Re: [Qemu-devel] [Qemu-arm] [PATCH v2 33/67] target/arm: Implement SVE reverse within elements

[Richard Henderson]

On 02/23/2018 07:50 AM, Peter Maydell wrote:
> On 17 February 2018 at 18:22, Richard Henderson
> <address@hidden> wrote:
>> Signed-off-by: Richard Henderson <address@hidden>
>> ---
>>  target/arm/helper-sve.h    | 14 ++++++++++++++
>>  target/arm/sve_helper.c    | 41 ++++++++++++++++++++++++++++++++++-------
>>  target/arm/translate-sve.c | 38 ++++++++++++++++++++++++++++++++++++++
>>  target/arm/sve.decode      |  7 +++++++
>>  4 files changed, 93 insertions(+), 7 deletions(-)
> 
>> +/* Swap 16-bit words within a 32-bit word.  */
>> +static inline uint32_t hswap32(uint32_t h)
>> +{
>> +    return rol32(h, 16);
>> +}
>> +
>> +/* Swap 16-bit words within a 64-bit word.  */
>> +static inline uint64_t hswap64(uint64_t h)
>> +{
>> +    uint64_t m = 0x0000ffff0000ffffull;
>> +    h = rol64(h, 32);
>> +    return ((h & m) << 16) | ((h >> 16) & m);
>> +}
>> +
>> +/* Swap 32-bit words within a 64-bit word.  */
>> +static inline uint64_t wswap64(uint64_t h)
>> +{
>> +    return rol64(h, 32);
>> +}
>> +
> 
> Were there cases in earlier patches that could have used these? I forget.

No, the earlier patches dealt with bits not bytes.

> I guess they're not useful enough to be worth putting in bswap.h.

Probably not.

>> -static inline uint64_t hswap64(uint64_t h)
>> -{
>> -    uint64_t m = 0x0000ffff0000ffffull;
>> -    h = rol64(h, 32);
>> -    return ((h & m) << 16) | ((h >> 16) & m);
>> -}
>> -
> 
> Better to put the function in the right place to start with.

Oops, yes.


r~