1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
|
.file "significandl.s"
// Copyright (C) 2000, 2001, Intel Corporation
// All rights reserved.
//
// Contributed 2/2/2000 by John Harrison, Ted Kubaska, Bob Norin, Shane Story,
// and Ping Tak Peter Tang of the Computational Software Lab, Intel Corporation.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//
// * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// * The name of Intel Corporation may not be used to endorse or promote
// products derived from this software without specific prior written
// permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTEL OR ITS
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
// OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY OR TORT (INCLUDING
// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Intel Corporation is the author of this code, and requests that all
// problem reports or change requests be submitted to it directly at
// http://developer.intel.com/opensource.
//
// History
//==============================================================
// 2/02/00: Initial version
// 2/03/00: Modified to improve speed
// 5/31/00: Fixed bug when x a double-extended denormal
//
// API
//==============================================================
// long double significandl(long double x)
//
// Overview of operation
//==============================================================
// If x = sig * 2**n with 1 <= sig < 2
// significandl returns sig
//
// predicate registers used:
// p6, p7
//
// floating-point registers used:
// f8, f9, f10
#include "libm_support.h"
.align 32
.global significandl#
.section .text
.proc significandl#
.align 32
significandl:
// qnan snan inf norm unorm 0 -+
// 1 1 1 0 0 1 11
// f10 gets f8(sign) with f1(exp,significand)
{ .mfi
nop.m 999
(p0) fmerge.s f10 = f8,f1
nop.i 999
}
{ .mfi
nop.m 999
(p0) fnorm f9 = f8
nop.i 999 ;;
}
// Test for denormal input
{ .mfi
nop.m 999
(p0) fclass.m.unc p7,p0 = f8, 0x0b
nop.i 999 ;;
}
// p6 = TRUE ==> x is not (nan,inf,0)
// return sign(f8) exp(f1) significand(f8)
// else x is (nan,inf,0)
// return sign(f8) exp(f8) significand(f8), normalized.
{ .mfi
nop.m 999
(p0) fclass.m.unc p0,p6 = f8, 0xe7
nop.i 999 ;;
}
{ .mmb
nop.m 999
nop.m 999
(p7) br.cond.spnt L(SIGNIFICAND_DENORM) ;; // Branch if x denormal
}
{ .mfi
nop.m 999
(p6) fmerge.se f8 = f10,f8
nop.i 999 ;;
}
{ .mfb
nop.m 999
(p0) fnorm f8 = f8
(p0) br.ret.sptk b0 ;;
}
L(SIGNIFICAND_DENORM):
// Here if x denorm
{ .mfi
nop.m 999
(p0) fmerge.se f8 = f10,f9
nop.i 999 ;;
}
// Check if fnorm(x) still denormal, means x double-extended denormal
{ .mfi
nop.m 999
(p0) fclass.m.unc p7,p0 = f9, 0x0b
nop.i 999 ;;
}
// This will be the final result unless x double-extended denormal
{ .mfi
nop.m 999
(p0) fnorm f8 = f8
nop.i 999 ;;
}
// If x double-extended denorm, then significand ok, but must merge in
// correct signexp
{ .mfi
nop.m 999
(p7) fmerge.se f8 = f10,f8
nop.i 999 ;;
}
// Final normalization if x double-extended denorm
{ .mfb
nop.m 999
(p7) fnorm f8 = f8
(p0) br.ret.sptk b0 ;;
}
.endp significandl
ASM_SIZE_DIRECTIVE(significandl)
|
