source: trunk/libs/newlib/src/newlib/libm/mathfp/s_floor.c @ 503

Last change on this file since 503 was 444, checked in by satin@…, 6 years ago

add newlib,libalmos-mkh, restructure shared_syscalls.h and mini-libc
File size: 1.4 KB
Line 
1
2/* @(#)z_floor.c 1.0 98/08/13 */
3
4/*
5FUNCTION
6<<floor>>, <<floorf>>, <<ceil>>, <<ceilf>>---floor and ceiling
7INDEX
8        floor
9INDEX
10        floorf
11INDEX
12        ceil
13INDEX
14        ceilf
15
16SYNOPSIS
17        #include <math.h>
18        double floor(double <[x]>);
19        float floorf(float <[x]>);
20        double ceil(double <[x]>);
21        float ceilf(float <[x]>);
22
23DESCRIPTION
24<<floor>> and <<floorf>> find
25@tex
26$\lfloor x \rfloor$,
27@end tex
28the nearest integer less than or equal to <[x]>.
29<<ceil>> and <<ceilf>> find
30@tex
31$\lceil x\rceil$,
32@end tex
33the nearest integer greater than or equal to <[x]>.
34
35RETURNS
36<<floor>> and <<ceil>> return the integer result as a double.
37<<floorf>> and <<ceilf>> return the integer result as a float.
38
39PORTABILITY
40<<floor>> and <<ceil>> are ANSI.
41<<floorf>> and <<ceilf>> are extensions.
42
43*/
44
45/*****************************************************************
46 * floor
47 *
48 * Input:
49 *   x  - floating point value
50 *
51 * Output:
52 *   Smallest integer less than x.
53 *
54 * Description:
55 *   This routine returns the smallest integer less than x.
56 *
57 *****************************************************************/
58
59#include "fdlibm.h"
60#include "zmath.h"
61
62#ifndef _DOUBLE_IS_32BITS
63
64double 
65floor (double x)
66{
67  double f, y;
68
69  if (x > -1.0 && x < 1.0)
70    return (x >= 0 ? 0 : -1.0);
71
72  y = modf (x, &f);
73
74  if (y == 0.0)
75    return (x);
76
77  return (x >= 0 ? f : f - 1.0);
78}
79
80#endif /* _DOUBLE_IS_32BITS */
Note: See TracBrowser for help on using the repository browser.