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/* Test of lround() function.
$Id: lround-01.c,v 1.2.2.1 2008/03/20 21:42:30 joerg_wunsch Exp $
*/
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include "progmem.h"
#ifndef __AVR__
# define PRINTFLN(line, fmt, ...) \
printf ("\nLine %d: " fmt "\n", line, ##__VA_ARGS__)
# define EXIT(code) exit ((code) < 255 ? (code) : 100 + (code) % 100)
#else
# if defined(__AVR_ATmega128__)
/* ATmega128 has enough RAM for sprintf(), print to 0x2000 in XRAM. */
# define PRINTFLN(line, fmt, ...) \
sprintf ((char *)0x2000, "\nLine %d: " fmt "\n", line, ##__VA_ARGS__)
# else
/* small AVR */
# define PRINTFLN(args...)
# endif
# define EXIT exit
#endif
union lofl_u {
long lo;
float fl;
};
/* Result is placed into SRAM variable, allocated at the start of
memory. This is convinient to debug: read a core dump. */
volatile long v = 1;
PROGMEM const struct { /* Table of test cases. */
union lofl_u x; /* argument */
long z; /* result */
} t[] = {
/* Zero */
{ { .fl= +0.0 }, 0 },
{ { .fl= -0.0 }, 0 },
/* A few of normal values */
{ { .fl= 0.1 }, 0 },
{ { .fl= 0.5 }, 1 },
{ { .fl= 0.9 }, 1 },
{ { .fl= 1.49999 }, 1 },
{ { .fl= 1.5 }, 2 },
{ { .fl= 1.9 }, 2 },
{ { .fl= 2.5 }, 3 },
{ { .fl= 1000000.5 }, 1000001 },
{ { .fl= -0.1 }, 0 },
{ { .fl= -0.5 }, -1 },
{ { .fl= -0.9 }, -1 },
{ { .fl= -1.49999 }, -1 },
{ { .fl= -1.5 }, -2 },
{ { .fl= -1.9 }, -2 },
{ { .fl= -2.5 }, -3 },
{ { .fl= -1000000.5 }, -1000001 },
/* Subnormal */
{ { 0x00000001 }, 0 },
{ { 0x00000100 }, 0 },
{ { 0x00010000 }, 0 },
{ { 0x007fffff }, 0 },
{ { 0x80000001 }, 0 },
{ { 0x80000100 }, 0 },
{ { 0x80010000 }, 0 },
{ { 0x807fffff }, 0 },
/* Margin values (positive). */
{ { 0x00800000 }, 0 }, /* the smallest nonzero normal */
{ { 0x3effffff }, 0 },
{ { 0x3f000000 }, 1 }, /* 0.5 */
{ { 0x3f000001 }, 1 },
{ { 0x3f7fffff }, 1 },
{ { 0x3f800000 }, 1 }, /* 1.0 */
{ { 0x3f800001 }, 1 },
{ { 0x3fbfffff }, 1 },
{ { 0x3fc00000 }, 2 }, /* 1.5 */
{ { 0x3fc00001 }, 2 },
{ { 0x401fffff }, 2 },
{ { 0x40200000 }, 3 }, /* 2.5 */
{ { 0x40200001 }, 3 },
{ { .fl= 0x0.fffffep+23 }, 0x7fffff },
{ { .fl= 0x0.ffffffp+23 }, 0x800000 },
{ { .fl= 0x1.000000p+23 }, 0x800000 },
{ { .fl= 0x0.ffffffp+31 }, 0x7fffff80 }, /* near overflow */
/* Margin values (negative). */
{ { 0x80800000 }, 0 }, /* the smallest nonzero normal */
{ { 0xbeffffff }, 0 },
{ { 0xbf000000 }, -1 }, /* -0.5 */
{ { 0xbf000001 }, -1 },
{ { 0xbf7fffff }, -1 },
{ { 0xbf800000 }, -1 }, /* -1.0 */
{ { 0xbf800001 }, -1 },
{ { 0xbfbfffff }, -1 },
{ { 0xbfc00000 }, -2 }, /* -1.5 */
{ { 0xbfc00001 }, -2 },
{ { 0xc01fffff }, -2 },
{ { 0xc0200000 }, -3 }, /* -2.5 */
{ { 0xc0200001 }, -3 },
{ { .fl= -0x0.fffffep+23 }, -0x7fffffL },
{ { .fl= -0x0.ffffffp+23 }, -0x800000L },
{ { .fl= -0x1.000000p+23 }, -0x800000L },
{ { .fl= -0x0.ffffffp+31 }, -0x7fffff80L }, /* near overflow */
{ { .fl= -0x1.000000p+31 }, 0x80000000L },
/* In addition to main(): shift 0xffffff to left . */
{ { .fl= 0x0.ffffffp+24 }, 0x00ffffff },
{ { .fl= 0x0.ffffffp+25 }, 0x01fffffe },
{ { .fl= 0x0.ffffffp+26 }, 0x03fffffc },
{ { .fl= 0x0.ffffffp+27 }, 0x07fffff8 },
{ { .fl= 0x0.ffffffp+28 }, 0x0ffffff0 },
{ { .fl= 0x0.ffffffp+29 }, 0x1fffffe0 },
{ { .fl= 0x0.ffffffp+30 }, 0x3fffffc0 },
{ { .fl= 0x0.ffffffp+31 }, 0x7fffff80 },
{ { .fl= -0x0.ffffffp+24 }, -0x00ffffffL },
{ { .fl= -0x0.ffffffp+25 }, -0x01fffffeL },
{ { .fl= -0x0.ffffffp+26 }, -0x03fffffcL },
{ { .fl= -0x0.ffffffp+27 }, -0x07fffff8L },
{ { .fl= -0x0.ffffffp+28 }, -0x0ffffff0L },
{ { .fl= -0x0.ffffffp+29 }, -0x1fffffe0L },
{ { .fl= -0x0.ffffffp+30 }, -0x3fffffc0L },
{ { .fl= -0x0.ffffffp+31 }, -0x7fffff80L },
/* Positive overflow */
{ { .fl= 0x0.800000p+32 }, 0x80000000 },
{ { .fl= 0x0.800001p+32 }, 0x80000000 },
{ { .fl= 0x0.ffffffp+32 }, 0x80000000 },
{ { .fl= 0x0.800000p+33 }, 0x80000000 },
{ { .fl= 0x0.ffffffp+33 }, 0x80000000 },
{ { .lo= 0x7f000000 }, 0x80000000 },
{ { .lo= 0x7f7fffff }, 0x80000000 },
{ { .lo= 0x7f800000 }, 0x80000000 }, /* +Inf */
/* Negative overflow */
{ { .fl= -0x0.800000p+32 }, 0x80000000 }, /* no overflow */
{ { .fl= -0x0.800001p+32 }, 0x80000000 },
{ { .fl= -0x0.ffffffp+32 }, 0x80000000 },
{ { .fl= -0x0.800000p+33 }, 0x80000000 },
{ { .fl= -0x0.ffffffp+33 }, 0x80000000 },
{ { .lo= 0xff000000 }, 0x80000000 },
{ { .lo= 0xff7fffff }, 0x80000000 },
{ { .lo= 0xff800000 }, 0x80000000 }, /* -Inf */
/* NaN */
{ { 0x7f800001 }, 0x80000000 },
{ { 0x7fc00000 }, 0x80000000 },
{ { 0x7fffffff }, 0x80000000 },
{ { 0xff800001 }, 0x80000000 },
{ { 0xffc00000 }, 0x80000000 },
{ { 0xffffffff }, 0x80000000 },
};
void x_exit (int index)
{
#ifndef __AVR__
fprintf (stderr, "t[%d]: %#lx\n", index - 1, v);
#endif
exit (index ? index : -1);
}
int main ()
{
union lofl_u x;
long z;
int i;
/* Table. */
for (i = 0; i < (int) (sizeof(t) / sizeof(t[0])); i++) {
x.lo = pgm_read_dword (& t[i].x);
z = pgm_read_dword (& t[i].z);
v = lround (x.fl);
if (v != z)
x_exit (i+1);
}
/* Check all possible shifts. Rounding is not needed. Both signs.
0x0.800000p+01 --> 1
0x0.800000p+02 --> 2
...
0x0.800000p+31 --> 0x40000000 */
for (x.fl = 1.0, i = 0; i < 31; i++) {
v = lround (x.fl);
if (v != (1L << i)) {
PRINTFLN (__LINE__, "i= %d v= %#lx", i, v);
EXIT (100 + i);
}
/* Change sign to minus. */
x.lo |= 0x80000000;
v = lround (x.fl);
if (v != -(1L << i)) {
PRINTFLN (__LINE__, "i= %d v= %#lx", i, v);
EXIT (200 + i);
}
/* Change sign again and increment exponent. */
x.lo += 0x80800000;
}
/* Check all possible shits with rounding.
0x0.c00000p+01 --> 2 1.5
0x0.a00000p+02 --> 3 2.5
0x0.900000p+03 --> 5 4.5
...
0x0.800001p+23 --> 0x400001 */
for (i = 1; i < 24; i++) {
x.fl = 1.0;
x.lo += (0x800000 * (i-1)); /* exponent */
x.lo |= (0x800000 >> i); /* += 0.5 */
v = lround (x.fl);
if (v != (1L << (i-1)) + 1) {
PRINTFLN (__LINE__, "i= %d v= %#lx", i, v);
EXIT (300 + i);
}
}
/* Rounding with carry. All possible shifts to right. Both signs.
0x0.ffffffp+00 --> 1
0x0.ffffffp+01 --> 2
...
0x0.ffffffp+23 --> 0x800000 */
for (x.fl = 0x0.ffffffp+00, i = 0; i < 24; i++) {
v = lround (x.fl);
if (v != (1L << i)) {
PRINTFLN (__LINE__, "i= %d v= %#lx", i, v);
EXIT (400 + i);
}
/* Change sign to minus. */
x.lo |= 0x80000000;
v = lround (x.fl);
if (v != -(1L << i)) {
PRINTFLN (__LINE__, "i= %d v= %#lx", i, v);
EXIT (500 + i);
}
/* Change sign again and increment exponent. */
x.lo += 0x80800000;
}
return 0;
}
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