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Diffstat (limited to 'arch/sparc/lib/urem.S')
| -rw-r--r-- | arch/sparc/lib/urem.S | 357 |
1 files changed, 357 insertions, 0 deletions
diff --git a/arch/sparc/lib/urem.S b/arch/sparc/lib/urem.S new file mode 100644 index 00000000000..77123eb83c4 --- /dev/null +++ b/arch/sparc/lib/urem.S | |||
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| 1 | /* | ||
| 2 | * urem.S: This routine was taken from glibc-1.09 and is covered | ||
| 3 | * by the GNU Library General Public License Version 2. | ||
| 4 | */ | ||
| 5 | |||
| 6 | /* This file is generated from divrem.m4; DO NOT EDIT! */ | ||
| 7 | /* | ||
| 8 | * Division and remainder, from Appendix E of the Sparc Version 8 | ||
| 9 | * Architecture Manual, with fixes from Gordon Irlam. | ||
| 10 | */ | ||
| 11 | |||
| 12 | /* | ||
| 13 | * Input: dividend and divisor in %o0 and %o1 respectively. | ||
| 14 | * | ||
| 15 | * m4 parameters: | ||
| 16 | * .urem name of function to generate | ||
| 17 | * rem rem=div => %o0 / %o1; rem=rem => %o0 % %o1 | ||
| 18 | * false false=true => signed; false=false => unsigned | ||
| 19 | * | ||
| 20 | * Algorithm parameters: | ||
| 21 | * N how many bits per iteration we try to get (4) | ||
| 22 | * WORDSIZE total number of bits (32) | ||
| 23 | * | ||
| 24 | * Derived constants: | ||
| 25 | * TOPBITS number of bits in the top decade of a number | ||
| 26 | * | ||
| 27 | * Important variables: | ||
| 28 | * Q the partial quotient under development (initially 0) | ||
| 29 | * R the remainder so far, initially the dividend | ||
| 30 | * ITER number of main division loop iterations required; | ||
| 31 | * equal to ceil(log2(quotient) / N). Note that this | ||
| 32 | * is the log base (2^N) of the quotient. | ||
| 33 | * V the current comparand, initially divisor*2^(ITER*N-1) | ||
| 34 | * | ||
| 35 | * Cost: | ||
| 36 | * Current estimate for non-large dividend is | ||
| 37 | * ceil(log2(quotient) / N) * (10 + 7N/2) + C | ||
| 38 | * A large dividend is one greater than 2^(31-TOPBITS) and takes a | ||
| 39 | * different path, as the upper bits of the quotient must be developed | ||
| 40 | * one bit at a time. | ||
| 41 | */ | ||
| 42 | |||
| 43 | .globl .urem | ||
| 44 | .globl _Urem | ||
| 45 | .urem: | ||
| 46 | _Urem: /* needed for export */ | ||
| 47 | |||
| 48 | ! Ready to divide. Compute size of quotient; scale comparand. | ||
| 49 | orcc %o1, %g0, %o5 | ||
| 50 | bne 1f | ||
| 51 | mov %o0, %o3 | ||
| 52 | |||
| 53 | ! Divide by zero trap. If it returns, return 0 (about as | ||
| 54 | ! wrong as possible, but that is what SunOS does...). | ||
| 55 | ta ST_DIV0 | ||
| 56 | retl | ||
| 57 | clr %o0 | ||
| 58 | |||
| 59 | 1: | ||
| 60 | cmp %o3, %o5 ! if %o1 exceeds %o0, done | ||
| 61 | blu Lgot_result ! (and algorithm fails otherwise) | ||
| 62 | clr %o2 | ||
| 63 | |||
| 64 | sethi %hi(1 << (32 - 4 - 1)), %g1 | ||
| 65 | |||
| 66 | cmp %o3, %g1 | ||
| 67 | blu Lnot_really_big | ||
| 68 | clr %o4 | ||
| 69 | |||
| 70 | ! Here the dividend is >= 2**(31-N) or so. We must be careful here, | ||
| 71 | ! as our usual N-at-a-shot divide step will cause overflow and havoc. | ||
| 72 | ! The number of bits in the result here is N*ITER+SC, where SC <= N. | ||
| 73 | ! Compute ITER in an unorthodox manner: know we need to shift V into | ||
| 74 | ! the top decade: so do not even bother to compare to R. | ||
| 75 | 1: | ||
| 76 | cmp %o5, %g1 | ||
| 77 | bgeu 3f | ||
| 78 | mov 1, %g7 | ||
| 79 | |||
| 80 | sll %o5, 4, %o5 | ||
| 81 | |||
| 82 | b 1b | ||
| 83 | add %o4, 1, %o4 | ||
| 84 | |||
| 85 | ! Now compute %g7. | ||
| 86 | 2: | ||
| 87 | addcc %o5, %o5, %o5 | ||
| 88 | bcc Lnot_too_big | ||
| 89 | add %g7, 1, %g7 | ||
| 90 | |||
| 91 | ! We get here if the %o1 overflowed while shifting. | ||
| 92 | ! This means that %o3 has the high-order bit set. | ||
| 93 | ! Restore %o5 and subtract from %o3. | ||
| 94 | sll %g1, 4, %g1 ! high order bit | ||
| 95 | srl %o5, 1, %o5 ! rest of %o5 | ||
| 96 | add %o5, %g1, %o5 | ||
| 97 | |||
| 98 | b Ldo_single_div | ||
| 99 | sub %g7, 1, %g7 | ||
| 100 | |||
| 101 | Lnot_too_big: | ||
| 102 | 3: | ||
| 103 | cmp %o5, %o3 | ||
| 104 | blu 2b | ||
| 105 | nop | ||
| 106 | |||
| 107 | be Ldo_single_div | ||
| 108 | nop | ||
| 109 | /* NB: these are commented out in the V8-Sparc manual as well */ | ||
| 110 | /* (I do not understand this) */ | ||
| 111 | ! %o5 > %o3: went too far: back up 1 step | ||
| 112 | ! srl %o5, 1, %o5 | ||
| 113 | ! dec %g7 | ||
| 114 | ! do single-bit divide steps | ||
| 115 | ! | ||
| 116 | ! We have to be careful here. We know that %o3 >= %o5, so we can do the | ||
| 117 | ! first divide step without thinking. BUT, the others are conditional, | ||
| 118 | ! and are only done if %o3 >= 0. Because both %o3 and %o5 may have the high- | ||
| 119 | ! order bit set in the first step, just falling into the regular | ||
| 120 | ! division loop will mess up the first time around. | ||
| 121 | ! So we unroll slightly... | ||
| 122 | Ldo_single_div: | ||
| 123 | subcc %g7, 1, %g7 | ||
| 124 | bl Lend_regular_divide | ||
| 125 | nop | ||
| 126 | |||
| 127 | sub %o3, %o5, %o3 | ||
| 128 | mov 1, %o2 | ||
| 129 | |||
| 130 | b Lend_single_divloop | ||
| 131 | nop | ||
| 132 | Lsingle_divloop: | ||
| 133 | sll %o2, 1, %o2 | ||
| 134 | bl 1f | ||
| 135 | srl %o5, 1, %o5 | ||
| 136 | ! %o3 >= 0 | ||
| 137 | sub %o3, %o5, %o3 | ||
| 138 | b 2f | ||
| 139 | add %o2, 1, %o2 | ||
| 140 | 1: ! %o3 < 0 | ||
| 141 | add %o3, %o5, %o3 | ||
| 142 | sub %o2, 1, %o2 | ||
| 143 | 2: | ||
| 144 | Lend_single_divloop: | ||
| 145 | subcc %g7, 1, %g7 | ||
| 146 | bge Lsingle_divloop | ||
| 147 | tst %o3 | ||
| 148 | |||
| 149 | b,a Lend_regular_divide | ||
| 150 | |||
| 151 | Lnot_really_big: | ||
| 152 | 1: | ||
| 153 | sll %o5, 4, %o5 | ||
| 154 | |||
| 155 | cmp %o5, %o3 | ||
| 156 | bleu 1b | ||
| 157 | addcc %o4, 1, %o4 | ||
| 158 | |||
| 159 | be Lgot_result | ||
| 160 | sub %o4, 1, %o4 | ||
| 161 | |||
| 162 | tst %o3 ! set up for initial iteration | ||
| 163 | Ldivloop: | ||
| 164 | sll %o2, 4, %o2 | ||
| 165 | ! depth 1, accumulated bits 0 | ||
| 166 | bl L.1.16 | ||
| 167 | srl %o5,1,%o5 | ||
| 168 | ! remainder is positive | ||
| 169 | subcc %o3,%o5,%o3 | ||
| 170 | ! depth 2, accumulated bits 1 | ||
| 171 | bl L.2.17 | ||
| 172 | srl %o5,1,%o5 | ||
| 173 | ! remainder is positive | ||
| 174 | subcc %o3,%o5,%o3 | ||
| 175 | ! depth 3, accumulated bits 3 | ||
| 176 | bl L.3.19 | ||
| 177 | srl %o5,1,%o5 | ||
| 178 | ! remainder is positive | ||
| 179 | subcc %o3,%o5,%o3 | ||
| 180 | ! depth 4, accumulated bits 7 | ||
| 181 | bl L.4.23 | ||
| 182 | srl %o5,1,%o5 | ||
| 183 | ! remainder is positive | ||
| 184 | subcc %o3,%o5,%o3 | ||
| 185 | b 9f | ||
| 186 | add %o2, (7*2+1), %o2 | ||
| 187 | |||
| 188 | L.4.23: | ||
| 189 | ! remainder is negative | ||
| 190 | addcc %o3,%o5,%o3 | ||
| 191 | b 9f | ||
| 192 | add %o2, (7*2-1), %o2 | ||
| 193 | |||
| 194 | L.3.19: | ||
| 195 | ! remainder is negative | ||
| 196 | addcc %o3,%o5,%o3 | ||
| 197 | ! depth 4, accumulated bits 5 | ||
| 198 | bl L.4.21 | ||
| 199 | srl %o5,1,%o5 | ||
| 200 | ! remainder is positive | ||
| 201 | subcc %o3,%o5,%o3 | ||
| 202 | b 9f | ||
| 203 | add %o2, (5*2+1), %o2 | ||
| 204 | |||
| 205 | L.4.21: | ||
| 206 | ! remainder is negative | ||
| 207 | addcc %o3,%o5,%o3 | ||
| 208 | b 9f | ||
| 209 | add %o2, (5*2-1), %o2 | ||
| 210 | |||
| 211 | L.2.17: | ||
| 212 | ! remainder is negative | ||
| 213 | addcc %o3,%o5,%o3 | ||
| 214 | ! depth 3, accumulated bits 1 | ||
| 215 | bl L.3.17 | ||
| 216 | srl %o5,1,%o5 | ||
| 217 | ! remainder is positive | ||
| 218 | subcc %o3,%o5,%o3 | ||
| 219 | ! depth 4, accumulated bits 3 | ||
| 220 | bl L.4.19 | ||
| 221 | srl %o5,1,%o5 | ||
| 222 | ! remainder is positive | ||
| 223 | subcc %o3,%o5,%o3 | ||
| 224 | b 9f | ||
| 225 | add %o2, (3*2+1), %o2 | ||
| 226 | |||
| 227 | L.4.19: | ||
| 228 | ! remainder is negative | ||
| 229 | addcc %o3,%o5,%o3 | ||
| 230 | b 9f | ||
| 231 | add %o2, (3*2-1), %o2 | ||
| 232 | |||
| 233 | L.3.17: | ||
| 234 | ! remainder is negative | ||
| 235 | addcc %o3,%o5,%o3 | ||
| 236 | ! depth 4, accumulated bits 1 | ||
| 237 | bl L.4.17 | ||
| 238 | srl %o5,1,%o5 | ||
| 239 | ! remainder is positive | ||
| 240 | subcc %o3,%o5,%o3 | ||
| 241 | b 9f | ||
| 242 | add %o2, (1*2+1), %o2 | ||
| 243 | |||
| 244 | L.4.17: | ||
| 245 | ! remainder is negative | ||
| 246 | addcc %o3,%o5,%o3 | ||
| 247 | b 9f | ||
| 248 | add %o2, (1*2-1), %o2 | ||
| 249 | |||
| 250 | L.1.16: | ||
| 251 | ! remainder is negative | ||
| 252 | addcc %o3,%o5,%o3 | ||
| 253 | ! depth 2, accumulated bits -1 | ||
| 254 | bl L.2.15 | ||
| 255 | srl %o5,1,%o5 | ||
| 256 | ! remainder is positive | ||
| 257 | subcc %o3,%o5,%o3 | ||
| 258 | ! depth 3, accumulated bits -1 | ||
| 259 | bl L.3.15 | ||
| 260 | srl %o5,1,%o5 | ||
| 261 | ! remainder is positive | ||
| 262 | subcc %o3,%o5,%o3 | ||
| 263 | ! depth 4, accumulated bits -1 | ||
| 264 | bl L.4.15 | ||
| 265 | srl %o5,1,%o5 | ||
| 266 | ! remainder is positive | ||
| 267 | subcc %o3,%o5,%o3 | ||
| 268 | b 9f | ||
| 269 | add %o2, (-1*2+1), %o2 | ||
| 270 | |||
| 271 | L.4.15: | ||
| 272 | ! remainder is negative | ||
| 273 | addcc %o3,%o5,%o3 | ||
| 274 | b 9f | ||
| 275 | add %o2, (-1*2-1), %o2 | ||
| 276 | |||
| 277 | L.3.15: | ||
| 278 | ! remainder is negative | ||
| 279 | addcc %o3,%o5,%o3 | ||
| 280 | ! depth 4, accumulated bits -3 | ||
| 281 | bl L.4.13 | ||
| 282 | srl %o5,1,%o5 | ||
| 283 | ! remainder is positive | ||
| 284 | subcc %o3,%o5,%o3 | ||
| 285 | b 9f | ||
| 286 | add %o2, (-3*2+1), %o2 | ||
| 287 | |||
| 288 | L.4.13: | ||
| 289 | ! remainder is negative | ||
| 290 | addcc %o3,%o5,%o3 | ||
| 291 | b 9f | ||
| 292 | add %o2, (-3*2-1), %o2 | ||
| 293 | |||
| 294 | L.2.15: | ||
| 295 | ! remainder is negative | ||
| 296 | addcc %o3,%o5,%o3 | ||
| 297 | ! depth 3, accumulated bits -3 | ||
| 298 | bl L.3.13 | ||
| 299 | srl %o5,1,%o5 | ||
| 300 | ! remainder is positive | ||
| 301 | subcc %o3,%o5,%o3 | ||
| 302 | ! depth 4, accumulated bits -5 | ||
| 303 | bl L.4.11 | ||
| 304 | srl %o5,1,%o5 | ||
| 305 | ! remainder is positive | ||
| 306 | subcc %o3,%o5,%o3 | ||
| 307 | b 9f | ||
| 308 | add %o2, (-5*2+1), %o2 | ||
| 309 | |||
| 310 | L.4.11: | ||
| 311 | ! remainder is negative | ||
| 312 | addcc %o3,%o5,%o3 | ||
| 313 | b 9f | ||
| 314 | add %o2, (-5*2-1), %o2 | ||
| 315 | |||
| 316 | L.3.13: | ||
| 317 | ! remainder is negative | ||
| 318 | addcc %o3,%o5,%o3 | ||
| 319 | ! depth 4, accumulated bits -7 | ||
| 320 | bl L.4.9 | ||
| 321 | srl %o5,1,%o5 | ||
| 322 | ! remainder is positive | ||
| 323 | subcc %o3,%o5,%o3 | ||
| 324 | b 9f | ||
| 325 | add %o2, (-7*2+1), %o2 | ||
| 326 | |||
| 327 | L.4.9: | ||
| 328 | ! remainder is negative | ||
| 329 | addcc %o3,%o5,%o3 | ||
| 330 | b 9f | ||
| 331 | add %o2, (-7*2-1), %o2 | ||
| 332 | |||
| 333 | 9: | ||
| 334 | Lend_regular_divide: | ||
| 335 | subcc %o4, 1, %o4 | ||
| 336 | bge Ldivloop | ||
| 337 | tst %o3 | ||
| 338 | |||
| 339 | bl,a Lgot_result | ||
| 340 | ! non-restoring fixup here (one instruction only!) | ||
| 341 | add %o3, %o1, %o3 | ||
| 342 | |||
| 343 | Lgot_result: | ||
| 344 | |||
| 345 | retl | ||
| 346 | mov %o3, %o0 | ||
| 347 | |||
| 348 | .globl .urem_patch | ||
| 349 | .urem_patch: | ||
| 350 | wr %g0, 0x0, %y | ||
| 351 | nop | ||
| 352 | nop | ||
| 353 | nop | ||
| 354 | udiv %o0, %o1, %o2 | ||
| 355 | umul %o2, %o1, %o2 | ||
| 356 | retl | ||
| 357 | sub %o0, %o2, %o0 | ||
