Implement vop for xoroshiro-next

		 (unsigned-byte 32))

  "recode as shifts and adds"

  (*-transformer y))

(in-package "VM")

#+random-xoroshiro

(progn

(defknown xoroshiro-next ((simple-array double-float (2)))

  (values (unsigned-byte 32) (unsigned-byte 32))

  (movable))

(define-vop (xoroshiro-next)

  (:policy :fast-safe)

  (:translate xoroshiro-next)

  (:args (state :scs (descriptor-reg) :to (:result 3)))

  (:arg-types simple-array-double-float)

  (:results (r1 :scs (unsigned-reg))

	    (r0 :scs (unsigned-reg)))

  (:result-types unsigned-num unsigned-num)

  ;; Must be sure to use %o registers for temps because we want to use

  ;; 64-bit registers that will get preserved.

  (:temporary (:sc unsigned-reg :offset nl5-offset) s0)

  (:temporary (:sc unsigned-reg :offset nl4-offset) s1)

  (:temporary (:sc unsigned-reg :offset nl3-offset) t0)

  (:generator 10

    (inst ldx s0 state (+ (* 0 double-float-bytes)

			  (- (* vm:vector-data-offset vm:word-bytes)

			     vm:other-pointer-type)))

    (inst ldx s1 state (+ (* 1 double-float-bytes)

			  (- (* vm:vector-data-offset vm:word-bytes)

			     vm:other-pointer-type)))

    ;; result = s0 + s1, split into low 32-bits in r0 and high 32-bits

    ;; in r1

    (inst add r0 s0 s1)

    (inst srlx r1 r0 32)

    ;; s1 = s1 ^ s0

    (inst xor s1 s1 s0)

    ;; s0 = rotl(s0,55) = s0 << 55 | s0 >> 9

    (inst sllx s0 s0 55)

    (inst srlx t0 s0 9)

    (inst or s0 t0)

    (inst xor s0 s1)			; s0 = s0 ^ s1

    (inst sllx t0 s1 14)		; t0 = s1 << 14

    (inst xor s0 t0)			; s0 = s0 ^ t0

    (inst stx s0 state (+ (* 0 double-float-bytes)

			  (- (* vm:vector-data-offset vm:word-bytes)

			     vm:other-pointer-type)))

    ;; s1 = rotl(s1, 36) = s1 << 36 | s1 >> 28, using t0 as temp

    (inst sllx s1 36)

    (inst srlx t0 s1 28)

    (inst or s1 t0)

    (inst stx s1 state (+ (* 1 double-float-bytes)

			  (- (* vm:vector-data-offset vm:word-bytes)

			     vm:other-pointer-type)))))

)