contrib/sb-rotate-byte/arm-vm.lisp

   1 (in-package "SB-ROTATE-BYTE")
   2
   3 (define-vop (%32bit-rotate-byte/c)
   4   (:policy :fast-safe)
   5   (:translate %unsigned-32-rotate-byte)
   6   (:note "inline 32-bit constant rotation")
   7   (:info count)
   8   (:args (integer :scs (sb-vm::unsigned-reg) :target res))
   9   (:arg-types (:constant (integer -31 31)) sb-vm::unsigned-byte-32)
  10   (:results (res :scs (sb-vm::unsigned-reg)))
  11   (:result-types sb-vm::unsigned-byte-32)
  12   (:generator 5
  13     ;; the 0 case is an identity operation and should be
  14     ;; DEFTRANSFORMed away.
  15     (aver (not (= count 0)))
  16     (inst mov res (sb-vm::ror integer (if (plusp count)
  17                                           (- 32 count)
  18                                           (- count))))))
  19
  20 (define-vop (%32bit-rotate-byte-fixnum/c)
  21   (:policy :fast-safe)
  22   (:translate %unsigned-32-rotate-byte)
  23   (:note "inline 32-bit constant rotation")
  24   (:info count)
  25   (:args (integer :scs (sb-vm::any-reg) :target res))
  26   (:arg-types (:constant (integer -31 31)) sb-vm::positive-fixnum)
  27   (:results (res :scs (sb-vm::unsigned-reg)))
  28   (:result-types sb-vm::unsigned-byte-32)
  29   (:generator 5
  30     (aver (not (= count 0)))
  31     (cond
  32       ((= count n-fixnum-tag-bits))
  33       (t
  34        (inst mov res (sb-vm::ror integer (if (> count 2)
  35                                              (- (+ 32 n-fixnum-tag-bits) count)
  36                                              (- 2 count))))))))
  37
  38 (macrolet ((def (name arg-type)
  39              `(define-vop (,name)
  40                (:policy :fast-safe)
  41                (:translate %unsigned-32-rotate-byte)
  42                (:note "inline 32-bit rotation")
  43                (:args (count :scs (sb-vm::signed-reg) :target res)
  44                       (integer :scs (sb-vm::unsigned-reg)))
  45                (:arg-types sb-vm::tagged-num ,arg-type)
  46                (:results (res :scs (sb-vm::unsigned-reg)))
  47                (:result-types sb-vm::unsigned-byte-32)
  48                (:generator 10
  49                 (inst cmp count 0)
  50                 (inst rsb :gt res count 32)
  51                 (inst rsb :le res count 0)
  52                 (inst mov res (sb-vm::ror integer res))))))
  53   (def %32bit-rotate-byte sb-vm::unsigned-byte-32)
  54   ;; FIXME: see x86-vm.lisp
  55   (def %32bit-rotate-byte-fixnum sb-vm::positive-fixnum))