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simplified u.r - albeit not sure whether it can be called a simplification. It's shorter though. #45

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simplified u.r - albeit not sure whether it can be called a simplification. It's shorter though. #45

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3ce11c2
simplified <= and >=
Bushmills Sep 25, 2019
d6e9e9e
added .( and s(
Sep 26, 2019
6ccdedc
simplified u.r
Sep 26, 2019
8bb4c04
simplified u.r
Sep 26, 2019
bc7e1b5
added u., used by makeshift .
Sep 27, 2019
a039e70
a handful of smaller simplifications, mostly by eliminating else branch.
Sep 27, 2019
72f0377
some simplifications, some removed else branches. some more factoring.
Sep 28, 2019
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43 changes: 21 additions & 22 deletions src/cforth/decomp2.fth
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Original file line number Diff line number Diff line change
Expand Up @@ -32,9 +32,8 @@ d# 300 2* /n* constant /positions
#out @ #line @ wljoin decompiler-ip rot 2! ( )
;
: ip>position ( ip -- true | #out #line false )
find-position if ( )
true ( true )
else ( adr )
find-position ( )
?dup 0= if
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I prefer the origin code in this case as it seems clearer to me.

2@ drop lwsplit ( #out #line )
false ( #out #line false )
then ( true | #out #line false )
Expand All @@ -45,7 +44,9 @@ d# 300 2* /n* constant /positions

headers
defer indent
: (indent) ( -- ) lmargin @ #out @ - 0 max spaces ;
: (indent) ( -- ) lmargin @ #out @ -
\ 0 max \ unnecessary, as spaces does that too.
spaces ;
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Formatting: if the definition fits entirely on one line, it can follow the stack diagram. Otherwise the entire body must be on a 3-space indent and the ; is on a line by itself

' (indent) is indent
headerless

Expand Down Expand Up @@ -122,10 +123,9 @@ variable break-type variable break-addr variable where-break
-1 break-addr ! ( prime stack)
end-breaks @ breaks ?do
i 2@ over break-addr @ u< if
break-type ! break-addr ! i where-break !
else
2drop
2dup break-type ! break-addr ! i where-break !
then
2drop
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This change seems hardly worth the effort. Your formulation compiles to slightly shorter code, but the improvement is so slight...

/n 2* +loop
break-addr @ -1 <> if -1 -1 where-break @ 2! then
;
Expand All @@ -142,7 +142,7 @@ variable break-type variable break-addr variable where-break
: bare-if? ( ip-of-branch-target -- f )
/branch - /token - dup token@ ( ip' possible-branch-acf )
dup ['] branch = \ unconditional branch means else or repeat
if drop drop false exit then ( ip' acf )
if 2drop false exit then ( ip' acf )
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Okay but add another space before the then (fixing my formatting error).

['] ?branch = \ cond. forw. branch is for an IF THEN with null body
if forward-branch? else drop true then
;
Expand Down Expand Up @@ -182,12 +182,11 @@ variable extent extent off
end-breaks @ breaks /breaks + >= ( adr,type full? )
abort" Decompiler table overflow" ( adr,type )
end-breaks @ breaks > if ( adr,type )
over end-breaks @ /n 2* - >r r@ 2@ ( adr,type adr prev-adr,type )
over end-breaks @ /n 2* - dup >r 2@ ( adr,type adr prev-adr,type )
['] .endof = -rot = and if ( adr,type )
r@ 2@ 2swap r> 2! ( prev-adr,type )
else ( adr,type )
r> drop ( adr,type )
r@ 2@ 2swap r@ 2! ( prev-adr,type )
then ( adr,type )
r> drop ( adr,type )
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I hope you aren't going to continue to swamp me with little tweaks of this magnitude...

then ( adr,type )
end-breaks @ 2! /n 2* end-breaks +! ( )
;
Expand All @@ -199,7 +198,7 @@ variable extent extent off
then
/n 2* +loop ( break-address break-type not-found? )

if add-break else 2drop then
if 2dup add-break then 2drop
;

: scan-of ( ip-of-(of -- ip' )
Expand Down Expand Up @@ -297,9 +296,9 @@ variable extent extent off
: type# ( $ -- ) \ render control characters as green #
bounds ?do
i c@ dup h# 20 < if
drop green-letters ." #" red-letters
drop green-letters ." #" red-letters
else
emit
emit
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Thanks for fixing the tabs and trailing whitespace

then
loop
;
Expand All @@ -316,7 +315,7 @@ variable extent extent off
: pretty-. ( n -- )
base @ d# 10 = if (.) else (u.) then ( adr len )
dup 3 + ?line indent add-position
green-letters
green-letters
base @ case
d# 10 of ." #" endof
d# 16 of ." $" endof
Expand Down Expand Up @@ -452,7 +451,7 @@ also forth definitions
['] dummy ['] do-scan (patch
['] dummy ['] .execution-class (patch
['] dummy ['] execution-class >body na1+
dup [ #decomp-classes ] literal ta+ tsearch
dup [ #decomp-classes ] literal ta+ tsearch
drop token!
;
previous definitions
Expand Down Expand Up @@ -482,10 +481,10 @@ headers
dup is decompiler-ip ( adr )
?cr ( adr )
break-addr @ over = if ( adr )
begin ( adr )
break-type @ execute ( adr )
next-break break-addr @ over <> ( adr done? )
until ( adr )
begin ( adr )
break-type @ execute ( adr )
next-break break-addr @ over <> ( adr done? )
until ( adr )
else ( adr )
.token ( adr' )
then ( adr' )
Expand Down Expand Up @@ -571,7 +570,7 @@ also forth definitions
: install-decomp-definer ( definer-acf display-acf -- )
['] dummy ['] .definition-class (patch
['] dummy ['] definition-class >body na1+
dup [ #definition-classes ] literal ta+ tsearch
dup [ #definition-classes ] literal ta+ tsearch
drop token!
;
previous definitions
Expand Down