Re: [Qemu-devel] [PATCH v2 3/6] target-ppc: add vrldnmi and vrlwmi instructions

[Nikunj A Dadhania]

David Gibson <address@hidden> writes:
>> diff --git a/target-ppc/int_helper.c b/target-ppc/int_helper.c
>> index dca4798..b54cd7c 100644
>> --- a/target-ppc/int_helper.c
>> +++ b/target-ppc/int_helper.c
>> @@ -1717,6 +1717,52 @@ void helper_vrsqrtefp(CPUPPCState *env, ppc_avr_t *r, 
>> ppc_avr_t *b)
>>      }
>>  }
>>  
>> +#define MASK(size, max_val)                                     \
>> +static inline uint##size##_t mask_u##size(uint##size##_t start, \
>> +                                uint##size##_t end)             \
>> +{                                                               \
>> +    uint##size##_t ret, max_bit = size - 1;                     \
>> +                                                                \
>> +    if (likely(start == 0)) {                                   \
>> +        ret = max_val << (max_bit - end);                       \
>> +    } else if (likely(end == max_bit)) {                        \
>> +        ret = max_val >> start;                                 \
>> +    } else {                                                    \
>> +        ret = (((uint##size##_t)(-1ULL)) >> (start)) ^          \
>> +            (((uint##size##_t)(-1ULL) >> (end)) >> 1);          \
>> +        if (unlikely(start > end)) {                            \
>> +            return ~ret;                                        \
>> +        }                                                       \
>> +    }                                                           \
>> +                                                                \
>> +    return ret;                                                 \
>> +}
>> +
>> +MASK(32, UINT32_MAX);
>> +MASK(64, UINT64_MAX);
>
> It would be nicer to merge this mask generation with the
> implementation in target-ppc/translate.c (called MASK()).

How about something like this in target-ppc/cpu.h

#define FUNC_MASK(name, ret_type, size, max_val)                  \
static inline ret_type name (uint##size##_t start,                \
                             uint##size##_t end)                  \
{                                                                 \
    ret_type ret, max_bit = size - 1;                             \
                                                                  \
    if (likely(start == 0)) {                                     \
        ret = max_val << (max_bit - end);                         \
    } else if (likely(end == max_bit)) {                          \
        ret = max_val >> start;                                   \
    } else {                                                      \
        ret = (((uint##size##_t)(-1ULL)) >> (start)) ^            \
            (((uint##size##_t)(-1ULL) >> (end)) >> 1);            \
        if (unlikely(start > end)) {                              \
            return ~ret;                                          \
        }                                                         \
    }                                                             \
                                                                  \
    return ret;                                                   \
}

#if defined(TARGET_PPC64)
FUNC_MASK(MASK, target_ulong, 64, UINT64_MAX);
#else
FUNC_MASK(MASK, target_ulong, 32, UINT32_MAX);
#endif
FUNC_MASK(mask_u32, uint32_t, 32, UINT32_MAX);
FUNC_MASK(mask_u64, uint64_t, 64, UINT64_MAX);

Regards
Nikunj