root/arch/m68k/fpsp040/x_unimp.S

   1 |
   2 |       x_unimp.sa 3.3 7/1/91
   3 |
   4 |       fpsp_unimp --- FPSP handler for unimplemented instruction
   5 |       exception.
   6 |
   7 | Invoked when the user program encounters a floating-point
   8 | op-code that hardware does not support.  Trap vector# 11
   9 | (See table 8-1 MC68030 User's Manual).
  10 |
  11 |
  12 | Note: An fsave for an unimplemented inst. will create a short
  13 | fsave stack.
  14 |
  15 |  Input: 1. Six word stack frame for unimplemented inst, four word
  16 |            for illegal
  17 |            (See table 8-7 MC68030 User's Manual).
  18 |         2. Unimp (short) fsave state frame created here by fsave
  19 |            instruction.
  20 |
  21 |
  22 |               Copyright (C) Motorola, Inc. 1990
  23 |                       All Rights Reserved
  24 |
  25 |       For details on the license for this file, please see the
  26 |       file, README, in this same directory.
  27 
  28 X_UNIMP:        |idnt    2,1 | Motorola 040 Floating Point Software Package
  29 
  30         |section        8
  31 
  32 #include "fpsp.h"
  33 
  34         |xref   get_op
  35         |xref   do_func
  36         |xref   sto_res
  37         |xref   gen_except
  38         |xref   fpsp_fmt_error
  39 
  40         .global fpsp_unimp
  41         .global uni_2
  42 fpsp_unimp:
  43         link            %a6,#-LOCAL_SIZE
  44         fsave           -(%a7)
  45 uni_2:
  46         moveml          %d0-%d1/%a0-%a1,USER_DA(%a6)
  47         fmovemx %fp0-%fp3,USER_FP0(%a6)
  48         fmoveml %fpcr/%fpsr/%fpiar,USER_FPCR(%a6)
  49         moveb           (%a7),%d0               |test for valid version num
  50         andib           #0xf0,%d0               |test for $4x
  51         cmpib           #VER_4,%d0      |must be $4x or exit
  52         bnel            fpsp_fmt_error
  53 |
  54 |       Temporary D25B Fix
  55 |       The following lines are used to ensure that the FPSR
  56 |       exception byte and condition codes are clear before proceeding
  57 |
  58         movel           USER_FPSR(%a6),%d0
  59         andl            #0xFF00FF,%d0   |clear all but accrued exceptions
  60         movel           %d0,USER_FPSR(%a6)
  61         fmovel          #0,%FPSR |clear all user bits
  62         fmovel          #0,%FPCR        |clear all user exceptions for FPSP
  63 
  64         clrb            UFLG_TMP(%a6)   |clr flag for unsupp data
  65 
  66         bsrl            get_op          |go get operand(s)
  67         clrb            STORE_FLG(%a6)
  68         bsrl            do_func         |do the function
  69         fsave           -(%a7)          |capture possible exc state
  70         tstb            STORE_FLG(%a6)
  71         bnes            no_store        |if STORE_FLG is set, no store
  72         bsrl            sto_res         |store the result in user space
  73 no_store:
  74         bral            gen_except      |post any exceptions and return
  75 
  76         |end