1| 2| x_fline.sa 3.3 1/10/91 3| 4| fpsp_fline --- FPSP handler for fline exception 5| 6| First determine if the exception is one of the unimplemented 7| floating point instructions. If so, let fpsp_unimp handle it. 8| Next, determine if the instruction is an fmovecr with a non-zero 9| <ea> field. If so, handle here and return. Otherwise, it 10| must be a real F-line exception. 11| 12 13| Copyright (C) Motorola, Inc. 1990 14| All Rights Reserved 15| 16| THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA 17| The copyright notice above does not evidence any 18| actual or intended publication of such source code. 19 20X_FLINE: |idnt 2,1 | Motorola 040 Floating Point Software Package 21 22 |section 8 23 24 .include "fpsp.h" 25 26 |xref real_fline 27 |xref fpsp_unimp 28 |xref uni_2 29 |xref mem_read 30 |xref fpsp_fmt_error 31 32 .global fpsp_fline 33fpsp_fline: 34| 35| check for unimplemented vector first. Use EXC_VEC-4 because 36| the equate is valid only after a 'link a6' has pushed one more 37| long onto the stack. 38| 39 cmpw #UNIMP_VEC,EXC_VEC-4(%a7) 40 beql fpsp_unimp 41 42| 43| fmovecr with non-zero <ea> handling here 44| 45 subl #4,%a7 |4 accounts for 2-word difference 46| ;between six word frame (unimp) and 47| ;four word frame 48 link %a6,#-LOCAL_SIZE 49 fsave -(%a7) 50 moveml %d0-%d1/%a0-%a1,USER_DA(%a6) 51 moveal EXC_PC+4(%a6),%a0 |get address of fline instruction 52 leal L_SCR1(%a6),%a1 |use L_SCR1 as scratch 53 movel #4,%d0 54 addl #4,%a6 |to offset the sub.l #4,a7 above so that 55| ;a6 can point correctly to the stack frame 56| ;before branching to mem_read 57 bsrl mem_read 58 subl #4,%a6 59 movel L_SCR1(%a6),%d0 |d0 contains the fline and command word 60 bfextu %d0{#4:#3},%d1 |extract coprocessor id 61 cmpib #1,%d1 |check if cpid=1 62 bne not_mvcr |exit if not 63 bfextu %d0{#16:#6},%d1 64 cmpib #0x17,%d1 |check if it is an FMOVECR encoding 65 bne not_mvcr 66| ;if an FMOVECR instruction, fix stack 67| ;and go to FPSP_UNIMP 68fix_stack: 69 cmpib #VER_40,(%a7) |test for orig unimp frame 70 bnes ck_rev 71 subl #UNIMP_40_SIZE-4,%a7 |emulate an orig fsave 72 moveb #VER_40,(%a7) 73 moveb #UNIMP_40_SIZE-4,1(%a7) 74 clrw 2(%a7) 75 bras fix_con 76ck_rev: 77 cmpib #VER_41,(%a7) |test for rev unimp frame 78 bnel fpsp_fmt_error |if not $40 or $41, exit with error 79 subl #UNIMP_41_SIZE-4,%a7 |emulate a rev fsave 80 moveb #VER_41,(%a7) 81 moveb #UNIMP_41_SIZE-4,1(%a7) 82 clrw 2(%a7) 83fix_con: 84 movew EXC_SR+4(%a6),EXC_SR(%a6) |move stacked sr to new position 85 movel EXC_PC+4(%a6),EXC_PC(%a6) |move stacked pc to new position 86 fmovel EXC_PC(%a6),%FPIAR |point FPIAR to fline inst 87 movel #4,%d1 88 addl %d1,EXC_PC(%a6) |increment stacked pc value to next inst 89 movew #0x202c,EXC_VEC(%a6) |reformat vector to unimp 90 clrl EXC_EA(%a6) |clear the EXC_EA field 91 movew %d0,CMDREG1B(%a6) |move the lower word into CMDREG1B 92 clrl E_BYTE(%a6) 93 bsetb #UFLAG,T_BYTE(%a6) 94 moveml USER_DA(%a6),%d0-%d1/%a0-%a1 |restore data registers 95 bral uni_2 96 97not_mvcr: 98 moveml USER_DA(%a6),%d0-%d1/%a0-%a1 |restore data registers 99 frestore (%a7)+ 100 unlk %a6 101 addl #4,%a7 102 bral real_fline 103 104 |end 105