;;; eventually invoke the C alloc() function. Once upon a time
;;; (before threads) allocation within an alloc_region could also be
;;; done inline, with the aid of two C symbols storing the current
-;;; allocation region boundaries; however, C cymbols are global.
+;;; allocation region boundaries; however, C symbols are global.
;;; C calls for allocation don't /seem/ to make an awful lot of
;;; difference to speed. Guessing from historical context, it looks
;;; which time all calls to alloc() would have needed a syscall to
;;; mask signals for the duration. Now we have pseudoatomic there's
;;; no need for that overhead. Still, inline alloc would be a neat
-;;; addition someday
+;;; addition someday (except see below).
+
+(defun allocation-dynamic-extent (alloc-tn size)
+ (inst sub esp-tn size)
+ ;; FIXME: SIZE _should_ be double-word aligned (suggested but
+ ;; unfortunately not enforced by PAD-DATA-BLOCK and
+ ;; WITH-FIXED-ALLOCATION), so that ESP is always divisible by 8 (for
+ ;; 32-bit lispobjs). In that case, this AND instruction is
+ ;; unneccessary and could be removed. If not, explain why. -- CSR,
+ ;; 2004-03-30
+ (inst and esp-tn #.(ldb (byte 32 0) (lognot lowtag-mask)))
+ (aver (not (location= alloc-tn esp-tn)))
+ (inst mov alloc-tn esp-tn)
+ (values))
+
+(defun allocation-notinline (alloc-tn size)
+ (let* ((alloc-tn-offset (tn-offset alloc-tn))
+ ;; C call to allocate via dispatch routines. Each
+ ;; destination has a special entry point. The size may be a
+ ;; register or a constant.
+ (tn-text (ecase alloc-tn-offset
+ (#.eax-offset "eax")
+ (#.ecx-offset "ecx")
+ (#.edx-offset "edx")
+ (#.ebx-offset "ebx")
+ (#.esi-offset "esi")
+ (#.edi-offset "edi")))
+ (size-text (case size (8 "8_") (16 "16_") (t ""))))
+ (unless (or (eql size 8) (eql size 16))
+ (unless (and (tn-p size) (location= alloc-tn size))
+ (inst mov alloc-tn size)))
+ (inst call (make-fixup (extern-alien-name
+ (concatenate 'string
+ "alloc_" size-text
+ "to_" tn-text))
+ :foreign))))
+
+(defun allocation-inline (alloc-tn size)
+ (let ((ok (gen-label))
+ (free-pointer
+ (make-ea :dword :disp
+ #!+sb-thread (* n-word-bytes thread-alloc-region-slot)
+ #!-sb-thread (make-fixup (extern-alien-name "boxed_region")
+ :foreign)
+ :scale 1)) ; thread->alloc_region.free_pointer
+ (end-addr
+ (make-ea :dword :disp
+ #!+sb-thread (* n-word-bytes (1+ thread-alloc-region-slot))
+ #!-sb-thread (make-fixup (extern-alien-name "boxed_region")
+ :foreign 4)
+ :scale 1))) ; thread->alloc_region.end_addr
+ (unless (and (tn-p size) (location= alloc-tn size))
+ (inst mov alloc-tn size))
+ #!+sb-thread (inst fs-segment-prefix)
+ (inst add alloc-tn free-pointer)
+ #!+sb-thread (inst fs-segment-prefix)
+ (inst cmp alloc-tn end-addr)
+ (inst jmp :be OK)
+ (let ((dst (ecase (tn-offset alloc-tn)
+ (#.eax-offset "alloc_overflow_eax")
+ (#.ecx-offset "alloc_overflow_ecx")
+ (#.edx-offset "alloc_overflow_edx")
+ (#.ebx-offset "alloc_overflow_ebx")
+ (#.esi-offset "alloc_overflow_esi")
+ (#.edi-offset "alloc_overflow_edi"))))
+ (inst call (make-fixup (extern-alien-name dst) :foreign)))
+ (emit-label ok)
+ #!+sb-thread (inst fs-segment-prefix)
+ (inst xchg free-pointer alloc-tn))
+ (values))
-(defvar *maybe-use-inline-allocation* t) ; FIXME unused
;;; Emit code to allocate an object with a size in bytes given by
-;;; Size. The size may be an integer of a TN. If Inline is a VOP
+;;; SIZE. The size may be an integer or a TN. If Inline is a VOP
;;; node-var then it is used to make an appropriate speed vs size
;;; decision.
-;;; This macro should only be used inside a pseudo-atomic section,
-;;; which should also cover subsequent initialization of the
-;;; object.
-(defun allocation (alloc-tn size &optional inline)
- ;; FIXME: since it appears that inline allocation is gone, we should
- ;; remove the INLINE parameter and *MAYBE-USE-INLINE-ALLOCATION*
- (declare (ignore inline))
- (flet ((load-size (dst-tn size)
- (unless (and (tn-p size) (location= alloc-tn size))
- (inst mov dst-tn size))))
- (let ((alloc-tn-offset (tn-offset alloc-tn)))
- ;; C call to allocate via dispatch routines. Each
- ;; destination has a special entry point. The size may be a
- ;; register or a constant.
- (ecase alloc-tn-offset
- (#.eax-offset
- (case size
- (8 (inst call (make-fixup (extern-alien-name "alloc_8_to_eax")
- :foreign)))
- (16 (inst call (make-fixup (extern-alien-name "alloc_16_to_eax")
- :foreign)))
- (t
- (load-size eax-tn size)
- (inst call (make-fixup (extern-alien-name "alloc_to_eax")
- :foreign)))))
- (#.ecx-offset
- (case size
- (8 (inst call (make-fixup (extern-alien-name "alloc_8_to_ecx")
- :foreign)))
- (16 (inst call (make-fixup (extern-alien-name "alloc_16_to_ecx")
- :foreign)))
- (t
- (load-size ecx-tn size)
- (inst call (make-fixup (extern-alien-name "alloc_to_ecx")
- :foreign)))))
- (#.edx-offset
- (case size
- (8 (inst call (make-fixup (extern-alien-name "alloc_8_to_edx")
- :foreign)))
- (16 (inst call (make-fixup (extern-alien-name "alloc_16_to_edx")
- :foreign)))
- (t
- (load-size edx-tn size)
- (inst call (make-fixup (extern-alien-name "alloc_to_edx")
- :foreign)))))
- (#.ebx-offset
- (case size
- (8 (inst call (make-fixup (extern-alien-name "alloc_8_to_ebx")
- :foreign)))
- (16 (inst call (make-fixup (extern-alien-name "alloc_16_to_ebx")
- :foreign)))
- (t
- (load-size ebx-tn size)
- (inst call (make-fixup (extern-alien-name "alloc_to_ebx")
- :foreign)))))
- (#.esi-offset
- (case size
- (8 (inst call (make-fixup (extern-alien-name "alloc_8_to_esi")
- :foreign)))
- (16 (inst call (make-fixup (extern-alien-name "alloc_16_to_esi")
- :foreign)))
- (t
- (load-size esi-tn size)
- (inst call (make-fixup (extern-alien-name "alloc_to_esi")
- :foreign)))))
- (#.edi-offset
- (case size
- (8 (inst call (make-fixup (extern-alien-name "alloc_8_to_edi")
- :foreign)))
- (16 (inst call (make-fixup (extern-alien-name "alloc_16_to_edi")
- :foreign)))
- (t
- (load-size edi-tn size)
- (inst call (make-fixup (extern-alien-name "alloc_to_edi")
- :foreign))))))))
+;;; Allocation should only be used inside a pseudo-atomic section, which
+;;; should also cover subsequent initialization of the object.
+
+;;; (FIXME: so why aren't we asserting this?)
+
+(defun allocation (alloc-tn size &optional inline dynamic-extent)
+ (cond
+ (dynamic-extent (allocation-dynamic-extent alloc-tn size))
+ ;; FIXME: for reasons unknown, inline allocation is a speed win on
+ ;; non-P4s, and a speed loss on P4s (and probably other such
+ ;; high-spec high-cache machines). :INLINE-ALLOCATION-IS-GOOD is
+ ;; a bit of a KLUDGE, really. -- CSR, 2004-08-05 (following
+ ;; observations made by ASF and Juho Snellman)
+ ((and (member :inline-allocation-is-good *backend-subfeatures*)
+ (or (null inline) (policy inline (>= speed space))))
+ (allocation-inline alloc-tn size))
+ (t (allocation-notinline alloc-tn size)))
(values))
;;; Allocate an other-pointer object of fixed SIZE with a single word
;;; set with a single operation and cleared with SHR *PSEUDO-ATOMIC-BITS*,-2;
;;; the ATOMIC bit is bit 0, the INTERRUPTED bit is bit 1, and you check
;;; the C flag after the shift to see whether you were interrupted.
+;;;
+;;; KLUDGE: since the stack on the x86 is treated conservatively, it
+;;; does not matter whether a signal occurs during construction of a
+;;; dynamic-extent object, as the half-finished construction of the
+;;; object will not cause any difficulty. We can therefore elide
+(defmacro maybe-pseudo-atomic (really-p &body forms)
+ `(if ,really-p
+ (progn ,@forms)
+ (pseudo-atomic ,@forms)))
#!+sb-thread
(defmacro pseudo-atomic (&rest forms)
(with-unique-names (label)
`(let ((,label (gen-label)))
- (inst fs-segment-prefix)
- (inst mov (make-ea :byte
- :disp (* 4 thread-pseudo-atomic-interrupted-slot)) 0)
- (inst fs-segment-prefix)
- (inst mov (make-ea :byte :disp (* 4 thread-pseudo-atomic-atomic-slot)) 1)
- ,@forms
- (inst fs-segment-prefix)
- (inst mov (make-ea :byte :disp (* 4 thread-pseudo-atomic-atomic-slot)) 0)
- (inst fs-segment-prefix)
- (inst cmp (make-ea :byte
- :disp (* 4 thread-pseudo-atomic-interrupted-slot)) 0)
- (inst jmp :eq ,label)
- ;; if PAI was set, interrupts were disabled at the same time
- ;; using the process signal mask.
- (inst break pending-interrupt-trap)
- (emit-label ,label))))
+ (inst fs-segment-prefix)
+ (inst mov (make-ea :byte
+ :disp (* 4 thread-pseudo-atomic-interrupted-slot)) 0)
+ (inst fs-segment-prefix)
+ (inst mov (make-ea :byte :disp (* 4 thread-pseudo-atomic-atomic-slot)) 1)
+ ,@forms
+ (inst fs-segment-prefix)
+ (inst mov (make-ea :byte :disp (* 4 thread-pseudo-atomic-atomic-slot)) 0)
+ (inst fs-segment-prefix)
+ (inst cmp (make-ea :byte
+ :disp (* 4 thread-pseudo-atomic-interrupted-slot)) 0)
+ (inst jmp :eq ,label)
+ ;; if PAI was set, interrupts were disabled at the same
+ ;; time using the process signal mask.
+ (inst break pending-interrupt-trap)
+ (emit-label ,label))))
#!-sb-thread
(defmacro pseudo-atomic (&rest forms)
(with-unique-names (label)
`(let ((,label (gen-label)))
- ;; FIXME: The MAKE-EA noise should become a MACROLET macro or
- ;; something. (perhaps SVLB, for static variable low byte)
- (inst mov (make-ea :byte :disp (+ nil-value
- (static-symbol-offset
- '*pseudo-atomic-interrupted*)
- (ash symbol-value-slot word-shift)
- ;; FIXME: Use mask, not minus, to
- ;; take out type bits.
- (- other-pointer-lowtag)))
- 0)
- (inst mov (make-ea :byte :disp (+ nil-value
- (static-symbol-offset
- '*pseudo-atomic-atomic*)
- (ash symbol-value-slot word-shift)
- (- other-pointer-lowtag)))
- (fixnumize 1))
- ,@forms
- (inst mov (make-ea :byte :disp (+ nil-value
- (static-symbol-offset
- '*pseudo-atomic-atomic*)
- (ash symbol-value-slot word-shift)
- (- other-pointer-lowtag)))
- 0)
- ;; KLUDGE: Is there any requirement for interrupts to be
- ;; handled in order? It seems as though an interrupt coming
- ;; in at this point will be executed before any pending interrupts.
- ;; Or do incoming interrupts check to see whether any interrupts
- ;; are pending? I wish I could find the documentation for
- ;; pseudo-atomics.. -- WHN 19991130
- (inst cmp (make-ea :byte
- :disp (+ nil-value
- (static-symbol-offset
- '*pseudo-atomic-interrupted*)
- (ash symbol-value-slot word-shift)
- (- other-pointer-lowtag)))
- 0)
- (inst jmp :eq ,label)
- ;; if PAI was set, interrupts were disabled at the same time
- ;; using the process signal mask.
- (inst break pending-interrupt-trap)
- (emit-label ,label))))
-
-
+ ;; FIXME: The MAKE-EA noise should become a MACROLET macro
+ ;; or something. (perhaps SVLB, for static variable low
+ ;; byte)
+ (inst mov (make-ea :byte :disp (+ nil-value
+ (static-symbol-offset
+ '*pseudo-atomic-interrupted*)
+ (ash symbol-value-slot word-shift)
+ ;; FIXME: Use mask, not minus, to
+ ;; take out type bits.
+ (- other-pointer-lowtag)))
+ 0)
+ (inst mov (make-ea :byte :disp (+ nil-value
+ (static-symbol-offset
+ '*pseudo-atomic-atomic*)
+ (ash symbol-value-slot word-shift)
+ (- other-pointer-lowtag)))
+ (fixnumize 1))
+ ,@forms
+ (inst mov (make-ea :byte :disp (+ nil-value
+ (static-symbol-offset
+ '*pseudo-atomic-atomic*)
+ (ash symbol-value-slot word-shift)
+ (- other-pointer-lowtag)))
+ 0)
+ ;; KLUDGE: Is there any requirement for interrupts to be
+ ;; handled in order? It seems as though an interrupt coming
+ ;; in at this point will be executed before any pending
+ ;; interrupts. Or do incoming interrupts check to see
+ ;; whether any interrupts are pending? I wish I could find
+ ;; the documentation for pseudo-atomics.. -- WHN 19991130
+ (inst cmp (make-ea :byte
+ :disp (+ nil-value
+ (static-symbol-offset
+ '*pseudo-atomic-interrupted*)
+ (ash symbol-value-slot word-shift)
+ (- other-pointer-lowtag)))
+ 0)
+ (inst jmp :eq ,label)
+ ;; if PAI was set, interrupts were disabled at the same
+ ;; time using the process signal mask.
+ (inst break pending-interrupt-trap)
+ (emit-label ,label))))
\f
;;;; indexed references
projects / sbcl.git / blobdiff