1 | 1 |
2 | scale.sa 3.3 7/30/91 2 | scale.sa 3.3 7/30/91
3 | 3 |
4 | The entry point sSCALE computes the de 4 | The entry point sSCALE computes the destination operand
5 | scaled by the source operand. If the 5 | scaled by the source operand. If the absolute value of
6 | the source operand is (>= 2^14) an ove 6 | the source operand is (>= 2^14) an overflow or underflow
7 | is returned. 7 | is returned.
8 | 8 |
9 | The entry point sscale is called from 9 | The entry point sscale is called from do_func to emulate
10 | the fscale unimplemented instruction. 10 | the fscale unimplemented instruction.
11 | 11 |
12 | Input: Double-extended destination ope 12 | Input: Double-extended destination operand in FPTEMP,
13 | double-extended source operand 13 | double-extended source operand in ETEMP.
14 | 14 |
15 | Output: The function returns scale(X,Y 15 | Output: The function returns scale(X,Y) to fp0.
16 | 16 |
17 | Modifies: fp0. 17 | Modifies: fp0.
18 | 18 |
19 | Algorithm: 19 | Algorithm:
20 | 20 |
21 | Copyright (C) Motorola, Inc. 1 21 | Copyright (C) Motorola, Inc. 1990
22 | All Rights Reserved 22 | All Rights Reserved
23 | 23 |
24 | For details on the license for this fi 24 | For details on the license for this file, please see the
25 | file, README, in this same directory. 25 | file, README, in this same directory.
26 26
27 |SCALE idnt 2,1 | Motorola 040 Floating 27 |SCALE idnt 2,1 | Motorola 040 Floating Point Software Package
28 28
29 |section 8 29 |section 8
30 30
31 #include "fpsp.h" 31 #include "fpsp.h"
32 32
33 |xref t_ovfl2 33 |xref t_ovfl2
34 |xref t_unfl 34 |xref t_unfl
35 |xref round 35 |xref round
36 |xref t_resdnrm 36 |xref t_resdnrm
37 37
38 SRC_BNDS: .short 0x3fff,0x400c 38 SRC_BNDS: .short 0x3fff,0x400c
39 39
40 | 40 |
41 | This entry point is used by the unimplemente 41 | This entry point is used by the unimplemented instruction exception
42 | handler. 42 | handler.
43 | 43 |
44 | 44 |
45 | 45 |
46 | FSCALE 46 | FSCALE
47 | 47 |
48 .global sscale 48 .global sscale
49 sscale: 49 sscale:
50 fmovel #0,%fpcr 50 fmovel #0,%fpcr |clr user enabled exc
51 clrl %d1 51 clrl %d1
52 movew FPTEMP(%a6),%d1 |get d 52 movew FPTEMP(%a6),%d1 |get dest exponent
53 smi L_SCR1(%a6) |use L 53 smi L_SCR1(%a6) |use L_SCR1 to hold sign
54 andil #0x7fff,%d1 |strip 54 andil #0x7fff,%d1 |strip sign
55 movew ETEMP(%a6),%d0 |check 55 movew ETEMP(%a6),%d0 |check src bounds
56 andiw #0x7fff,%d0 |clr s 56 andiw #0x7fff,%d0 |clr sign bit
57 cmp2w SRC_BNDS,%d0 57 cmp2w SRC_BNDS,%d0
58 bccs src_in 58 bccs src_in
59 cmpiw #0x400c,%d0 |test 59 cmpiw #0x400c,%d0 |test for too large
60 bge src_out 60 bge src_out
61 | 61 |
62 | The source input is below 1, so we check for 62 | The source input is below 1, so we check for denormalized numbers
63 | and set unfl. 63 | and set unfl.
64 | 64 |
65 src_small: 65 src_small:
66 moveb DTAG(%a6),%d0 66 moveb DTAG(%a6),%d0
67 andib #0xe0,%d0 67 andib #0xe0,%d0
68 tstb %d0 68 tstb %d0
69 beqs no_denorm 69 beqs no_denorm
70 st STORE_FLG(%a6) |dest 70 st STORE_FLG(%a6) |dest already contains result
71 orl #unfl_mask,USER_FPSR(% 71 orl #unfl_mask,USER_FPSR(%a6) |set UNFL
72 den_done: 72 den_done:
73 leal FPTEMP(%a6),%a0 73 leal FPTEMP(%a6),%a0
74 bra t_resdnrm 74 bra t_resdnrm
75 no_denorm: 75 no_denorm:
76 fmovel USER_FPCR(%a6),%FPCR 76 fmovel USER_FPCR(%a6),%FPCR
77 fmovex FPTEMP(%a6),%fp0 77 fmovex FPTEMP(%a6),%fp0 |simply return dest
78 rts 78 rts
79 79
80 80
81 | 81 |
82 | Source is within 2^14 range. To perform the 82 | Source is within 2^14 range. To perform the int operation,
83 | move it to d0. 83 | move it to d0.
84 | 84 |
85 src_in: 85 src_in:
86 fmovex ETEMP(%a6),%fp0 |move 86 fmovex ETEMP(%a6),%fp0 |move in src for int
87 fmovel #rz_mode,%fpcr |force 87 fmovel #rz_mode,%fpcr |force rz for src conversion
88 fmovel %fp0,%d0 88 fmovel %fp0,%d0 |int src to d0
89 fmovel #0,%FPSR 89 fmovel #0,%FPSR |clr status from above
90 tstw ETEMP(%a6) |check 90 tstw ETEMP(%a6) |check src sign
91 blt src_neg 91 blt src_neg
92 | 92 |
93 | Source is positive. Add the src to the dest 93 | Source is positive. Add the src to the dest exponent.
94 | The result can be denormalized, if src = 0, 94 | The result can be denormalized, if src = 0, or overflow,
95 | if the result of the add sets a bit in the u 95 | if the result of the add sets a bit in the upper word.
96 | 96 |
97 src_pos: 97 src_pos:
98 tstw %d1 |check 98 tstw %d1 |check for denorm
99 beq dst_dnrm 99 beq dst_dnrm
100 addl %d0,%d1 |add s 100 addl %d0,%d1 |add src to dest exp
101 beqs denorm |if ze 101 beqs denorm |if zero, result is denorm
102 cmpil #0x7fff,%d1 |test 102 cmpil #0x7fff,%d1 |test for overflow
103 bges ovfl 103 bges ovfl
104 tstb L_SCR1(%a6) 104 tstb L_SCR1(%a6)
105 beqs spos_pos 105 beqs spos_pos
106 orw #0x8000,%d1 106 orw #0x8000,%d1
107 spos_pos: 107 spos_pos:
108 movew %d1,FPTEMP(%a6) |resul 108 movew %d1,FPTEMP(%a6) |result in FPTEMP
109 fmovel USER_FPCR(%a6),%FPCR 109 fmovel USER_FPCR(%a6),%FPCR
110 fmovex FPTEMP(%a6),%fp0 110 fmovex FPTEMP(%a6),%fp0 |write result to fp0
111 rts 111 rts
112 ovfl: 112 ovfl:
113 tstb L_SCR1(%a6) 113 tstb L_SCR1(%a6)
114 beqs sovl_pos 114 beqs sovl_pos
115 orw #0x8000,%d1 115 orw #0x8000,%d1
116 sovl_pos: 116 sovl_pos:
117 movew FPTEMP(%a6),ETEMP(%a6) 117 movew FPTEMP(%a6),ETEMP(%a6) |result in ETEMP
118 movel FPTEMP_HI(%a6),ETEMP_H 118 movel FPTEMP_HI(%a6),ETEMP_HI(%a6)
119 movel FPTEMP_LO(%a6),ETEMP_L 119 movel FPTEMP_LO(%a6),ETEMP_LO(%a6)
120 bra t_ovfl2 120 bra t_ovfl2
121 121
122 denorm: 122 denorm:
123 tstb L_SCR1(%a6) 123 tstb L_SCR1(%a6)
124 beqs den_pos 124 beqs den_pos
125 orw #0x8000,%d1 125 orw #0x8000,%d1
126 den_pos: 126 den_pos:
127 tstl FPTEMP_HI(%a6) |check 127 tstl FPTEMP_HI(%a6) |check j bit
128 blts nden_exit |if se 128 blts nden_exit |if set, not denorm
129 movew %d1,ETEMP(%a6) |input 129 movew %d1,ETEMP(%a6) |input expected in ETEMP
130 movel FPTEMP_HI(%a6),ETEMP_H 130 movel FPTEMP_HI(%a6),ETEMP_HI(%a6)
131 movel FPTEMP_LO(%a6),ETEMP_L 131 movel FPTEMP_LO(%a6),ETEMP_LO(%a6)
132 orl #unfl_bit,USER_FPSR(%a 132 orl #unfl_bit,USER_FPSR(%a6) |set unfl
133 leal ETEMP(%a6),%a0 133 leal ETEMP(%a6),%a0
134 bra t_resdnrm 134 bra t_resdnrm
135 nden_exit: 135 nden_exit:
136 movew %d1,FPTEMP(%a6) |resul 136 movew %d1,FPTEMP(%a6) |result in FPTEMP
137 fmovel USER_FPCR(%a6),%FPCR 137 fmovel USER_FPCR(%a6),%FPCR
138 fmovex FPTEMP(%a6),%fp0 138 fmovex FPTEMP(%a6),%fp0 |write result to fp0
139 rts 139 rts
140 140
141 | 141 |
142 | Source is negative. Add the src to the dest 142 | Source is negative. Add the src to the dest exponent.
143 | (The result exponent will be reduced). The 143 | (The result exponent will be reduced). The result can be
144 | denormalized. 144 | denormalized.
145 | 145 |
146 src_neg: 146 src_neg:
147 addl %d0,%d1 |add s 147 addl %d0,%d1 |add src to dest
148 beqs denorm |if ze 148 beqs denorm |if zero, result is denorm
149 blts fix_dnrm |if ne 149 blts fix_dnrm |if negative, result is
150 | ;needi 150 | ;needing denormalization
151 tstb L_SCR1(%a6) 151 tstb L_SCR1(%a6)
152 beqs sneg_pos 152 beqs sneg_pos
153 orw #0x8000,%d1 153 orw #0x8000,%d1
154 sneg_pos: 154 sneg_pos:
155 movew %d1,FPTEMP(%a6) |resul 155 movew %d1,FPTEMP(%a6) |result in FPTEMP
156 fmovel USER_FPCR(%a6),%FPCR 156 fmovel USER_FPCR(%a6),%FPCR
157 fmovex FPTEMP(%a6),%fp0 157 fmovex FPTEMP(%a6),%fp0 |write result to fp0
158 rts 158 rts
159 159
160 160
161 | 161 |
162 | The result exponent is below denorm value. 162 | The result exponent is below denorm value. Test for catastrophic
163 | underflow and force zero if true. If not, t 163 | underflow and force zero if true. If not, try to shift the
164 | mantissa right until a zero exponent exists. 164 | mantissa right until a zero exponent exists.
165 | 165 |
166 fix_dnrm: 166 fix_dnrm:
167 cmpiw #0xffc0,%d1 |lower 167 cmpiw #0xffc0,%d1 |lower bound for normalization
168 blt fix_unfl |if lo 168 blt fix_unfl |if lower, catastrophic unfl
169 movew %d1,%d0 |use d 169 movew %d1,%d0 |use d0 for exp
170 movel %d2,-(%a7) |free 170 movel %d2,-(%a7) |free d2 for norm
171 movel FPTEMP_HI(%a6),%d1 171 movel FPTEMP_HI(%a6),%d1
172 movel FPTEMP_LO(%a6),%d2 172 movel FPTEMP_LO(%a6),%d2
173 clrl L_SCR2(%a6) 173 clrl L_SCR2(%a6)
174 fix_loop: 174 fix_loop:
175 addw #1,%d0 |drive 175 addw #1,%d0 |drive d0 to 0
176 lsrl #1,%d1 |while 176 lsrl #1,%d1 |while shifting the
177 roxrl #1,%d2 |manti 177 roxrl #1,%d2 |mantissa to the right
178 bccs no_carry 178 bccs no_carry
179 st L_SCR2(%a6) |use L 179 st L_SCR2(%a6) |use L_SCR2 to capture inex
180 no_carry: 180 no_carry:
181 tstw %d0 |it is 181 tstw %d0 |it is finished when
182 blts fix_loop |d0 is 182 blts fix_loop |d0 is zero or the mantissa
183 tstb L_SCR2(%a6) 183 tstb L_SCR2(%a6)
184 beqs tst_zero 184 beqs tst_zero
185 orl #unfl_inx_mask,USER_FP 185 orl #unfl_inx_mask,USER_FPSR(%a6)
186 | ;set u 186 | ;set unfl, aunfl, ainex
187 | 187 |
188 | Test for zero. If zero, simply use fmove to 188 | Test for zero. If zero, simply use fmove to return +/- zero
189 | to the fpu. 189 | to the fpu.
190 | 190 |
191 tst_zero: 191 tst_zero:
192 clrw FPTEMP_EX(%a6) 192 clrw FPTEMP_EX(%a6)
193 tstb L_SCR1(%a6) |test 193 tstb L_SCR1(%a6) |test for sign
194 beqs tst_con 194 beqs tst_con
195 orw #0x8000,FPTEMP_EX(%a6) 195 orw #0x8000,FPTEMP_EX(%a6) |set sign bit
196 tst_con: 196 tst_con:
197 movel %d1,FPTEMP_HI(%a6) 197 movel %d1,FPTEMP_HI(%a6)
198 movel %d2,FPTEMP_LO(%a6) 198 movel %d2,FPTEMP_LO(%a6)
199 movel (%a7)+,%d2 199 movel (%a7)+,%d2
200 tstl %d1 200 tstl %d1
201 bnes not_zero 201 bnes not_zero
202 tstl FPTEMP_LO(%a6) 202 tstl FPTEMP_LO(%a6)
203 bnes not_zero 203 bnes not_zero
204 | 204 |
205 | Result is zero. Check for rounding mode to 205 | Result is zero. Check for rounding mode to set lsb. If the
206 | mode is rp, and the zero is positive, return 206 | mode is rp, and the zero is positive, return smallest denorm.
207 | If the mode is rm, and the zero is negative, 207 | If the mode is rm, and the zero is negative, return smallest
208 | negative denorm. 208 | negative denorm.
209 | 209 |
210 btstb #5,FPCR_MODE(%a6) |tes 210 btstb #5,FPCR_MODE(%a6) |test if rm or rp
211 beqs no_dir 211 beqs no_dir
212 btstb #4,FPCR_MODE(%a6) |che 212 btstb #4,FPCR_MODE(%a6) |check which one
213 beqs zer_rm 213 beqs zer_rm
214 zer_rp: 214 zer_rp:
215 tstb L_SCR1(%a6) |check 215 tstb L_SCR1(%a6) |check sign
216 bnes no_dir |if se 216 bnes no_dir |if set, neg op, no inc
217 movel #1,FPTEMP_LO(%a6) |set 217 movel #1,FPTEMP_LO(%a6) |set lsb
218 bras sm_dnrm 218 bras sm_dnrm
219 zer_rm: 219 zer_rm:
220 tstb L_SCR1(%a6) |check 220 tstb L_SCR1(%a6) |check sign
221 beqs no_dir |if cl 221 beqs no_dir |if clr, neg op, no inc
222 movel #1,FPTEMP_LO(%a6) |set 222 movel #1,FPTEMP_LO(%a6) |set lsb
223 orl #neg_mask,USER_FPSR(%a 223 orl #neg_mask,USER_FPSR(%a6) |set N
224 bras sm_dnrm 224 bras sm_dnrm
225 no_dir: 225 no_dir:
226 fmovel USER_FPCR(%a6),%FPCR 226 fmovel USER_FPCR(%a6),%FPCR
227 fmovex FPTEMP(%a6),%fp0 227 fmovex FPTEMP(%a6),%fp0 |use fmove to set cc's
228 rts 228 rts
229 229
230 | 230 |
231 | The rounding mode changed the zero to a smal 231 | The rounding mode changed the zero to a smallest denorm. Call
232 | t_resdnrm with exceptional operand in ETEMP. 232 | t_resdnrm with exceptional operand in ETEMP.
233 | 233 |
234 sm_dnrm: 234 sm_dnrm:
235 movel FPTEMP_EX(%a6),ETEMP_E 235 movel FPTEMP_EX(%a6),ETEMP_EX(%a6)
236 movel FPTEMP_HI(%a6),ETEMP_H 236 movel FPTEMP_HI(%a6),ETEMP_HI(%a6)
237 movel FPTEMP_LO(%a6),ETEMP_L 237 movel FPTEMP_LO(%a6),ETEMP_LO(%a6)
238 leal ETEMP(%a6),%a0 238 leal ETEMP(%a6),%a0
239 bra t_resdnrm 239 bra t_resdnrm
240 240
241 | 241 |
242 | Result is still denormalized. 242 | Result is still denormalized.
243 | 243 |
244 not_zero: 244 not_zero:
245 orl #unfl_mask,USER_FPSR(% 245 orl #unfl_mask,USER_FPSR(%a6) |set unfl
246 tstb L_SCR1(%a6) |check 246 tstb L_SCR1(%a6) |check for sign
247 beqs fix_exit 247 beqs fix_exit
248 orl #neg_mask,USER_FPSR(%a 248 orl #neg_mask,USER_FPSR(%a6) |set N
249 fix_exit: 249 fix_exit:
250 bras sm_dnrm 250 bras sm_dnrm
251 251
252 252
253 | 253 |
254 | The result has underflowed to zero. Return z 254 | The result has underflowed to zero. Return zero and set
255 | unfl, aunfl, and ainex. 255 | unfl, aunfl, and ainex.
256 | 256 |
257 fix_unfl: 257 fix_unfl:
258 orl #unfl_inx_mask,USER_FP 258 orl #unfl_inx_mask,USER_FPSR(%a6)
259 btstb #5,FPCR_MODE(%a6) |tes 259 btstb #5,FPCR_MODE(%a6) |test if rm or rp
260 beqs no_dir2 260 beqs no_dir2
261 btstb #4,FPCR_MODE(%a6) |che 261 btstb #4,FPCR_MODE(%a6) |check which one
262 beqs zer_rm2 262 beqs zer_rm2
263 zer_rp2: 263 zer_rp2:
264 tstb L_SCR1(%a6) |check 264 tstb L_SCR1(%a6) |check sign
265 bnes no_dir2 |if se 265 bnes no_dir2 |if set, neg op, no inc
266 clrl FPTEMP_EX(%a6) 266 clrl FPTEMP_EX(%a6)
267 clrl FPTEMP_HI(%a6) 267 clrl FPTEMP_HI(%a6)
268 movel #1,FPTEMP_LO(%a6) |set 268 movel #1,FPTEMP_LO(%a6) |set lsb
269 bras sm_dnrm |retur 269 bras sm_dnrm |return smallest denorm
270 zer_rm2: 270 zer_rm2:
271 tstb L_SCR1(%a6) |check 271 tstb L_SCR1(%a6) |check sign
272 beqs no_dir2 |if cl 272 beqs no_dir2 |if clr, neg op, no inc
273 movew #0x8000,FPTEMP_EX(%a6) 273 movew #0x8000,FPTEMP_EX(%a6)
274 clrl FPTEMP_HI(%a6) 274 clrl FPTEMP_HI(%a6)
275 movel #1,FPTEMP_LO(%a6) |set 275 movel #1,FPTEMP_LO(%a6) |set lsb
276 orl #neg_mask,USER_FPSR(%a 276 orl #neg_mask,USER_FPSR(%a6) |set N
277 bra sm_dnrm |retur 277 bra sm_dnrm |return smallest denorm
278 278
279 no_dir2: 279 no_dir2:
280 tstb L_SCR1(%a6) 280 tstb L_SCR1(%a6)
281 bges pos_zero 281 bges pos_zero
282 neg_zero: 282 neg_zero:
283 clrl FP_SCR1(%a6) |clear 283 clrl FP_SCR1(%a6) |clear the exceptional operand
284 clrl FP_SCR1+4(%a6) |for g 284 clrl FP_SCR1+4(%a6) |for gen_except.
285 clrl FP_SCR1+8(%a6) 285 clrl FP_SCR1+8(%a6)
286 fmoves #0x80000000,%fp0 286 fmoves #0x80000000,%fp0
287 rts 287 rts
288 pos_zero: 288 pos_zero:
289 clrl FP_SCR1(%a6) |clear 289 clrl FP_SCR1(%a6) |clear the exceptional operand
290 clrl FP_SCR1+4(%a6) |for g 290 clrl FP_SCR1+4(%a6) |for gen_except.
291 clrl FP_SCR1+8(%a6) 291 clrl FP_SCR1+8(%a6)
292 fmoves #0x00000000,%fp0 292 fmoves #0x00000000,%fp0
293 rts 293 rts
294 294
295 | 295 |
296 | The destination is a denormalized number. I 296 | The destination is a denormalized number. It must be handled
297 | by first shifting the bits in the mantissa u 297 | by first shifting the bits in the mantissa until it is normalized,
298 | then adding the remainder of the source to t 298 | then adding the remainder of the source to the exponent.
299 | 299 |
300 dst_dnrm: 300 dst_dnrm:
301 moveml %d2/%d3,-(%a7) 301 moveml %d2/%d3,-(%a7)
302 movew FPTEMP_EX(%a6),%d1 302 movew FPTEMP_EX(%a6),%d1
303 movel FPTEMP_HI(%a6),%d2 303 movel FPTEMP_HI(%a6),%d2
304 movel FPTEMP_LO(%a6),%d3 304 movel FPTEMP_LO(%a6),%d3
305 dst_loop: 305 dst_loop:
306 tstl %d2 |test 306 tstl %d2 |test for normalized result
307 blts dst_norm |exit 307 blts dst_norm |exit loop if so
308 tstl %d0 |other 308 tstl %d0 |otherwise, test shift count
309 beqs dst_fin |if ze 309 beqs dst_fin |if zero, shifting is done
310 subil #1,%d0 |dec s 310 subil #1,%d0 |dec src
311 lsll #1,%d3 311 lsll #1,%d3
312 roxll #1,%d2 312 roxll #1,%d2
313 bras dst_loop 313 bras dst_loop
314 | 314 |
315 | Destination became normalized. Simply add t 315 | Destination became normalized. Simply add the remaining
316 | portion of the src to the exponent. 316 | portion of the src to the exponent.
317 | 317 |
318 dst_norm: 318 dst_norm:
319 addw %d0,%d1 |dst i 319 addw %d0,%d1 |dst is normalized; add src
320 tstb L_SCR1(%a6) 320 tstb L_SCR1(%a6)
321 beqs dnrm_pos 321 beqs dnrm_pos
322 orl #0x8000,%d1 322 orl #0x8000,%d1
323 dnrm_pos: 323 dnrm_pos:
324 movemw %d1,FPTEMP_EX(%a6) 324 movemw %d1,FPTEMP_EX(%a6)
325 moveml %d2,FPTEMP_HI(%a6) 325 moveml %d2,FPTEMP_HI(%a6)
326 moveml %d3,FPTEMP_LO(%a6) 326 moveml %d3,FPTEMP_LO(%a6)
327 fmovel USER_FPCR(%a6),%FPCR 327 fmovel USER_FPCR(%a6),%FPCR
328 fmovex FPTEMP(%a6),%fp0 328 fmovex FPTEMP(%a6),%fp0
329 moveml (%a7)+,%d2/%d3 329 moveml (%a7)+,%d2/%d3
330 rts 330 rts
331 331
332 | 332 |
333 | Destination remained denormalized. Call t_e 333 | Destination remained denormalized. Call t_excdnrm with
334 | exceptional operand in ETEMP. 334 | exceptional operand in ETEMP.
335 | 335 |
336 dst_fin: 336 dst_fin:
337 tstb L_SCR1(%a6) |check 337 tstb L_SCR1(%a6) |check for sign
338 beqs dst_exit 338 beqs dst_exit
339 orl #neg_mask,USER_FPSR(%a 339 orl #neg_mask,USER_FPSR(%a6) |set N
340 orl #0x8000,%d1 340 orl #0x8000,%d1
341 dst_exit: 341 dst_exit:
342 movemw %d1,ETEMP_EX(%a6) 342 movemw %d1,ETEMP_EX(%a6)
343 moveml %d2,ETEMP_HI(%a6) 343 moveml %d2,ETEMP_HI(%a6)
344 moveml %d3,ETEMP_LO(%a6) 344 moveml %d3,ETEMP_LO(%a6)
345 orl #unfl_mask,USER_FPSR(% 345 orl #unfl_mask,USER_FPSR(%a6) |set unfl
346 moveml (%a7)+,%d2/%d3 346 moveml (%a7)+,%d2/%d3
347 leal ETEMP(%a6),%a0 347 leal ETEMP(%a6),%a0
348 bra t_resdnrm 348 bra t_resdnrm
349 349
350 | 350 |
351 | Source is outside of 2^14 range. Test the s 351 | Source is outside of 2^14 range. Test the sign and branch
352 | to the appropriate exception handler. 352 | to the appropriate exception handler.
353 | 353 |
354 src_out: 354 src_out:
355 tstb L_SCR1(%a6) 355 tstb L_SCR1(%a6)
356 beqs scro_pos 356 beqs scro_pos
357 orl #0x8000,%d1 357 orl #0x8000,%d1
358 scro_pos: 358 scro_pos:
359 movel FPTEMP_HI(%a6),ETEMP_H 359 movel FPTEMP_HI(%a6),ETEMP_HI(%a6)
360 movel FPTEMP_LO(%a6),ETEMP_L 360 movel FPTEMP_LO(%a6),ETEMP_LO(%a6)
361 tstw ETEMP(%a6) 361 tstw ETEMP(%a6)
362 blts res_neg 362 blts res_neg
363 res_pos: 363 res_pos:
364 movew %d1,ETEMP(%a6) |resul 364 movew %d1,ETEMP(%a6) |result in ETEMP
365 bra t_ovfl2 365 bra t_ovfl2
366 res_neg: 366 res_neg:
367 movew %d1,ETEMP(%a6) |resul 367 movew %d1,ETEMP(%a6) |result in ETEMP
368 leal ETEMP(%a6),%a0 368 leal ETEMP(%a6),%a0
369 bra t_unfl 369 bra t_unfl
370 |end 370 |end
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