src/code/alpha-vm.lisp

   1 ;;;; Alpha-specific implementation stuff
   2
   3 ;;;; This software is part of the SBCL system. See the README file for
   4 ;;;; more information.
   5 ;;;;
   6 ;;;; This software is derived from the CMU CL system, which was
   7 ;;;; written at Carnegie Mellon University and released into the
   8 ;;;; public domain. The software is in the public domain and is
   9 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
  10 ;;;; files for more information.
  11
  12 (in-package "SB!VM")
  13
  14 ;;; See x86-vm.lisp for a description of this.
  15 (define-alien-type os-context-t (struct os-context-t-struct))
  16 \f
  17 ;;;; MACHINE-TYPE
  18
  19 (defun machine-type ()
  20   "Return a string describing the type of the local machine."
  21   "Alpha")
  22 \f
  23 (defun fixup-code-object (code offset value kind)
  24   (unless (zerop (rem offset n-word-bytes))
  25     (error "Unaligned instruction?  offset=#x~X." offset))
  26   (without-gcing
  27    (let ((sap (%primitive code-instructions code)))
  28      (ecase kind
  29        (:jmp-hint
  30         (aver (zerop (ldb (byte 2 0) value)))
  31         #+nil
  32         (setf (sap-ref-16 sap offset)
  33               (logior (sap-ref-16 sap offset)
  34                       (ldb (byte 14 0) (ash value -2)))))
  35        (:bits-63-48
  36         (let* ((value (if (logbitp 15 value) (+ value (ash 1 16)) value))
  37                (value (if (logbitp 31 value) (+ value (ash 1 32)) value))
  38                (value (if (logbitp 47 value) (+ value (ash 1 48)) value)))
  39           (setf (sap-ref-8 sap offset) (ldb (byte 8 48) value))
  40           (setf (sap-ref-8 sap (1+ offset)) (ldb (byte 8 56) value))))
  41        (:bits-47-32
  42         (let* ((value (if (logbitp 15 value) (+ value (ash 1 16)) value))
  43                (value (if (logbitp 31 value) (+ value (ash 1 32)) value)))
  44           (setf (sap-ref-8 sap offset) (ldb (byte 8 32) value))
  45           (setf (sap-ref-8 sap (1+ offset)) (ldb (byte 8 40) value))))
  46        (:ldah
  47         (let ((value (if (logbitp 15 value) (+ value (ash 1 16)) value)))
  48           (setf (sap-ref-8 sap offset) (ldb (byte 8 16) value))
  49           (setf (sap-ref-8 sap (1+ offset)) (ldb (byte 8 24) value))))
  50        (:lda
  51         (setf (sap-ref-8 sap offset) (ldb (byte 8 0) value))
  52         (setf (sap-ref-8 sap (1+ offset)) (ldb (byte 8 8) value)))))))
  53 \f
  54 ;;;; "sigcontext" access functions, cut & pasted from x86-vm.lisp then
  55 ;;;; hacked for types.
  56 ;;;;
  57 ;;;; KLUDGE: The alpha has 64-bit registers, so these potentially
  58 ;;;; return 64 bit numbers (which means bignums ... ew) We think that
  59 ;;;; 99 times of 100 (i.e. unless something is badly wrong) we'll get
  60 ;;;; answers that fit in 32 bits anyway. Which probably won't help us
  61 ;;;; stop passing bignums around as the compiler can't prove they fit
  62 ;;;; in 32 bits. But maybe the stuff it does on x86 to unbox 32-bit
  63 ;;;; constants happens magically for 64-bit constants here. Just
  64 ;;;; maybe. -- Dan Barlow, ca. 2001-05-05
  65 ;;;;
  66 ;;;; See also x86-vm for commentary on signed vs unsigned.
  67
  68 (define-alien-routine ("os_context_pc_addr" context-pc-addr) (* unsigned-long)
  69   (context (* os-context-t)))
  70
  71 (defun context-pc (context)
  72   (declare (type (alien (* os-context-t)) context))
  73   (int-sap (deref (context-pc-addr context))))
  74
  75 (define-alien-routine ("os_context_register_addr" context-register-addr)
  76   (* unsigned-long)
  77   (context (* os-context-t))
  78   (index int))
  79
  80 ;;; FIXME: Should this and CONTEXT-PC be INLINE to reduce consing?
  81 ;;; (Are they used in anything time-critical, or just the debugger?)
  82 (defun context-register (context index)
  83   (declare (type (alien (* os-context-t)) context))
  84   (deref (the (alien (* unsigned-long))
  85            (context-register-addr context index))))
  86
  87 (defun %set-context-register (context index new)
  88   (declare (type (alien (* os-context-t)) context))
  89   (setf (deref (the (alien (* unsigned-long))
  90                  (context-register-addr context index)))
  91         new))
  92
  93 ;;; This is like CONTEXT-REGISTER, but returns the value of a float
  94 ;;; register. FORMAT is the type of float to return.
  95
  96 ;;; FIXME: Whether COERCE actually knows how to make a float out of a
  97 ;;; long is another question. This stuff still needs testing.
  98 (define-alien-routine ("os_context_float_register_addr"
  99                        context-float-register-addr)
 100   (* long)
 101   (context (* os-context-t))
 102   (index int))
 103 (defun context-float-register (context index format)
 104   (declare (type (alien (* os-context-t)) context))
 105   (coerce (deref (context-float-register-addr context index)) format))
 106 (defun %set-context-float-register (context index format new)
 107   (declare (type (alien (* os-context-t)) context))
 108   (setf (deref (context-float-register-addr context index))
 109         (coerce new format)))
 110
 111 ;;; This sets the software fp_control word, which is not the same
 112 ;;; thing as the hardware fpcr.  We have to do this so that OS FPU
 113 ;;; completion works properly
 114
 115 ;;; Note that this means we can't set rounding modes; we'd have to do
 116 ;;; that separately.  That said, almost everybody seems to agree that
 117 ;;; changing the rounding mode is rarely a good idea, because it upsets
 118 ;;; libm functions.  So adding that is not a priority.  Sorry.
 119 ;;; -dan 2001.02.06
 120
 121 (define-alien-routine
 122     ("arch_get_fp_control" floating-point-modes) (unsigned 64))
 123
 124 (define-alien-routine
 125     ("arch_set_fp_control" %floating-point-modes-setter) void (fp (unsigned 64)))
 126
 127 (defun (setf floating-point-modes) (val) (%floating-point-modes-setter val))
 128
 129 ;;; Given a signal context, return the floating point modes word in
 130 ;;; the same format as returned by FLOATING-POINT-MODES.
 131 (define-alien-routine ("os_context_fp_control" context-floating-point-modes)
 132     (unsigned 64) (context (* os-context-t)))
 133
 134 \f
 135 ;;;; INTERNAL-ERROR-ARGS
 136
 137 ;;; Given a (POSIX) signal context, extract the internal error
 138 ;;; arguments from the instruction stream.  This is e.g.
 139 ;;; 4       23      254     240     2       0       0       0
 140 ;;; |       ~~~~~~~~~~~~~~~~~~~~~~~~~
 141 ;;; length         data              (everything is an octet)
 142 ;;;  (pc)
 143 ;;; (example from undefined_tramp: "(gdb) x/40ub 0x10148" for yourself
 144 ;;; to replicate)
 145 (defun internal-error-args (context)
 146   (declare (type (alien (* os-context-t)) context))
 147   (let ((pc (context-pc context)))
 148     (declare (type system-area-pointer pc))
 149     ;; pc is a SAP pointing at - or actually, shortly after -
 150     ;; the instruction that got us into this mess in the first place
 151     (let* ((length (sap-ref-8 pc 4))
 152            (vector (make-array length :element-type '(unsigned-byte 8))))
 153       (declare (type (unsigned-byte 8) length)
 154                (type (simple-array (unsigned-byte 8) (*)) vector))
 155       (copy-ub8-from-system-area pc 5 vector 0 length)
 156       (let* ((index 0)
 157              (error-number (sb!c:read-var-integer vector index)))
 158         (collect ((sc-offsets))
 159                  (loop
 160                   (when (>= index length)
 161                     (return))
 162                   (sc-offsets (sb!c:read-var-integer vector index)))
 163                  (values error-number (sc-offsets)))))))
 164