30 Jan
2011
30 Jan
'11
3:29 p.m.
On Sun, Jan 30, 2011 at 02:46:21PM +0100, Philipp Überbacher wrote:
If your machine uses BCD integers you could have some surprises...
If you don't like m <<= 1, just write m *= 2. The compiler will
very probably use a bit shift to do this even at low optimisation
levels.
Ciao,
--
FA
There are three of them, and Alleline.
Thanks, I see this now after Peter did another test
with quite different
results. I looked at it out of context because I simply don't understand
the context. I only know what a ft does but not how it works, nor have I
implemented a fft, so the code with its two-letter variables is
meaningless to me.
It's not clear if Peter's test included the '+ 1e-6'. I'd expect the
result to be correct then even with -O3. If not, increasing the added
constant should fix it.
There's
nothing funky about them, they are part of C and C++.
They were funky to me mainly because I had to look them up but also
because operating on the bit representation requires a different mode of
thinking. I bet it also has its own set of pitfalls.