jehanne/qa/kern/float.c

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#include <u.h>
#include <lib9.h>
#define DPRECSTR "0.0000004000000000125"
#define DPREC 0.0000004000000000125
#define DIEEELO 0x9ac0499f
#define DIEEEHI 0x3e9ad7f2
jmp_buf errj;
char *err;
void
catcher(void *u, char *s)
{
err = 0;
if(strncmp(s, "sys: fp:", 8) == 0){
err = s;
notejmp(u, errj, 0);
}
noted(NDFLT);
}
void
tstdiv(double p)
{
double r = 1.0;
r /= p;
fprint(2, "1/%0.20g = %0.20g\n", p, r);
}
typedef union I2UL
{
int d[2];
unsigned long l;
}I2UL;
typedef union D2UL
{
double d;
unsigned long l;
}D2UL;
void
main(void)
{
double p = DPREC;
int d[2] = { DIEEELO, DIEEEHI };
I2UL i2l;
D2UL d2l;
uint64_t dieee, q;
i2l.d[0] = d[0];
i2l.d[1] = d[1];
dieee = i2l.l;
d2l.d = p;
q = d2l.l;
err = 0;
notify(catcher);
setjmp(errj);
if(err){
fprint(2, "FAIL: %s\n", err);
exits("FAIL");
}
fprint(2, "Double-precision test number: %s\n", DPRECSTR);
fprint(2, "Expected internal representation: %ullx\n", dieee);
fprint(2, "Actual internal representation: %ullx\n", q);
if(q != dieee) {
print("FAIL\n");
exits("FAIL");
}
tstdiv(p);
print("PASS\n");
exits("PASS");
}