21 Jan
2005
21 Jan
'05
9:36 p.m.
On Fri, 21 Jan 2005 17:17:43 +0000
Neil Klepeis <nklepeis(a)sbcglobal.net> wrote:
Hi all,
The denormal problem with freeverb/ardour on P-4's is killing me.
Since CMT plugin development seems to be a little stagnant, I decided
to take it into my own hands a bit, but I might need a little help from
a kind someone out there. Is there anyone who can give me a tip on
proper syntax for changing the denormals.h file in freeverb (assuming
this is where the problem lies)?
Details:
On this list and/or posts elsewhere I found that the denormals.h file
for freeverb doesn't work too well with some newer gcc compilers; one
recommendation was to exchange the first statement below with the second
definition:
#define undenormalise(sample) if(((*(unsigned
int*)&sample)&0x7f800000)==0) sample=0.0f
I think your mail client has wrapped something incorrectly there.
Personally , I would avoid doing this useing integer operations and I
would also avoid macros; inline functions are simply so much better.
static inline float
undenormalise(volatile float s)
{
s += 9.8607615E-32f;
return s - 9.8607615E-32f;
}
That looks OK to me, and the optimiser should not discard it because s
is volatile. Have you looked at the assembler output?
#define static inline float undenormalise(volatile
float s) { s +=
9.8607615E-32f; return s - 9.8607615E-32f; }
That is definitle WAAAAAY wrong. what you are doing there is replacing
all instances of the string "static" with "inline float ......".
You can probably see that I have no idea what I'm
doing, but this seems
like it should be so _simple_.
The static inline function you have above should be OK. Look at the
assembler output (use gcc -S to generate assembler) to make sure that
the addition and subtraction isn't being optimised out.
Maybe now is the time to go read up on C++.
There's never a good time to read up on C++
Erik
--
+-----------------------------------------------------------+
Erik de Castro Lopo nospam(a)mega-nerd.com (Yes it's valid)
+-----------------------------------------------------------+
"To me C++ seems to be a language that has sacrificed orthogonality
and elegance for random expediency." -- Meilir Page-Jones