Re: [PATCH v3 26/60] target/arm: Replace sentinels with ARRAY_SIZE in cpregs.h

[Richard Henderson <richard.henderson@linaro.org>]

On 4/22/22 02:37, Peter Maydell wrote:
> On Sun, 17 Apr 2022 at 19:08, Richard Henderson
> <richard.henderson@linaro.org> wrote:
>>
>> Remove a possible source of error by removing REGINFO_SENTINEL
>> and using ARRAY_SIZE (convinently hidden inside a macro) to
>> find the end of the set of regs being registered or modified.
>>
>> The space saved by not having the extra array element reduces
>> the executable's .data.rel.ro section by about 9k.
>>
>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>> ---
> 
> 
> 
> 
>> +#define define_arm_cp_regs_with_opaque(CPU, REGS, OPAQUE)               \
>> +    do {                                                                \
>> +        QEMU_BUILD_BUG_ON(ARRAY_SIZE(REGS) == 0);                       \
>> +        if (ARRAY_SIZE(REGS) == 1) {                                    \
>> +            define_one_arm_cp_reg_with_opaque(CPU, REGS, OPAQUE);       \
>> +        } else {                                                        \
>> +            define_arm_cp_regs_with_opaque_len(CPU, REGS, OPAQUE,       \
>> +                                               ARRAY_SIZE(REGS));       \
>> +        }                                                               \
>> +    } while (0)
> 
> Do we actually need to special case "array has one element" here,
> or is this just efficiency?
> 
> Anyway
> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

Just efficiency.  There seem to be a lot of these.


r~