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review.blissroms.org / platform_bionic / 3a629af0add238c2801b64aade52ee983c9012bc / . / libm / arm / s_floor.S
blob: 44053581ea5ec13c0a0c60d5b9f2bc6ecab9d027 [file] [log] [blame]
Shu Zhang3a629af2014-07-23 16:59:22 +0800[diff] [blame^]1/*
2 * Copyright (c) 2013-2014, NVIDIA Corporation. All rights reserved.
3 * Johnny Qiu <joqiu@nvidia.com>
4 * Shu Zhang <chazhang@nvidia.com>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are
8 * met:
9 * * Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * * Redistributions in binary form must reproduce the above
12 * copyright notice, this list of conditions and the following
13 * disclaimer in the documentation and/or other materials provided
14 * with the distribution.
15 * * Neither the name of The Linux Foundation nor the names of its
16 * contributors may be used to endorse or promote products derived
17 * from this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
20 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
21 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
26 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
28 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
29 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include <float.h>
33#include <private/bionic_asm.h>
34
35ENTRY(floor) /* x in r0, r1 */
36
37 and r3, r1, #0x80000000 /* sign(x) */
38 bic r1, r1, #0x80000000 /* x = abs(x) */
39
40 /* extract exp of x */
41 lsr r2, r1, #20
42 sub r2, r2, #0x3fc
43 subs r2, r2, #0x3 /* r2 <- exp */
44
45 /* |x| < 1.0? */
46 blt .Lx_lt_one
47
48 /* x < 0? */
49 cmp r3, #0
50 bne .Lclr_frac_neg
51
52 /* |x| <= 2^20? */
53 cmp r2, #20
54 ble .Lclr_frac_r1
55
56 /* |x| < 2^52? */
57 cmp r2, #52
58 blt .Lclr_frac_r0
59
60 /* return x */
61 bx lr
62
63.Lclr_frac_r1:
64 rsb r2, r2, #20
65 lsr r1, r1, r2
66 lsl r1, r1, r2
67 mov r0, #0
68 bx lr
69
70.Lclr_frac_r0:
71 rsb r2, r2, #52
72 lsr r0, r0, r2
73 lsl r0, r0, r2
74 bx lr
75
76.Lclr_frac_neg:
77 /* |x| <= 2^20? */
78 cmp r2, #20
79 ble .Lclr_frac_r1_neg
80
81 /* |x| < 2^52? */
82 cmp r2, #52
83 blt .Lclr_frac_r0_neg
84
85 /* return x */
86 orr r1, r1, #0x80000000
87 bx lr
88
89.Lclr_frac_r1_neg:
90 rsb r2, r2, #20
91 mov r3, #1
92 lsl r3, r3, r2
93 sub r3, r3, #1
94 and r3, r1, r3
95 orr r3, r3, r0
96 lsr r1, r1, r2
97 lsl r1, r1, r2
98 mov r0, #0
99 b .Lreturn_x_neg
100
101.Lclr_frac_r0_neg:
102 rsb r2, r2, #52
103 mov r3, #1
104 lsl r3, r3, r2
105 sub r3, r3, #1
106 and r3, r0, r3
107 lsr r0, r0, r2
108 lsl r0, r0, r2
109 b .Lreturn_x_neg
110
111.Lx_lt_one:
112 /* x == +-0? */
113 cmp r0, #0
114 cmpeq r1, #0
115 orreq r1, r1, r3
116 bxeq lr
117
118 /* (x > 0) ? 0 : -1 */
119 mov r1, #0x00100000
120 mov r0, #0
121 cmp r3, #0
122 movne r1, #0xc0000000
123 sub r1, r1, #0x00100000
124 bx lr
125
126.Lreturn_x_neg:
127 cmp r3, #0
128 orr r1, r1, #0x80000000
129 bxeq lr
130
131 vmov d16, r0, r1
132 vmov.f64 d18, #1.0
133 vsub.f64 d16, d16, d18
134 vmov r0, r1, d16
135 bx lr
136
137END(floor)
138
139#if LDBL_MANT_DIG == 53
140 .weak floorl
141 .equ floorl,floor
142#endif