RISC-V:Add '-m[no]-csr-check' option in gcc.

  From: Jiawei <jiawei@iscas.ac.cn>

Add -m[no]-csr-check option in gcc part, when enable -mcsr-check option,
it will add csr-check in .option section and pass this to assembler.

gcc/ChangeLog:

        * config/riscv/riscv.cc (riscv_file_start): New .option.
        * config/riscv/riscv.opt: New options.
        * doc/invoke.texi: New definations.

---
 gcc/config/riscv/riscv.cc  | 5 +++++
 gcc/config/riscv/riscv.opt | 6 ++++++
 gcc/doc/invoke.texi        | 6 ++++++
 3 files changed, 17 insertions(+)
  

Hi Jiawei:

Could you add check in config/configure.ac and gcc/config.in to make
sure the binutils has support for that or not?

You can reference the commit for -misa-spec to see how it work and how it add:
https://github.com/gcc-mirror/gcc/commit/4b81528241ca682025d92558ff6aeec91dafdca8

Thanks :)

On Thu, Sep 8, 2022 at 9:51 AM jiawei <jiawei@iscas.ac.cn> wrote:
>
> From: Jiawei <jiawei@iscas.ac.cn>
>
> Add -m[no]-csr-check option in gcc part, when enable -mcsr-check option,
> it will add csr-check in .option section and pass this to assembler.
>
> gcc/ChangeLog:
>
>         * config/riscv/riscv.cc (riscv_file_start): New .option.
>         * config/riscv/riscv.opt: New options.
>         * doc/invoke.texi: New definations.
>
> ---
>  gcc/config/riscv/riscv.cc  | 5 +++++
>  gcc/config/riscv/riscv.opt | 6 ++++++
>  gcc/doc/invoke.texi        | 6 ++++++
>  3 files changed, 17 insertions(+)
>
> diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
> index 675d92c0961..e98e6b1f561 100644
> --- a/gcc/config/riscv/riscv.cc
> +++ b/gcc/config/riscv/riscv.cc
> @@ -5135,6 +5135,11 @@ riscv_file_start (void)
>    if (! riscv_mrelax)
>      fprintf (asm_out_file, "\t.option norelax\n");
>
> +  /* If the user specifies "-mcsr-check" on the command line then enable csr
> +     check in the assembler.  */
> +  if (riscv_mcsr_check)
> +    fprintf (asm_out_file, "\t.option csr-check\n");
> +
>    if (riscv_emit_attribute_p)
>      riscv_emit_attribute ();
>  }
> diff --git a/gcc/config/riscv/riscv.opt b/gcc/config/riscv/riscv.opt
> index fbca91b956c..3a12dd47310 100644
> --- a/gcc/config/riscv/riscv.opt
> +++ b/gcc/config/riscv/riscv.opt
> @@ -132,6 +132,12 @@ Target Bool Var(riscv_mrelax) Init(1)
>  Take advantage of linker relaxations to reduce the number of instructions
>  required to materialize symbol addresses.
>
> +mcsr-check
> +Target Bool Var(riscv_mcsr_check) Init(1)
> +Enable the CSR checking for the ISA-dependent CRS and the read-only CSR.
> +The ISA-dependent CSR are only valid when the specific ISA is set.  The
> +read-only CSR can not be written by the CSR instructions.
> +
>  Mask(64BIT)
>
>  Mask(MUL)
> diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
> index dd3302fcd15..7caade26b94 100644
> --- a/gcc/doc/invoke.texi
> +++ b/gcc/doc/invoke.texi
> @@ -1224,6 +1224,7 @@ See RS/6000 and PowerPC Options.
>  -mbig-endian  -mlittle-endian @gol
>  -mstack-protector-guard=@var{guard}  -mstack-protector-guard-reg=@var{reg} @gol
>  -mstack-protector-guard-offset=@var{offset}}
> +-mcsr-check -mno-csr-check @gol
>
>  @emph{RL78 Options}
>  @gccoptlist{-msim  -mmul=none  -mmul=g13  -mmul=g14  -mallregs @gol
> @@ -28551,6 +28552,11 @@ linker relaxations.
>  Emit (do not emit) RISC-V attribute to record extra information into ELF
>  objects.  This feature requires at least binutils 2.32.
>
> +@item -mcsr-check
> +@itemx -mno-csr-check
> +@opindex mcsr-check
> +Enables or disables the CSR checking.
> +
>  @item -malign-data=@var{type}
>  @opindex malign-data
>  Control how GCC aligns variables and constants of array, structure, or union
> --
> 2.34.1
>