shared/fpsp/x_unsupp.S

0001 #include "fpsp-namespace.h"
0002 //
0003 //
0004 //  x_unsupp.sa 3.3 7/1/91
0005 //
0006 //  fpsp_unsupp --- FPSP handler for unsupported data type exception
0007 //
0008 // Trap vector #55  (See table 8-1 Mc68030 User's manual).
0009 // Invoked when the user program encounters a data format (packed) that
0010 // hardware does not support or a data type (denormalized numbers or un-
0011 // normalized numbers).
0012 // Normalizes denorms and unnorms, unpacks packed numbers then stores
0013 // them back into the machine to let the 040 finish the operation.
0014 //
0015 // Unsupp calls two routines:
0016 //  1. get_op -  gets the operand(s)
0017 //  2. res_func - restore the function back into the 040 or
0018 //          if fmove.p fpm,<ea> then pack source (fpm)
0019 //          and store in users memory <ea>.
0020 //
0021 //  Input: Long fsave stack frame
0022 //
0023 //
0024
0025 //      Copyright (C) Motorola, Inc. 1990
0026 //          All Rights Reserved
0027 //
0028 //  THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA
0029 //  The copyright notice above does not evidence any
0030 //  actual or intended publication of such source code.
0031
0032 X_UNSUPP:   //idnt    2,1 | Motorola 040 Floating Point Software Package
0033
0034     |section    8
0035
0036 #include "fpsp.defs"
0037
0038     |xref   get_op
0039     |xref   res_func
0040     |xref   gen_except
0041     |xref   fpsp_fmt_error
0042
0043     .global fpsp_unsupp
0044 fpsp_unsupp:
0045 //
0046     link        %a6,#-LOCAL_SIZE
0047     fsave       -(%a7)
0048     moveml      %d0-%d1/%a0-%a1,USER_DA(%a6)
0049     fmovemx %fp0-%fp3,USER_FP0(%a6)
0050     fmoveml %fpcr/%fpsr/%fpiar,USER_FPCR(%a6)
0051
0052
0053     moveb       (%a7),VER_TMP(%a6) //save version number
0054     moveb       (%a7),%d0       //test for valid version num
0055     andib       #0xf0,%d0       //test for $4x
0056     cmpib       #VER_4,%d0  //must be $4x or exit
0057     bnel        fpsp_fmt_error
0058
0059     fmovel      #0,%FPSR        //clear all user status bits
0060     fmovel      #0,%FPCR        //clear all user control bits
0061 //
0062 //  The following lines are used to ensure that the FPSR
0063 //  exception byte and condition codes are clear before proceeding,
0064 //  except in the case of fmove, which leaves the cc's intact.
0065 //
0066 unsupp_con:
0067     movel       USER_FPSR(%a6),%d1
0068     btst        #5,CMDREG1B(%a6)    //looking for fmove out
0069     bne     fmove_con
0070     andl        #0xFF00FF,%d1   //clear all but aexcs and qbyte
0071     bras        end_fix
0072 fmove_con:
0073     andl        #0x0FFF40FF,%d1 //clear all but cc's, snan bit, aexcs, and qbyte
0074 end_fix:
0075     movel       %d1,USER_FPSR(%a6)
0076
0077     st      UFLG_TMP(%a6)   //set flag for unsupp data
0078
0079     bsrl        get_op      //everything okay, go get operand(s)
0080     bsrl        res_func    //fix up stack frame so can restore it
0081     clrl        -(%a7)
0082     moveb       VER_TMP(%a6),(%a7) //move idle fmt word to top of stack
0083     bral        gen_except
0084 //
0085     |end