(in-package "SB-ROTATE-BYTE") (define-vop (%32bit-rotate-byte/c)   (:policy :fast-safe)   (:translate %unsigned-32-rotate-byte)   (:note "inline 32-bit constant rotation")   (:info count)   (:args (integer :scs (sb-vm::unsigned-reg) :target res))   (:arg-types (:constant (integer -31 31)) sb-vm::unsigned-byte-32)   (:results (res :scs (sb-vm::unsigned-reg)))   (:result-types sb-vm::unsigned-byte-32)   (:generator 5     ;; the 0 case is an identity operation and should be    ;; DEFTRANSFORMed away.    (aver (not (= count 0)))     (if (> count 0)         (inst rotlwi res integer count)         (inst rotrwi res integer (- count))))) (define-vop (%32bit-rotate-byte-fixnum/c)   (:policy :fast-safe)   (:translate %unsigned-32-rotate-byte)   (:note "inline 32-bit constant rotation")   (:info count)   (:args (integer :scs (sb-vm::any-reg) :target res))   (:arg-types (:constant (integer -31 31)) sb-vm::positive-fixnum)   (:results (res :scs (sb-vm::unsigned-reg)))   (:result-types sb-vm::unsigned-byte-32)   (:generator 5     (aver (not (= count 0)))     (cond       ;; FIXME: all these 2s should be n-fixnum-tag-bits.      ((= count 2))       ((> count 2) (inst rotlwi res integer (- count 2)))       (t (inst rotrwi res integer (- 2 count)))))) (macrolet ((def (name arg-type)              `(define-vop (,name)                (:policy :fast-safe)                (:translate %unsigned-32-rotate-byte)                (:note "inline 32-bit rotation")                (:args (count :scs (sb-vm::signed-reg))                       (integer :scs (sb-vm::unsigned-reg) :target res))                (:arg-types sb-vm::tagged-num ,arg-type)                (:temporary (:scs (sb-vm::unsigned-reg) :from (:argument 0))                            realcount)                (:results (res :scs (sb-vm::unsigned-reg)))                (:result-types sb-vm::unsigned-byte-32)                (:generator 10                 (let ((label (gen-label))                       (end (gen-label)))                   (inst cmpwi count 0)                   (inst bge label)                   (inst addi realcount count 32)                   (inst rotlw res integer realcount)                   (inst b end)                   (emit-label label)                   (inst rotlw res integer count)                   (emit-label end))))))   (def %32bit-rotate-byte sb-vm::unsigned-byte-32)   ;; FIXME: see x86-vm.lisp  (def %32bit-rotate-byte-fixnum sb-vm::positive-fixnum))