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