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+|
+| 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
+|
+| THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA
+| The copyright notice above does not evidence any
+| actual or intended publication of such source code.
+
+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