Re: [Chicken-hackers] Fix solaris9 build for missing trunc, round, isinf math functions

[Florian Zumbiehl]

Hi,

> I've spotted an error in the patch.
> 
> static inline double trunc(double x) { return (x > 0 ? floor(x) :
> floor(x) + 1); }
> 
> should be:
> 
> static inline double trunc(double x) { return (x >= 0 ? floor(x) :
> floor(x) + 1); }

| $ cat foo.c
| 
| #include <stdio.h>
| #include <math.h>
| 
| double trunc_x(double x) { return (x >= 0 ? floor(x) : floor(x) + 1); }
| double round_x(double x) { return (x - floor(x) >= 0.5 ? floor(x) + 1 : 
floor(x)); }
| 
| int main(){
|         printf("%f %f\n",trunc(-42),trunc_x(-42));
|         printf("%f %f\n",round(-42.5),round_x(-42.5));
| }
| 
| $ gcc -lm -o foo foo.c && ./foo
| -42.000000 -41.000000
| -43.000000 -42.000000

AFAICT, there are a few more bugs in there, in particular in the handling
of infinities and NaN, and I think even the number handling is incorrect in
more corner cases, but I currently don't have the time to think about that
in detail.

Florian