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1da177e4 LT |
1 | | |
2 | | get_op.sa 3.6 5/19/92 | |
3 | | | |
4 | | get_op.sa 3.5 4/26/91 | |
5 | | | |
6 | | Description: This routine is called by the unsupported format/data | |
7 | | type exception handler ('unsupp' - vector 55) and the unimplemented | |
8 | | instruction exception handler ('unimp' - vector 11). 'get_op' | |
9 | | determines the opclass (0, 2, or 3) and branches to the | |
10 | | opclass handler routine. See 68881/2 User's Manual table 4-11 | |
11 | | for a description of the opclasses. | |
12 | | | |
13 | | For UNSUPPORTED data/format (exception vector 55) and for | |
14 | | UNIMPLEMENTED instructions (exception vector 11) the following | |
15 | | applies: | |
16 | | | |
17 | | - For unnormalized numbers (opclass 0, 2, or 3) the | |
18 | | number(s) is normalized and the operand type tag is updated. | |
19 | | | |
20 | | - For a packed number (opclass 2) the number is unpacked and the | |
21 | | operand type tag is updated. | |
22 | | | |
23 | | - For denormalized numbers (opclass 0 or 2) the number(s) is not | |
24 | | changed but passed to the next module. The next module for | |
25 | | unimp is do_func, the next module for unsupp is res_func. | |
26 | | | |
27 | | For UNSUPPORTED data/format (exception vector 55) only the | |
28 | | following applies: | |
29 | | | |
30 | | - If there is a move out with a packed number (opclass 3) the | |
31 | | number is packed and written to user memory. For the other | |
32 | | opclasses the number(s) are written back to the fsave stack | |
33 | | and the instruction is then restored back into the '040. The | |
34 | | '040 is then able to complete the instruction. | |
35 | | | |
36 | | For example: | |
37 | | fadd.x fpm,fpn where the fpm contains an unnormalized number. | |
38 | | The '040 takes an unsupported data trap and gets to this | |
39 | | routine. The number is normalized, put back on the stack and | |
40 | | then an frestore is done to restore the instruction back into | |
41 | | the '040. The '040 then re-executes the fadd.x fpm,fpn with | |
42 | | a normalized number in the source and the instruction is | |
43 | | successful. | |
44 | | | |
45 | | Next consider if in the process of normalizing the un- | |
46 | | normalized number it becomes a denormalized number. The | |
47 | | routine which converts the unnorm to a norm (called mk_norm) | |
48 | | detects this and tags the number as a denorm. The routine | |
49 | | res_func sees the denorm tag and converts the denorm to a | |
50 | | norm. The instruction is then restored back into the '040 | |
51 | | which re_executes the instruction. | |
52 | | | |
53 | | | |
54 | | Copyright (C) Motorola, Inc. 1990 | |
55 | | All Rights Reserved | |
56 | | | |
e00d82d0 MW |
57 | | For details on the license for this file, please see the |
58 | | file, README, in this same directory. | |
1da177e4 LT |
59 | |
60 | GET_OP: |idnt 2,1 | Motorola 040 Floating Point Software Package | |
61 | ||
62 | |section 8 | |
63 | ||
64 | #include "fpsp.h" | |
65 | ||
66 | .global PIRN,PIRZRM,PIRP | |
67 | .global SMALRN,SMALRZRM,SMALRP | |
68 | .global BIGRN,BIGRZRM,BIGRP | |
69 | ||
70 | PIRN: | |
71 | .long 0x40000000,0xc90fdaa2,0x2168c235 |pi | |
72 | PIRZRM: | |
73 | .long 0x40000000,0xc90fdaa2,0x2168c234 |pi | |
74 | PIRP: | |
75 | .long 0x40000000,0xc90fdaa2,0x2168c235 |pi | |
76 | ||
77 | |round to nearest | |
78 | SMALRN: | |
79 | .long 0x3ffd0000,0x9a209a84,0xfbcff798 |log10(2) | |
80 | .long 0x40000000,0xadf85458,0xa2bb4a9a |e | |
81 | .long 0x3fff0000,0xb8aa3b29,0x5c17f0bc |log2(e) | |
82 | .long 0x3ffd0000,0xde5bd8a9,0x37287195 |log10(e) | |
83 | .long 0x00000000,0x00000000,0x00000000 |0.0 | |
84 | | round to zero;round to negative infinity | |
85 | SMALRZRM: | |
86 | .long 0x3ffd0000,0x9a209a84,0xfbcff798 |log10(2) | |
87 | .long 0x40000000,0xadf85458,0xa2bb4a9a |e | |
88 | .long 0x3fff0000,0xb8aa3b29,0x5c17f0bb |log2(e) | |
89 | .long 0x3ffd0000,0xde5bd8a9,0x37287195 |log10(e) | |
90 | .long 0x00000000,0x00000000,0x00000000 |0.0 | |
91 | | round to positive infinity | |
92 | SMALRP: | |
93 | .long 0x3ffd0000,0x9a209a84,0xfbcff799 |log10(2) | |
94 | .long 0x40000000,0xadf85458,0xa2bb4a9b |e | |
95 | .long 0x3fff0000,0xb8aa3b29,0x5c17f0bc |log2(e) | |
96 | .long 0x3ffd0000,0xde5bd8a9,0x37287195 |log10(e) | |
97 | .long 0x00000000,0x00000000,0x00000000 |0.0 | |
98 | ||
99 | |round to nearest | |
100 | BIGRN: | |
101 | .long 0x3ffe0000,0xb17217f7,0xd1cf79ac |ln(2) | |
102 | .long 0x40000000,0x935d8ddd,0xaaa8ac17 |ln(10) | |
103 | .long 0x3fff0000,0x80000000,0x00000000 |10 ^ 0 | |
104 | ||
105 | .global PTENRN | |
106 | PTENRN: | |
107 | .long 0x40020000,0xA0000000,0x00000000 |10 ^ 1 | |
108 | .long 0x40050000,0xC8000000,0x00000000 |10 ^ 2 | |
109 | .long 0x400C0000,0x9C400000,0x00000000 |10 ^ 4 | |
110 | .long 0x40190000,0xBEBC2000,0x00000000 |10 ^ 8 | |
111 | .long 0x40340000,0x8E1BC9BF,0x04000000 |10 ^ 16 | |
112 | .long 0x40690000,0x9DC5ADA8,0x2B70B59E |10 ^ 32 | |
113 | .long 0x40D30000,0xC2781F49,0xFFCFA6D5 |10 ^ 64 | |
114 | .long 0x41A80000,0x93BA47C9,0x80E98CE0 |10 ^ 128 | |
115 | .long 0x43510000,0xAA7EEBFB,0x9DF9DE8E |10 ^ 256 | |
116 | .long 0x46A30000,0xE319A0AE,0xA60E91C7 |10 ^ 512 | |
117 | .long 0x4D480000,0xC9767586,0x81750C17 |10 ^ 1024 | |
118 | .long 0x5A920000,0x9E8B3B5D,0xC53D5DE5 |10 ^ 2048 | |
119 | .long 0x75250000,0xC4605202,0x8A20979B |10 ^ 4096 | |
120 | |round to minus infinity | |
121 | BIGRZRM: | |
122 | .long 0x3ffe0000,0xb17217f7,0xd1cf79ab |ln(2) | |
123 | .long 0x40000000,0x935d8ddd,0xaaa8ac16 |ln(10) | |
124 | .long 0x3fff0000,0x80000000,0x00000000 |10 ^ 0 | |
125 | ||
126 | .global PTENRM | |
127 | PTENRM: | |
128 | .long 0x40020000,0xA0000000,0x00000000 |10 ^ 1 | |
129 | .long 0x40050000,0xC8000000,0x00000000 |10 ^ 2 | |
130 | .long 0x400C0000,0x9C400000,0x00000000 |10 ^ 4 | |
131 | .long 0x40190000,0xBEBC2000,0x00000000 |10 ^ 8 | |
132 | .long 0x40340000,0x8E1BC9BF,0x04000000 |10 ^ 16 | |
133 | .long 0x40690000,0x9DC5ADA8,0x2B70B59D |10 ^ 32 | |
134 | .long 0x40D30000,0xC2781F49,0xFFCFA6D5 |10 ^ 64 | |
135 | .long 0x41A80000,0x93BA47C9,0x80E98CDF |10 ^ 128 | |
136 | .long 0x43510000,0xAA7EEBFB,0x9DF9DE8D |10 ^ 256 | |
137 | .long 0x46A30000,0xE319A0AE,0xA60E91C6 |10 ^ 512 | |
138 | .long 0x4D480000,0xC9767586,0x81750C17 |10 ^ 1024 | |
139 | .long 0x5A920000,0x9E8B3B5D,0xC53D5DE5 |10 ^ 2048 | |
140 | .long 0x75250000,0xC4605202,0x8A20979A |10 ^ 4096 | |
141 | |round to positive infinity | |
142 | BIGRP: | |
143 | .long 0x3ffe0000,0xb17217f7,0xd1cf79ac |ln(2) | |
144 | .long 0x40000000,0x935d8ddd,0xaaa8ac17 |ln(10) | |
145 | .long 0x3fff0000,0x80000000,0x00000000 |10 ^ 0 | |
146 | ||
147 | .global PTENRP | |
148 | PTENRP: | |
149 | .long 0x40020000,0xA0000000,0x00000000 |10 ^ 1 | |
150 | .long 0x40050000,0xC8000000,0x00000000 |10 ^ 2 | |
151 | .long 0x400C0000,0x9C400000,0x00000000 |10 ^ 4 | |
152 | .long 0x40190000,0xBEBC2000,0x00000000 |10 ^ 8 | |
153 | .long 0x40340000,0x8E1BC9BF,0x04000000 |10 ^ 16 | |
154 | .long 0x40690000,0x9DC5ADA8,0x2B70B59E |10 ^ 32 | |
155 | .long 0x40D30000,0xC2781F49,0xFFCFA6D6 |10 ^ 64 | |
156 | .long 0x41A80000,0x93BA47C9,0x80E98CE0 |10 ^ 128 | |
157 | .long 0x43510000,0xAA7EEBFB,0x9DF9DE8E |10 ^ 256 | |
158 | .long 0x46A30000,0xE319A0AE,0xA60E91C7 |10 ^ 512 | |
159 | .long 0x4D480000,0xC9767586,0x81750C18 |10 ^ 1024 | |
160 | .long 0x5A920000,0x9E8B3B5D,0xC53D5DE6 |10 ^ 2048 | |
161 | .long 0x75250000,0xC4605202,0x8A20979B |10 ^ 4096 | |
162 | ||
163 | |xref nrm_zero | |
164 | |xref decbin | |
165 | |xref round | |
166 | ||
167 | .global get_op | |
168 | .global uns_getop | |
169 | .global uni_getop | |
170 | get_op: | |
171 | clrb DY_MO_FLG(%a6) | |
172 | tstb UFLG_TMP(%a6) |test flag for unsupp/unimp state | |
173 | beq uni_getop | |
174 | ||
175 | uns_getop: | |
176 | btstb #direction_bit,CMDREG1B(%a6) | |
177 | bne opclass3 |branch if a fmove out (any kind) | |
178 | btstb #6,CMDREG1B(%a6) | |
179 | beqs uns_notpacked | |
180 | ||
181 | bfextu CMDREG1B(%a6){#3:#3},%d0 | |
182 | cmpb #3,%d0 | |
183 | beq pack_source |check for a packed src op, branch if so | |
184 | uns_notpacked: | |
185 | bsr chk_dy_mo |set the dyadic/monadic flag | |
186 | tstb DY_MO_FLG(%a6) | |
187 | beqs src_op_ck |if monadic, go check src op | |
188 | | ;else, check dst op (fall through) | |
189 | ||
190 | btstb #7,DTAG(%a6) | |
191 | beqs src_op_ck |if dst op is norm, check src op | |
192 | bras dst_ex_dnrm |else, handle destination unnorm/dnrm | |
193 | ||
194 | uni_getop: | |
195 | bfextu CMDREG1B(%a6){#0:#6},%d0 |get opclass and src fields | |
196 | cmpil #0x17,%d0 |if op class and size fields are $17, | |
197 | | ;it is FMOVECR; if not, continue | |
198 | | | |
199 | | If the instruction is fmovecr, exit get_op. It is handled | |
200 | | in do_func and smovecr.sa. | |
201 | | | |
202 | bne not_fmovecr |handle fmovecr as an unimplemented inst | |
203 | rts | |
204 | ||
205 | not_fmovecr: | |
206 | btstb #E1,E_BYTE(%a6) |if set, there is a packed operand | |
207 | bne pack_source |check for packed src op, branch if so | |
208 | ||
209 | | The following lines of are coded to optimize on normalized operands | |
210 | moveb STAG(%a6),%d0 | |
211 | orb DTAG(%a6),%d0 |check if either of STAG/DTAG msb set | |
212 | bmis dest_op_ck |if so, some op needs to be fixed | |
213 | rts | |
214 | ||
215 | dest_op_ck: | |
216 | btstb #7,DTAG(%a6) |check for unsupported data types in | |
217 | beqs src_op_ck |the destination, if not, check src op | |
218 | bsr chk_dy_mo |set dyadic/monadic flag | |
219 | tstb DY_MO_FLG(%a6) | | |
220 | beqs src_op_ck |if monadic, check src op | |
221 | | | |
222 | | At this point, destination has an extended denorm or unnorm. | |
223 | | | |
224 | dst_ex_dnrm: | |
225 | movew FPTEMP_EX(%a6),%d0 |get destination exponent | |
226 | andiw #0x7fff,%d0 |mask sign, check if exp = 0000 | |
227 | beqs src_op_ck |if denorm then check source op. | |
228 | | ;denorms are taken care of in res_func | |
229 | | ;(unsupp) or do_func (unimp) | |
230 | | ;else unnorm fall through | |
231 | leal FPTEMP(%a6),%a0 |point a0 to dop - used in mk_norm | |
232 | bsr mk_norm |go normalize - mk_norm returns: | |
233 | | ;L_SCR1{7:5} = operand tag | |
234 | | ; (000 = norm, 100 = denorm) | |
235 | | ;L_SCR1{4} = fpte15 or ete15 | |
236 | | ; 0 = exp > $3fff | |
237 | | ; 1 = exp <= $3fff | |
238 | | ;and puts the normalized num back | |
239 | | ;on the fsave stack | |
240 | | | |
241 | moveb L_SCR1(%a6),DTAG(%a6) |write the new tag & fpte15 | |
242 | | ;to the fsave stack and fall | |
243 | | ;through to check source operand | |
244 | | | |
245 | src_op_ck: | |
246 | btstb #7,STAG(%a6) | |
247 | beq end_getop |check for unsupported data types on the | |
248 | | ;source operand | |
249 | btstb #5,STAG(%a6) | |
250 | bnes src_sd_dnrm |if bit 5 set, handle sgl/dbl denorms | |
251 | | | |
252 | | At this point only unnorms or extended denorms are possible. | |
253 | | | |
254 | src_ex_dnrm: | |
255 | movew ETEMP_EX(%a6),%d0 |get source exponent | |
256 | andiw #0x7fff,%d0 |mask sign, check if exp = 0000 | |
257 | beq end_getop |if denorm then exit, denorms are | |
258 | | ;handled in do_func | |
259 | leal ETEMP(%a6),%a0 |point a0 to sop - used in mk_norm | |
260 | bsr mk_norm |go normalize - mk_norm returns: | |
261 | | ;L_SCR1{7:5} = operand tag | |
262 | | ; (000 = norm, 100 = denorm) | |
263 | | ;L_SCR1{4} = fpte15 or ete15 | |
264 | | ; 0 = exp > $3fff | |
265 | | ; 1 = exp <= $3fff | |
266 | | ;and puts the normalized num back | |
267 | | ;on the fsave stack | |
268 | | | |
269 | moveb L_SCR1(%a6),STAG(%a6) |write the new tag & ete15 | |
270 | rts |end_getop | |
271 | ||
272 | | | |
273 | | At this point, only single or double denorms are possible. | |
274 | | If the inst is not fmove, normalize the source. If it is, | |
275 | | do nothing to the input. | |
276 | | | |
277 | src_sd_dnrm: | |
278 | btstb #4,CMDREG1B(%a6) |differentiate between sgl/dbl denorm | |
279 | bnes is_double | |
280 | is_single: | |
281 | movew #0x3f81,%d1 |write bias for sgl denorm | |
282 | bras common |goto the common code | |
283 | is_double: | |
284 | movew #0x3c01,%d1 |write the bias for a dbl denorm | |
285 | common: | |
286 | btstb #sign_bit,ETEMP_EX(%a6) |grab sign bit of mantissa | |
287 | beqs pos | |
288 | bset #15,%d1 |set sign bit because it is negative | |
289 | pos: | |
290 | movew %d1,ETEMP_EX(%a6) | |
291 | | ;put exponent on stack | |
292 | ||
293 | movew CMDREG1B(%a6),%d1 | |
294 | andw #0xe3ff,%d1 |clear out source specifier | |
295 | orw #0x0800,%d1 |set source specifier to extended prec | |
296 | movew %d1,CMDREG1B(%a6) |write back to the command word in stack | |
297 | | ;this is needed to fix unsupp data stack | |
298 | leal ETEMP(%a6),%a0 |point a0 to sop | |
299 | ||
300 | bsr mk_norm |convert sgl/dbl denorm to norm | |
301 | moveb L_SCR1(%a6),STAG(%a6) |put tag into source tag reg - d0 | |
302 | rts |end_getop | |
303 | | | |
304 | | At this point, the source is definitely packed, whether | |
305 | | instruction is dyadic or monadic is still unknown | |
306 | | | |
307 | pack_source: | |
308 | movel FPTEMP_LO(%a6),ETEMP(%a6) |write ms part of packed | |
309 | | ;number to etemp slot | |
310 | bsr chk_dy_mo |set dyadic/monadic flag | |
311 | bsr unpack | |
312 | ||
313 | tstb DY_MO_FLG(%a6) | |
314 | beqs end_getop |if monadic, exit | |
315 | | ;else, fix FPTEMP | |
316 | pack_dya: | |
317 | bfextu CMDREG1B(%a6){#6:#3},%d0 |extract dest fp reg | |
318 | movel #7,%d1 | |
319 | subl %d0,%d1 | |
320 | clrl %d0 | |
321 | bsetl %d1,%d0 |set up d0 as a dynamic register mask | |
322 | fmovemx %d0,FPTEMP(%a6) |write to FPTEMP | |
323 | ||
324 | btstb #7,DTAG(%a6) |check dest tag for unnorm or denorm | |
325 | bne dst_ex_dnrm |else, handle the unnorm or ext denorm | |
326 | | | |
327 | | Dest is not denormalized. Check for norm, and set fpte15 | |
328 | | accordingly. | |
329 | | | |
330 | moveb DTAG(%a6),%d0 | |
331 | andib #0xf0,%d0 |strip to only dtag:fpte15 | |
332 | tstb %d0 |check for normalized value | |
333 | bnes end_getop |if inf/nan/zero leave get_op | |
334 | movew FPTEMP_EX(%a6),%d0 | |
335 | andiw #0x7fff,%d0 | |
336 | cmpiw #0x3fff,%d0 |check if fpte15 needs setting | |
337 | bges end_getop |if >= $3fff, leave fpte15=0 | |
338 | orb #0x10,DTAG(%a6) | |
339 | bras end_getop | |
340 | ||
341 | | | |
342 | | At this point, it is either an fmoveout packed, unnorm or denorm | |
343 | | | |
344 | opclass3: | |
345 | clrb DY_MO_FLG(%a6) |set dyadic/monadic flag to monadic | |
346 | bfextu CMDREG1B(%a6){#4:#2},%d0 | |
347 | cmpib #3,%d0 | |
348 | bne src_ex_dnrm |if not equal, must be unnorm or denorm | |
349 | | ;else it is a packed move out | |
350 | | ;exit | |
351 | end_getop: | |
352 | rts | |
353 | ||
354 | | | |
355 | | Sets the DY_MO_FLG correctly. This is used only on if it is an | |
356 | | unsupported data type exception. Set if dyadic. | |
357 | | | |
358 | chk_dy_mo: | |
359 | movew CMDREG1B(%a6),%d0 | |
360 | btstl #5,%d0 |testing extension command word | |
361 | beqs set_mon |if bit 5 = 0 then monadic | |
362 | btstl #4,%d0 |know that bit 5 = 1 | |
363 | beqs set_dya |if bit 4 = 0 then dyadic | |
364 | andiw #0x007f,%d0 |get rid of all but extension bits {6:0} | |
365 | cmpiw #0x0038,%d0 |if extension = $38 then fcmp (dyadic) | |
366 | bnes set_mon | |
367 | set_dya: | |
368 | st DY_MO_FLG(%a6) |set the inst flag type to dyadic | |
369 | rts | |
370 | set_mon: | |
371 | clrb DY_MO_FLG(%a6) |set the inst flag type to monadic | |
372 | rts | |
373 | | | |
374 | | MK_NORM | |
375 | | | |
376 | | Normalizes unnormalized numbers, sets tag to norm or denorm, sets unfl | |
377 | | exception if denorm. | |
378 | | | |
379 | | CASE opclass 0x0 unsupp | |
380 | | mk_norm till msb set | |
381 | | set tag = norm | |
382 | | | |
383 | | CASE opclass 0x0 unimp | |
384 | | mk_norm till msb set or exp = 0 | |
385 | | if integer bit = 0 | |
386 | | tag = denorm | |
387 | | else | |
388 | | tag = norm | |
389 | | | |
390 | | CASE opclass 011 unsupp | |
391 | | mk_norm till msb set or exp = 0 | |
392 | | if integer bit = 0 | |
393 | | tag = denorm | |
394 | | set unfl_nmcexe = 1 | |
395 | | else | |
396 | | tag = norm | |
397 | | | |
398 | | if exp <= $3fff | |
399 | | set ete15 or fpte15 = 1 | |
400 | | else set ete15 or fpte15 = 0 | |
401 | ||
402 | | input: | |
403 | | a0 = points to operand to be normalized | |
404 | | output: | |
405 | | L_SCR1{7:5} = operand tag (000 = norm, 100 = denorm) | |
406 | | L_SCR1{4} = fpte15 or ete15 (0 = exp > $3fff, 1 = exp <=$3fff) | |
407 | | the normalized operand is placed back on the fsave stack | |
408 | mk_norm: | |
409 | clrl L_SCR1(%a6) | |
410 | bclrb #sign_bit,LOCAL_EX(%a0) | |
411 | sne LOCAL_SGN(%a0) |transform into internal extended format | |
412 | ||
413 | cmpib #0x2c,1+EXC_VEC(%a6) |check if unimp | |
414 | bnes uns_data |branch if unsupp | |
415 | bsr uni_inst |call if unimp (opclass 0x0) | |
416 | bras reload | |
417 | uns_data: | |
418 | btstb #direction_bit,CMDREG1B(%a6) |check transfer direction | |
419 | bnes bit_set |branch if set (opclass 011) | |
420 | bsr uns_opx |call if opclass 0x0 | |
421 | bras reload | |
422 | bit_set: | |
423 | bsr uns_op3 |opclass 011 | |
424 | reload: | |
425 | cmpw #0x3fff,LOCAL_EX(%a0) |if exp > $3fff | |
426 | bgts end_mk | fpte15/ete15 already set to 0 | |
427 | bsetb #4,L_SCR1(%a6) |else set fpte15/ete15 to 1 | |
428 | | ;calling routine actually sets the | |
429 | | ;value on the stack (along with the | |
430 | | ;tag), since this routine doesn't | |
431 | | ;know if it should set ete15 or fpte15 | |
432 | | ;ie, it doesn't know if this is the | |
433 | | ;src op or dest op. | |
434 | end_mk: | |
435 | bfclr LOCAL_SGN(%a0){#0:#8} | |
436 | beqs end_mk_pos | |
437 | bsetb #sign_bit,LOCAL_EX(%a0) |convert back to IEEE format | |
438 | end_mk_pos: | |
439 | rts | |
440 | | | |
441 | | CASE opclass 011 unsupp | |
442 | | | |
443 | uns_op3: | |
444 | bsr nrm_zero |normalize till msb = 1 or exp = zero | |
445 | btstb #7,LOCAL_HI(%a0) |if msb = 1 | |
446 | bnes no_unfl |then branch | |
447 | set_unfl: | |
448 | orw #dnrm_tag,L_SCR1(%a6) |set denorm tag | |
449 | bsetb #unfl_bit,FPSR_EXCEPT(%a6) |set unfl exception bit | |
450 | no_unfl: | |
451 | rts | |
452 | | | |
453 | | CASE opclass 0x0 unsupp | |
454 | | | |
455 | uns_opx: | |
456 | bsr nrm_zero |normalize the number | |
457 | btstb #7,LOCAL_HI(%a0) |check if integer bit (j-bit) is set | |
458 | beqs uns_den |if clear then now have a denorm | |
459 | uns_nrm: | |
460 | orb #norm_tag,L_SCR1(%a6) |set tag to norm | |
461 | rts | |
462 | uns_den: | |
463 | orb #dnrm_tag,L_SCR1(%a6) |set tag to denorm | |
464 | rts | |
465 | | | |
466 | | CASE opclass 0x0 unimp | |
467 | | | |
468 | uni_inst: | |
469 | bsr nrm_zero | |
470 | btstb #7,LOCAL_HI(%a0) |check if integer bit (j-bit) is set | |
471 | beqs uni_den |if clear then now have a denorm | |
472 | uni_nrm: | |
473 | orb #norm_tag,L_SCR1(%a6) |set tag to norm | |
474 | rts | |
475 | uni_den: | |
476 | orb #dnrm_tag,L_SCR1(%a6) |set tag to denorm | |
477 | rts | |
478 | ||
479 | | | |
480 | | Decimal to binary conversion | |
481 | | | |
482 | | Special cases of inf and NaNs are completed outside of decbin. | |
483 | | If the input is an snan, the snan bit is not set. | |
484 | | | |
485 | | input: | |
486 | | ETEMP(a6) - points to packed decimal string in memory | |
487 | | output: | |
488 | | fp0 - contains packed string converted to extended precision | |
489 | | ETEMP - same as fp0 | |
490 | unpack: | |
491 | movew CMDREG1B(%a6),%d0 |examine command word, looking for fmove's | |
492 | andw #0x3b,%d0 | |
493 | beq move_unpack |special handling for fmove: must set FPSR_CC | |
494 | ||
495 | movew ETEMP(%a6),%d0 |get word with inf information | |
496 | bfextu %d0{#20:#12},%d1 |get exponent into d1 | |
497 | cmpiw #0x0fff,%d1 |test for inf or NaN | |
498 | bnes try_zero |if not equal, it is not special | |
499 | bfextu %d0{#17:#3},%d1 |get SE and y bits into d1 | |
500 | cmpiw #7,%d1 |SE and y bits must be on for special | |
501 | bnes try_zero |if not on, it is not special | |
502 | |input is of the special cases of inf and NaN | |
503 | tstl ETEMP_HI(%a6) |check ms mantissa | |
504 | bnes fix_nan |if non-zero, it is a NaN | |
505 | tstl ETEMP_LO(%a6) |check ls mantissa | |
506 | bnes fix_nan |if non-zero, it is a NaN | |
507 | bra finish |special already on stack | |
508 | fix_nan: | |
509 | btstb #signan_bit,ETEMP_HI(%a6) |test for snan | |
510 | bne finish | |
511 | orl #snaniop_mask,USER_FPSR(%a6) |always set snan if it is so | |
512 | bra finish | |
513 | try_zero: | |
514 | movew ETEMP_EX+2(%a6),%d0 |get word 4 | |
515 | andiw #0x000f,%d0 |clear all but last ni(y)bble | |
516 | tstw %d0 |check for zero. | |
517 | bne not_spec | |
518 | tstl ETEMP_HI(%a6) |check words 3 and 2 | |
519 | bne not_spec | |
520 | tstl ETEMP_LO(%a6) |check words 1 and 0 | |
521 | bne not_spec | |
522 | tstl ETEMP(%a6) |test sign of the zero | |
523 | bges pos_zero | |
524 | movel #0x80000000,ETEMP(%a6) |write neg zero to etemp | |
525 | clrl ETEMP_HI(%a6) | |
526 | clrl ETEMP_LO(%a6) | |
527 | bra finish | |
528 | pos_zero: | |
529 | clrl ETEMP(%a6) | |
530 | clrl ETEMP_HI(%a6) | |
531 | clrl ETEMP_LO(%a6) | |
532 | bra finish | |
533 | ||
534 | not_spec: | |
535 | fmovemx %fp0-%fp1,-(%a7) |save fp0 - decbin returns in it | |
536 | bsr decbin | |
537 | fmovex %fp0,ETEMP(%a6) |put the unpacked sop in the fsave stack | |
538 | fmovemx (%a7)+,%fp0-%fp1 | |
539 | fmovel #0,%FPSR |clr fpsr from decbin | |
540 | bra finish | |
541 | ||
542 | | | |
543 | | Special handling for packed move in: Same results as all other | |
544 | | packed cases, but we must set the FPSR condition codes properly. | |
545 | | | |
546 | move_unpack: | |
547 | movew ETEMP(%a6),%d0 |get word with inf information | |
548 | bfextu %d0{#20:#12},%d1 |get exponent into d1 | |
549 | cmpiw #0x0fff,%d1 |test for inf or NaN | |
550 | bnes mtry_zero |if not equal, it is not special | |
551 | bfextu %d0{#17:#3},%d1 |get SE and y bits into d1 | |
552 | cmpiw #7,%d1 |SE and y bits must be on for special | |
553 | bnes mtry_zero |if not on, it is not special | |
554 | |input is of the special cases of inf and NaN | |
555 | tstl ETEMP_HI(%a6) |check ms mantissa | |
556 | bnes mfix_nan |if non-zero, it is a NaN | |
557 | tstl ETEMP_LO(%a6) |check ls mantissa | |
558 | bnes mfix_nan |if non-zero, it is a NaN | |
559 | |input is inf | |
560 | orl #inf_mask,USER_FPSR(%a6) |set I bit | |
561 | tstl ETEMP(%a6) |check sign | |
562 | bge finish | |
563 | orl #neg_mask,USER_FPSR(%a6) |set N bit | |
564 | bra finish |special already on stack | |
565 | mfix_nan: | |
566 | orl #nan_mask,USER_FPSR(%a6) |set NaN bit | |
567 | moveb #nan_tag,STAG(%a6) |set stag to NaN | |
568 | btstb #signan_bit,ETEMP_HI(%a6) |test for snan | |
569 | bnes mn_snan | |
570 | orl #snaniop_mask,USER_FPSR(%a6) |set snan bit | |
571 | btstb #snan_bit,FPCR_ENABLE(%a6) |test for snan enabled | |
572 | bnes mn_snan | |
573 | bsetb #signan_bit,ETEMP_HI(%a6) |force snans to qnans | |
574 | mn_snan: | |
575 | tstl ETEMP(%a6) |check for sign | |
576 | bge finish |if clr, go on | |
577 | orl #neg_mask,USER_FPSR(%a6) |set N bit | |
578 | bra finish | |
579 | ||
580 | mtry_zero: | |
581 | movew ETEMP_EX+2(%a6),%d0 |get word 4 | |
582 | andiw #0x000f,%d0 |clear all but last ni(y)bble | |
583 | tstw %d0 |check for zero. | |
584 | bnes mnot_spec | |
585 | tstl ETEMP_HI(%a6) |check words 3 and 2 | |
586 | bnes mnot_spec | |
587 | tstl ETEMP_LO(%a6) |check words 1 and 0 | |
588 | bnes mnot_spec | |
589 | tstl ETEMP(%a6) |test sign of the zero | |
590 | bges mpos_zero | |
591 | orl #neg_mask+z_mask,USER_FPSR(%a6) |set N and Z | |
592 | movel #0x80000000,ETEMP(%a6) |write neg zero to etemp | |
593 | clrl ETEMP_HI(%a6) | |
594 | clrl ETEMP_LO(%a6) | |
595 | bras finish | |
596 | mpos_zero: | |
597 | orl #z_mask,USER_FPSR(%a6) |set Z | |
598 | clrl ETEMP(%a6) | |
599 | clrl ETEMP_HI(%a6) | |
600 | clrl ETEMP_LO(%a6) | |
601 | bras finish | |
602 | ||
603 | mnot_spec: | |
604 | fmovemx %fp0-%fp1,-(%a7) |save fp0 ,fp1 - decbin returns in fp0 | |
605 | bsr decbin | |
606 | fmovex %fp0,ETEMP(%a6) | |
607 | | ;put the unpacked sop in the fsave stack | |
608 | fmovemx (%a7)+,%fp0-%fp1 | |
609 | ||
610 | finish: | |
611 | movew CMDREG1B(%a6),%d0 |get the command word | |
612 | andw #0xfbff,%d0 |change the source specifier field to | |
613 | | ;extended (was packed). | |
614 | movew %d0,CMDREG1B(%a6) |write command word back to fsave stack | |
615 | | ;we need to do this so the 040 will | |
616 | | ;re-execute the inst. without taking | |
617 | | ;another packed trap. | |
618 | ||
619 | fix_stag: | |
620 | |Converted result is now in etemp on fsave stack, now set the source | |
621 | |tag (stag) | |
622 | | if (ete =$7fff) then INF or NAN | |
623 | | if (etemp = $x.0----0) then | |
624 | | stag = INF | |
625 | | else | |
626 | | stag = NAN | |
627 | | else | |
628 | | if (ete = $0000) then | |
629 | | stag = ZERO | |
630 | | else | |
631 | | stag = NORM | |
632 | | | |
633 | | Note also that the etemp_15 bit (just right of the stag) must | |
634 | | be set accordingly. | |
635 | | | |
636 | movew ETEMP_EX(%a6),%d1 | |
637 | andiw #0x7fff,%d1 |strip sign | |
638 | cmpw #0x7fff,%d1 | |
639 | bnes z_or_nrm | |
640 | movel ETEMP_HI(%a6),%d1 | |
641 | bnes is_nan | |
642 | movel ETEMP_LO(%a6),%d1 | |
643 | bnes is_nan | |
644 | is_inf: | |
645 | moveb #0x40,STAG(%a6) | |
646 | movel #0x40,%d0 | |
647 | rts | |
648 | is_nan: | |
649 | moveb #0x60,STAG(%a6) | |
650 | movel #0x60,%d0 | |
651 | rts | |
652 | z_or_nrm: | |
653 | tstw %d1 | |
654 | bnes is_nrm | |
655 | is_zro: | |
656 | | For a zero, set etemp_15 | |
657 | moveb #0x30,STAG(%a6) | |
658 | movel #0x20,%d0 | |
659 | rts | |
660 | is_nrm: | |
661 | | For a norm, check if the exp <= $3fff; if so, set etemp_15 | |
662 | cmpiw #0x3fff,%d1 | |
663 | bles set_bit15 | |
664 | moveb #0,STAG(%a6) | |
665 | bras end_is_nrm | |
666 | set_bit15: | |
667 | moveb #0x10,STAG(%a6) | |
668 | end_is_nrm: | |
669 | movel #0,%d0 | |
670 | end_fix: | |
671 | rts | |
672 | ||
673 | end_get: | |
674 | rts | |
675 | |end |