openpower/isa/fixedshift.mdwn

   1 <!-- This defines instructions described in PowerISA Version 3.0 B Book 1 -->
   2
   3 <!-- Section 3.3.14 Fixed-Point Rotate and Shift Instructions pages 101 - 110 -->
   4 <!-- Section 3.3.14.1 Fixed-Point Rotate Instructions pages 101 - 106 -->
   5 <!-- Section 3.3.14.2 Fixed-Point Shift Instructions pages 107 - 110 -->
   6
   7 <!-- The Fixed-Point Facility performs rotation operations on data from a GPR and -->
   8 <!-- returns the result, or a portion of the result, to a GPR. -->
   9
  10
  11 <!-- Section 3.3.14.1 Fixed-Point Rotate Instructions pages 101 - 106 -->
  12
  13 # Rotate Left Word Immediate then AND with Mask
  14
  15 M-Form
  16
  17 * rlwinm RA,RS,SH,MB,ME (Rc=0)
  18 * rlwinm.  RA,RS,SH,MB,ME (Rc=1)
  19
  20 Pseudo-code:
  21
  22     n <- SH
  23     r <- ROTL32((RS)[XLEN/2:XLEN-1], n)
  24     m <- MASK32(MB, ME)
  25     RA <- r & m
  26
  27 Special Registers Altered:
  28
  29     CR0                    (if Rc=1)
  30
  31 # Rotate Left Word then AND with Mask
  32
  33 M-Form
  34
  35 * rlwnm RA,RS,RB,MB,ME (Rc=0)
  36 * rlwnm.  RA,RS,RB,MB,ME (Rc=1)
  37
  38 Pseudo-code:
  39
  40     n <- (RB)[XLEN-5:XLEN-1]
  41     r <- ROTL32((RS)[32:63], n)
  42     m <- MASK32(MB, ME)
  43     RA <- r & m
  44
  45 Special Registers Altered:
  46
  47     CR0                    (if Rc=1)
  48
  49 # Rotate Left Word Immediate then Mask Insert
  50
  51 M-Form
  52
  53 * rlwimi RA,RS,SH,MB,ME (Rc=0)
  54 * rlwimi.  RA,RS,SH,MB,ME (Rc=1)
  55
  56 Pseudo-code:
  57
  58     n <- SH
  59     r <- ROTL32((RS)[XLEN/2:XLEN-1], n)
  60     m <- MASK32(MB, ME)
  61     RA <- r&m | (RA) & ¬m
  62
  63 Special Registers Altered:
  64
  65     CR0                    (if Rc=1)
  66
  67 # Rotate Left Doubleword Immediate then Clear Left
  68
  69 MD-Form
  70
  71 * rldicl RA,RS,SH,MB (Rc=0)
  72 * rldicl.  RA,RS,SH,MB (Rc=1)
  73
  74 Pseudo-code:
  75
  76     n <- sh
  77     r <- ROTL64((RS), n)
  78     b <- mb[5] || mb[0:4]
  79     m <- MASK(b, (XLEN-1))
  80     RA <- r & m
  81
  82 Special Registers Altered:
  83
  84     CR0                    (if Rc=1)
  85
  86 # Rotate Left Doubleword Immediate then Clear Right
  87
  88 MD-Form
  89
  90 * rldicr RA,RS,SH,ME (Rc=0)
  91 * rldicr.  RA,RS,SH,ME (Rc=1)
  92
  93 Pseudo-code:
  94
  95     n <- sh
  96     r <- ROTL64((RS), n)
  97     e <- me[5] || me[0:4]
  98     m <- MASK(0, e)
  99     RA <- r & m
 100
 101 Special Registers Altered:
 102
 103     CR0                    (if Rc=1)
 104
 105 # Rotate Left Doubleword Immediate then Clear
 106
 107 MD-Form
 108
 109 * rldic RA,RS,SH,MB (Rc=0)
 110 * rldic.  RA,RS,SH,MB (Rc=1)
 111
 112 Pseudo-code:
 113
 114     n <- sh
 115     r <- ROTL64((RS), n)
 116     b <- mb[5] || mb[0:4]
 117     m <- MASK(b,  ¬n)
 118     RA <- r & m
 119
 120 Special Registers Altered:
 121
 122     CR0                    (if Rc=1)
 123
 124 # Rotate Left Doubleword then Clear Left
 125
 126 MDS-Form
 127
 128 * rldcl RA,RS,RB,MB (Rc=0)
 129 * rldcl.  RA,RS,RB,MB (Rc=1)
 130
 131 Pseudo-code:
 132
 133     n <- (RB)[XLEN-5:XLEN-1]
 134     r <- ROTL64((RS), n)
 135     b <- mb[5] || mb[0:4]
 136     m <- MASK(b, (XLEN-1))
 137     RA <- r & m
 138
 139 Special Registers Altered:
 140
 141     CR0                    (if Rc=1)
 142
 143 # Rotate Left Doubleword then Clear Right
 144
 145 MDS-Form
 146
 147 * rldcr RA,RS,RB,ME (Rc=0)
 148 * rldcr.  RA,RS,RB,ME (Rc=1)
 149
 150 Pseudo-code:
 151
 152     n <- (RB)[XLEN-5:XLEN-1]
 153     r <- ROTL64((RS), n)
 154     e <- me[5] || me[0:4]
 155     m <- MASK(0, e)
 156     RA <- r & m
 157
 158 Special Registers Altered:
 159
 160     CR0                    (if Rc=1)
 161
 162 # Rotate Left Doubleword Immediate then Mask Insert
 163
 164 MD-Form
 165
 166 * rldimi RA,RS,SH,MB (Rc=0)
 167 * rldimi.  RA,RS,SH,MB (Rc=1)
 168
 169 Pseudo-code:
 170
 171     n <- sh
 172     r <- ROTL64((RS), n)
 173     b <- mb[5] || mb[0:4]
 174     m <- MASK(b,  ¬n)
 175     RA <- r&m | (RA)& ¬m
 176
 177 Special Registers Altered:
 178
 179     CR0                    (if Rc=1)
 180
 181
 182 <!-- Section 3.3.14.2 Fixed-Point Shift Instructions pages 107 - 110 -->
 183
 184 # Shift Left Word
 185
 186 X-Form
 187
 188 * slw RA,RS,RB (Rc=0)
 189 * slw.  RA,RS,RB (Rc=1)
 190
 191 Pseudo-code:
 192
 193     n <- (RB)[XLEN-5:XLEN-1]
 194     r <- ROTL32((RS)[XLEN/2:XLEN-1], n)
 195     if (RB)[XLEN-6] = 0 then
 196          m <- MASK32(0, ((XLEN/2)-1-n))
 197     else m <- [0]*XLEN
 198     RA <- r & m
 199
 200 Special Registers Altered:
 201
 202     CR0                    (if Rc=1)
 203
 204 # Shift Right Word
 205
 206 X-Form
 207
 208 * srw RA,RS,RB (Rc=0)
 209 * srw.  RA,RS,RB (Rc=1)
 210
 211 Pseudo-code:
 212
 213     n <- (RB)[XLEN-5:XLEN-1]
 214     r <- ROTL32((RS)[XLEN/2:XLEN-1], XLEN-n)
 215     if (RB)[XLEN-6] = 0 then
 216         m <- MASK32(n, ((XLEN/2)-1))
 217     else m <- [0]*XLEN
 218     RA <- r & m
 219
 220 Special Registers Altered:
 221
 222     CR0                    (if Rc=1)
 223
 224 # Shift Right Algebraic Word Immediate
 225
 226 X-Form
 227
 228 * srawi RA,RS,SH (Rc=0)
 229 * srawi.  RA,RS,SH (Rc=1)
 230
 231 Pseudo-code:
 232
 233     n <- SH
 234     r <- ROTL32((RS)[XLEN/2:XLEN-1], 64-n)
 235     m <- MASK32(n, ((XLEN/2)-1))
 236     s <- (RS)[XLEN/2]
 237     RA <- r&m | ([s]*XLEN)& ¬m
 238     carry <- s & ((r&¬m)[XLEN/2:XLEN-1] != 0)
 239     CA    <- carry
 240     CA32  <- carry
 241
 242 Special Registers Altered:
 243
 244     CA CA32
 245     CR0                    (if Rc=1)
 246
 247 # Shift Right Algebraic Word
 248
 249 X-Form
 250
 251 * sraw RA,RS,RB (Rc=0)
 252 * sraw.  RA,RS,RB (Rc=1)
 253
 254 Pseudo-code:
 255
 256     n <- (RB)[XLEN-5:XLEN-1]
 257     r <- ROTL32((RS)[XLEN/2:XLEN-1], XLEN-n)
 258     if (RB)[XLEN-6] = 0 then
 259         m <- MASK32(n, ((XLEN/2)-1))
 260     else m <- [0]*XLEN
 261     s <- (RS)[XLEN/2]
 262     RA <- r&m | ([s]*XLEN)& ¬m
 263     carry <-  s & ((r&¬m)[XLEN/2:XLEN-1] != 0)
 264     CA    <-  carry
 265     CA32  <-  carry
 266
 267 Special Registers Altered:
 268
 269     CA CA32
 270     CR0                    (if Rc=1)
 271
 272 # Shift Left Doubleword
 273
 274 X-Form
 275
 276 * sld RA,RS,RB (Rc=0)
 277 * sld.  RA,RS,RB (Rc=1)
 278
 279 Pseudo-code:
 280
 281     n <- (RB)[XLEN-6:XLEN-1]
 282     r <- ROTL64((RS), n)
 283     if (RB)[XLEN-7] = 0 then
 284          m <- MASK(0, XLEN-1-n)
 285     else m <- [0]*XLEN
 286     RA <- r & m
 287
 288 Special Registers Altered:
 289
 290     CR0                    (if Rc=1)
 291
 292 # Shift Right Doubleword
 293
 294 X-Form
 295
 296 * srd RA,RS,RB (Rc=0)
 297 * srd.  RA,RS,RB (Rc=1)
 298
 299 Pseudo-code:
 300
 301     n <- (RB)[XLEN-6:XLEN-1]
 302     r <- ROTL64((RS), XLEN-n)
 303     if (RB)[XLEN-7] = 0 then
 304         m <-  MASK(n, (XLEN-1))
 305     else m <- [0]*XLEN
 306     RA <- r & m
 307
 308 Special Registers Altered:
 309
 310     CR0                    (if Rc=1)
 311
 312 # Shift Right Algebraic Doubleword Immediate
 313
 314 XS-Form
 315
 316 * sradi RA,RS,SH (Rc=0)
 317 * sradi.  RA,RS,SH (Rc=1)
 318
 319 Pseudo-code:
 320
 321     n <- sh
 322     r <- ROTL64((RS), XLEN-n)
 323     m <- MASK(n, (XLEN-1))
 324     s <- (RS)[0]
 325     RA <- r&m | ([s]*XLEN)& ¬m
 326     carry <- s & ((r& ¬m) != 0)
 327     CA    <- carry
 328     CA32  <- carry
 329
 330 Special Registers Altered:
 331
 332     CA CA32
 333     CR0                    (if Rc=1)
 334
 335 # Shift Right Algebraic Doubleword
 336
 337 X-Form
 338
 339 * srad RA,RS,RB (Rc=0)
 340 * srad.  RA,RS,RB (Rc=1)
 341
 342 Pseudo-code:
 343
 344     n <- (RB)[58:63]
 345     r <- ROTL64((RS), 64-n)
 346     if (RB)[57] = 0 then
 347         m <-  MASK(n, 63)
 348     else m <- [0]*64
 349     s <- (RS)[0]
 350     RA <- r&m | ([s]*64)& ¬m
 351     carry <-  s & ((r&¬m) != 0)
 352     CA    <-  carry
 353     CA32  <-  carry
 354
 355 Special Registers Altered:
 356
 357     CA CA32
 358     CR0                    (if Rc=1)
 359
 360 # Extend-Sign Word and Shift Left Immediate
 361
 362 XS-Form
 363
 364 * extswsli RA,RS,SH (Rc=0)
 365 * extswsli.  RA,RS,SH (Rc=1)
 366
 367 Pseudo-code:
 368
 369     n  <- sh
 370     r  <- ROTL64(EXTS64(RS[XLEN/2:XLEN-1]), n)
 371     m  <- MASK(0, XLEN-1-n)
 372     RA <- r & m
 373
 374 Special Registers Altered:
 375
 376     CR0                     (if Rc=1)
 377
 378 <!-- Checked March 2021 -->