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softfloat.h
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1 
2 /*
3 ===============================================================================
4 
5 This C header file is part of the SoftFloat IEC/IEEE Floating-point
6 Arithmetic Package, Release 2.
7 
8 Written by John R. Hauser. This work was made possible in part by the
9 International Computer Science Institute, located at Suite 600, 1947 Center
10 Street, Berkeley, California 94704. Funding was partially provided by the
11 National Science Foundation under grant MIP-9311980. The original version
12 of this code was written as part of a project to build a fixed-point vector
13 processor in collaboration with the University of California at Berkeley,
14 overseen by Profs. Nelson Morgan and John Wawrzynek. More information
15 is available through the Web page
16 http://www.jhauser.us/arithmetic/SoftFloat-2b/SoftFloat-source.txt
17 
18 THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE. Although reasonable effort
19 has been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT WILL AT
20 TIMES RESULT IN INCORRECT BEHAVIOR. USE OF THIS SOFTWARE IS RESTRICTED TO
21 PERSONS AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ANY
22 AND ALL LOSSES, COSTS, OR OTHER PROBLEMS ARISING FROM ITS USE.
23 
24 Derivative works are acceptable, even for commercial purposes, so long as
25 (1) they include prominent notice that the work is derivative, and (2) they
26 include prominent notice akin to these three paragraphs for those parts of
27 this code that are retained.
28 
29 ===============================================================================
30 */
31 
32 #ifndef __SOFTFLOAT_H__
33 #define __SOFTFLOAT_H__
34 
35 
36 /*
37 -------------------------------------------------------------------------------
38 The macro `FLOATX80' must be defined to enable the extended double-precision
39 floating-point format `floatx80'. If this macro is not defined, the
40 `floatx80' type will not be defined, and none of the functions that either
41 input or output the `floatx80' type will be defined.
42 -------------------------------------------------------------------------------
43 */
44 #ifdef CONFIG_FPE_NWFPE_XP
45 #define FLOATX80
46 #endif
47 
48 /*
49 -------------------------------------------------------------------------------
50 Software IEC/IEEE floating-point types.
51 -------------------------------------------------------------------------------
52 */
53 typedef u32 float32;
54 typedef u64 float64;
55 typedef struct {
56 #ifdef __ARMEB__
57  u16 __padding;
58  u16 high;
59 #else
60  u16 high;
61  u16 __padding;
62 #endif
63  u64 low;
64 } __attribute__ ((packed,aligned(4))) floatx80;
65 
66 /*
67 -------------------------------------------------------------------------------
68 Software IEC/IEEE floating-point underflow tininess-detection mode.
69 -------------------------------------------------------------------------------
70 */
71 extern signed char float_detect_tininess;
72 enum {
73  float_tininess_after_rounding = 0,
74  float_tininess_before_rounding = 1
75 };
76 
77 /*
78 -------------------------------------------------------------------------------
79 Software IEC/IEEE floating-point rounding mode.
80 -------------------------------------------------------------------------------
81 */
82 //extern int8 float_rounding_mode;
83 enum {
84  float_round_nearest_even = 0,
85  float_round_to_zero = 1,
86  float_round_down = 2,
87  float_round_up = 3
88 };
89 
90 /*
91 -------------------------------------------------------------------------------
92 Software IEC/IEEE floating-point exception flags.
93 -------------------------------------------------------------------------------
94 enum {
95  float_flag_inexact = 1,
96  float_flag_underflow = 2,
97  float_flag_overflow = 4,
98  float_flag_divbyzero = 8,
99  float_flag_invalid = 16
100 };
101 
102 ScottB: November 4, 1998
103 Changed the enumeration to match the bit order in the FPA11.
104 */
105 
106 enum {
107  float_flag_invalid = 1,
108  float_flag_divbyzero = 2,
109  float_flag_overflow = 4,
110  float_flag_underflow = 8,
111  float_flag_inexact = 16
112 };
113 
114 /*
115 -------------------------------------------------------------------------------
116 Routine to raise any or all of the software IEC/IEEE floating-point
117 exception flags.
118 -------------------------------------------------------------------------------
119 */
120 void float_raise( signed char );
121 
122 /*
123 -------------------------------------------------------------------------------
124 Software IEC/IEEE integer-to-floating-point conversion routines.
125 -------------------------------------------------------------------------------
126 */
127 float32 int32_to_float32( struct roundingData *, signed int );
128 float64 int32_to_float64( signed int );
129 #ifdef FLOATX80
130 floatx80 int32_to_floatx80( signed int );
131 #endif
132 
133 /*
134 -------------------------------------------------------------------------------
135 Software IEC/IEEE single-precision conversion routines.
136 -------------------------------------------------------------------------------
137 */
138 signed int float32_to_int32( struct roundingData *, float32 );
139 signed int float32_to_int32_round_to_zero( float32 );
140 float64 float32_to_float64( float32 );
141 #ifdef FLOATX80
142 floatx80 float32_to_floatx80( float32 );
143 #endif
144 
145 /*
146 -------------------------------------------------------------------------------
147 Software IEC/IEEE single-precision operations.
148 -------------------------------------------------------------------------------
149 */
150 float32 float32_round_to_int( struct roundingData*, float32 );
151 float32 float32_add( struct roundingData *, float32, float32 );
152 float32 float32_sub( struct roundingData *, float32, float32 );
153 float32 float32_mul( struct roundingData *, float32, float32 );
154 float32 float32_div( struct roundingData *, float32, float32 );
155 float32 float32_rem( struct roundingData *, float32, float32 );
156 float32 float32_sqrt( struct roundingData*, float32 );
157 char float32_eq( float32, float32 );
158 char float32_le( float32, float32 );
159 char float32_lt( float32, float32 );
160 char float32_eq_signaling( float32, float32 );
161 char float32_le_quiet( float32, float32 );
162 char float32_lt_quiet( float32, float32 );
163 char float32_is_signaling_nan( float32 );
164 
165 /*
166 -------------------------------------------------------------------------------
167 Software IEC/IEEE double-precision conversion routines.
168 -------------------------------------------------------------------------------
169 */
170 signed int float64_to_int32( struct roundingData *, float64 );
171 signed int float64_to_int32_round_to_zero( float64 );
172 float32 float64_to_float32( struct roundingData *, float64 );
173 #ifdef FLOATX80
174 floatx80 float64_to_floatx80( float64 );
175 #endif
176 
177 /*
178 -------------------------------------------------------------------------------
179 Software IEC/IEEE double-precision operations.
180 -------------------------------------------------------------------------------
181 */
182 float64 float64_round_to_int( struct roundingData *, float64 );
183 float64 float64_add( struct roundingData *, float64, float64 );
184 float64 float64_sub( struct roundingData *, float64, float64 );
185 float64 float64_mul( struct roundingData *, float64, float64 );
186 float64 float64_div( struct roundingData *, float64, float64 );
187 float64 float64_rem( struct roundingData *, float64, float64 );
188 float64 float64_sqrt( struct roundingData *, float64 );
189 char float64_eq( float64, float64 );
190 char float64_le( float64, float64 );
191 char float64_lt( float64, float64 );
192 char float64_eq_signaling( float64, float64 );
193 char float64_le_quiet( float64, float64 );
194 char float64_lt_quiet( float64, float64 );
195 char float64_is_signaling_nan( float64 );
196 
197 #ifdef FLOATX80
198 
199 /*
200 -------------------------------------------------------------------------------
201 Software IEC/IEEE extended double-precision conversion routines.
202 -------------------------------------------------------------------------------
203 */
204 signed int floatx80_to_int32( struct roundingData *, floatx80 );
205 signed int floatx80_to_int32_round_to_zero( floatx80 );
206 float32 floatx80_to_float32( struct roundingData *, floatx80 );
207 float64 floatx80_to_float64( struct roundingData *, floatx80 );
208 
209 /*
210 -------------------------------------------------------------------------------
211 Software IEC/IEEE extended double-precision operations.
212 -------------------------------------------------------------------------------
213 */
214 floatx80 floatx80_round_to_int( struct roundingData *, floatx80 );
215 floatx80 floatx80_add( struct roundingData *, floatx80, floatx80 );
216 floatx80 floatx80_sub( struct roundingData *, floatx80, floatx80 );
217 floatx80 floatx80_mul( struct roundingData *, floatx80, floatx80 );
218 floatx80 floatx80_div( struct roundingData *, floatx80, floatx80 );
219 floatx80 floatx80_rem( struct roundingData *, floatx80, floatx80 );
220 floatx80 floatx80_sqrt( struct roundingData *, floatx80 );
221 char floatx80_eq( floatx80, floatx80 );
222 char floatx80_le( floatx80, floatx80 );
223 char floatx80_lt( floatx80, floatx80 );
224 char floatx80_eq_signaling( floatx80, floatx80 );
225 char floatx80_le_quiet( floatx80, floatx80 );
226 char floatx80_lt_quiet( floatx80, floatx80 );
227 char floatx80_is_signaling_nan( floatx80 );
228 
229 extern flag floatx80_is_nan(floatx80);
230 
231 #endif
232 
233 static inline flag extractFloat32Sign(float32 a)
234 {
235  return a >> 31;
236 }
237 
238 static inline flag float32_eq_nocheck(float32 a, float32 b)
239 {
240  return (a == b) || ((bits32) ((a | b) << 1) == 0);
241 }
242 
243 static inline flag float32_lt_nocheck(float32 a, float32 b)
244 {
245  flag aSign, bSign;
246 
247  aSign = extractFloat32Sign(a);
248  bSign = extractFloat32Sign(b);
249  if (aSign != bSign)
250  return aSign && ((bits32) ((a | b) << 1) != 0);
251  return (a != b) && (aSign ^ (a < b));
252 }
253 
254 static inline flag extractFloat64Sign(float64 a)
255 {
256  return a >> 63;
257 }
258 
259 static inline flag float64_eq_nocheck(float64 a, float64 b)
260 {
261  return (a == b) || ((bits64) ((a | b) << 1) == 0);
262 }
263 
264 static inline flag float64_lt_nocheck(float64 a, float64 b)
265 {
266  flag aSign, bSign;
267 
268  aSign = extractFloat64Sign(a);
269  bSign = extractFloat64Sign(b);
270  if (aSign != bSign)
271  return aSign && ((bits64) ((a | b) << 1) != 0);
272  return (a != b) && (aSign ^ (a < b));
273 }
274 
275 extern flag float32_is_nan( float32 a );
276 extern flag float64_is_nan( float64 a );
277 
278 extern int32 float64_to_uint32( struct roundingData *roundData, float64 a );
279 extern int32 float64_to_uint32_round_to_zero( float64 a );
280 
281 #endif
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