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514 lines
14 KiB
Plaintext
514 lines
14 KiB
Plaintext
;
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; File: BugFix.a
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;
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; Contains: Workaround for bug #1238 in the 040 (D43B masks)
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;
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; Originally Written by: Motorola Inc.
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; Adapted to Apple/MPW: Jon Okada
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;
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; Copyright: © 1991 by Apple Computer, Inc., all rights reserved.
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;
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; This file is used in these builds: Mac32
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;
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; Change History (most recent first):
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;
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; <1> 3/30/91 BG First checked into TERROR/BBS.
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;
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; bugfix.a
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; Based upon Motorola file 'bugfix.sa' (version 3.2, 1/31/91).
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; CHANGE LOG:
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; 05 Mar 91 JPO Renamed label "finish" to "bffinish". Deleted
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; a branch to following instruction.
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*
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* bugfix.sa 3.2 1/31/91
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*
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*
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* This file contains workarounds for bugs in the 040
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* relating to the Floating-Point Software Package (FPSP)
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*
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* Fixes for bugs: 1238
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*
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* Bug: 1238
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*
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*
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* /* The following dirty_bit clear should be left in
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* * the handler permanently to improve throughput.
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* * The dirty_bits are located at bits [23:16] in
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* * longword $08 in the busy frame $4x60. Bit 16
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* * corresponds to FP0, bit 17 corresponds to FP1,
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* * and so on.
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* */
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* if (E3_exception_just_serviced) {
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* dirty_bit[cmdreg3b[9:7]] = 0;
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* }
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*
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* if (fsave_format_version != $40) {goto NOFIX}
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*
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* if !(E3_exception_just_serviced) {goto NOFIX}
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* if (cupc == 0000000) {goto NOFIX}
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* if ((cmdreg1b[15:13] != 000) &&
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* (cmdreg1b[15:10] != 010001)) {goto NOFIX}
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* if (((cmdreg1b[15:13] != 000) || ((cmdreg1b[12:10] != cmdreg2b[9:7]) &&
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* (cmdreg1b[12:10] != cmdreg3b[9:7])) ) &&
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* ((cmdreg1b[ 9: 7] != cmdreg2b[9:7]) &&
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* (cmdreg1b[ 9: 7] != cmdreg3b[9:7])) ) {goto NOFIX}
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*
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* /* Note: for 6d43b or 8d43b, you may want to add the following code
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* * to get better coverage. (If you do not insert this code, the part
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* * won't lock up; it will simply get the wrong answer.)
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* * Do NOT insert this code for 10d43b or later parts.
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* *
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* * if (fpiarcu == integer stack return address) {
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* * cupc = 0000000;
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* * goto NOFIX;
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* * }
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* */
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*
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* if (cmdreg1b[15:13] != 000) {goto FIX_OPCLASS2}
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* FIX_OPCLASS0:
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* if (((cmdreg1b[12:10] == cmdreg2b[9:7]) ||
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* (cmdreg1b[ 9: 7] == cmdreg2b[9:7])) &&
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* (cmdreg1b[12:10] != cmdreg3b[9:7]) &&
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* (cmdreg1b[ 9: 7] != cmdreg3b[9:7])) { /* xu conflict only */
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* /* We execute the following code if there is an
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* xu conflict and NOT an nu conflict */
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*
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* /* first save some values on the fsave frame */
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* stag_temp = STAG[fsave_frame];
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* cmdreg1b_temp = CMDREG1B[fsave_frame];
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* dtag_temp = DTAG[fsave_frame];
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* ete15_temp = ETE15[fsave_frame];
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*
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* CUPC[fsave_frame] = 0000000;
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* FRESTORE
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* FSAVE
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*
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* /* If the xu instruction is exceptional, we punt.
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* * Otherwise, we would have to include OVFL/UNFL handler
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* * code here to get the correct answer.
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* */
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* if (fsave_frame_format == $4060) {goto KILL_PROCESS}
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*
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* fsave_frame = /* build a long frame of all zeros */
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* fsave_frame_format = $4060; /* label it as long frame */
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*
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* /* load it with the temps we saved */
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* STAG[fsave_frame] = stag_temp;
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* CMDREG1B[fsave_frame] = cmdreg1b_temp;
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* DTAG[fsave_frame] = dtag_temp;
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* ETE15[fsave_frame] = ete15_temp;
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*
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* /* Make sure that the cmdreg3b dest reg is not going to
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* * be destroyed by a FMOVEM at the end of all this code.
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* * If it is, you should move the current value of the reg
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* * onto the stack so that the reg will loaded with that value.
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* */
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*
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* /* All done. Proceed with the code below */
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* }
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*
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* etemp = FP_reg_[cmdreg1b[12:10]];
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* ete15 = ~ete14;
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* cmdreg1b[15:10] = 010010;
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* clear(bug_flag_procIDxxxx);
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* FRESTORE and return;
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*
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*
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* FIX_OPCLASS2:
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* if ((cmdreg1b[9:7] == cmdreg2b[9:7]) &&
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* (cmdreg1b[9:7] != cmdreg3b[9:7])) { /* xu conflict only */
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* /* We execute the following code if there is an
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* xu conflict and NOT an nu conflict */
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*
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* /* first save some values on the fsave frame */
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* stag_temp = STAG[fsave_frame];
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* cmdreg1b_temp = CMDREG1B[fsave_frame];
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* dtag_temp = DTAG[fsave_frame];
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* ete15_temp = ETE15[fsave_frame];
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* etemp_temp = ETEMP[fsave_frame];
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*
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* CUPC[fsave_frame] = 0000000;
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* FRESTORE
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* FSAVE
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*
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*
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* /* If the xu instruction is exceptional, we punt.
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* * Otherwise, we would have to include OVFL/UNFL handler
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* * code here to get the correct answer.
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* */
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* if (fsave_frame_format == $4060) {goto KILL_PROCESS}
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*
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* fsave_frame = /* build a long frame of all zeros */
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* fsave_frame_format = $4060; /* label it as long frame */
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*
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* /* load it with the temps we saved */
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* STAG[fsave_frame] = stag_temp;
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* CMDREG1B[fsave_frame] = cmdreg1b_temp;
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* DTAG[fsave_frame] = dtag_temp;
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* ETE15[fsave_frame] = ete15_temp;
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* ETEMP[fsave_frame] = etemp_temp;
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*
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* /* Make sure that the cmdreg3b dest reg is not going to
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* * be destroyed by a FMOVEM at the end of all this code.
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* * If it is, you should move the current value of the reg
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* * onto the stack so that the reg will loaded with that value.
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* */
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*
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* /* All done. Proceed with the code below */
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* }
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*
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* if (etemp_exponent == min_sgl) etemp_exponent = min_dbl;
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* if (etemp_exponent == max_sgl) etemp_exponent = max_dbl;
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* cmdreg1b[15:10] = 010101;
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* clear(bug_flag_procIDxxxx);
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* FRESTORE and return;
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*
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*
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* NOFIX:
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* clear(bug_flag_procIDxxxx);
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* FRESTORE and return;
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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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* THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA
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* The copyright notice above does not evidence any
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* actual or intended publication of such source code.
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* BUGFIX IDNT 2,1 Motorola 040 Floating Point Software Package
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b1238_fix:
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*
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* This code is entered only on completion of the handling of an
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* nu-generated ovfl, unfl, or inex exception. If the version
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* number of the fsave is not $40, this handler is not necessary.
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* Simply branch to fix_done and exit normally.
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*
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cmpi.b #VER_40,4(a7)
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bne.w fix_done
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*
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* Test for cu_savepc equal to zero. If not, this is not a bug
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* #1238 case.
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*
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move.b CU_SAVEPC(a6),d0
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andi.b #$FE,d0
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beq fix_done ;if zero, this is not bug #1238
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*
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* Test the register conflict aspect. If opclass0, check for
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* cu src equal to xu dest or equal to nu dest. If so, go to
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* op0. Else, or if opclass2, check for cu dest equal to
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* xu dest or equal to nu dest. If so, go to tst_opcl. Else,
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* exit, it is not the bug case.
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*
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* Check for opclass 0. If not, go and check for opclass 2 and sgl.
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*
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move.w CMDREG1B(a6),d0
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andi.w #$E000,d0 ;strip all but opclass
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bne op2sgl ;not opclass 0, check op2
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*
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* Check for cu and nu register conflict. If one exists, this takes
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* priority over a cu and xu conflict.
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*
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bfextu CMDREG1B(a6){3:3},d0 ;get 1st src
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bfextu CMDREG3B(a6){6:3},d1 ;get 3rd dest
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cmp.b d0,d1
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beq.b op0 ;if equal, continue bugfix
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*
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* Check for cu dest equal to nu dest. If so, go and fix the
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* bug condition. Otherwise, exit.
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*
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bfextu CMDREG1B(a6){6:3},d0 ;get 1st dest
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cmp.b d0,d1 ;cmp 1st dest with 3rd dest
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beq.b op0 ;if equal, continue bugfix
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*
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* Check for cu and xu register conflict.
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*
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bfextu CMDREG2B(a6){6:3},d1 ;get 2nd dest
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cmp.b d0,d1 ;cmp 1st dest with 2nd dest
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beq.b op0_xu ;if equal, continue bugfix
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bfextu CMDREG1B(a6){3:3},d0 ;get 1st src
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cmp.b d0,d1 ;cmp 1st src with 2nd dest
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beq.b op0_xu
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bne fix_done ;if the reg checks fail, exit
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*
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* We have the opclass 0 situation.
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*
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op0:
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bfextu CMDREG1B(a6){3:3},d0 ;get source register no
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move.l #7,d1
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sub.l d0,d1
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clr.l d0
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bset.l d1,d0
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fmovem.x d0,ETEMP(a6) ;load source to ETEMP
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move.b #$12,d0
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bfins d0,CMDREG1B(a6){0:6} ;opclass 2, extended
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*
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* Set ETEMP exponent bit 15 as the opposite of ete14
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*
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btst #6,ETEMP_EX(a6) ;check etemp exponent bit 14
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beq.b setete15
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bclr #etemp15_bit,STAG(a6)
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bra bffinish ; label RENAMED <3/5/91, JPO>
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setete15:
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bset #etemp15_bit,STAG(a6)
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bra bffinish ; label RENAMED <3/5/91, JPO>
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*
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* We have the case in which a conflict exists between the cu src or
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* dest and the dest of the xu. We must clear the instruction in
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* the cu and restore the state, allowing the instruction in the
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* xu to complete. Remember, the instruction in the nu
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* was exceptional, and was completed by the appropriate handler.
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* If the result of the xu instruction is not exceptional, we can
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* restore the instruction from the cu to the frame and continue
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* processing the original exception. If the result is also
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* exceptional, we choose to kill the process.
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*
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* Items saved from the stack:
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*
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* $3c stag - L_SCR1
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* $40 cmdreg1b - L_SCR2
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* $44 dtag - L_SCR3
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*
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* The cu savepc is set to zero, and the frame is restored to the
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* fpu.
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*
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op0_xu:
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move.l STAG(a6),L_SCR1(a6)
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move.l CMDREG1B(a6),L_SCR2(a6)
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move.l DTAG(a6),L_SCR3(a6)
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andi.l #$e0000000,L_SCR3(a6)
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move.b #0,CU_SAVEPC(a6)
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move.l (a7)+,d1 ;save return address from bsr
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frestore (a7)+
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fsave -(a7)
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*
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* Check if the instruction which just completed was exceptional.
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*
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cmp.w #$4060,(a7)
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beq op0_xb
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*
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* It is necessary to isolate the result of the instruction in the
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* xu if it is to fp0 - fp3 and write that value to the USER_FPn
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* locations on the stack. The correct destination register is in
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* cmdreg2b.
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*
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bfextu CMDREG2B(a6){6:3},d0 ;get dest register no
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cmpi.l #3,d0
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bgt.b op0_xi
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beq.b op0_fp3
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cmpi.l #1,d0
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blt.b op0_fp0
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beq.b op0_fp1
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op0_fp2:
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fmovem.x fp2,USER_FP2(a6)
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bra.b op0_xi
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op0_fp1:
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fmovem.x fp1,USER_FP1(a6)
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bra.b op0_xi
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op0_fp0:
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fmovem.x fp0,USER_FP0(a6)
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bra.b op0_xi
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op0_fp3:
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fmovem.x fp3,USER_FP3(a6)
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*
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* The frame returned is idle. We must build a busy frame to hold
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* the cu state information and setup etemp.
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*
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op0_xi:
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move.l #22,d0 ;clear 23 lwords
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clr.l (a7)
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op0_loop:
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clr.l -(a7)
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dbf d0,op0_loop
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move.l #$40600000,-(a7)
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move.l L_SCR1(a6),STAG(a6)
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move.l L_SCR2(a6),CMDREG1B(a6)
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move.l L_SCR3(a6),DTAG(a6)
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move.b #$6,CU_SAVEPC(a6)
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move.l d1,-(a7) ;return bsr return address
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bfextu CMDREG1B(a6){3:3},d0 ;get source register no
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move.l #7,d1
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sub.l d0,d1
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clr.l d0
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bset.l d1,d0
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fmovem.x d0,ETEMP(a6) ;load source to ETEMP
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move.b #$12,d0
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bfins d0,CMDREG1B(a6){0:6} ;opclass 2, extended
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*
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* Set ETEMP exponent bit 15 as the opposite of ete14
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*
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btst #6,ETEMP_EX(a6) ;check etemp exponent bit 14
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beq.b op0_sete15
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bclr #etemp15_bit,STAG(a6)
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bra bffinish ; label RENAMED <3/5/91, JPO>
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op0_sete15:
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bset #etemp15_bit,STAG(a6)
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bra bffinish ; label RENAMED <3/5/91, JPO>
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*
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* The frame returned is busy. It is not possible to reconstruct
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* the code sequence to allow completion. We will jump to
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* fpsp_fmt_error and allow the kernel to kill the process.
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*
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op0_xb:
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jmp fpsp_fmt_error
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*
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* Check for opclass 2 and single size. If not both, exit.
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*
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op2sgl:
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move.w CMDREG1B(a6),d0
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andi.w #$FC00,d0 ;strip all but opclass and size
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cmpi.w #$4400,d0 ;test for opclass 2 and size=sgl
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bne fix_done ;if not, it is not bug 1238
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*
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* Check for cu dest equal to nu dest or equal to xu dest, with
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* a cu and nu conflict taking priority an nu conflict. If either,
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* go and fix the bug condition. Otherwise, exit.
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*
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bfextu CMDREG1B(a6){6:3},d0 ;get 1st dest
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bfextu CMDREG3B(a6){6:3},d1 ;get 3rd dest
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cmp.b d0,d1 ;cmp 1st dest with 3rd dest
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beq op2_com ;if equal, continue bugfix
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bfextu CMDREG2B(a6){6:3},d1 ;get 2nd dest
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cmp.b d0,d1 ;cmp 1st dest with 2nd dest
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bne fix_done ;if the reg checks fail, exit
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*
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* We have the case in which a conflict exists between the cu src or
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* dest and the dest of the xu. We must clear the instruction in
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* the cu and restore the state, allowing the instruction in the
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* xu to complete. Remember, the instruction in the nu
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* was exceptional, and was completed by the appropriate handler.
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* If the result of the xu instruction is not exceptional, we can
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* restore the instruction from the cu to the frame and continue
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* processing the original exception. If the result is also
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* exceptional, we choose to kill the process.
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*
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* Items saved from the stack:
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*
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* $3c stag - L_SCR1
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* $40 cmdreg1b - L_SCR2
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* $44 dtag - L_SCR3
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* etemp - FP_SCR2
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*
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* The cu savepc is set to zero, and the frame is restored to the
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* fpu.
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*
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op2_xu:
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move.l STAG(a6),L_SCR1(a6)
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move.l CMDREG1B(a6),L_SCR2(a6)
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move.l DTAG(a6),L_SCR3(a6)
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andi.l #$e0000000,L_SCR3(a6)
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move.b #0,CU_SAVEPC(a6)
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move.l ETEMP(a6),FP_SCR2(a6)
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move.l ETEMP_HI(a6),FP_SCR2+4(a6)
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move.l ETEMP_LO(a6),FP_SCR2+8(a6)
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move.l (a7)+,d1 ;save return address from bsr
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frestore (a7)+
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fsave -(a7)
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*
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* Check if the instruction which just completed was exceptional.
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*
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cmp.w #$4060,(a7)
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beq op2_xb
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*
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* It is necessary to isolate the result of the instruction in the
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* xu if it is to fp0 - fp3 and write that value to the USER_FPn
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* locations on the stack. The correct destination register is in
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* cmdreg2b.
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*
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bfextu CMDREG2B(a6){6:3},d0 ;get dest register no
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cmpi.l #3,d0
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bgt.b op2_xi
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beq.b op2_fp3
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cmpi.l #1,d0
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blt.b op2_fp0
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beq.b op2_fp1
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op2_fp2:
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fmovem.x fp2,USER_FP2(a6)
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bra.b op2_xi
|
|
op2_fp1:
|
|
fmovem.x fp1,USER_FP1(a6)
|
|
bra.b op2_xi
|
|
op2_fp0:
|
|
fmovem.x fp0,USER_FP0(a6)
|
|
bra.b op2_xi
|
|
op2_fp3:
|
|
fmovem.x fp3,USER_FP3(a6)
|
|
*
|
|
* The frame returned is idle. We must build a busy frame to hold
|
|
* the cu state information and fix up etemp.
|
|
*
|
|
op2_xi:
|
|
move.l #22,d0 ;clear 23 lwords
|
|
clr.l (a7)
|
|
op2_loop:
|
|
clr.l -(a7)
|
|
dbf d0,op2_loop
|
|
move.l #$40600000,-(a7)
|
|
move.l L_SCR1(a6),STAG(a6)
|
|
move.l L_SCR2(a6),CMDREG1B(a6)
|
|
move.l L_SCR3(a6),DTAG(a6)
|
|
move.b #$6,CU_SAVEPC(a6)
|
|
move.l FP_SCR2(a6),ETEMP(a6)
|
|
move.l FP_SCR2+4(a6),ETEMP_HI(a6)
|
|
move.l FP_SCR2+8(a6),ETEMP_LO(a6)
|
|
move.l d1,-(a7)
|
|
; bra op2_com ; DELETED <3/5/91, JPO>
|
|
|
|
*
|
|
* We have the opclass 2 single source situation.
|
|
*
|
|
op2_com:
|
|
move.b #$15,d0
|
|
bfins d0,CMDREG1B(a6){0:6} ;opclass 2, double
|
|
|
|
cmp.w #$407F,ETEMP_EX(a6) ;single +max
|
|
bne.b case2
|
|
move.w #$43FF,ETEMP_EX(a6) ;to double +max
|
|
bra.b bffinish ; label RENAMED <3/5/91, JPO>
|
|
case2:
|
|
cmp.w #$C07F,ETEMP_EX(a6) ;single -max
|
|
bne.b case3
|
|
move.w #$C3FF,ETEMP_EX(a6) ;to double -max
|
|
bra.b bffinish ; label RENAMED <3/5/91, JPO>
|
|
case3:
|
|
cmp.w #$3F80,ETEMP_EX(a6) ;single +min
|
|
bne.b case4
|
|
move.w #$3C00,ETEMP_EX(a6) ;to double +min
|
|
bra.b bffinish ; label RENAMED <3/5/91, JPO>
|
|
case4:
|
|
cmp.w #$BF80,ETEMP_EX(a6) ;single -min
|
|
bne.b fix_done
|
|
move.w #$BC00,ETEMP_EX(a6) ;to double -min
|
|
bra.b bffinish ; label RENAMED <3/5/91, JPO>
|
|
*
|
|
* The frame returned is busy. It is not possible to reconstruct
|
|
* the code sequence to allow completion. fpsp_fmt_error causes
|
|
* an fline illegal instruction to be executed.
|
|
*
|
|
* You should replace the jump to fpsp_fmt_error with a jump
|
|
* to the entry point used to kill a process.
|
|
*
|
|
op2_xb:
|
|
jmp fpsp_fmt_error
|
|
|
|
*
|
|
* Enter here if the case is not of the situations affected by
|
|
* bug #1238, or if the fix is completed, and exit.
|
|
*
|
|
bffinish: ; label RENAMED <3/5/91, JPO>
|
|
fix_done:
|
|
rts
|
|
|