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| x_unsupp.sa 3.3 7/1/91
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| fpsp_unsupp --- FPSP handler for unsupported data type exception
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|
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| Trap vector #55 (See table 8-1 Mc68030 User's manual).
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| Invoked when the user program encounters a data format (packed) that
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| hardware does not support or a data type (denormalized numbers or un-
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| normalized numbers).
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| Normalizes denorms and unnorms, unpacks packed numbers then stores
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| them back into the machine to let the 040 finish the operation.
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|
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| Unsupp calls two routines:
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| 1. get_op - gets the operand(s)
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| 2. res_func - restore the function back into the 040 or
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| if fmove.p fpm,<ea> then pack source (fpm)
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| and store in users memory <ea>.
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|
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| Input: Long fsave stack frame
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|
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| Copyright (C) Motorola, Inc. 1990
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| All Rights Reserved
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|
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| For details on the license for this file, please see the
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| file, README, in this same directory.
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|
X_UNSUPP: |idnt 2,1 | Motorola 040 Floating Point Software Package
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|
|section 8
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|
#include "fpsp.h"
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|
|xref get_op
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|xref res_func
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|xref gen_except
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|xref fpsp_fmt_error
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.global fpsp_unsupp
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fpsp_unsupp:
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link %a6,#-LOCAL_SIZE
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fsave -(%a7)
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moveml %d0-%d1/%a0-%a1,USER_DA(%a6)
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fmovemx %fp0-%fp3,USER_FP0(%a6)
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fmoveml %fpcr/%fpsr/%fpiar,USER_FPCR(%a6)
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moveb (%a7),VER_TMP(%a6) |save version number
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moveb (%a7),%d0 |test for valid version num
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andib #0xf0,%d0 |test for $4x
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cmpib #VER_4,%d0 |must be $4x or exit
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bnel fpsp_fmt_error
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fmovel #0,%FPSR |clear all user status bits
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fmovel #0,%FPCR |clear all user control bits
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|
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| The following lines are used to ensure that the FPSR
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| exception byte and condition codes are clear before proceeding,
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| except in the case of fmove, which leaves the cc's intact.
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unsupp_con:
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movel USER_FPSR(%a6),%d1
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btst #5,CMDREG1B(%a6) |looking for fmove out
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bne fmove_con
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andl #0xFF00FF,%d1 |clear all but aexcs and qbyte
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bras end_fix
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fmove_con:
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andl #0x0FFF40FF,%d1 |clear all but cc's, snan bit, aexcs, and qbyte
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end_fix:
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movel %d1,USER_FPSR(%a6)
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st UFLG_TMP(%a6) |set flag for unsupp data
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bsrl get_op |everything okay, go get operand(s)
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bsrl res_func |fix up stack frame so can restore it
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clrl -(%a7)
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moveb VER_TMP(%a6),(%a7) |move idle fmt word to top of stack
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bral gen_except
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|end
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