Re: [RFC PATCH v3 11/34] Hexagon (target/hexagon) register fields

[Richard Henderson]

On 8/18/20 8:50 AM, Taylor Simpson wrote:
> Declare bitfields within registers such as user status register (USR)
> 
> Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
> ---
>  target/hexagon/reg_fields.h     | 40 +++++++++++++++++++++
>  target/hexagon/reg_fields_def.h | 78 
> +++++++++++++++++++++++++++++++++++++++++
>  target/hexagon/reg_fields.c     | 28 +++++++++++++++
>  3 files changed, 146 insertions(+)
>  create mode 100644 target/hexagon/reg_fields.h
>  create mode 100644 target/hexagon/reg_fields_def.h
>  create mode 100644 target/hexagon/reg_fields.c
> 
> diff --git a/target/hexagon/reg_fields.h b/target/hexagon/reg_fields.h
> new file mode 100644
> index 0000000..cf168f0
> --- /dev/null
> +++ b/target/hexagon/reg_fields.h
> @@ -0,0 +1,40 @@
> +/*
> + *  Copyright(c) 2019-2020 Qualcomm Innovation Center, Inc. All Rights 
> Reserved.
> + *
> + *  This program is free software; you can redistribute it and/or modify
> + *  it under the terms of the GNU General Public License as published by
> + *  the Free Software Foundation; either version 2 of the License, or
> + *  (at your option) any later version.
> + *
> + *  This program is distributed in the hope that it will be useful,
> + *  but WITHOUT ANY WARRANTY; without even the implied warranty of
> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + *  GNU General Public License for more details.
> + *
> + *  You should have received a copy of the GNU General Public License
> + *  along with this program; if not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#ifndef HEXAGON_REG_FIELDS_H
> +#define HEXAGON_REG_FIELDS_H
> +
> +#define NUM_GEN_REGS 32

What's this?  It doesn't appear to be field related.

> +extern reg_field_t reg_field_info[];

const.

> +enum reg_fields_enum {

Doesn't follow naming guidelines.  But you don't actually use the name at all,
so better to just drop the name entirely?

> +/* USR fields */
> +DEF_REG_FIELD(USR_OVF,
> +    "ovf", 0, 1,
> +    "Sticky Saturation Overflow - "
> +    "Set when saturation occurs while executing instruction that specifies "
> +    "optional saturation, remains set until explicitly cleared by a USR=Rs "
> +    "instruction.")

Is the description as a string really useful, or even used?
A comment would seem to do just as well, not consume space in the final binary,
and even then seems redundant with the actual architecture manual.


r~