path: root/arch/m68k/fpsp040/bugfix.S

|
|	bugfix.sa 3.2 1/31/91
|
|
|	This file contains workarounds for bugs in the 040
|	relating to the Floating-Point Software Package (FPSP)
|
|	Fixes for bugs: 1238
|
|	Bug: 1238
|
|
|    /* The following dirty_bit clear should be left in
|     * the handler permanently to improve throughput.
|     * The dirty_bits are located at bits [23:16] in
|     * longword $08 in the busy frame $4x60.  Bit 16
|     * corresponds to FP0, bit 17 corresponds to FP1,
|     * and so on.
|     */
|    if  (E3_exception_just_serviced)   {
|         dirty_bit[cmdreg3b[9:7]] = 0;
|         }
|
|    if  (fsave_format_version != $40)  {goto NOFIX}
|
|    if !(E3_exception_just_serviced)   {goto NOFIX}
|    if  (cupc == 0000000)              {goto NOFIX}
|    if  ((cmdreg1b[15:13] != 000) &&
|         (cmdreg1b[15:10] != 010001))  {goto NOFIX}
|    if (((cmdreg1b[15:13] != 000) || ((cmdreg1b[12:10] != cmdreg2b[9:7]) &&
|				      (cmdreg1b[12:10] != cmdreg3b[9:7]))  ) &&
|	 ((cmdreg1b[ 9: 7] != cmdreg2b[9:7]) &&
|	  (cmdreg1b[ 9: 7] != cmdreg3b[9:7])) )  {goto NOFIX}
|
|    /* Note: for 6d43b or 8d43b, you may want to add the following code
|     * to get better coverage.  (If you do not insert this code, the part
|     * won't lock up; it will simply get the wrong answer.)
|     * Do NOT insert this code for 10d43b or later parts.
|     *
|     *  if (fpiarcu == integer stack return address) {
|     *       cupc = 0000000;
|     *       goto NOFIX;
|     *       }
|     */
|
|    if (cmdreg1b[15:13] != 000)   {goto FIX_OPCLASS2}
|    FIX_OPCLASS0:
|    if (((cmdreg1b[12:10] == cmdreg2b[9:7]) ||
|	 (cmdreg1b[ 9: 7] == cmdreg2b[9:7])) &&
|	(cmdreg1b[12:10] != cmdreg3b[9:7]) &&
|	(cmdreg1b[ 9: 7] != cmdreg3b[9:7]))  {  /* xu conflict only */
|	/* We execute the following code if there is an
|	   xu conflict and NOT an nu conflict */
|
|	/* first save some values on the fsave frame */
|	stag_temp     = STAG[fsave_frame];
|	cmdreg1b_temp = CMDREG1B[fsave_frame];
|	dtag_temp     = DTAG[fsave_frame];
|	ete15_temp    = ETE15[fsave_frame];
|
|	CUPC[fsave_frame] = 0000000;
|	FRESTORE
|	FSAVE
|
|	/* If the xu instruction is exceptional, we punt.
|	 * Otherwise, we would have to include OVFL/UNFL handler
|	 * code here to get the correct answer.
|	 */
|	if (fsave_frame_format == $4060) {goto KILL_PROCESS}
|
|	fsave_frame = /* build a long frame of all zeros */
|	fsave_frame_format = $4060;  /* label it as long frame */
|
|	/* load it with the temps we saved */
|	STAG[fsave_frame]     =  stag_temp;
|	CMDREG1B[fsave_frame] =  cmdreg1b_temp;
|	DTAG[fsave_frame]     =  dtag_temp;
|	ETE15[fsave_frame]    =  ete15_temp;
|
|	/* Make sure that the cmdreg3b dest reg is not going to
|	 * be destroyed by a FMOVEM at the end of all this code.
|	 * If it is, you should move the current value of the reg
|	 * onto the stack so that the reg will loaded with that value.
|	 */
|
|	/* All done.  Proceed with the code below */
|    }
|
|    etemp  = FP_reg_[cmdreg1b[12:10]];
|    ete15  = ~ete14;
|    cmdreg1b[15:10] = 010010;
|    clear(bug_flag_procIDxxxx);
|    FRESTORE and return;
|
|
|    FIX_OPCLASS2:
|    if ((cmdreg1b[9:7] == cmdreg2b[9:7]) &&
|	(cmdreg1b[9:7] != cmdreg3b[9:7]))  {  /* xu conflict only */
|	/* We execute the following code if there is an
|	   xu conflict and NOT an nu conflict */
|
|	/* first save some values on the fsave frame */
|	stag_temp     = STAG[fsave_frame];
|	cmdreg1b_temp = CMDREG1B[fsave_frame];
|	dtag_temp     = DTAG[fsave_frame];
|	ete15_temp    = ETE15[fsave_frame];
|	etemp_temp    = ETEMP[fsave_frame];
|
|	CUPC[fsave_frame] = 0000000;
|	FRESTORE
|	FSAVE
|
|
|	/* If the xu instruction is exceptional, we punt.
|	 * Otherwise, we would have to include OVFL/UNFL handler
|	 * code here to get the correct answer.
|	 */
|	if (fsave_frame_format == $4060) {goto KILL_PROCESS}
|
|	fsave_frame = /* build a long frame of all zeros */
|	fsave_frame_format = $4060;  /* label it as long frame */
|
|	/* load it with the temps we saved */
|	STAG[fsave_frame]     =  stag_temp;
|	CMDREG1B[fsave_frame] =  cmdreg1b_temp;
|	DTAG[fsave_frame]     =  dtag_temp;
|	ETE15[fsave_frame]    =  ete15_temp;
|	ETEMP[fsave_frame]    =  etemp_temp;
|
|	/* Make