;;;; type testing and checking VOPs for the ARM VM

;;;; This software is part of the SBCL system. See the README file for
;;;; more information.
;;;;
;;;; This software is derived from the CMU CL system, which was
;;;; written at Carnegie Mellon University and released into the
;;;; public domain. The software is in the public domain and is
;;;; provided with absolutely no warranty. See the COPYING and CREDITS
;;;; files for more information.

(in-package "SB-VM")

(defun %test-fixnum (value temp target not-p)
  (declare (ignore temp))
  (assemble ()
    #.(assert (= fixnum-tag-mask 1))
    (if not-p
        (inst tbnz* value 0 target)
        (inst tbz* value 0 target))))

(defun %test-fixnum-immediate-and-headers (value temp target not-p immediate
                                           headers &key value-tn-ref)
  (let ((drop-through (gen-label)))
    #.(assert (= fixnum-tag-mask 1))
    (inst tbz* value 0 (if not-p drop-through target))
    (%test-immediate-and-headers value temp target not-p immediate headers
                                 :drop-through drop-through
                                 :value-tn-ref value-tn-ref)))

(defun %test-immediate-and-headers (value temp target not-p immediate headers
                                    &key (drop-through (gen-label))
                                         value-tn-ref)
  (cond ((= immediate single-float-widetag)
         (inst cmp (32-bit-reg value) single-float-widetag))
        (t
         (inst mov temp immediate)
         (inst cmp temp (extend value :uxtb))))
  (inst b :eq (if not-p drop-through target))
  (%test-headers value temp target not-p nil headers
                 :drop-through drop-through
                 :value-tn-ref value-tn-ref))

(defun %test-fixnum-and-headers (value temp target not-p headers
                                 &key value-tn-ref)
  (let ((drop-through (gen-label)))
    (assemble ()
      #.(assert (= fixnum-tag-mask 1))
      (inst tbz* value 0 (if not-p drop-through target)))
    (%test-headers value temp target not-p nil headers
                   :drop-through drop-through
                   :value-tn-ref value-tn-ref)))

(defun %test-immediate (value temp target not-p immediate)
  (cond ((= immediate unbound-marker-widetag)
         (inst cmp value immediate))
        (t
         (inst and temp value widetag-mask)
         (inst cmp temp immediate)))
  (inst b (if not-p :ne :eq) target))

(defun %test-lowtag (value temp target not-p lowtag)
  (assemble ()
    (inst and temp value lowtag-mask)
    (inst cmp temp lowtag)
    (inst b (if not-p :ne :eq) target)))

(defun %test-headers (value temp target not-p function-p headers
                      &key (drop-through (gen-label))
                           value-tn-ref)
  (let ((lowtag (if function-p fun-pointer-lowtag other-pointer-lowtag)))
    (flet ((%logical-mask (x)
             (cond ((encode-logical-immediate x)
                    x)
                   ;; The remaining bits of the widetag are zero, no
                   ;; need to mask them off. Possible to encode more
                   ;; values that way.
                   ((let ((extend (dpb x (byte 8 0) most-positive-word)))
                      (and (encode-logical-immediate extend)
                           extend)))
                   (t
                    (logical-mask x)))))
      (multiple-value-bind (when-true when-false)
          (if not-p
              (values drop-through target)
              (values target drop-through))
        (assemble ()
          (unless (and value-tn-ref
                       (eq lowtag other-pointer-lowtag)
                       (other-pointer-tn-ref-p value-tn-ref))
            (%test-lowtag value temp when-false t lowtag))
          (load-type temp value (- lowtag))
          (do ((remaining headers (cdr remaining)))
              ((null remaining))
            (let ((header (car remaining))
                  (last (null (cdr remaining))))
              (cond
                ((atom header)
                 (cond
                   ((and (not last) (null (cddr remaining))
                         (atom (cadr remaining))
                         (= (logcount (logxor header (cadr remaining))) 1))
                    (inst and temp temp (%logical-mask
                                         (ldb (byte 8 0) (logeqv header (cadr remaining)))))
                    (inst cmp temp (ldb (byte 8 0) (logand header (cadr remaining))))
                    (inst b (if not-p :ne :eq) target)
                    (return))
                   (t
                    (inst cmp temp header)
                    (if last
                        (inst b (if not-p :ne :eq) target)
                        (inst b :eq when-true)))))
                (t
                 (let ((start (car header))
                       (end (cdr header)))
                   (cond
                     ((and last (not (= start bignum-widetag))
                           (= (+ start 4) end)
                           (= (logcount (logxor start end)) 1))
                      (inst and temp temp (%logical-mask
                                           (ldb (byte 8 0) (logeqv start end))))
                      (inst cmp temp (ldb (byte 8 0) (logand start end)))
                      (inst b (if not-p :ne :eq) target))
                     ((and (not last) (null (cddr remaining))
                           (= (+ start 4) end) (= (logcount (logxor start end)) 1)
                           (listp (cadr remaining))
                           (= (+ (caadr remaining) 4) (cdadr remaining))
                           (= (logcount (logxor (caadr remaining) (cdadr remaining))) 1)
                           (= (logcount (logxor (caadr remaining) start)) 1))
                      (inst and temp temp (ldb (byte 8 0) (logeqv start (cdadr remaining))))
                      (inst cmp temp (ldb (byte 8 0) (logand start (cdadr remaining))))
                      (inst b (if not-p :ne :eq) target)
                      (return))
                     ((and last
                           (/= start bignum-widetag)
                           (/= end complex-array-widetag))
                      (inst sub temp temp start)
                      (inst cmp temp (- end start))
                      (inst b (if not-p :hi :ls) target))
                     (t
                      (unless (= start bignum-widetag)
                        (inst cmp temp start)
                        (if (= end complex-array-widetag)
                            (progn
                              (aver last)
                              (inst b (if not-p :lt :ge) target))
                            (inst b :lt when-false)))
                      (unless (= end complex-array-widetag)
                        (inst cmp temp end)
                        (if last
                            (inst b (if not-p :gt :le) target)
                            (inst b :le when-true))))))))))
          (emit-label drop-through))))))

;;;; Other integer ranges.

;;; A (signed-byte 64) can be represented with either fixnum or a bignum with
;;; exactly one digit.
(define-vop (signed-byte-64-p type-predicate)
  (:translate signed-byte-64-p)
  (:generator 10
    (let ((fixnum-p (types-equal-or-intersect (tn-ref-type args) (specifier-type 'fixnum))))
      (multiple-value-bind (yep nope)
          (if not-p
              (values not-target target)
              (values target not-target))
        (assemble ()
          (when fixnum-p
            (inst tbz* value 0 yep))
          (unless (fixnum-or-other-pointer-tn-ref-p args)
            (test-type value temp nope t (other-pointer-lowtag)))
          (loadw temp value 0 other-pointer-lowtag)
          (inst cmp temp (+ (ash 1 n-widetag-bits) bignum-widetag))
          (inst b (if not-p :ne :eq) target))))
    not-target))

(define-vop (signed-byte-64-p/unsigned)
  (:args (value :scs (unsigned-reg)))
  (:arg-types unsigned-num)
  (:conditional :eq)
  (:policy :fast-safe)
  (:translate signed-byte-64-p)
  (:generator 5
    (inst tst value (ash 1 (1- n-word-bits)))))

;;; An (UNSIGNED-BYTE 64) can be represented with either a positive
;;; fixnum, a bignum with exactly one positive digit, or a bignum with
;;; exactly two digits and the second digit all zeros.
(define-vop (unsigned-byte-64-p type-predicate)
  (:translate unsigned-byte-64-p)
  (:generator 10
    (let ((fixnum-p (types-equal-or-intersect (tn-ref-type args) (specifier-type 'fixnum)))
          (other-pointer-p (fixnum-or-other-pointer-tn-ref-p args)))
      (multiple-value-bind (yep nope)
          (if not-p
              (values not-target target)
              (values target not-target))
        (assemble ()
          (cond ((not other-pointer-p)
                 ;; Move to a temporary and mask off the lowtag,
                 ;; but leave the sign bit for testing for positive fixnums.
                 ;; When using 32-bit registers that bit will not be visible.
                 (inst and temp value (logior (ash 1 (1- n-word-bits)) lowtag-mask)))
                (fixnum-p
                 (move temp value)))
          (when fixnum-p
            (%test-fixnum temp nil fixnum nil))
          (unless other-pointer-p
            (inst cmp (32-bit-reg temp) other-pointer-lowtag)
            (inst b :ne nope))
          ;; Get the header.
          (loadw temp value 0 other-pointer-lowtag)
          ;; Is it one?
          (inst cmp temp (+ (ash 1 n-widetag-bits) bignum-widetag))
          (inst b :eq single-word)
          ;; If it's other than two, it can't be an (unsigned-byte 64)
          (inst cmp temp (+ (ash 2 n-widetag-bits) bignum-widetag))
          (inst b :ne nope)
          ;; Get the second digit.
          (loadw temp value (1+ bignum-digits-offset) other-pointer-lowtag)
          ;; All zeros, it's an (unsigned-byte 64).
          (inst cbz temp yep)
          (inst b nope)

          single-word
          ;; Get the single digit.
          (loadw temp value bignum-digits-offset other-pointer-lowtag)

          ;; positive implies (unsigned-byte 64).
          fixnum
          (if not-p
              (inst tbnz* temp (1- n-word-bits) target)
              (inst tbz* temp (1- n-word-bits) target))))
      (values))
    NOT-TARGET))

(define-vop (fixnump/unsigned)
  (:policy :fast-safe)
  (:args (value :scs (unsigned-reg)))
  (:arg-types unsigned-num)
  (:translate fixnump)
  (:conditional :eq)
  (:generator 3
    (inst tst value (ash (1- (ash 1 (- n-word-bits
                                   n-positive-fixnum-bits)))
                     n-positive-fixnum-bits))))

(define-vop (fixnump/signed)
  (:args (value :scs (signed-reg)))
  (:policy :fast-safe)
  (:conditional :vc)
  (:info)
  (:arg-types signed-num)
  (:translate fixnump)
  (:generator 3
    (inst adds zr-tn value value)))

(define-vop (>-integer-fixnum)
  (:translate >)
  (:args (integer :scs (descriptor-reg))
         (fixnum :scs (immediate any-reg)))
  (:arg-types (:or integer bignum) tagged-num)
  (:temporary (:sc non-descriptor-reg) temp)
  (:conditional)
  (:info target not-p)
  (:args-var args)
  (:policy :fast-safe)
  (:variant-vars comparison)
  (:variant :gt)
  (:generator 10
    (unless (sc-is (tn-ref-tn args) descriptor-reg control-stack)
      (setf args (tn-ref-across args)))
    (let* ((integer-p (csubtypep (tn-ref-type args) (specifier-type 'integer)))
           (other-pointer-p (fixnum-or-other-pointer-tn-ref-p args))
           negative-p
           (fixnum (if (sc-is fixnum immediate)
                       (let* ((value (fixnumize (tn-value fixnum)))
                              (abs (abs value)))
                         (cond ((add-sub-immediate-p abs)
                                (when (minusp value)
                                  (setf negative-p t))
                                abs)
                               (t
                                (add-sub-immediate value))))
                       fixnum)))
      (multiple-value-bind (yep nope)
          (if not-p
              (values not-target target)
              (values target not-target))
        (assemble ()
          (when (types-equal-or-intersect (tn-ref-type args) (specifier-type 'fixnum))
            (cond ((or other-pointer-p
                       (not (and (eql fixnum 0)
                                 (eq comparison :ge))))
                   (inst tbnz integer 0 bignum)
                   (cond
                     ((and (eql fixnum 0)
                           (case comparison
                             (:lt
                              (inst tbnz* integer 63 yep)
                              t)
                             (:ge
                              (inst tbz* integer 63 yep)
                              t))))
                     ((and (eql fixnum -1)
                           (case comparison
                             (:le
                              (inst tbnz* integer 63 yep)
                              t)
                             (:gt
                              (inst tbz* integer 63 yep)
                              t))))
                     (negative-p
                      (inst cmn integer fixnum)
                      (inst b comparison yep))
                     (t
                      (inst cmp integer fixnum)
                      (inst b comparison yep)))
                   (inst b nope))
                  (t
                   (inst tst integer (lognot (fixnumize most-positive-fixnum)))
                   (inst b :eq yep))))
          bignum
          (unless other-pointer-p
            (test-type integer temp nope t (other-pointer-lowtag)))
          (loadw temp integer 0 other-pointer-lowtag)
          (unless integer-p
            (inst and tmp-tn temp widetag-mask)
            (inst cmp tmp-tn bignum-widetag)
            (inst b :ne nope))
          #.(assert (= (integer-length bignum-widetag) 5))
          (inst add temp integer (lsr temp 5))
          (inst ldr temp (@ temp (- other-pointer-lowtag)))
          (if (case comparison
                ((:gt :ge) not-p)
                (t (not not-p)))
              (inst tbnz* temp (1- n-word-bits) target)
              (inst tbz* temp (1- n-word-bits) target)))))
    not-target))

(define-vop (<-integer-fixnum >-integer-fixnum)
  (:translate <)
  (:variant :lt))

(define-vop (>-fixnum-integer >-integer-fixnum)
  (:translate >)
  (:args (fixnum :scs (immediate any-reg))
         (integer :scs (descriptor-reg)))
  (:arg-types tagged-num (:or integer bignum))
  (:variant :lt))

(define-vop (<-fixnum-integer >-fixnum-integer)
  (:translate <)
  (:variant :gt))

;;; For integerp+cmp
(define-vop (<=-integer-fixnum >-integer-fixnum)
  (:translate)
  (:variant :le))
(define-vop (>=-integer-fixnum <-integer-fixnum)
  (:translate)
  (:variant :ge))
(define-vop (<=-fixnum-integer >-fixnum-integer)
  (:translate)
  (:variant :le))
(define-vop (>=-fixnum-integer <-fixnum-integer)
  (:translate)
  (:variant :ge))


;;; MOD type checks
(defun power-of-two-limit-p (x)
  (and (fixnump x)
       (= (logcount (1+ x)) 1)))

(define-vop (test-fixnum-mod-power-of-two)
  (:args (value :scs (any-reg descriptor-reg
                      unsigned-reg signed-reg)))
  (:arg-types *
              (:constant (satisfies power-of-two-limit-p)))
  (:translate fixnum-mod-p)
  (:conditional :eq)
  (:info hi)
  (:policy :fast-safe)
  (:generator 2
     (let* ((fixnum-hi (if (sc-is value unsigned-reg signed-reg)
                           hi
                           (fixnumize hi))))
       (inst tst value (lognot fixnum-hi)))))

(defun add-sub-immediate-p+1 (x)
  (add-sub-immediate-p (1+ x)))

(defun fixnum-add-sub-immediate-p+1 (x)
  (fixnum-add-sub-immediate-p (1+ x)))

(defun fixnum-add-sub-immediate-p/+1 (x)
  (or (fixnum-add-sub-immediate-p x)
      (fixnum-add-sub-immediate-p (1+ x))))

(define-vop (test-fixnum-mod-signed-unsigned-imm)
  (:args (value :scs (unsigned-reg signed-reg)))
  (:arg-types (:or unsigned-num signed-num)
              (:constant (satisfies add-sub-immediate-p)))
  (:translate fixnum-mod-p)
  (:conditional :ls)
  (:info hi)
  (:policy :fast-safe)
  (:generator 3
    (inst cmp value hi)))

(define-vop (test-fixnum-mod-signed-unsigned-imm+1 test-fixnum-mod-signed-unsigned-imm)
  (:arg-types (:or unsigned-num signed-num)
              (:constant (satisfies add-sub-immediate-p+1)))
  (:conditional :lo)
  (:generator 3
    (inst cmp value (1+ hi))))

(define-vop (test-fixnum-mod-tagged-imm)
  (:args (value :scs (any-reg)))
  (:arg-types tagged-num
              (:constant (satisfies fixnum-add-sub-immediate-p)))
  (:translate fixnum-mod-p)
  (:conditional :ls)
  (:info hi)
  (:policy :fast-safe)
  (:generator 3
    (inst cmp value (fixnumize hi))))

(define-vop (test-fixnum-mod-tagged-imm+1 test-fixnum-mod-tagged-imm)
  (:arg-types tagged-num
              (:constant (satisfies fixnum-add-sub-immediate-p+1)))
  (:conditional :lo)
  (:generator 3
    (inst cmp value (fixnumize (1+ hi)))))

(define-vop (test-fixnum-mod-signed-unsigned-imm)
  (:args (value :scs (unsigned-reg signed-reg)))
  (:arg-types (:or unsigned-num signed-num)
              (:constant (satisfies add-sub-immediate-p)))
  (:translate fixnum-mod-p)
  (:conditional :ls)
  (:info hi)
  (:policy :fast-safe)
  (:generator 3
    (inst cmp value hi)))

(define-vop (test-fixnum-mod-signed-unsigned-imm+1 test-fixnum-mod-signed-unsigned-imm)
  (:arg-types (:or unsigned-num signed-num)
              (:constant (satisfies add-sub-immediate-p+1)))
  (:conditional :lo)
  (:generator 3
    (inst cmp value (1+ hi))))

(define-vop (test-fixnum-mod-tagged-imm)
  (:args (value :scs (any-reg)))
  (:arg-types tagged-num
              (:constant (satisfies fixnum-add-sub-immediate-p)))
  (:translate fixnum-mod-p)
  (:conditional :ls)
  (:info hi)
  (:policy :fast-safe)
  (:generator 3
    (inst cmp value (fixnumize hi))))

(define-vop (test-fixnum-mod-tagged-imm+1 test-fixnum-mod-tagged-imm)
  (:arg-types tagged-num
              (:constant (satisfies fixnum-add-sub-immediate-p+1)))
  (:conditional :lo)
  (:generator 3
    (inst cmp value (fixnumize (1+ hi)))))

(define-vop (test-fixnum-mod-tagged-unsigned)
  (:args (value :scs (any-reg unsigned-reg signed-reg)))
  (:arg-types (:or tagged-num unsigned-num signed-num)
              (:constant fixnum))
  (:temporary (:scs (non-descriptor-reg)) temp)
  (:translate fixnum-mod-p)
  (:conditional :ls)
  (:info hi)
  (:policy :fast-safe)
  (:generator 4
    (let ((fixnum-hi (if (sc-is value unsigned-reg signed-reg)
                         hi
                         (fixnumize hi))))
      (load-immediate-word temp fixnum-hi)
      (inst cmp value temp))))

(define-vop (test-fixnum-mod-*-imm)
  (:args (value :scs (any-reg descriptor-reg)))
  (:arg-types * (:constant (satisfies fixnum-add-sub-immediate-p/+1)))
  (:translate fixnum-mod-p)
  (:conditional)
  (:info target not-p hi)
  (:policy :fast-safe)
  (:generator 5
    (let* ((1+ (not (fixnum-add-sub-immediate-p hi)))
           (fixnum-hi (fixnumize (if 1+
                                     (1+ hi)
                                     hi))))
      #.(assert (= fixnum-tag-mask 1))
      (inst tbnz* value 0 (if not-p target skip))
      (inst cmp value fixnum-hi)
      (inst b (if not-p
                  (if 1+ :hs :hi)
                  (if 1+ :lo :ls))
            target))
    skip))

(define-vop (test-fixnum-mod-*)
  (:args (value :scs (any-reg descriptor-reg)))
  (:arg-types * (:constant fixnum))
  (:translate fixnum-mod-p)
  (:temporary (:scs (any-reg)) temp)
  (:conditional)
  (:info target not-p hi)
  (:policy :fast-safe)
  (:generator 6
    #.(assert (= fixnum-tag-mask 1))
    (inst tbnz* value 0 (if not-p target skip))
    (let ((condition (if not-p :hi :ls)))
      (load-immediate-word temp (fixnumize hi))
      (inst cmp value temp)
      (inst b condition target))
    SKIP))

;;;; List/symbol types:
;;;
;;; symbolp (or symbol (eq nil))
;;; consp (and list (not (eq nil)))

(define-vop (symbolp type-predicate)
  (:translate symbolp)
  (:generator 12
    (let* ((drop-thru (gen-label))
           (is-symbol-label (if not-p drop-thru target)))
      (inst cmp value null-tn)
      (inst b :eq is-symbol-label)
      (test-type value temp target not-p (symbol-widetag))
      (emit-label drop-thru))))

(define-vop (consp type-predicate)
  (:translate consp)
  (:conditional :ne)
  (:info)
  (:generator 8
    (inst and temp value lowtag-mask)
    (inst cmp temp list-pointer-lowtag)
    (inst ccmp value null-tn :eq 4)))

(define-vop (single-float-p)
  (:args (value :scs (any-reg descriptor-reg)))
  (:conditional :eq)
  (:policy :fast-safe)
  (:translate single-float-p)
  (:generator 7
    (inst cmp (32-bit-reg value) single-float-widetag)))
