[PD] Lost at compilig cyclone ;-((((

[Krzysztof Czaja]

hi Guenter,

this fails, though:

int result[25];

void pass1(void)
{
     int i;
     float f = 0.0001, *fp = &f;

     for (i=0;i<25;i++) {
         *fp*=0.0001;
         if (PD_BADFLOAT(*fp)) result[i] = 1;
         else result[i] = 0;
     }
}

void pass2(void)
{
     int i;
     float f = 0.0001;
     for (i=0;i<25;i++) {
         f*=0.0001;
         if (result[i]) printf("%d badfloat %g %08x\n",i,f,*(int*)&f);
         else printf("%d goodfloat %g %08x\n",i,f,*(int*)&f);
     }
}

If compiled with "gcc-3.3 -O6...", you will get:

...
8 goodfloat 9.99995e-41 000116c2
9 goodfloat 9.80909e-45 00000007
...

while without "-O6" it works ok.  The bottom line is, that I do not
know the rules (if there are any).

Krzysztof

guenter geiger wrote:
...
> I just tested this with gcc 3.3.4 from Debian and it seems to work.