >
> > - Part-1: Select suitable vector regsiters for vector type arguments and return
> >   values according to the proposal.
> > - Part-2: Allocate frame area for callee-saved vector registers and save/restore
> >   them in prologue and epilogue.
> > - Part-3: Generate .variant_cc directive for vector function in assembly code.
> >
> > [1] https://github.com/riscv-non-isa/riscv-elf-psabi-doc/pull/389
> > [2] https://github.com/riscv-non-isa/rvv-intrinsic-doc/blob/master/rvv-intrinsic-rfc.md#type-system
> > [3] https://github.com/riscv-non-isa/riscv-asm-manual/blob/master/riscv-asm.md#pseudo-ops
> >
> > Best,
> > Lehua
> >
> > Lehua Ding (3):
> >   RISC-V: Part-1: Select suitable vector registers for vector type args
> >     and returns
> >   RISC-V: Part-2: Save/Restore vector registers which need to be
> >     preversed
> >   RISC-V: Part-3: Output .variant_cc directive for vector function
> >
> >  gcc/config/riscv/riscv-protos.h               |   4 +
> >  gcc/config/riscv/riscv-sr.cc                  |   8 +-
> >  gcc/config/riscv/riscv-vector-builtins.cc     |  10 +
> >  gcc/config/riscv/riscv.cc                     | 484 ++++++++++++++++--
> >  gcc/config/riscv/riscv.h                      |  43 ++
> >  gcc/config/riscv/riscv.md                     |  51 +-
> >  gcc/config/riscv/riscv.opt                    |   5 +
> >  .../riscv/rvv/base/abi-call-args-1-run.c      | 127 +++++
> >  .../riscv/rvv/base/abi-call-args-1.c          | 197 +++++++
> >  .../riscv/rvv/base/abi-call-args-2-run.c      |  34 ++
> >  .../riscv/rvv/base/abi-call-args-2.c          |  27 +
> >  .../riscv/rvv/base/abi-call-args-3-run.c      | 260 ++++++++++
> >  .../riscv/rvv/base/abi-call-args-3.c          | 116 +++++
> >  .../riscv/rvv/base/abi-call-args-4-run.c      | 145 ++++++
> >  .../riscv/rvv/base/abi-call-args-4.c          | 111 ++++
> >  .../riscv/rvv/base/abi-call-error-1.c         |  11 +
> >  .../riscv/rvv/base/abi-call-return-run.c      | 127 +++++
> >  .../riscv/rvv/base/abi-call-return.c          | 197 +++++++
> >  .../riscv/rvv/base/abi-call-variant_cc.c      |  39 ++
> >  .../rvv/base/abi-callee-saved-1-fixed-1.c     |  86 ++++
> >  .../rvv/base/abi-callee-saved-1-fixed-2.c     |  86 ++++
> >  .../base/abi-callee-saved-1-save-restore.c    |  85 +++
> >  .../riscv/rvv/base/abi-callee-saved-1-zcmp.c  |  85 +++
> >  .../riscv/rvv/base/abi-callee-saved-1.c       |  88 ++++
> >  .../base/abi-callee-saved-2-save-restore.c    | 108 ++++
> >  .../riscv/rvv/base/abi-callee-saved-2-zcmp.c  | 107 ++++
> >  .../riscv/rvv/base/abi-callee-saved-2.c       | 117 +++++
> >  27 files changed, 2709 insertions(+), 49 deletions(-)
> >  create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/base/abi-call-args-1-run.c
> >  create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/base/abi-call-args-1.c
> >  create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/base/abi-call-args-2-run.c
> >  create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/base/abi-call-args-2.c
> >  create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/base/abi-call-args-3-run.c
> >  create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/base/abi-call-args-3.c
> >  create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/base/abi-call-args-4-run.c
> >  create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/base/abi-call-args-4.c
> >  create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/base/abi-call-error-1.c
> >  create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/base/abi-call-return-run.c
> >  create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/base/abi-call-return.c
> >  create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/base/abi-call-variant_cc.c
> >  create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/base/abi-callee-saved-1-fixed-1.c
> >  create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/base/abi-callee-saved-1-fixed-2.c
> >  create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/base/abi-callee-saved-1-save-restore.c
> >  create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/base/abi-callee-saved-1-zcmp.c
> >  create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/base/abi-callee-saved-1.c
> >  create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/base/abi-callee-saved-2-save-restore.c
> >  create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/base/abi-callee-saved-2-zcmp.c
> >  create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/base/abi-callee-saved-2.c
> >
> > --
> > 2.36.3
> >