(cons :positive-infinity float-round-to-positive)
(cons :negative-infinity float-round-to-negative)))
+#!+x86
+(defparameter *precision-mode-alist*
+ (list (cons :24-bit float-precision-24-bit)
+ (cons :53-bit float-precision-53-bit)
+ (cons :64-bit float-precision-64-bit)))
+
;;; Return a mask with all the specified float trap bits set.
(defun float-trap-mask (names)
(reduce #'logior
names)))
) ; EVAL-WHEN
-;;; interpreter stubs
-(defun floating-point-modes () (floating-point-modes))
-(defun (setf floating-point-modes) (new) (setf (floating-point-modes) new))
+;;; interpreter stubs for floating point modes get/setters for the
+;;; alpha have been removed to alpha-vm.lisp, as they are implemented
+;;; in C rather than as VOPs.
+#!-alpha
+(progn
+ (defun floating-point-modes ()
+ (floating-point-modes))
+ (defun (setf floating-point-modes) (new)
+ (setf (floating-point-modes) new)))
;;; This function sets options controlling the floating-point
;;; hardware. If a keyword is not supplied, then the current value is
;;; :TRAPS
;;; A list of the exception conditions that should cause traps.
;;; Possible exceptions are :UNDERFLOW, :OVERFLOW, :INEXACT, :INVALID,
-;;; :DIVIDE-BY-ZERO, and on the X86 :DENORMALIZED-OPERAND. Initially
-;;; all traps except :INEXACT are enabled.
+;;; :DIVIDE-BY-ZERO, and on the X86 :DENORMALIZED-OPERAND.
;;;
;;;:ROUNDING-MODE
;;; The rounding mode to use when the result is not exact. Possible
;;; values are :NEAREST, :POSITIVE-INFINITY, :NEGATIVE-INFINITY and
-;;; :ZERO. Initially, the rounding mode is :NEAREST.
+;;; :ZERO. Setting this away from :NEAREST is liable to upset SBCL's
+;;; maths routines which depend on it.
;;;
;;;:CURRENT-EXCEPTIONS
;;;:ACCRUED-EXCEPTIONS
;;;
;;;:FAST-MODE
;;; Set the hardware's \"fast mode\" flag, if any. When set, IEEE
-;;; conformance or debuggability may be impaired. Some machines may not
-;;; have this feature, in which case the value is always NIL.
+;;; conformance or debuggability may be impaired. Some machines don't
+;;; have this feature, and some SBCL ports don't implement it anyway
+;;; -- in such cases the value is always NIL.
+;;;
+;;;:PRECISION (x86 only) :24-bit, :53-bit and :64-bit, for the
+;;;internal precision of the mantissa.
;;;
;;; GET-FLOATING-POINT-MODES may be used to find the floating point modes
-;;; currently in effect.
+;;; currently in effect. See cold-init.lisp for the list of initially
+;;; enabled traps
+
(defun set-floating-point-modes (&key (traps nil traps-p)
(rounding-mode nil round-p)
(current-exceptions nil current-x-p)
(accrued-exceptions nil accrued-x-p)
- (fast-mode nil fast-mode-p))
+ (fast-mode nil fast-mode-p)
+ #!+x86 (precision nil precisionp))
(let ((modes (floating-point-modes)))
(when traps-p
(setf (ldb float-traps-byte modes) (float-trap-mask traps)))
(if fast-mode
(setq modes (logior float-fast-bit modes))
(setq modes (logand (lognot float-fast-bit) modes))))
- (setf (floating-point-modes) modes))
+ #!+x86
+ (when precisionp
+ (setf (ldb float-precision-control modes)
+ (or (cdr (assoc precision *precision-mode-alist*))
+ (error "unknown precision mode: ~S" precision))))
+ ;; FIXME: This apparently doesn't work on Darwin
+ #!-darwin (setf (floating-point-modes) modes))
(values))
*rounding-mode-alist*))
:current-exceptions ,(exc-keys (ldb float-exceptions-byte modes))
:accrued-exceptions ,(exc-keys (ldb float-sticky-bits modes))
- :fast-mode ,(logtest float-fast-bit modes)))))
+ :fast-mode ,(logtest float-fast-bit modes)
+ #!+x86 :precision
+ #!+x86 ,(car (rassoc (ldb float-precision-control modes)
+ *precision-mode-alist*))))))
;;; Return true if any of the named traps are currently trapped, false
;;; otherwise.
;;; Signal the appropriate condition when we get a floating-point error.
(defun sigfpe-handler (signal info context)
- (declare (ignore signal info context))
+ (declare (ignore signal info))
(declare (type system-area-pointer context))
- ;; FIXME: The find-the-detailed-problem code below went stale with
- ;; the big switchover to POSIX signal handling and signal contexts
- ;; which are opaque at the Lisp level ca. sbcl-0.6.7. It needs to be
- ;; revived, which will require writing a C-level os-dependent
- ;; function to extract floating point modes, and a Lisp-level
- ;; DEFINE-ALIEN-ROUTINE to get to the C-level os-dependent function.
- ;; Meanwhile we just say "something went wrong".
- (error 'floating-point-exception)
- #|
(let* ((modes (context-floating-point-modes
(sb!alien:sap-alien context (* os-context-t))))
(traps (logand (ldb float-exceptions-byte modes)
(error 'floating-point-exception
:traps (getf (get-floating-point-modes) :traps)))
(t
- (error "SIGFPE with no exceptions currently enabled?"))))
- |#
- )
+ (error 'floating-point-exception)))))
;;; Execute BODY with the floating point exceptions listed in TRAPS
;;; masked (disabled). TRAPS should be a list of possible exceptions
projects / sbcl.git / blobdiff