--- gforth/prims2x.fs	2001/10/26 12:00:15	1.99
+++ gforth/prims2x.fs	2002/12/31 14:50:53	1.126
@@ -60,9 +60,9 @@ include startup.fs
 : struct% struct ; \ struct is redefined in gray
 
 warnings off
+\ warnings on
 
 include ./gray.fs
-
 32 constant max-effect \ number of things on one side of a stack effect
 4 constant max-stacks  \ the max. number of stacks (including inst-stream).
 255 constant maxchar
@@ -78,10 +78,25 @@ variable line-start \ pointer to start o
 0 line !
 2variable filename \ filename of original input file
 0 0 filename 2!
+2variable out-filename \ filename of the output file (for sync lines)
+0 0 out-filename 2!
 2variable f-comment
 0 0 f-comment 2!
 variable skipsynclines \ are sync lines ("#line ...") invisible to the parser?
-skipsynclines on 
+skipsynclines on
+variable out-nls \ newlines in output (for output sync lines)
+0 out-nls !
+variable store-optimization \ use store optimization?
+store-optimization off
+
+variable include-skipped-insts
+\ does the threaded code for a combined instruction include the cells
+\ for the component instructions (true) or only the cells for the
+\ inline arguments (false)
+include-skipped-insts off
+
+variable immarg \ values for immediate arguments (to be used in IMM_ARG macros)
+$12340000 immarg !
 
 : th ( addr1 n -- addr2 )
     cells + ;
@@ -121,12 +136,24 @@ skipsynclines on
 	    0
 	recover endtry
 	r> to outfile-id throw
-	abort
+	1 (bye) \ abort
     endif ;
 
 : quote ( -- )
     [char] " emit ;
 
+\ count output lines to generate sync lines for output
+
+: count-nls ( addr u -- )
+    bounds u+do
+	i c@ nl-char = negate out-nls +!
+    loop ;
+
+:noname ( addr u -- )
+    2dup count-nls
+    defers type ;
+is type
+
 variable output          \ xt ( -- ) of output word for simple primitives
 variable output-combined \ xt ( -- ) of output word for combined primitives
 
@@ -135,6 +162,7 @@ struct%
     cell% 2* field stack-pointer \ stackpointer name
     cell%    field stack-type \ name for default type of stack items
     cell%    field stack-in-index-xt \ ( in-size item -- in-index )
+    cell%    field stack-access-transform \ ( nitem -- index )
 end-struct stack%
 
 struct%
@@ -170,9 +198,17 @@ create stacks max-stacks cells allot \ a
     1 next-stack-number +!
     r@ stack-type !
     save-mem r@ stack-pointer 2! 
-    ['] stack-in-index r> stack-in-index-xt ! ;
+    ['] stack-in-index r@ stack-in-index-xt !
+    ['] noop r@ stack-access-transform !
+    rdrop ;
 
 : map-stacks { xt -- }
+    \ perform xt for all stacks
+    next-stack-number @ 0 +do
+	stacks i th @ xt execute
+    loop ;
+
+: map-stacks1 { xt -- }
     \ perform xt for all stacks except inst-stream
     next-stack-number @ 1 +do
 	stacks i th @ xt execute
@@ -227,9 +263,24 @@ end-struct prim%
 variable in-part \ true if processing a part
  in-part off
 
+: prim-context ( ... p xt -- ... )
+    \ execute xt with prim set to p
+    prim >r
+    swap to prim
+    catch
+    r> to prim
+    throw ;
+
 1000 constant max-combined
 create combined-prims max-combined cells allot
 variable num-combined
+variable part-num \ current part number during process-combined
+
+: map-combined { xt -- }
+    \ perform xt for all components of the current combined instruction
+    num-combined @ 0 +do
+	combined-prims i th @ xt execute
+    loop ;
 
 table constant combinations
   \ the keys are the sequences of pointers to primitives
@@ -238,6 +289,19 @@ create current-depth max-stacks cells al
 create max-depth     max-stacks cells allot
 create min-depth     max-stacks cells allot
 
+create sp-update-in max-stacks cells allot
+\ where max-depth occured the first time
+create max-depths max-stacks max-combined 1+ * cells allot
+\ maximum depth at start of each part: array[parts] of array[stack]
+create max-back-depths max-stacks max-combined 1+ * cells allot
+\ maximun depth from end of the combination to the start of the each part
+
+: s-c-max-depth ( nstack ncomponent -- addr )
+    max-stacks * + cells max-depths + ;
+
+: s-c-max-back-depth ( nstack ncomponent -- addr )
+    max-stacks * + cells max-back-depths + ;
+
 wordlist constant primitives
 
 : create-prim ( prim -- )
@@ -267,25 +331,38 @@ Variable function-number 0 function-numb
 : complement ( set1 -- set2 )
  empty ['] bit-equivalent binary-set-operation ;
 
+\ forward declaration for inst-stream (breaks cycle in definitions)
+defer inst-stream-f ( -- stack )
+
 \ stack access stuff
 
+: normal-stack-access0 { n stack -- }
+    n stack stack-access-transform @ execute ." [" 0 .r ." ]" ;
+    
+: normal-stack-access1 { n stack -- }
+    stack stack-pointer 2@ type
+    n if
+	n stack normal-stack-access0
+    else
+	." TOS"
+    endif ;
+
 : normal-stack-access ( n stack -- )
-    stack-pointer 2@ type
-    dup
-    if
-	." [" 0 .r ." ]"
+    dup inst-stream-f = if
+	." IMM_ARG(" normal-stack-access1 ." ," immarg ? ." )"
+	1 immarg +!
     else
-	drop ." TOS"
+	normal-stack-access1
     endif ;
 
-\ forward declaration for inst-stream (breaks cycle in definitions)
-defer inst-stream-f ( -- stack )
+: stack-depth { stack -- n }
+    current-depth stack stack-number @ th @ ;
 
 : part-stack-access { n stack -- }
     \ print _<stack><x>, x=inst-stream? n : maxdepth-currentdepth-n-1
     ." _" stack stack-pointer 2@ type
     stack stack-number @ { stack# }
-    current-depth stack# th @ n + { access-depth }
+    stack stack-depth n + { access-depth }
     stack inst-stream-f = if
 	access-depth
     else
@@ -295,10 +372,42 @@ defer inst-stream-f ( -- stack )
     endif
     0 .r ;
 
-: stack-access ( n stack -- )
+: part-stack-read { n stack -- }
+    stack stack-depth n + ( ndepth )
+    stack stack-number @ part-num @ s-c-max-depth @
+\    max-depth stack stack-number @ th @ ( ndepth nmaxdepth )
+    over <= if ( ndepth ) \ load from memory
+	stack normal-stack-access
+    else
+	drop n stack part-stack-access
+    endif ;
+
+: stack-diff ( stack -- n )
+    \ in-out
+    dup stack-in @ swap stack-out @ - ;
+
+: part-stack-write { n stack -- }
+    stack stack-depth n +
+    stack stack-number @ part-num @ s-c-max-back-depth @
+    over <= if ( ndepth )
+	stack combined ['] stack-diff prim-context -
+	stack normal-stack-access
+    else
+	drop n stack part-stack-access
+    endif ;
+
+: stack-read ( n stack -- )
     \ print a stack access at index n of stack
     in-part @ if
-	part-stack-access
+	part-stack-read
+    else
+	normal-stack-access
+    endif ;
+
+: stack-write ( n stack -- )
+    \ print a stack access at index n of stack
+    in-part @ if
+	part-stack-write
     else
 	normal-stack-access
     endif ;
@@ -312,26 +421,26 @@ defer inst-stream-f ( -- stack )
     item-stack @ stack-type @ type-c-name 2@ ;
 
 : fetch-single ( item -- )
- \ fetch a single stack item from its stack
- >r
- r@ item-name 2@ type
- ."  = vm_" r@ item-stack-type-name type
- ." 2" r@ item-type @ print-type-prefix ." ("
- r@ item-in-index r@ item-stack @ stack-access
- ." );" cr
- rdrop ; 
+    \ fetch a single stack item from its stack
+    >r
+    ." vm_" r@ item-stack-type-name type
+    ." 2" r@ item-type @ print-type-prefix ." ("
+    r@ item-in-index r@ item-stack @ stack-read ." ,"
+    r@ item-name 2@ type
+    ." );" cr
+    rdrop ; 
 
 : fetch-double ( item -- )
- \ fetch a double stack item from its stack
- >r
- ." vm_two"
- r@ item-stack-type-name type ." 2"
- r@ item-type @ print-type-prefix ." ("
- r@ item-name 2@ type ." , "
- r@ item-in-index r@ item-stack @ 2dup ." (Cell)" stack-access
- ." , "                      -1 under+ ." (Cell)" stack-access
- ." );" cr
- rdrop ;
+    \ fetch a double stack item from its stack
+    >r
+    ." vm_two"
+    r@ item-stack-type-name type ." 2"
+    r@ item-type @ print-type-prefix ." ("
+    r@ item-in-index r@ item-stack @ 2dup ." (Cell)" stack-read
+    ." , "                      -1 under+ ." (Cell)" stack-read
+    ." , " r@ item-name 2@ type
+    ." )" cr
+    rdrop ;
 
 : same-as-in? ( item -- f )
  \ f is true iff the offset and stack of item is the same as on input
@@ -355,26 +464,25 @@ defer inst-stream-f ( -- stack )
     >r r@ item-stack @ stack-out @ r> item-offset @ - 1- ;
 
 : really-store-single ( item -- )
- >r
- r@ item-out-index r@ item-stack @ stack-access ."  = vm_"
- r@ item-type @ print-type-prefix ." 2"
- r@ item-stack-type-name type ." ("
- r@ item-name 2@ type ." );"
- rdrop ;
+    >r
+    ." vm_"
+    r@ item-type @ print-type-prefix ." 2"
+    r@ item-stack-type-name type ." ("
+    r@ item-name 2@ type ." ,"
+    r@ item-out-index r@ item-stack @ stack-write ." );"
+    rdrop ;
 
 : store-single ( item -- )
- >r
- r@ same-as-in?
- if
-   r@ item-in-index 0= r@ item-out-index 0= xor
-   if
-       ." IF_" r@ item-stack @ stack-pointer 2@ type
-       ." TOS(" r@ really-store-single ." );" cr
-   endif
- else
-   r@ really-store-single cr
- endif
- rdrop ;
+    >r
+    store-optimization @ in-part @ 0= and r@ same-as-in? and if
+	r@ item-in-index 0= r@ item-out-index 0= xor if
+	    ." IF_" r@ item-stack @ stack-pointer 2@ type
+	    ." TOS(" r@ really-store-single ." );" cr
+	endif
+    else
+	r@ really-store-single cr
+    endif
+    rdrop ;
 
 : store-double ( item -- )
 \ !! store optimization is not performed, because it is not yet needed
@@ -383,9 +491,9 @@ defer inst-stream-f ( -- stack )
  r@ item-type @ print-type-prefix ." 2two"
  r@ item-stack-type-name type ." ("
  r@ item-name 2@ type ." , "
- r@ item-out-index r@ item-stack @ 2dup stack-access
- ." , "                       -1 under+ stack-access
- ." );" cr
+ r@ item-out-index r@ item-stack @ 2dup stack-write
+ ." , "                       -1 under+ stack-write
+ ." )" cr
  rdrop ;
 
 : single ( -- xt1 xt2 n )
@@ -423,7 +531,7 @@ wordlist constant prefixes
     stack r@ type-stack !
     rdrop ;
 
-: type-prefix ( xt1 xt2 n stack "prefix" -- )
+: type-prefix ( addr u xt1 xt2 n stack "prefix" -- )
     get-current >r prefixes set-current
     create-type r> set-current
 does> ( item -- )
@@ -523,12 +631,11 @@ stack inst-stream IP Cell
 : compute-offset-out ( addr1 addr2 -- )
     ['] stack-out compute-offset ;
 
-: clear-stack { -- }
+: clear-stack ( stack -- )
     dup stack-in off stack-out off ;
 
 : compute-offsets ( -- )
     ['] clear-stack map-stacks
-    inst-stream clear-stack
     prim prim-effect-in  prim prim-effect-in-end  @ ['] compute-offset-in  map-items
     prim prim-effect-out prim prim-effect-out-end @ ['] compute-offset-out map-items
     inst-stream stack-out @ 0= s" # can only be on the input side" ?print-error ;
@@ -543,22 +650,22 @@ stack inst-stream IP Cell
     stack stack-out @ 0<> stack stack-in @ 0= and
     if
 	." IF_" stack stack-pointer 2@ 2dup type ." TOS("
-	2dup type ." [0] = " type ." TOS);" cr
+	2dup type 0 stack normal-stack-access0 ."  = " type ." TOS);" cr
     endif ;
 
 : flush-tos ( -- )
-    ['] flush-a-tos map-stacks ;
+    ['] flush-a-tos map-stacks1 ;
 
 : fill-a-tos { stack -- }
     stack stack-out @ 0= stack stack-in @ 0<> and
     if
 	." IF_" stack stack-pointer 2@ 2dup type ." TOS("
-	2dup type ." TOS = " type ." [0]);" cr
+	2dup type ." TOS = " type 0 stack normal-stack-access0 ." );" cr
     endif ;
 
 : fill-tos ( -- )
     \ !! inst-stream for prefetching?
-    ['] fill-a-tos map-stacks ;
+    ['] fill-a-tos map-stacks1 ;
 
 : fetch ( addr -- )
     dup item-type @ type-fetch @ execute ;
@@ -566,20 +673,25 @@ stack inst-stream IP Cell
 : fetches ( -- )
     prim prim-effect-in prim prim-effect-in-end @ ['] fetch map-items ;
 
+: stack-update-transform ( n1 stack -- n2 )
+    \ n2 is the number by which the stack pointer should be
+    \ incremented to pop n1 items
+    stack-access-transform @ dup >r execute
+    0 r> execute - ;
+
 : stack-pointer-update { stack -- }
-    \ stack grow downwards
-    stack stack-in @ stack stack-out @ -
+    \ stacks grow downwards
+    stack stack-diff
     ?dup-if \ this check is not necessary, gcc would do this for us
-	stack stack-pointer 2@ type ."  += " 0 .r ." ;" cr
-    endif ;
-
-: inst-pointer-update ( -- )
-    inst-stream stack-in @ ?dup-if
-	." INC_IP(" 0 .r ." );" cr
+	stack inst-stream = if
+	    ." INC_IP(" 0 .r ." );" cr
+	else
+	    stack stack-pointer 2@ type ."  += "
+	    stack stack-update-transform 0 .r ." ;" cr
+	endif
     endif ;
 
 : stack-pointer-updates ( -- )
-    inst-pointer-update
     ['] stack-pointer-update map-stacks ;
 
 : store ( item -- )
@@ -624,58 +736,89 @@ stack inst-stream IP Cell
     endif
     2drop ;
 
-: output-c-tail ( -- )
-    \ the final part of the generated C code
+: output-nextp2 ( -- )
+    ." NEXT_P2;" cr ;
+
+variable tail-nextp2 \ xt to execute for printing NEXT_P2 in INST_TAIL
+' output-nextp2 tail-nextp2 !
+
+: output-label2 ( -- )
+    ." LABEL2(" prim prim-c-name 2@ type ." )" cr
+    ." NEXT_P2;" cr ;
+
+: output-c-tail1 { xt -- }
+    \ the final part of the generated C code, with xt printing LABEL2 or not.
     output-super-end
     print-debug-results
     ." NEXT_P1;" cr
     stores
-    fill-tos
-    ." NEXT_P2;" ;
+    fill-tos 
+    xt execute ;
+
+: output-c-tail1-no-stores { xt -- }
+    \ the final part of the generated C code for combinations
+    output-super-end
+    ." NEXT_P1;" cr
+    fill-tos 
+    xt execute ;
+
+: output-c-tail ( -- )
+    tail-nextp2 @ output-c-tail1 ;
+
+: output-c-tail2 ( -- )
+    ['] output-label2 output-c-tail1 ;
+
+: output-c-tail-no-stores ( -- )
+    tail-nextp2 @ output-c-tail1-no-stores ;
+
+: output-c-tail2-no-stores ( -- )
+    ['] output-label2 output-c-tail1-no-stores ;
 
 : type-c-code ( c-addr u xt -- )
-    \ like TYPE, but replaces "TAIL;" with tail code produced by xt
+    \ like TYPE, but replaces "INST_TAIL;" with tail code produced by xt
     { xt }
+    ." {" cr
+    ." #line " c-line @ . quote c-filename 2@ type quote cr
     begin ( c-addr1 u1 )
-	2dup s" TAIL;" search
+	2dup s" INST_TAIL;" search
     while ( c-addr1 u1 c-addr3 u3 )
 	2dup 2>r drop nip over - type
 	xt execute
-	2r> 5 /string
+	2r> 10 /string
 	\ !! resync #line missing
     repeat
-    2drop type ;
+    2drop type
+    ." #line " out-nls @ 2 + . quote out-filename 2@ type quote cr
+    ." }" cr ;
 
 : print-entry ( -- )
-    ." CASE I_" prim prim-c-name 2@ type ." :" ;
+    ." LABEL(" prim prim-c-name 2@ type ." )" ;
     
 : output-c ( -- ) 
- print-entry ."  /* " prim prim-name 2@ type ."  ( " prim prim-stack-string 2@ type ." ) */" cr
- ." /* " prim prim-doc 2@ type ."  */" cr
- ." NAME(" quote prim prim-name 2@ type quote ." )" cr \ debugging
- ." {" cr
- ." DEF_CA" cr
- print-declarations
- ." NEXT_P0;" cr
- flush-tos
- fetches
- print-debug-args
- stack-pointer-updates
- ." {" cr
- ." #line " c-line @ . quote c-filename 2@ type quote cr
- prim prim-c-code 2@ ['] output-c-tail type-c-code
- ." }" cr
- output-c-tail
- ." }" cr
- cr
+    print-entry ."  /* " prim prim-name 2@ type ."  ( " prim prim-stack-string 2@ type ." ) */" cr
+    ." /* " prim prim-doc 2@ type ."  */" cr
+    ." NAME(" quote prim prim-name 2@ type quote ." )" cr \ debugging
+    ." {" cr
+    ." DEF_CA" cr
+    print-declarations
+    ." NEXT_P0;" cr
+    flush-tos
+    fetches
+    print-debug-args
+    stack-pointer-updates
+    prim prim-c-code 2@ ['] output-c-tail type-c-code
+    output-c-tail2
+    ." }" cr
+    cr
 ;
 
 : disasm-arg { item -- }
     item item-stack @ inst-stream = if
-	."   fputc(' ', vm_out); "
-	." printarg_" item item-type @ print-type-prefix
-	." ((" item item-type @ type-c-name 2@ type ." )"
-	." ip[" item item-offset @ 1+ 0 .r ." ]);" cr
+	." {" cr
+	item print-declaration
+	item fetch
+	item print-debug-arg
+	." }" cr
     endif ;
 
 : disasm-args ( -- )
@@ -683,7 +826,7 @@ stack inst-stream IP Cell
 
 : output-disasm ( -- )
     \ generate code for disassembling VM instructions
-    ." if (ip[0] == prim[" function-number @ 0 .r ." ]) {" cr
+    ." if (VM_IS_INST(*ip, " function-number @ 0 .r ." )) {" cr
     ."   fputs(" quote prim prim-name 2@ type quote ." , vm_out);" cr
     disasm-args
     ."   ip += " inst-stream stack-in @ 1+ 0 .r ." ;" cr
@@ -693,7 +836,7 @@ stack inst-stream IP Cell
 : output-profile ( -- )
     \ generate code for postprocessing the VM block profile stuff
     ." if (VM_IS_INST(*ip, " function-number @ 0 .r ." )) {" cr
-    ."   add_inst(b, " quote  prim prim-name 2@ type quote ." );" cr
+    ."   add_inst(b, " quote prim prim-name 2@ type quote ." );" cr
     ."   ip += " inst-stream stack-in @ 1+ 0 .r ." ;" cr
     prim prim-c-code 2@  s" SET_IP"    search nip nip
     prim prim-c-code 2@  s" SUPER_END" search nip nip or if
@@ -703,6 +846,31 @@ stack inst-stream IP Cell
     endif
     ." }" cr ;
 
+: output-profile-part ( p )
+    ."   add_inst(b, " quote
+    prim-name 2@ type
+    quote ." );" cr ;
+    
+: output-profile-combined ( -- )
+    \ generate code for postprocessing the VM block profile stuff
+    ." if (VM_IS_INST(*ip, " function-number @ 0 .r ." )) {" cr
+    ['] output-profile-part map-combined
+    ."   ip += " inst-stream stack-in @ 1+ 0 .r ." ;" cr
+    combined-prims num-combined @ 1- th @ prim-c-code 2@  s" SET_IP"    search nip nip
+    combined-prims num-combined @ 1- th @ prim-c-code 2@  s" SUPER_END" search nip nip or if
+	."   return;" cr
+    else
+	."   goto _endif_;" cr
+    endif
+    ." }" cr ;
+
+: output-superend ( -- )
+    \ output flag specifying whether the current word ends a dynamic superinst
+    prim prim-c-code 2@  s" SET_IP"    search nip nip
+    prim prim-c-code 2@  s" SUPER_END" search nip nip or 0<>
+    prim prim-c-code 2@  s" SUPER_CONTINUE" search nip nip 0= and
+    negate 0 .r ." , /* " prim prim-name 2@ type ."  */" cr ;
+
 : gen-arg-parm { item -- }
     item item-stack @ inst-stream = if
 	." , " item item-type @ type-c-name 2@ type space
@@ -767,11 +935,14 @@ stack inst-stream IP Cell
 \      cr ;
 
 : output-label ( -- )  
-    ." (Label)&&I_" prim prim-c-name 2@ type ." ," cr ;
+    ." INST_ADDR(" prim prim-c-name 2@ type ." )" cr ;
 
 : output-alias ( -- ) 
     ( primitive-number @ . ." alias " ) ." Primitive " prim prim-name 2@ type cr ;
 
+: output-c-prim-num ( -- )
+    ." #define N_" prim prim-c-name 2@ type prim prim-num @ 8 + 4 .r cr ;
+
 : output-forth ( -- )  
     prim prim-forth-code @ 0=
     IF    	\ output-alias
@@ -799,6 +970,11 @@ stack inst-stream IP Cell
     name-line @ 0 .r
     ." ,0" cr ;
 
+: output-vi-tag ( -- )
+    name-filename 2@ type #tab emit
+    prim prim-name 2@ type #tab emit
+    ." /^" prim prim-name 2@ type ."  *(/" cr ;
+
 [IFDEF] documentation
 : register-doc ( -- )
     prim prim-name 2@ documentation ['] create insert-wordlist
@@ -868,9 +1044,7 @@ stack inst-stream IP Cell
 \  #line 516 "./prim"
 \  n = n1+n2;
 \  }
-\  NEXT_P1;
 \  _x_sp0 = (Cell)n;
-\  NEXT_P2;
 \  }
 \  NEXT_P1;
 \  spTOS = (Cell)_x_sp0;
@@ -880,6 +1054,7 @@ stack inst-stream IP Cell
     prim to combined
     0 num-combined !
     current-depth max-stacks cells erase
+    include-skipped-insts @ current-depth 0 th !
     max-depth     max-stacks cells erase
     min-depth     max-stacks cells erase
     prim prim-effect-in  prim prim-effect-in-end  !
@@ -891,24 +1066,33 @@ stack inst-stream IP Cell
 : min! ( n addr -- )
     tuck @ min swap ! ;
 
+: inst-stream-adjustment ( nstack -- n )
+    \ number of stack items to add for each part
+    0= include-skipped-insts @ and negate ;
+
 : add-depths { p -- }
     \ combine stack effect of p with *-depths
     max-stacks 0 ?do
 	current-depth i th @
-	p prim-stacks-in  i th @ +
+	p prim-stacks-in  i th @ + i inst-stream-adjustment +
 	dup max-depth i th max!
 	p prim-stacks-out i th @ -
 	dup min-depth i th min!
 	current-depth i th !
     loop ;
 
+: copy-maxdepths ( n -- )
+    max-depth max-depths rot max-stacks * th max-stacks cells move ;
+
 : add-prim ( addr u -- )
     \ add primitive given by "addr u" to combined-prims
     primitives search-wordlist s" unknown primitive" ?print-error
     execute { p }
     p combined-prims num-combined @ th !
+    num-combined @ copy-maxdepths
     1 num-combined +!
-    p add-depths ;
+    p add-depths
+    num-combined @ copy-maxdepths ;
 
 : compute-effects { q -- }
     \ compute the stack effects of q from the depths
@@ -941,6 +1125,27 @@ stack inst-stream IP Cell
 	i q prim-stacks-out i th @ q prim-effect-out-end make-effect-items
     loop ;
 
+: compute-stack-max-back-depths ( stack -- )
+    stack-number @ { stack# }
+    current-depth stack# th @ dup
+    dup stack# num-combined @ s-c-max-back-depth !
+    -1 num-combined @ 1- -do ( max-depth current-depth )
+	combined-prims i th @ { p }
+	p prim-stacks-out stack# th @ +
+	dup >r max r>
+	over stack# i s-c-max-back-depth !
+	p prim-stacks-in stack# th @ -
+	stack# inst-stream-adjustment -
+    1 -loop
+    assert( dup stack# inst-stream-adjustment negate = )
+    assert( over max-depth stack# th @ = )
+    2drop ;
+
+: compute-max-back-depths ( -- )
+    \ compute max-back-depths.
+    \ assumes that current-depths is correct for the end of the combination
+    ['] compute-stack-max-back-depths map-stacks ;
+
 : process-combined ( -- )
     combined combined-prims num-combined @ cells
     combinations ['] constant insert-wordlist
@@ -948,6 +1153,7 @@ stack inst-stream IP Cell
     @ prim-c-code 2@ prim prim-c-code 2! \ used by output-super-end
     prim compute-effects
     prim init-effects
+    compute-max-back-depths
     output-combined perform ;
 
 \ C output
@@ -973,10 +1179,20 @@ stack inst-stream IP Cell
 
 : output-combined-tail ( -- )
     part-output-c-tail
-    prim >r combined to prim
     in-part @ >r in-part off
-    output-c-tail
-    r> in-part ! r> to prim ;
+    combined ['] output-c-tail-no-stores prim-context
+    r> in-part ! ;
+
+: part-stack-pointer-updates ( -- )
+    next-stack-number @ 0 +do
+	i part-num @ 1+ s-c-max-depth @ dup
+	i num-combined @ s-c-max-depth @ =    \ final depth
+	swap i part-num @ s-c-max-depth @ <> \ just reached now
+	part-num @ 0= \ first part
+	or and if
+	    stacks i th @ stack-pointer-update
+	endif
+    loop ;
 
 : output-part ( p -- )
     to prim
@@ -986,20 +1202,18 @@ stack inst-stream IP Cell
     print-declarations
     part-fetches
     print-debug-args
+    combined ['] part-stack-pointer-updates prim-context
+    1 part-num +!
     prim add-depths \ !! right place?
-    ." {" cr
-    ." #line " c-line @ . quote c-filename 2@ type quote cr
     prim prim-c-code 2@ ['] output-combined-tail type-c-code
-    ." }" cr
     part-output-c-tail
     ." }" cr ;
 
 : output-parts ( -- )
     prim >r in-part on
     current-depth max-stacks cells erase
-    num-combined @ 0 +do
-	combined-prims i th @ output-part
-    loop
+    0 part-num !
+    ['] output-part map-combined
     in-part off
     r> to prim ;
 
@@ -1011,11 +1225,11 @@ stack inst-stream IP Cell
     print-declarations-combined
     ." NEXT_P0;" cr
     flush-tos
-    fetches
+    \ fetches \ now in parts
     \ print-debug-args
-    stack-pointer-updates
+    \ stack-pointer-updates now in parts
     output-parts
-    output-c-tail
+    output-c-tail2-no-stores
     ." }" cr
     cr ;
 
@@ -1025,13 +1239,16 @@ stack inst-stream IP Cell
 
 \ peephole optimization rules
 
+\ data for a simple peephole optimizer that always tries to combine
+\ the currently compiled instruction with the last one.
+
 \ in order for this to work as intended, shorter combinations for each
 \ length must be present, and the longer combinations must follow
 \ shorter ones (this restriction may go away in the future).
   
 : output-peephole ( -- )
     combined-prims num-combined @ 1- cells combinations search-wordlist
-    s" the prefix for this combination must be defined earlier" ?print-error
+    s" the prefix for this superinstruction must be defined earlier" ?print-error
     ." {"
     execute prim-num @ 5 .r ." ,"
     combined-prims num-combined @ 1- th @ prim-num @ 5 .r ." ,"
@@ -1039,15 +1256,53 @@ stack inst-stream IP Cell
     combined prim-c-name 2@ type ."  */"
     cr ;
 
-: output-forth-peephole ( -- )
-    combined-prims num-combined @ 1- cells combinations search-wordlist
-    s" the prefix for this combination must be defined earlier" ?print-error
-    execute prim-num @ 5 .r
-    combined-prims num-combined @ 1- th @ prim-num @ 5 .r
-    combined prim-num @ 5 .r ."  prim, \ "
-    combined prim-c-name 2@ type
-    cr ;
 
+\ cost and superinstruction data for a sophisticated combiner (e.g.,
+\ shortest path)
+
+\ This is intended as initializer for a structure like this
+
+\  struct cost {
+\    int loads;       /* number of stack loads */
+\    int stores;      /* number of stack stores */
+\    int updates;     /* number of stack pointer updates */
+\    int length;      /* number of components */
+\    int *components; /* array of vm_prim indexes of components */
+\  };
+
+\ How do you know which primitive or combined instruction this
+\ structure refers to?  By the order of cost structures, as in most
+\ other cases.
+
+: compute-costs { p -- nloads nstores nupdates }
+    \ compute the number of loads, stores, and stack pointer updates
+    \ of a primitive or combined instruction; does not take TOS
+    \ caching into account, nor that IP updates are combined with
+    \ other stuff
+    0 max-stacks 0 +do
+	p prim-stacks-in i th @ +
+    loop
+    0 max-stacks 0 +do
+	p prim-stacks-out i th @ +
+    loop
+    0 max-stacks 0 +do
+	p prim-stacks-in i th @ p prim-stacks-out i th @ <> -
+    loop ;
+
+: output-num-part ( p -- )
+    prim-num @ 4 .r ." ," ;
+
+: output-costs ( -- )
+    ." {" prim compute-costs
+    rot 2 .r ." ," swap 2 .r ." ," 2 .r ." ,"
+    combined if
+	num-combined @ 2 .r
+	." , ((int []){" ['] output-num-part map-combined ." })}, /* "
+    else
+	."  1, ((int []){" prim prim-num @ 4 .r ." })}, /* "
+    endif
+    prim prim-name 2@ type ."  */"
+    cr ;
 
 \ the parser
 
@@ -1077,7 +1332,7 @@ print-token !
     \ when input points to a newline, check if the next line is a
     \ sync line.  If it is, perform the appropriate actions.
     rawinput @ >r
-    s" #line " r@ over compare 0<> if
+    s" #line " r@ over compare if
 	rdrop 1 line +! EXIT
     endif
     0. r> 6 chars + 20 >number drop >r drop line ! r> ( c-addr )
@@ -1126,6 +1381,8 @@ bl singleton tab-char over add-member
 nl-char singleton eof-char over add-member complement	charclass nonl
 nl-char singleton eof-char over add-member
     char : over add-member complement                   charclass nocolonnl
+nl-char singleton eof-char over add-member
+    char } over add-member complement                   charclass nobracenl
 bl 1+ maxchar .. char \ singleton complement intersection
                                                         charclass nowhitebq
 bl 1+ maxchar ..                                        charclass nowhite
@@ -1137,7 +1394,7 @@ nl-char singleton eof-char over add-memb
 (( letter (( letter || digit )) **
 )) <- c-ident ( -- )
 
-(( ` # ?? (( letter || digit || ` : )) **
+(( ` # ?? (( letter || digit || ` : )) ++
 )) <- stack-ident ( -- )
 
 (( nowhitebq nowhite ** ))
@@ -1179,7 +1436,7 @@ Variable c-flag
 (( (( ` g || ` G )) {{ start }} nonl **
    {{ end
       forth-flag @ IF  ." group " type cr  THEN
-      c-flag @     IF  ." GROUP(" type ." )" cr  THEN }}
+      c-flag @     IF  ." GROUP(" type ." , " function-number @ 0 .r ." )" cr  THEN }}
 )) <- group-comment
 
 (( (( eval-comment || forth-comment || c-comment || else-comment || if-comment || group-comment )) ?? nonl ** )) <- comment-body
@@ -1200,7 +1457,10 @@ Variable c-flag
       (( {{ start }}  c-ident {{ end prim prim-c-name 2! }} )) ??
    )) ??  nleof
    (( ` " ` "  {{ start }} (( noquote ++ ` " )) ++ {{ end 1- prim prim-doc 2! }} ` " white ** nleof )) ??
-   {{ skipsynclines off line @ c-line ! filename 2@ c-filename 2! start }} (( nocolonnl nonl **  nleof white ** )) ** {{ end prim prim-c-code 2! skipsynclines on }}
+   {{ skipsynclines off line @ c-line ! filename 2@ c-filename 2! start }}
+   (( (( ` { nonl ** nleof (( (( nobracenl {{ line @ drop }} nonl ** )) ?? nleof )) ** ` } white ** nleof white ** ))
+   || (( nocolonnl nonl **  nleof white ** )) ** ))
+   {{ end prim prim-c-code 2! skipsynclines on }}
    (( ` :  white ** nleof
       {{ start }} (( nonl ++  nleof white ** )) ++ {{ end prim prim-forth-code 2! }}
    )) ?? {{ process-simple }}
@@ -1215,7 +1475,9 @@ Variable c-flag
 (( {{ make-prim to prim 0 to combined
       line @ name-line ! filename 2@ name-filename 2!
       function-number @ prim prim-num !
-      start }} forth-ident {{ end 2dup prim prim-name 2! prim prim-c-name 2! }}  white ++
+      start }} [ifdef] vmgen c-ident [else] forth-ident [then] {{ end
+      2dup prim prim-name 2! prim prim-c-name 2! }}  white **
+   (( ` / white ** {{ start }} c-ident {{ end prim prim-c-name 2! }} white ** )) ??
    (( simple-primitive || combined-primitive )) {{ 1 function-number +! }}
 )) <- primitive ( -- )