Re: [PATCH 2/2] RISC-V: remove CM_PIC as it doesn't do much

[Palmer Dabbelt <palmer@rivosinc.com>]

On Tue, 30 Aug 2022 10:48:30 PDT (-0700), Vineet Gupta wrote:
> CM_PIC is no longer doing anything directly. Removing it might
> potentially affect USE_LOAD_ADDRESS_MACRO() but seems unlikely.

At least in the short term, there's kind of a mess here that needs to 
get sorted out but just removing CM_PIC doesn't really get us there.

> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com>
> ---
>  gcc/config/riscv/riscv-c.cc   | 4 ----
>  gcc/config/riscv/riscv-opts.h | 3 +--
>  gcc/config/riscv/riscv.cc     | 2 +-
>  3 files changed, 2 insertions(+), 7 deletions(-)
>
> diff --git a/gcc/config/riscv/riscv-c.cc b/gcc/config/riscv/riscv-c.cc
> index bba72cf77a82..7064fcf142fe 100644
> --- a/gcc/config/riscv/riscv-c.cc
> +++ b/gcc/config/riscv/riscv-c.cc
> @@ -92,13 +92,9 @@ riscv_cpu_cpp_builtins (cpp_reader *pfile)
>        builtin_define ("__riscv_cmodel_medlow");
>        break;
>
> -    case CM_PIC:
> -      /* FALLTHROUGH. */
> -
>      case CM_MEDANY:
>        builtin_define ("__riscv_cmodel_medany");
>        break;
> -
>      }
>
>    if (TARGET_MIN_VLEN != 0)
> diff --git a/gcc/config/riscv/riscv-opts.h b/gcc/config/riscv/riscv-opts.h
> index 85e869e62e3a..ce3237beca7a 100644
> --- a/gcc/config/riscv/riscv-opts.h
> +++ b/gcc/config/riscv/riscv-opts.h
> @@ -34,8 +34,7 @@ extern enum riscv_abi_type riscv_abi;
>
>  enum riscv_code_model {
>    CM_MEDLOW,
> -  CM_MEDANY,
> -  CM_PIC
> +  CM_MEDANY
>  };
>  extern enum riscv_code_model riscv_cmodel;
>
> diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
> index 7c120eaa8e33..a239fe43047c 100644
> --- a/gcc/config/riscv/riscv.cc
> +++ b/gcc/config/riscv/riscv.cc
> @@ -5162,7 +5162,7 @@ riscv_option_override (void)
>    init_machine_status = &riscv_init_machine_status;
>
>    if (flag_pic)
> -    riscv_cmodel = CM_PIC;
> +    riscv_cmodel = CM_MEDANY;
>
>    /* We get better code with explicit relocs for CM_MEDLOW, but
>       worse code for the others (for now).  Pick the best default.  */

I'm fine either way on this one: having CM_PIC gone makes it a bit more 
likely to confuse CM_MEDANY with PIC, but flag_pic is overriding 
riscv_cmodel anyway so this isn't really used and deleting code is 
always a plus.