xref: /titanic_41/usr/src/lib/libm/common/R/floorf.c (revision de5d74c22760a6d2cefd94d0e7f0fd87214fb71f)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
24  */
25 /*
26  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
27  * Use is subject to license terms.
28  */
29 
30 #pragma weak __ceilf = ceilf
31 #pragma weak __floorf = floorf
32 
33 /* INDENT OFF */
34 /*
35  * ceilf(x)	return the biggest integral value (in float) below x
36  * floorf(x)	return the least integral value (in float) above x
37  *
38  * NOTE: ceilf(x) and floorf(x) return result
39  * with the same sign as x's,  including 0.0F.
40  */
41 
42 #include "libm.h"
43 
44 static const float xf[] = {
45 /* ZEROF */	0.0f,
46 /* ONEF */	1.0f,
47 /* MONEF */	-1.0f,
48 /* HUGEF */	1.0e30f,
49 };
50 
51 #define	ZEROF	xf[0]
52 #define	ONEF	xf[1]
53 #define	MONEF	xf[2]
54 #define	HUGEF	xf[3]
55 /* INDENT ON */
56 
57 float
58 ceilf(float x) {
59 	volatile float dummy;
60 	int hx, k, j, ix;
61 
62 	hx = *(int *) &x;
63 	ix = hx & ~0x80000000;
64 	k = ix >> 23;
65 	if (((k - 127) ^ (k - 150)) < 0) {
66 		k = (1 << (150 - k)) - 1;
67 		if ((k & hx) != 0)
68 			dummy = HUGEF + x;	/* raise inexact */
69 		j = k & (~(hx >> 31));
70 		*(int *) &x = (hx + j) & ~k;
71 		return (x);
72 	} else if (k <= 126) {
73 		dummy = HUGEF + x;
74 		if (hx > 0)
75 			return (ONEF);
76 		else if (ix == 0)
77 			return (x);
78 		else
79 			return (-ZEROF);
80 	} else
81 		/* signal invalid if x is a SNaN */
82 		return (x * ONEF);		/* +0 -> *1 for Cheetah */
83 }
84 
85 float
86 floorf(float x) {
87 	volatile float dummy;
88 	int hx, k, j, ix;
89 
90 	hx = *(int *) &x;
91 	ix = hx & ~0x80000000;
92 	k = ix >> 23;
93 	if (((k - 127) ^ (k - 150)) < 0) {
94 		k = (1 << (150 - k)) - 1;
95 		if ((k & hx) != 0)
96 			dummy = HUGEF + x;	/* raise inexact */
97 		j = k & (hx >> 31);
98 		*(int *) &x = (hx + j) & ~k;
99 		return (x);
100 	} else if (k <= 126) {
101 		dummy = HUGEF + x;
102 		if (hx > 0)
103 			return (ZEROF);
104 		else if (ix == 0)
105 			return (x);
106 		else
107 			return (MONEF);
108 	} else
109 		/* signal invalid if x is a SNaN */
110 		return (x * ONEF);		/* +0 -> *1 for Cheetah */
111 }
112