Re: [PATCH 1/2] target/arm: Export aarch64_sve_zcr_get_valid_len

[Peter Maydell <peter.maydell@linaro.org>]

On Wed, 14 Jul 2021 at 19:06, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> Rename from sve_zcr_get_valid_len and make accessible
> from outside of helper.c.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  target/arm/cpu.h    | 2 ++
>  target/arm/helper.c | 8 +++++---
>  2 files changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/target/arm/cpu.h b/target/arm/cpu.h
> index be9a4dceae..52e99344c5 100644
> --- a/target/arm/cpu.h
> +++ b/target/arm/cpu.h
> @@ -1060,6 +1060,8 @@ int arm_cpu_write_elf64_note(WriteCoreDumpFunction f, CPUState *cs,
>  int arm_cpu_write_elf32_note(WriteCoreDumpFunction f, CPUState *cs,
>                               int cpuid, void *opaque);
>
> +uint32_t aarch64_sve_zcr_get_valid_len(ARMCPU *cpu, uint32_t start_len);

We only need this in cpu.c, I think, so I would favour putting it
in internals.h. A brief comment defining its purpose would also be good.

> +
>  #ifdef TARGET_AARCH64
>  int aarch64_cpu_gdb_read_register(CPUState *cpu, GByteArray *buf, int reg);
>  int aarch64_cpu_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg);
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index 910ace4274..a49067c115 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -6454,11 +6454,13 @@ int sve_exception_el(CPUARMState *env, int el)
>      return 0;
>  }
>
> -static uint32_t sve_zcr_get_valid_len(ARMCPU *cpu, uint32_t start_len)
> +uint32_t aarch64_sve_zcr_get_valid_len(ARMCPU *cpu, uint32_t start_len)
>  {
>      uint32_t end_len;
>
> -    end_len = start_len &= 0xf;
> +    start_len = MIN(start_len, ARM_MAX_VQ - 1);
> +    end_len = start_len;
> +

This seems to also be making a functional change? That should be
a separate patch.

>      if (!test_bit(start_len, cpu->sve_vq_map)) {
>          end_len = find_last_bit(cpu->sve_vq_map, start_len);
>          assert(end_len < start_len);
> @@ -6484,7 +6486,7 @@ uint32_t sve_zcr_len_for_el(CPUARMState *env, int el)
>          zcr_len = MIN(zcr_len, 0xf & (uint32_t)env->vfp.zcr_el[3]);
>      }
>
> -    return sve_zcr_get_valid_len(cpu, zcr_len);
> +    return aarch64_sve_zcr_get_valid_len(cpu, zcr_len);
>  }

thanks
-- PMM