Re: [Qemu-devel] [PATCH v1 17/30] RISC-V: Replace __builtin_popcount with ctpop8 in PLIC

[Alistair Francis]

On Tue, May 22, 2018 at 5:15 PM, Michael Clark <address@hidden> wrote:
> The mode variable only uses the lower 4-bits (M,H,S,U) so
> replace the GCC specific __builtin_popcount with ctpop8.
>
> Cc: Palmer Dabbelt <address@hidden>
> Cc: Sagar Karandikar <address@hidden>
> Cc: Bastian Koppelmann <address@hidden>
> Cc: Alistair Francis <address@hidden>
> Signed-off-by: Michael Clark <address@hidden>

Reviewed-by: Alistair Francis <address@hidden>

Alistair

> ---
>  hw/riscv/sifive_plic.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/hw/riscv/sifive_plic.c b/hw/riscv/sifive_plic.c
> index b267ff88902d..dc6f4924e282 100644
> --- a/hw/riscv/sifive_plic.c
> +++ b/hw/riscv/sifive_plic.c
> @@ -383,7 +383,7 @@ static void parse_hart_config(SiFivePLICState *plic)
>      p = plic->hart_config;
>      while ((c = *p++)) {
>          if (c == ',') {
> -            addrid += __builtin_popcount(modes);
> +            addrid += ctpop8(modes);
>              modes = 0;
>              hartid++;
>          } else {
> @@ -397,7 +397,7 @@ static void parse_hart_config(SiFivePLICState *plic)
>          }
>      }
>      if (modes) {
> -        addrid += __builtin_popcount(modes);
> +        addrid += ctpop8(modes);
>      }
>      hartid++;
>
> --
> 2.7.0
>
>