Re: Is PSHUFW instruction MMX or SSE or SSE2? Is NASM manual correct?


"Betov" <betov@xxxxxxx> wrote in message
news:XnF9A11AD90A194Abetovfreefr@xxxxxxxxxxxxxxx
santosh <santosh.k83@xxxxxxxxx> écrivait news:fkqqhb$5v2$1
@registered.motzarella.org:

Tell you what, if you are up to it, lets do a routine to convert an
hexadecimal string (without '0x' prefix or 'h' suffix) into the
corresponding 64 bit numerical value. You do yours in assembler and
I'll do mine in C and lets compare the relative speed for a few million
passes over the test string. We can use C's clock() function or RDTSC,
whichever you prefer. Respond if you are up to it and I'll post my
version's source and test run on my machine

The problem is not with speed, nor size. It is with
readability. Recently shown C++ example:

NminusI = (i==0)? 0 : (N-i);


Something wrong with a no-conditional form?

NminusI = (N-i)*(!!i);

... meaning (we have been told):

If I = 0
NminusI = 0
Else
NminusI = DN - I
End_If


Where'd the D come from?

NminusI = N - I


Rod Pemberton

.

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