| | |
| | x_fline.sa 3.3 1/10/91 |
| | |
| | fpsp_fline --- FPSP handler for fline exception |
| | |
| | First determine if the exception is one of the unimplemented |
| | floating point instructions. If so, let fpsp_unimp handle it. |
| | Next, determine if the instruction is an fmovecr with a non-zero |
| | <ea> field. If so, handle here and return. Otherwise, it |
| | must be a real F-line exception. |
| | |
| |
| | Copyright (C) Motorola, Inc. 1990 |
| | All Rights Reserved |
| | |
| | For details on the license for this file, please see the |
| | file, README, in this same directory. |
| |
| X_FLINE: |idnt 2,1 | Motorola 040 Floating Point Software Package |
| |
| |section 8 |
| |
| #include "fpsp.h" |
| |
| |xref real_fline |
| |xref fpsp_unimp |
| |xref uni_2 |
| |xref mem_read |
| |xref fpsp_fmt_error |
| |
| .global fpsp_fline |
| fpsp_fline: |
| | |
| | check for unimplemented vector first. Use EXC_VEC-4 because |
| | the equate is valid only after a 'link a6' has pushed one more |
| | long onto the stack. |
| | |
| cmpw #UNIMP_VEC,EXC_VEC-4(%a7) |
| beql fpsp_unimp |
| |
| | |
| | fmovecr with non-zero <ea> handling here |
| | |
| subl #4,%a7 |4 accounts for 2-word difference |
| | ;between six word frame (unimp) and |
| | ;four word frame |
| link %a6,#-LOCAL_SIZE |
| fsave -(%a7) |
| moveml %d0-%d1/%a0-%a1,USER_DA(%a6) |
| moveal EXC_PC+4(%a6),%a0 |get address of fline instruction |
| leal L_SCR1(%a6),%a1 |use L_SCR1 as scratch |
| movel #4,%d0 |
| addl #4,%a6 |to offset the sub.l #4,a7 above so that |
| | ;a6 can point correctly to the stack frame |
| | ;before branching to mem_read |
| bsrl mem_read |
| subl #4,%a6 |
| movel L_SCR1(%a6),%d0 |d0 contains the fline and command word |
| bfextu %d0{#4:#3},%d1 |extract coprocessor id |
| cmpib #1,%d1 |check if cpid=1 |
| bne not_mvcr |exit if not |
| bfextu %d0{#16:#6},%d1 |
| cmpib #0x17,%d1 |check if it is an FMOVECR encoding |
| bne not_mvcr |
| | ;if an FMOVECR instruction, fix stack |
| | ;and go to FPSP_UNIMP |
| fix_stack: |
| cmpib #VER_40,(%a7) |test for orig unimp frame |
| bnes ck_rev |
| subl #UNIMP_40_SIZE-4,%a7 |emulate an orig fsave |
| moveb #VER_40,(%a7) |
| moveb #UNIMP_40_SIZE-4,1(%a7) |
| clrw 2(%a7) |
| bras fix_con |
| ck_rev: |
| cmpib #VER_41,(%a7) |test for rev unimp frame |
| bnel fpsp_fmt_error |if not $40 or $41, exit with error |
| subl #UNIMP_41_SIZE-4,%a7 |emulate a rev fsave |
| moveb #VER_41,(%a7) |
| moveb #UNIMP_41_SIZE-4,1(%a7) |
| clrw 2(%a7) |
| fix_con: |
| movew EXC_SR+4(%a6),EXC_SR(%a6) |move stacked sr to new position |
| movel EXC_PC+4(%a6),EXC_PC(%a6) |move stacked pc to new position |
| fmovel EXC_PC(%a6),%FPIAR |point FPIAR to fline inst |
| movel #4,%d1 |
| addl %d1,EXC_PC(%a6) |increment stacked pc value to next inst |
| movew #0x202c,EXC_VEC(%a6) |reformat vector to unimp |
| clrl EXC_EA(%a6) |clear the EXC_EA field |
| movew %d0,CMDREG1B(%a6) |move the lower word into CMDREG1B |
| clrl E_BYTE(%a6) |
| bsetb #UFLAG,T_BYTE(%a6) |
| moveml USER_DA(%a6),%d0-%d1/%a0-%a1 |restore data registers |
| bral uni_2 |
| |
| not_mvcr: |
| moveml USER_DA(%a6),%d0-%d1/%a0-%a1 |restore data registers |
| frestore (%a7)+ |
| unlk %a6 |
| addl #4,%a7 |
| bral real_fline |
| |
| |end |
