[Ffmpeg-devel] [PATCH] SSE counterpart of ff_imdct_calc_3dn2

[Loren Merritt]

On Thu, 24 Aug 2006, Luca Barbato wrote:

> Loren Merritt wrote:
>> On Thu, 24 Aug 2006, Luca Barbato wrote:
>>
>>> Zuxy Meng wrote:
>>>
>>>> +    n = 1 << s->nbits;
>>>> +    n8 = n >> 3;
>>> [...]
>>>> +    z += n8;
>>> [...]
>>>> +    for(k = 0; k < n8; k += 2) {
>>> [...]
>>>> +        asm (
>>>> +            "movaps          %4, %%xmm0 \n\t"   // xmm0 = 0 1 2 3
>>>> +            "movaps          %5, %%xmm1 \n\t"   // xmm1 = 4 5 6 7
>>> [...]
>>>> +            :"m"(z[k]), "m"(z[-2 - k])
>>>
>>> I'm missing something or it could be unaligned?
>>> z is 8 byte not 16.
>>
>> The array index is even.
> I know
>
>> In order for n8 to be odd you'd need an 8
>> element fft.
>
> I need an odd multiple of 8

But fft size can only be a power of 2.

--Loren Merritt