c-call.lisp

开源跨平台Lisp编译器

;;;; VOPs and other machine-specific support routines for call-out to C

;;;; 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")

;;; Return the number of bytes needed for the current non-descriptor
;;; stack frame.  Non-descriptor stack frames must be multiples of 16
;;; bytes under the PPC SVr4 ABI (though the EABI may be less
;;; restrictive).  On linux, two words are reserved for the stack
;;; backlink and saved LR (see SB!VM::NUMBER-STACK-DISPLACEMENT).

(defconstant +stack-alignment-bytes+
  ;; Duh.  PPC Linux (and VxWorks) adhere to the EABI.
  #!-darwin 7
  ;; But Darwin doesn't
  #!+darwin 15)

(defun my-make-wired-tn (prim-type-name sc-name offset)
  (make-wired-tn (primitive-type-or-lose prim-type-name)
                 (sc-number-or-lose sc-name)
                 offset))

(defstruct arg-state
  (gpr-args 0)
  (fpr-args 0)
  ;; SVR4 [a]abi wants two words on stack (callee saved lr,
  ;; backpointer).
  #!-darwin (stack-frame-size 2)
  ;; PowerOpen ABI wants 8 words on the stack corresponding to GPR3-10
  ;; in addition to the 6 words of link area (see number-stack-displacement)
  #!+darwin (stack-frame-size (+ 8 6)))

(defun int-arg (state prim-type reg-sc stack-sc)
  (let ((reg-args (arg-state-gpr-args state)))
    (cond ((< reg-args 8)
           (setf (arg-state-gpr-args state) (1+ reg-args))
           (my-make-wired-tn prim-type reg-sc (+ reg-args nl0-offset)))
          (t
           (let ((frame-size (arg-state-stack-frame-size state)))
             (setf (arg-state-stack-frame-size state) (1+ frame-size))
             (my-make-wired-tn prim-type stack-sc frame-size))))))

(define-alien-type-method (integer :arg-tn) (type state)
  (if (alien-integer-type-signed type)
      (int-arg state 'signed-byte-32 'signed-reg 'signed-stack)
      (int-arg state 'unsigned-byte-32 'unsigned-reg 'unsigned-stack)))

(define-alien-type-method (system-area-pointer :arg-tn) (type state)
  (declare (ignore type))
  (int-arg state 'system-area-pointer 'sap-reg 'sap-stack))

;;; The Linux/PPC 32bit ABI says:
;;;
;;;   If a single-float arg has to go on the stack, it's promoted to
;;;   a double.
;;;
;;; gcc does:
;;;
;;;   Excess floats stored on the stack are stored as floats.
;;;
;;; We follow gcc.
#!-darwin
(define-alien-type-method (single-float :arg-tn) (type state)
  (declare (ignore type))
  (let* ((fprs (arg-state-fpr-args state)))
    (cond ((< fprs 8)
           (incf (arg-state-fpr-args state))
           ;; Assign outgoing FPRs starting at FP1
           (my-make-wired-tn 'single-float 'single-reg (1+ fprs)))
          (t
           (let* ((stack-offset (arg-state-stack-frame-size state)))
             (setf (arg-state-stack-frame-size state) (+ stack-offset 1))
             (my-make-wired-tn 'single-float 'single-stack stack-offset))))))

;;; If a single-float arg has to go on the stack, it's promoted to
;;; double.  That way, C programs can get subtle rounding errors when
;;; unrelated arguments are introduced.
#!+darwin
(define-alien-type-method (single-float :arg-tn) (type state)
  (declare (ignore type))
  (let* ((fprs (arg-state-fpr-args state))
         (gprs (arg-state-gpr-args state)))
    (cond ((< gprs 8) ; and by implication also (< fprs 13)
           (incf (arg-state-fpr-args state))
           ;; Assign outgoing FPRs starting at FP1
           (list (my-make-wired-tn 'single-float 'single-reg (1+ fprs))
                 (int-arg state 'signed-byte-32 'signed-reg 'signed-stack)))
          ((< fprs 13)
           ;; See comments below for double-float.
           (incf (arg-state-fpr-args state))
           (incf (arg-state-stack-frame-size state))
           (my-make-wired-tn 'single-float 'single-reg (1+ fprs)))
          (t
           ;; Pass on stack only
           (let ((stack-offset (arg-state-stack-frame-size state)))
             (incf (arg-state-stack-frame-size state))
             (my-make-wired-tn 'single-float 'single-stack stack-offset))))))

#!-darwin
(define-alien-type-method (double-float :arg-tn) (type state)
  (declare (ignore type))
  (let* ((fprs (arg-state-fpr-args state)))
    (cond ((< fprs 8)
           (incf (arg-state-fpr-args state))
           ;; Assign outgoing FPRs starting at FP1
           (my-make-wired-tn 'double-float 'double-reg (1+ fprs)))
          (t
           (let* ((stack-offset (arg-state-stack-frame-size state)))
             (if (oddp stack-offset)
               (incf stack-offset))
             (setf (arg-state-stack-frame-size state) (+ stack-offset 2))
             (my-make-wired-tn 'double-float 'double-stack stack-offset))))))

#!+darwin
(define-alien-type-method (double-float :arg-tn) (type state)
  (declare (ignore type))
  (let ((fprs (arg-state-fpr-args state))
        (gprs (arg-state-gpr-args state)))
    (cond ((< gprs 8) ; and by implication also (< fprs 13)
           (incf (arg-state-fpr-args state))
           ;; Assign outgoing FPRs starting at FP1
           ;;
           ;; The PowerOpen ABI says float values are stored in float
           ;; regs.  But if we're calling a varargs function, we also
           ;; need to put the float into some gprs.  We indicate this
           ;; to %alien-funcall ir2-convert by making a list of the
           ;; TNs for the float reg and for the int regs.
           ;;
           (list (my-make-wired-tn 'double-float 'double-reg (1+ fprs))
                 (int-arg state 'signed-byte-32 'signed-reg 'signed-stack)
                 (int-arg state 'unsigned-byte-32 'unsigned-reg 'unsigned-stack)))
          ((< fprs 13)
           (incf (arg-state-fpr-args state))
           (list (my-make-wired-tn 'double-float 'double-reg (1+ fprs))
                 (int-arg state 'signed-byte-32 'signed-reg 'signed-stack)
                 (int-arg state 'unsigned-byte-32 'unsigned-reg 'unsigned-stack)))
          (t
           ;; Pass on stack only
           (let ((stack-offset (arg-state-stack-frame-size state)))
             (incf (arg-state-stack-frame-size state) 2)
             (my-make-wired-tn 'double-float 'double-stack stack-offset))))))

;;; Result state handling

(defstruct result-state
  (num-results 0))

(defun result-reg-offset (slot)
  (ecase slot
    (0 nl0-offset)
    (1 nl1-offset)))

;;; FIXME: These #!-DARWIN methods should be adjusted to take a state
;;; argument, firstly because that's our "official" API (see
;;; src/code/host-alieneval) and secondly because that way we can
;;; probably have less duplication of code.  -- CSR, 2003-07-29

(define-alien-type-method (system-area-pointer :result-tn) (type state)
  (declare (ignore type))
  (let ((num-results (result-state-num-results state)))
    (setf (result-state-num-results state) (1+ num-results))
    (my-make-wired-tn 'system-area-pointer 'sap-reg
                      (result-reg-offset num-results))))

(define-alien-type-method (single-float :result-tn) (type state)
  (declare (ignore type state))
  (my-make-wired-tn 'single-float 'single-reg 1))

(define-alien-type-method (double-float :result-tn) (type state)
  (declare (ignore type state))
  (my-make-wired-tn 'double-float 'double-reg 1))

(define-alien-type-method (values :result-tn) (type state)
  (let ((values (alien-values-type-values type)))
    (when (> (length values) 2)
      (error "Too many result values from c-call."))
    (mapcar #'(lambda (type)
                (invoke-alien-type-method :result-tn type state))
            values)))

(define-alien-type-method (integer :result-tn) (type state)
  (let ((num-results (result-state-num-results state)))
    (setf (result-state-num-results state) (1+ num-results))
    (multiple-value-bind (ptype reg-sc)
        (if (alien-integer-type-signed type)
            (values 'signed-byte-32 'signed-reg)
            (values 'unsigned-byte-32 'unsigned-reg))
      (my-make-wired-tn ptype reg-sc (result-reg-offset num-results)))))

(!def-vm-support-routine make-call-out-tns (type)
  (declare (type alien-fun-type type))
  (let ((arg-state (make-arg-state)))
    (collect ((arg-tns))
      (dolist (arg-type (alien-fun-type-arg-types type))
        (arg-tns (invoke-alien-type-method :arg-tn arg-type arg-state)))
      (values (my-make-wired-tn 'positive-fixnum 'any-reg nsp-offset)
              (* (arg-state-stack-frame-size arg-state) n-word-bytes)
              (arg-tns)
              (invoke-alien-type-method
               :result-tn
               (alien-fun-type-result-type type)
               (make-result-state))))))


;;; Sort out long longs, by splitting them up.  However, need to take
;;; care about register/stack alignment and whether they will fully
;;; fit into registers or must go on the stack.
#!-darwin
(deftransform %alien-funcall ((function type &rest args))
  (aver (sb!c::constant-lvar-p type))
  (let* ((type (sb!c::lvar-value type))
         (arg-types (alien-fun-type-arg-types type))
         (result-type (alien-fun-type-result-type type))
         (gprs 0)
         (fprs 0)
         (stack 0))
    (aver (= (length arg-types) (length args)))
    ;; We need to do something special for 64-bit integer arguments
    ;; and results.
    (if (or (some #'(lambda (type)
                      (and (alien-integer-type-p type)
                           (> (sb!alien::alien-integer-type-bits type) 32)))
                  arg-types)
            (and (alien-integer-type-p result-type)
                 (> (sb!alien::alien-integer-type-bits result-type) 32)))
        (collect ((new-args) (lambda-vars) (new-arg-types))
          (dolist (type arg-types)
            (let ((arg (gensym)))
              (lambda-vars arg)
              (cond ((and (alien-integer-type-p type)
                          (> (sb!alien::alien-integer-type-bits type) 32))
                     (when (or
                            (oddp gprs)
                            (and
                             (oddp stack)
                             (> gprs 7)))
                       ;; Need to pad for alignment.
                       (if (oddp gprs)
                           (incf gprs)
                           (incf stack))
                       (new-args 0)
                       (new-arg-types (parse-alien-type
                                       '(unsigned 32)
                                       (sb!kernel:make-null-lexenv))))
                     (if (< gprs 8)
                         (incf gprs 2)
                         (incf stack 2))
                     (new-args `(ash ,arg -32))
                     (new-args `(logand ,arg #xffffffff))
                     (if (alien-integer-type-signed type)
                         (new-arg-types (parse-alien-type
                                         '(signed 32)
                                         (sb!kernel:make-null-lexenv)))
                         (new-arg-types (parse-alien-type
                                         '(unsigned 32)
                                         (sb!kernel:make-null-lexenv))))
                     (new-arg-types (parse-alien-type
                                     '(unsigned 32)
                                     (sb!kernel:make-null-lexenv))))
                    ((alien-single-float-type-p type)
                     (if (< fprs 8)
                         (incf fprs)
                         (incf stack))
                     (new-args arg)
                     (new-arg-types type))
                    ((alien-double-float-type-p type)
                     (if (< fprs 8)
                         (incf fprs)
                         (if (oddp stack)
                             (incf stack 3)   ; Doubles are aligned on
                             (incf stack 2))) ; the stack.
                     (new-args arg)
                     (new-arg-types type))
                    (t ;; integer or SAP
                     (if (< gprs 8)
                         (incf gprs 1)
                         (incf stack 1))
                     (new-args arg)
                     (new-arg-types type)))))
                 (cond ((and (alien-integer-type-p result-type)
                             (> (sb!alien::alien-integer-type-bits result-type) 32))
                        (let ((new-result-type