Files
ueforth/common/assembler.fs
2022-10-21 21:59:25 -07:00

127 lines
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\ Copyright 2022 Bradley D. Nelson
\
\ Licensed under the Apache License, Version 2.0 (the "License");
\ you may not use this file except in compliance with the License.
\ You may obtain a copy of the License at
\
\ http://www.apache.org/licenses/LICENSE-2.0
\
\ Unless required by applicable law or agreed to in writing, software
\ distributed under the License is distributed on an "AS IS" BASIS,
\ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
\ See the License for the specific language governing permissions and
\ limitations under the License.
( Lazy loaded assembler/disassembler framework )
: assembler r|
current @
also internals
also asm definitions
-1 1 rshift invert constant high-bit
: odd? ( n -- f ) 1 and ;
: >>1 ( n -- n ) 1 rshift ;
: enmask ( n m -- n )
0 -rot cell 8 * 1- for
rot >>1 -rot
dup odd? if
over odd? if rot high-bit or -rot then
swap >>1 swap
then
>>1
next
2drop
;
: demask ( n m -- n )
0 >r begin dup while
dup 0< if over 0< if r> 2* 1+ >r else r> 2* >r then then
2* swap 2* swap
repeat 2drop r>
;
variable length variable pattern variable mask
: bit! ( n a -- ) dup @ 2* rot 1 and or swap ! ;
: >opmask& ( xt -- a ) >body ;
: >next ( xt -- xt ) >body cell+ @ ;
: >inop ( a -- a ) >body 2 cells + @ ;
: >printop ( a -- a ) >body 3 cells + @ ;
variable operands
: for-operands ( xt -- )
>r operands @ begin dup while r> 2dup >r >r execute r> >next repeat rdrop drop ;
: reset-operand ( xt -- ) >opmask& 0 swap ! ;
: reset 0 length ! 0 mask ! 0 pattern ! ['] reset-operand for-operands ;
: advance-operand ( xt -- ) >opmask& 0 swap bit! ;
: advance ['] advance-operand for-operands ;
: skip 1 length +! 0 mask bit! 0 pattern bit! advance ;
: bit ( n -- ) 1 length +! 1 mask bit! pattern bit! advance ;
: bits ( val n ) 1- for dup r@ rshift bit next drop ;
: o 0 bit ; : l 1 bit ;
( struct: pattern next inop printop )
: operand ( inop printop "name" )
create 0 , operands @ , latestxt operands ! swap , ,
does> skip 1 swap +! ;
: names ( n "names"*n --) 0 swap 1- for dup constant 1+ next drop ;
: coden, ( val n -- ) 8 / 1- for dup code1, 8 rshift next drop ;
( struct: length pattern mask [xt pattern]* 0 )
variable opcodes
: op-snap ( xt -- ) dup >opmask& @ if dup , >opmask& @ , else drop then ;
: >xt ( a -- xt ) 2 cells - ;
: >length ( xt -- a ) >body cell+ @ ;
: >pattern ( xt -- a ) >body 2 cells + @ ;
: >mask ( xt -- a ) >body 3 cells + @ ;
: >operands ( xt -- a ) >body 4 cells + ;
: op ( "name" )
create opcodes @ , latestxt opcodes !
length @ , pattern @ , mask @ ,
['] op-snap for-operands 0 , reset
does> >xt >r
r@ >pattern
0 r@ >operands begin dup @ while >r 1+ r> 2 cells + repeat
swap for aft
2 cells - dup >r cell+ @ swap >r enmask r> swap r@ @ >inop execute or r>
then next
drop
r> >length coden,
;
: for-ops ( xt -- )
>r opcodes @ begin dup while r> 2dup >r >r execute r> >body @ repeat rdrop drop ;
: m@ ( a -- n ) 0 swap cell 0 do dup ca@ i 8 * lshift swap >r or r> 1+ loop drop ;
: m. ( n n -- ) base @ hex >r >r <# r> 1- for # # next #> type r> base ! ;
variable istep
: matchit ( a xt -- a )
>r dup m@ r@ >mask and r@ >pattern = if
r@ >operands begin dup @ while
>r dup m@ r@ cell+ @ demask r@ @ >printop execute r> 2 cells +
repeat drop
r@ see.
r@ >length 8 / istep !
then rdrop ;
: disasm1 ( a -- a )
dup . ." -- " 0 istep ! ['] matchit for-ops
istep @ 0= if 1 istep ! ." UNKNOWN!!!" then
9 emit 9 emit ." -- " dup m@ istep @ m.
istep @ +
cr
;
: disasm ( a n -- ) for aft disasm1 then next drop ;
previous previous
also forth definitions
: assembler asm ;
previous
assembler
current !
| evaluate ;