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Diffstat (limited to 'arch/parisc/math-emu/dfcmp.c')
-rw-r--r-- | arch/parisc/math-emu/dfcmp.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/arch/parisc/math-emu/dfcmp.c b/arch/parisc/math-emu/dfcmp.c new file mode 100644 index 000000000000..59521267ffcc --- /dev/null +++ b/arch/parisc/math-emu/dfcmp.c | |||
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1 | /* | ||
2 | * Linux/PA-RISC Project (http://www.parisc-linux.org/) | ||
3 | * | ||
4 | * Floating-point emulation code | ||
5 | * Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org> | ||
6 | * | ||
7 | * This program is free software; you can redistribute it and/or modify | ||
8 | * it under the terms of the GNU General Public License as published by | ||
9 | * the Free Software Foundation; either version 2, or (at your option) | ||
10 | * any later version. | ||
11 | * | ||
12 | * This program is distributed in the hope that it will be useful, | ||
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
15 | * GNU General Public License for more details. | ||
16 | * | ||
17 | * You should have received a copy of the GNU General Public License | ||
18 | * along with this program; if not, write to the Free Software | ||
19 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | ||
20 | */ | ||
21 | /* | ||
22 | * BEGIN_DESC | ||
23 | * | ||
24 | * File: | ||
25 | * @(#) pa/spmath/dfcmp.c $Revision: 1.1 $ | ||
26 | * | ||
27 | * Purpose: | ||
28 | * dbl_cmp: compare two values | ||
29 | * | ||
30 | * External Interfaces: | ||
31 | * dbl_fcmp(leftptr, rightptr, cond, status) | ||
32 | * | ||
33 | * Internal Interfaces: | ||
34 | * | ||
35 | * Theory: | ||
36 | * <<please update with a overview of the operation of this file>> | ||
37 | * | ||
38 | * END_DESC | ||
39 | */ | ||
40 | |||
41 | |||
42 | |||
43 | #include "float.h" | ||
44 | #include "dbl_float.h" | ||
45 | |||
46 | /* | ||
47 | * dbl_cmp: compare two values | ||
48 | */ | ||
49 | int | ||
50 | dbl_fcmp (dbl_floating_point * leftptr, dbl_floating_point * rightptr, | ||
51 | unsigned int cond, unsigned int *status) | ||
52 | |||
53 | /* The predicate to be tested */ | ||
54 | |||
55 | { | ||
56 | register unsigned int leftp1, leftp2, rightp1, rightp2; | ||
57 | register int xorresult; | ||
58 | |||
59 | /* Create local copies of the numbers */ | ||
60 | Dbl_copyfromptr(leftptr,leftp1,leftp2); | ||
61 | Dbl_copyfromptr(rightptr,rightp1,rightp2); | ||
62 | /* | ||
63 | * Test for NaN | ||
64 | */ | ||
65 | if( (Dbl_exponent(leftp1) == DBL_INFINITY_EXPONENT) | ||
66 | || (Dbl_exponent(rightp1) == DBL_INFINITY_EXPONENT) ) | ||
67 | { | ||
68 | /* Check if a NaN is involved. Signal an invalid exception when | ||
69 | * comparing a signaling NaN or when comparing quiet NaNs and the | ||
70 | * low bit of the condition is set */ | ||
71 | if( ((Dbl_exponent(leftp1) == DBL_INFINITY_EXPONENT) | ||
72 | && Dbl_isnotzero_mantissa(leftp1,leftp2) | ||
73 | && (Exception(cond) || Dbl_isone_signaling(leftp1))) | ||
74 | || | ||
75 | ((Dbl_exponent(rightp1) == DBL_INFINITY_EXPONENT) | ||
76 | && Dbl_isnotzero_mantissa(rightp1,rightp2) | ||
77 | && (Exception(cond) || Dbl_isone_signaling(rightp1))) ) | ||
78 | { | ||
79 | if( Is_invalidtrap_enabled() ) { | ||
80 | Set_status_cbit(Unordered(cond)); | ||
81 | return(INVALIDEXCEPTION); | ||
82 | } | ||
83 | else Set_invalidflag(); | ||
84 | Set_status_cbit(Unordered(cond)); | ||
85 | return(NOEXCEPTION); | ||
86 | } | ||
87 | /* All the exceptional conditions are handled, now special case | ||
88 | NaN compares */ | ||
89 | else if( ((Dbl_exponent(leftp1) == DBL_INFINITY_EXPONENT) | ||
90 | && Dbl_isnotzero_mantissa(leftp1,leftp2)) | ||
91 | || | ||
92 | ((Dbl_exponent(rightp1) == DBL_INFINITY_EXPONENT) | ||
93 | && Dbl_isnotzero_mantissa(rightp1,rightp2)) ) | ||
94 | { | ||
95 | /* NaNs always compare unordered. */ | ||
96 | Set_status_cbit(Unordered(cond)); | ||
97 | return(NOEXCEPTION); | ||
98 | } | ||
99 | /* infinities will drop down to the normal compare mechanisms */ | ||
100 | } | ||
101 | /* First compare for unequal signs => less or greater or | ||
102 | * special equal case */ | ||
103 | Dbl_xortointp1(leftp1,rightp1,xorresult); | ||
104 | if( xorresult < 0 ) | ||
105 | { | ||
106 | /* left negative => less, left positive => greater. | ||
107 | * equal is possible if both operands are zeros. */ | ||
108 | if( Dbl_iszero_exponentmantissa(leftp1,leftp2) | ||
109 | && Dbl_iszero_exponentmantissa(rightp1,rightp2) ) | ||
110 | { | ||
111 | Set_status_cbit(Equal(cond)); | ||
112 | } | ||
113 | else if( Dbl_isone_sign(leftp1) ) | ||
114 | { | ||
115 | Set_status_cbit(Lessthan(cond)); | ||
116 | } | ||
117 | else | ||
118 | { | ||
119 | Set_status_cbit(Greaterthan(cond)); | ||
120 | } | ||
121 | } | ||
122 | /* Signs are the same. Treat negative numbers separately | ||
123 | * from the positives because of the reversed sense. */ | ||
124 | else if(Dbl_isequal(leftp1,leftp2,rightp1,rightp2)) | ||
125 | { | ||
126 | Set_status_cbit(Equal(cond)); | ||
127 | } | ||
128 | else if( Dbl_iszero_sign(leftp1) ) | ||
129 | { | ||
130 | /* Positive compare */ | ||
131 | if( Dbl_allp1(leftp1) < Dbl_allp1(rightp1) ) | ||
132 | { | ||
133 | Set_status_cbit(Lessthan(cond)); | ||
134 | } | ||
135 | else if( Dbl_allp1(leftp1) > Dbl_allp1(rightp1) ) | ||
136 | { | ||
137 | Set_status_cbit(Greaterthan(cond)); | ||
138 | } | ||
139 | else | ||
140 | { | ||
141 | /* Equal first parts. Now we must use unsigned compares to | ||
142 | * resolve the two possibilities. */ | ||
143 | if( Dbl_allp2(leftp2) < Dbl_allp2(rightp2) ) | ||
144 | { | ||
145 | Set_status_cbit(Lessthan(cond)); | ||
146 | } | ||
147 | else | ||
148 | { | ||
149 | Set_status_cbit(Greaterthan(cond)); | ||
150 | } | ||
151 | } | ||
152 | } | ||
153 | else | ||
154 | { | ||
155 | /* Negative compare. Signed or unsigned compares | ||
156 | * both work the same. That distinction is only | ||
157 | * important when the sign bits differ. */ | ||
158 | if( Dbl_allp1(leftp1) > Dbl_allp1(rightp1) ) | ||
159 | { | ||
160 | Set_status_cbit(Lessthan(cond)); | ||
161 | } | ||
162 | else if( Dbl_allp1(leftp1) < Dbl_allp1(rightp1) ) | ||
163 | { | ||
164 | Set_status_cbit(Greaterthan(cond)); | ||
165 | } | ||
166 | else | ||
167 | { | ||
168 | /* Equal first parts. Now we must use unsigned compares to | ||
169 | * resolve the two possibilities. */ | ||
170 | if( Dbl_allp2(leftp2) > Dbl_allp2(rightp2) ) | ||
171 | { | ||
172 | Set_status_cbit(Lessthan(cond)); | ||
173 | } | ||
174 | else | ||
175 | { | ||
176 | Set_status_cbit(Greaterthan(cond)); | ||
177 | } | ||
178 | } | ||
179 | } | ||
180 | return(NOEXCEPTION); | ||
181 | } | ||