Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | NetWinder Floating Point Emulator | |
3 | (c) Rebel.COM, 1998,1999 | |
4 | (c) Philip Blundell, 1999, 2001 | |
5 | ||
6 | Direct questions, comments to Scott Bambrough <scottb@netwinder.org> | |
7 | ||
8 | This program is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with this program; if not, write to the Free Software | |
20 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
21 | */ | |
22 | ||
1da177e4 LT |
23 | #include "fpa11.h" |
24 | #include "fpopcode.h" | |
25 | #include "fpa11.inl" | |
26 | #include "fpmodule.h" | |
27 | #include "fpmodule.inl" | |
6ec5e7f3 | 28 | #include "softfloat.h" |
1da177e4 LT |
29 | |
30 | #ifdef CONFIG_FPE_NWFPE_XP | |
31 | extern flag floatx80_is_nan(floatx80); | |
32 | #endif | |
1da177e4 | 33 | |
1da177e4 LT |
34 | unsigned int PerformFLT(const unsigned int opcode); |
35 | unsigned int PerformFIX(const unsigned int opcode); | |
36 | ||
37 | static unsigned int PerformComparison(const unsigned int opcode); | |
38 | ||
39 | unsigned int EmulateCPRT(const unsigned int opcode) | |
40 | { | |
41 | ||
42 | if (opcode & 0x800000) { | |
43 | /* This is some variant of a comparison (PerformComparison | |
44 | will sort out which one). Since most of the other CPRT | |
45 | instructions are oddball cases of some sort or other it | |
46 | makes sense to pull this out into a fast path. */ | |
47 | return PerformComparison(opcode); | |
48 | } | |
49 | ||
50 | /* Hint to GCC that we'd like a jump table rather than a load of CMPs */ | |
51 | switch ((opcode & 0x700000) >> 20) { | |
52 | case FLT_CODE >> 20: | |
53 | return PerformFLT(opcode); | |
54 | break; | |
55 | case FIX_CODE >> 20: | |
56 | return PerformFIX(opcode); | |
57 | break; | |
58 | ||
59 | case WFS_CODE >> 20: | |
60 | writeFPSR(readRegister(getRd(opcode))); | |
61 | break; | |
62 | case RFS_CODE >> 20: | |
63 | writeRegister(getRd(opcode), readFPSR()); | |
64 | break; | |
65 | ||
66 | default: | |
67 | return 0; | |
68 | } | |
69 | ||
70 | return 1; | |
71 | } | |
72 | ||
73 | unsigned int PerformFLT(const unsigned int opcode) | |
74 | { | |
75 | FPA11 *fpa11 = GET_FPA11(); | |
f148af25 RP |
76 | struct roundingData roundData; |
77 | ||
78 | roundData.mode = SetRoundingMode(opcode); | |
79 | roundData.precision = SetRoundingPrecision(opcode); | |
80 | roundData.exception = 0; | |
1da177e4 LT |
81 | |
82 | switch (opcode & MASK_ROUNDING_PRECISION) { | |
83 | case ROUND_SINGLE: | |
84 | { | |
85 | fpa11->fType[getFn(opcode)] = typeSingle; | |
f148af25 | 86 | fpa11->fpreg[getFn(opcode)].fSingle = int32_to_float32(&roundData, readRegister(getRd(opcode))); |
1da177e4 LT |
87 | } |
88 | break; | |
89 | ||
90 | case ROUND_DOUBLE: | |
91 | { | |
92 | fpa11->fType[getFn(opcode)] = typeDouble; | |
93 | fpa11->fpreg[getFn(opcode)].fDouble = int32_to_float64(readRegister(getRd(opcode))); | |
94 | } | |
95 | break; | |
96 | ||
97 | #ifdef CONFIG_FPE_NWFPE_XP | |
98 | case ROUND_EXTENDED: | |
99 | { | |
100 | fpa11->fType[getFn(opcode)] = typeExtended; | |
101 | fpa11->fpreg[getFn(opcode)].fExtended = int32_to_floatx80(readRegister(getRd(opcode))); | |
102 | } | |
103 | break; | |
104 | #endif | |
105 | ||
106 | default: | |
107 | return 0; | |
108 | } | |
109 | ||
f148af25 RP |
110 | if (roundData.exception) |
111 | float_raise(roundData.exception); | |
112 | ||
1da177e4 LT |
113 | return 1; |
114 | } | |
115 | ||
116 | unsigned int PerformFIX(const unsigned int opcode) | |
117 | { | |
118 | FPA11 *fpa11 = GET_FPA11(); | |
119 | unsigned int Fn = getFm(opcode); | |
f148af25 | 120 | struct roundingData roundData; |
1da177e4 | 121 | |
f148af25 RP |
122 | roundData.mode = SetRoundingMode(opcode); |
123 | roundData.precision = SetRoundingPrecision(opcode); | |
124 | roundData.exception = 0; | |
1da177e4 LT |
125 | |
126 | switch (fpa11->fType[Fn]) { | |
127 | case typeSingle: | |
128 | { | |
f148af25 | 129 | writeRegister(getRd(opcode), float32_to_int32(&roundData, fpa11->fpreg[Fn].fSingle)); |
1da177e4 LT |
130 | } |
131 | break; | |
132 | ||
133 | case typeDouble: | |
134 | { | |
f148af25 | 135 | writeRegister(getRd(opcode), float64_to_int32(&roundData, fpa11->fpreg[Fn].fDouble)); |
1da177e4 LT |
136 | } |
137 | break; | |
138 | ||
139 | #ifdef CONFIG_FPE_NWFPE_XP | |
140 | case typeExtended: | |
141 | { | |
f148af25 | 142 | writeRegister(getRd(opcode), floatx80_to_int32(&roundData, fpa11->fpreg[Fn].fExtended)); |
1da177e4 LT |
143 | } |
144 | break; | |
145 | #endif | |
146 | ||
147 | default: | |
148 | return 0; | |
149 | } | |
150 | ||
f148af25 RP |
151 | if (roundData.exception) |
152 | float_raise(roundData.exception); | |
153 | ||
1da177e4 LT |
154 | return 1; |
155 | } | |
156 | ||
157 | /* This instruction sets the flags N, Z, C, V in the FPSR. */ | |
158 | static unsigned int PerformComparison(const unsigned int opcode) | |
159 | { | |
160 | FPA11 *fpa11 = GET_FPA11(); | |
161 | unsigned int Fn = getFn(opcode), Fm = getFm(opcode); | |
162 | int e_flag = opcode & 0x400000; /* 1 if CxFE */ | |
163 | int n_flag = opcode & 0x200000; /* 1 if CNxx */ | |
164 | unsigned int flags = 0; | |
165 | ||
166 | #ifdef CONFIG_FPE_NWFPE_XP | |
167 | floatx80 rFn, rFm; | |
168 | ||
169 | /* Check for unordered condition and convert all operands to 80-bit | |
170 | format. | |
171 | ?? Might be some mileage in avoiding this conversion if possible. | |
172 | Eg, if both operands are 32-bit, detect this and do a 32-bit | |
173 | comparison (cheaper than an 80-bit one). */ | |
174 | switch (fpa11->fType[Fn]) { | |
175 | case typeSingle: | |
176 | //printk("single.\n"); | |
177 | if (float32_is_nan(fpa11->fpreg[Fn].fSingle)) | |
178 | goto unordered; | |
179 | rFn = float32_to_floatx80(fpa11->fpreg[Fn].fSingle); | |
180 | break; | |
181 | ||
182 | case typeDouble: | |
183 | //printk("double.\n"); | |
184 | if (float64_is_nan(fpa11->fpreg[Fn].fDouble)) | |
185 | goto unordered; | |
186 | rFn = float64_to_floatx80(fpa11->fpreg[Fn].fDouble); | |
187 | break; | |
188 | ||
189 | case typeExtended: | |
190 | //printk("extended.\n"); | |
191 | if (floatx80_is_nan(fpa11->fpreg[Fn].fExtended)) | |
192 | goto unordered; | |
193 | rFn = fpa11->fpreg[Fn].fExtended; | |
194 | break; | |
195 | ||
196 | default: | |
197 | return 0; | |
198 | } | |
199 | ||
200 | if (CONSTANT_FM(opcode)) { | |
201 | //printk("Fm is a constant: #%d.\n",Fm); | |
202 | rFm = getExtendedConstant(Fm); | |
203 | if (floatx80_is_nan(rFm)) | |
204 | goto unordered; | |
205 | } else { | |
206 | //printk("Fm = r%d which contains a ",Fm); | |
207 | switch (fpa11->fType[Fm]) { | |
208 | case typeSingle: | |
209 | //printk("single.\n"); | |
210 | if (float32_is_nan(fpa11->fpreg[Fm].fSingle)) | |
211 | goto unordered; | |
212 | rFm = float32_to_floatx80(fpa11->fpreg[Fm].fSingle); | |
213 | break; | |
214 | ||
215 | case typeDouble: | |
216 | //printk("double.\n"); | |
217 | if (float64_is_nan(fpa11->fpreg[Fm].fDouble)) | |
218 | goto unordered; | |
219 | rFm = float64_to_floatx80(fpa11->fpreg[Fm].fDouble); | |
220 | break; | |
221 | ||
222 | case typeExtended: | |
223 | //printk("extended.\n"); | |
224 | if (floatx80_is_nan(fpa11->fpreg[Fm].fExtended)) | |
225 | goto unordered; | |
226 | rFm = fpa11->fpreg[Fm].fExtended; | |
227 | break; | |
228 | ||
229 | default: | |
230 | return 0; | |
231 | } | |
232 | } | |
233 | ||
234 | if (n_flag) | |
235 | rFm.high ^= 0x8000; | |
236 | ||
237 | /* test for less than condition */ | |
238 | if (floatx80_lt(rFn, rFm)) | |
239 | flags |= CC_NEGATIVE; | |
240 | ||
241 | /* test for equal condition */ | |
242 | if (floatx80_eq(rFn, rFm)) | |
243 | flags |= CC_ZERO; | |
244 | ||
245 | /* test for greater than or equal condition */ | |
246 | if (floatx80_lt(rFm, rFn)) | |
247 | flags |= CC_CARRY; | |
248 | ||
249 | #else | |
250 | if (CONSTANT_FM(opcode)) { | |
251 | /* Fm is a constant. Do the comparison in whatever precision | |
252 | Fn happens to be stored in. */ | |
253 | if (fpa11->fType[Fn] == typeSingle) { | |
254 | float32 rFm = getSingleConstant(Fm); | |
255 | float32 rFn = fpa11->fpreg[Fn].fSingle; | |
256 | ||
257 | if (float32_is_nan(rFn)) | |
258 | goto unordered; | |
259 | ||
260 | if (n_flag) | |
261 | rFm ^= 0x80000000; | |
262 | ||
263 | /* test for less than condition */ | |
264 | if (float32_lt_nocheck(rFn, rFm)) | |
265 | flags |= CC_NEGATIVE; | |
266 | ||
267 | /* test for equal condition */ | |
268 | if (float32_eq_nocheck(rFn, rFm)) | |
269 | flags |= CC_ZERO; | |
270 | ||
271 | /* test for greater than or equal condition */ | |
272 | if (float32_lt_nocheck(rFm, rFn)) | |
273 | flags |= CC_CARRY; | |
274 | } else { | |
275 | float64 rFm = getDoubleConstant(Fm); | |
276 | float64 rFn = fpa11->fpreg[Fn].fDouble; | |
277 | ||
278 | if (float64_is_nan(rFn)) | |
279 | goto unordered; | |
280 | ||
281 | if (n_flag) | |
282 | rFm ^= 0x8000000000000000ULL; | |
283 | ||
284 | /* test for less than condition */ | |
285 | if (float64_lt_nocheck(rFn, rFm)) | |
286 | flags |= CC_NEGATIVE; | |
287 | ||
288 | /* test for equal condition */ | |
289 | if (float64_eq_nocheck(rFn, rFm)) | |
290 | flags |= CC_ZERO; | |
291 | ||
292 | /* test for greater than or equal condition */ | |
293 | if (float64_lt_nocheck(rFm, rFn)) | |
294 | flags |= CC_CARRY; | |
295 | } | |
296 | } else { | |
297 | /* Both operands are in registers. */ | |
298 | if (fpa11->fType[Fn] == typeSingle | |
299 | && fpa11->fType[Fm] == typeSingle) { | |
300 | float32 rFm = fpa11->fpreg[Fm].fSingle; | |
301 | float32 rFn = fpa11->fpreg[Fn].fSingle; | |
302 | ||
303 | if (float32_is_nan(rFn) | |
304 | || float32_is_nan(rFm)) | |
305 | goto unordered; | |
306 | ||
307 | if (n_flag) | |
308 | rFm ^= 0x80000000; | |
309 | ||
310 | /* test for less than condition */ | |
311 | if (float32_lt_nocheck(rFn, rFm)) | |
312 | flags |= CC_NEGATIVE; | |
313 | ||
314 | /* test for equal condition */ | |
315 | if (float32_eq_nocheck(rFn, rFm)) | |
316 | flags |= CC_ZERO; | |
317 | ||
318 | /* test for greater than or equal condition */ | |
319 | if (float32_lt_nocheck(rFm, rFn)) | |
320 | flags |= CC_CARRY; | |
321 | } else { | |
322 | /* Promote 32-bit operand to 64 bits. */ | |
323 | float64 rFm, rFn; | |
324 | ||
325 | rFm = (fpa11->fType[Fm] == typeSingle) ? | |
326 | float32_to_float64(fpa11->fpreg[Fm].fSingle) | |
327 | : fpa11->fpreg[Fm].fDouble; | |
328 | ||
329 | rFn = (fpa11->fType[Fn] == typeSingle) ? | |
330 | float32_to_float64(fpa11->fpreg[Fn].fSingle) | |
331 | : fpa11->fpreg[Fn].fDouble; | |
332 | ||
333 | if (float64_is_nan(rFn) | |
334 | || float64_is_nan(rFm)) | |
335 | goto unordered; | |
336 | ||
337 | if (n_flag) | |
338 | rFm ^= 0x8000000000000000ULL; | |
339 | ||
340 | /* test for less than condition */ | |
341 | if (float64_lt_nocheck(rFn, rFm)) | |
342 | flags |= CC_NEGATIVE; | |
343 | ||
344 | /* test for equal condition */ | |
345 | if (float64_eq_nocheck(rFn, rFm)) | |
346 | flags |= CC_ZERO; | |
347 | ||
348 | /* test for greater than or equal condition */ | |
349 | if (float64_lt_nocheck(rFm, rFn)) | |
350 | flags |= CC_CARRY; | |
351 | } | |
352 | } | |
353 | ||
354 | #endif | |
355 | ||
356 | writeConditionCodes(flags); | |
357 | ||
358 | return 1; | |
359 | ||
360 | unordered: | |
361 | /* ?? The FPA data sheet is pretty vague about this, in particular | |
362 | about whether the non-E comparisons can ever raise exceptions. | |
363 | This implementation is based on a combination of what it says in | |
364 | the data sheet, observation of how the Acorn emulator actually | |
365 | behaves (and how programs expect it to) and guesswork. */ | |
366 | flags |= CC_OVERFLOW; | |
367 | flags &= ~(CC_ZERO | CC_NEGATIVE); | |
368 | ||
369 | if (BIT_AC & readFPSR()) | |
370 | flags |= CC_CARRY; | |
371 | ||
372 | if (e_flag) | |
373 | float_raise(float_flag_invalid); | |
374 | ||
375 | writeConditionCodes(flags); | |
376 | return 1; | |
377 | } |