src/assembly/x86/arith.lisp

   1 ;;;; simple cases for generic arithmetic
   2
   3 ;;;; This software is part of the SBCL system. See the README file for
   4 ;;;; more information.
   5 ;;;;
   6 ;;;; This software is derived from the CMU CL system, which was
   7 ;;;; written at Carnegie Mellon University and released into the
   8 ;;;; public domain. The software is in the public domain and is
   9 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
  10 ;;;; files for more information.
  11
  12 (in-package "SB!VM")
  13 \f
  14 ;;;; addition, subtraction, and multiplication
  15
  16 (macrolet ((define-generic-arith-routine ((fun cost) &body body)
  17              `(define-assembly-routine (,(symbolicate "GENERIC-" fun)
  18                                         (:cost ,cost)
  19                                         (:return-style :full-call)
  20                                         (:translate ,fun)
  21                                         (:policy :safe)
  22                                         (:save-p t))
  23                 ((:arg x (descriptor-reg any-reg) edx-offset)
  24                  (:arg y (descriptor-reg any-reg)
  25                        ;; this seems wrong esi-offset -- FIXME: What's it mean?
  26                        edi-offset)
  27
  28                  (:res res (descriptor-reg any-reg) edx-offset)
  29
  30                  (:temp eax unsigned-reg eax-offset)
  31                  (:temp ecx unsigned-reg ecx-offset))
  32
  33                 (inst mov ecx x)
  34                 (inst or ecx y)
  35                 (inst test ecx fixnum-tag-mask)  ; both fixnums?
  36                 (inst jmp :nz DO-STATIC-FUN)     ; no - do generic
  37
  38                 ,@body
  39                 (inst clc) ; single-value return
  40                 (inst ret)
  41
  42                 DO-STATIC-FUN
  43                 (inst pop eax)
  44                 (inst push ebp-tn)
  45                 (inst lea
  46                       ebp-tn
  47                       (make-ea :dword :base esp-tn :disp n-word-bytes))
  48                 (inst sub esp-tn (fixnumize 2))
  49                 (inst push eax)  ; callers return addr
  50                 (inst mov ecx (fixnumize 2)) ; arg count
  51                 (inst jmp
  52                       (make-ea :dword
  53                                :disp (+ nil-value
  54                                         (static-fun-offset
  55                                          ',(symbolicate "TWO-ARG-" fun))))))))
  56
  57   (define-generic-arith-routine (+ 10)
  58     (move res x)
  59     (inst add res y)
  60     (inst jmp :no OKAY)
  61     (inst rcr res 1)                  ; carry has correct sign
  62     (inst sar res 1)                  ; remove type bits
  63
  64     (move ecx res)
  65
  66     (with-fixed-allocation (res bignum-widetag (1+ bignum-digits-offset))
  67       (storew ecx res bignum-digits-offset other-pointer-lowtag))
  68
  69     OKAY)
  70
  71   (define-generic-arith-routine (- 10)
  72     (move res x)
  73     (inst sub res y)
  74     (inst jmp :no OKAY)
  75     (inst cmc)                        ; carry has correct sign now
  76     (inst rcr res 1)
  77     (inst sar res 1)                  ; remove type bits
  78
  79     (move ecx res)
  80
  81     (with-fixed-allocation (res bignum-widetag (1+ bignum-digits-offset))
  82       (storew ecx res bignum-digits-offset other-pointer-lowtag))
  83     OKAY)
  84
  85   (define-generic-arith-routine (* 30)
  86     (move eax x)                          ; must use eax for 64-bit result
  87     (inst sar eax n-fixnum-tag-bits)      ; remove *4 fixnum bias
  88     (inst imul y)                         ; result in edx:eax
  89     (inst jmp :no okay)                   ; still fixnum
  90
  91     ;; zzz jrd changed edx to ebx in here, as edx isn't listed as a temp, above
  92     ;;     pfw says that loses big -- edx is target for arg x and result res
  93     ;;     note that 'edx' is not defined -- using x
  94     (inst shrd eax x n-fixnum-tag-bits)    ; high bits from edx
  95     (inst sar x n-fixnum-tag-bits)         ; now shift edx too
  96
  97     (move ecx x)                           ; save high bits from cdq
  98     (inst cdq)                             ; edx:eax <- sign-extend of eax
  99     (inst cmp x ecx)
 100     (inst jmp :e SINGLE-WORD-BIGNUM)
 101
 102     (with-fixed-allocation (res bignum-widetag (+ bignum-digits-offset 2))
 103       (storew eax res bignum-digits-offset other-pointer-lowtag)
 104       (storew ecx res (1+ bignum-digits-offset) other-pointer-lowtag))
 105     (inst jmp DONE)
 106
 107     SINGLE-WORD-BIGNUM
 108
 109     (with-fixed-allocation (res bignum-widetag (1+ bignum-digits-offset))
 110       (storew eax res bignum-digits-offset other-pointer-lowtag))
 111     (inst jmp DONE)
 112
 113     OKAY
 114     (move res eax)
 115     DONE))
 116 \f
 117 ;;;; negation
 118
 119 (define-assembly-routine (generic-negate
 120                           (:cost 10)
 121                           (:return-style :full-call)
 122                           (:policy :safe)
 123                           (:translate %negate)
 124                           (:save-p t))
 125                          ((:arg x (descriptor-reg any-reg) edx-offset)
 126                           (:res res (descriptor-reg any-reg) edx-offset)
 127
 128                           (:temp eax unsigned-reg eax-offset)
 129                           (:temp ecx unsigned-reg ecx-offset))
 130   (inst test x fixnum-tag-mask)
 131   (inst jmp :z FIXNUM)
 132
 133   (inst pop eax)
 134   (inst push ebp-tn)
 135   (inst lea ebp-tn (make-ea :dword :base esp-tn :disp n-word-bytes))
 136   (inst sub esp-tn (fixnumize 2))
 137   (inst push eax)
 138   (inst mov ecx (fixnumize 1))    ; arg count
 139   (inst jmp (make-ea :dword
 140                      :disp (+ nil-value (static-fun-offset '%negate))))
 141
 142   FIXNUM
 143   (move res x)
 144   (inst neg res)                        ; (- most-negative-fixnum) is BIGNUM
 145   (inst jmp :no OKAY)
 146   (inst shr res n-fixnum-tag-bits)      ; sign bit is data - remove type bits
 147   (move ecx res)
 148
 149   (with-fixed-allocation (res bignum-widetag (1+ bignum-digits-offset))
 150     (storew ecx res bignum-digits-offset other-pointer-lowtag))
 151
 152   OKAY)
 153 \f
 154 ;;;; comparison
 155
 156 (macrolet ((define-cond-assem-rtn (name translate static-fn test)
 157              `(define-assembly-routine (,name
 158                                         (:cost 10)
 159                                         (:return-style :full-call)
 160                                         (:policy :safe)
 161                                         (:translate ,translate)
 162                                         (:save-p t))
 163                 ((:arg x (descriptor-reg any-reg) edx-offset)
 164                  (:arg y (descriptor-reg any-reg) edi-offset)
 165
 166                  (:res res descriptor-reg edx-offset)
 167
 168                  (:temp eax unsigned-reg eax-offset)
 169                  (:temp ecx unsigned-reg ecx-offset))
 170
 171                 (inst mov ecx x)
 172                 (inst or ecx y)
 173                 (inst test ecx fixnum-tag-mask)
 174                 (inst jmp :nz DO-STATIC-FUN)  ; are both fixnums?
 175
 176                 (inst cmp x y)
 177                 (cond ((member :cmov *backend-subfeatures*)
 178                        (load-symbol res t)
 179                        (inst mov eax nil-value)
 180                        (inst cmov ,test res eax))
 181                       (t
 182                        (inst mov res nil-value)
 183                        (inst jmp ,test RETURN)
 184                        (load-symbol res t)))
 185                 RETURN
 186                 (inst clc)     ; single-value return
 187                 (inst ret)
 188
 189                 DO-STATIC-FUN
 190                 (inst pop eax)
 191                 (inst push ebp-tn)
 192                 (inst lea ebp-tn (make-ea :dword
 193                                           :base esp-tn
 194                                           :disp n-word-bytes))
 195                 (inst sub esp-tn (fixnumize 2)) ; FIXME: Push 2 words on stack,
 196                                                 ; weirdly?
 197                 (inst push eax)
 198                 (inst mov ecx (fixnumize 2)) ; FIXME: FIXNUMIZE and
 199                                         ; SINGLE-FLOAT-BITS are parallel,
 200                                         ; should be named parallelly.
 201                 (inst jmp (make-ea :dword
 202                                    :disp (+ nil-value
 203                                             (static-fun-offset ',static-fn)))))))
 204
 205   (define-cond-assem-rtn generic-< < two-arg-< :ge)
 206   (define-cond-assem-rtn generic-> > two-arg-> :le))
 207
 208 (define-assembly-routine (generic-eql
 209                           (:cost 10)
 210                           (:return-style :full-call)
 211                           (:policy :safe)
 212                           (:translate eql)
 213                           (:save-p t))
 214                          ((:arg x (descriptor-reg any-reg) edx-offset)
 215                           (:arg y (descriptor-reg any-reg) edi-offset)
 216
 217                           (:res res descriptor-reg edx-offset)
 218
 219                           (:temp eax unsigned-reg eax-offset)
 220                           (:temp ecx unsigned-reg ecx-offset))
 221   (inst mov ecx x)
 222   (inst and ecx y)
 223   (inst test ecx fixnum-tag-mask)
 224   (inst jmp :nz DO-STATIC-FUN)
 225
 226   ;; At least one fixnum
 227   (inst cmp x y)
 228   (load-symbol res t)
 229   (cond ((member :cmov *backend-subfeatures*)
 230          (inst mov eax nil-value)
 231          (inst cmov :ne res eax))
 232         (t
 233          (inst jmp :e RETURN)
 234          (inst mov res nil-value)))
 235   RETURN
 236   (inst clc)
 237   (inst ret)
 238
 239   ;; FIXME: We could handle all non-numbers here easily enough: go to
 240   ;; TWO-ARG-EQL only if lowtags and widetags match, lowtag is
 241   ;; other-pointer-lowtag and widetag is < code-header-widetag.
 242   DO-STATIC-FUN
 243   (inst pop eax)
 244   (inst push ebp-tn)
 245   (inst lea ebp-tn (make-ea :dword :base esp-tn :disp n-word-bytes))
 246   (inst sub esp-tn (fixnumize 2))
 247   (inst push eax)
 248   (inst mov ecx (fixnumize 2))
 249   (inst jmp (make-ea :dword
 250                      :disp (+ nil-value (static-fun-offset 'eql)))))
 251
 252 (define-assembly-routine (generic-=
 253                           (:cost 10)
 254                           (:return-style :full-call)
 255                           (:policy :safe)
 256                           (:translate =)
 257                           (:save-p t))
 258                          ((:arg x (descriptor-reg any-reg) edx-offset)
 259                           (:arg y (descriptor-reg any-reg) edi-offset)
 260
 261                           (:res res descriptor-reg edx-offset)
 262
 263                           (:temp eax unsigned-reg eax-offset)
 264                           (:temp ecx unsigned-reg ecx-offset))
 265   (inst mov ecx x)
 266   (inst or ecx y)
 267   (inst test ecx fixnum-tag-mask)        ; both fixnums?
 268   (inst jmp :nz DO-STATIC-FUN)
 269
 270   (inst cmp x y)
 271   (load-symbol res t)
 272   (cond ((member :cmov *backend-subfeatures*)
 273          (inst mov eax nil-value)
 274          (inst cmov :ne res eax))
 275         (t
 276          (inst jmp :e RETURN)
 277          (inst mov res nil-value)))
 278   RETURN
 279   (inst clc)
 280   (inst ret)
 281
 282   DO-STATIC-FUN
 283   (inst pop eax)
 284   (inst push ebp-tn)
 285   (inst lea ebp-tn (make-ea :dword :base esp-tn :disp n-word-bytes))
 286   (inst sub esp-tn (fixnumize 2))
 287   (inst push eax)
 288   (inst mov ecx (fixnumize 2))
 289   (inst jmp (make-ea :dword
 290                      :disp (+ nil-value (static-fun-offset 'two-arg-=)))))
 291
 292 \f
 293 ;;; Support for the Mersenne Twister, MT19937, random number generator
 294 ;;; due to Matsumoto and Nishimura.
 295 ;;;
 296 ;;; Makoto Matsumoto and T. Nishimura, "Mersenne twister: A
 297 ;;; 623-dimensionally equidistributed uniform pseudorandom number
 298 ;;; generator.", ACM Transactions on Modeling and Computer Simulation,
 299 ;;; 1997, to appear.
 300 ;;;
 301 ;;; State:
 302 ;;;  0-1:   Constant matrix A. [0, #x9908b0df] (not used here)
 303 ;;;  2:     Index; init. to 1.
 304 ;;;  3-626: State.
 305
 306 ;;; This assembly routine is called from the inline VOP and updates
 307 ;;; the state vector with new random numbers. The state vector is
 308 ;;; passed in the EAX register.
 309 #+sb-assembling ; We don't want a vop for this one.
 310 (define-assembly-routine
 311     (random-mt19937-update)
 312     ((:temp state unsigned-reg eax-offset)
 313      (:temp k unsigned-reg ebx-offset)
 314      (:temp y unsigned-reg ecx-offset)
 315      (:temp tmp unsigned-reg edx-offset))
 316
 317   ;; Save the temporary registers.
 318   (inst push k)
 319   (inst push y)
 320   (inst push tmp)
 321
 322   ;; Generate a new set of results.
 323   (inst xor k k)
 324   LOOP1
 325   (inst mov y (make-ea-for-vector-data state :index k :offset 3))
 326   (inst mov tmp (make-ea-for-vector-data state :index k :offset (+ 1 3)))
 327   (inst and y #x80000000)
 328   (inst and tmp #x7fffffff)
 329   (inst or y tmp)
 330   (inst shr y 1)
 331   (inst jmp :nc skip1)
 332   (inst xor y #x9908b0df)
 333   SKIP1
 334   (inst xor y (make-ea-for-vector-data state :index k :offset (+ 397 3)))
 335   (inst mov (make-ea-for-vector-data state :index k :offset 3) y)
 336   (inst inc k)
 337   (inst cmp k (- 624 397))
 338   (inst jmp :b loop1)
 339   LOOP2
 340   (inst mov y (make-ea-for-vector-data state :index k :offset 3))
 341   (inst mov tmp (make-ea-for-vector-data state :index k :offset (+ 1 3)))
 342   (inst and y #x80000000)
 343   (inst and tmp #x7fffffff)
 344   (inst or y tmp)
 345   (inst shr y 1)
 346   (inst jmp :nc skip2)
 347   (inst xor y #x9908b0df)
 348   SKIP2
 349   (inst xor y (make-ea-for-vector-data state :index k :offset (+ (- 397 624) 3)))
 350   (inst mov (make-ea-for-vector-data state :index k :offset 3) y)
 351   (inst inc k)
 352   (inst cmp k (- 624 1))
 353   (inst jmp :b loop2)
 354
 355   (inst mov y (make-ea-for-vector-data state :offset (+ (- 624 1) 3)))
 356   (inst mov tmp (make-ea-for-vector-data state :offset (+ 0 3)))
 357   (inst and y #x80000000)
 358   (inst and tmp #x7fffffff)
 359   (inst or y tmp)
 360   (inst shr y 1)
 361   (inst jmp :nc skip3)
 362   (inst xor y #x9908b0df)
 363   SKIP3
 364   (inst xor y (make-ea-for-vector-data state :offset (+ (- 397 1) 3)))
 365   (inst mov (make-ea-for-vector-data state :offset (+ (- 624 1) 3)) y)
 366
 367   ;; Restore the temporary registers and return.
 368   (inst pop tmp)
 369   (inst pop y)
 370   (inst pop k)
 371   (inst ret))