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