z80: small optimization in cell execution

We now have a stable ABI that is pretty cleared up...

blk/070

@@ -2,7 +2,7 @@ Implementation notes
 
 71 Execution model             73 Executing a word
 75 Stack management            77 Dictionary
-80 System variables            85 Word routines
+80 System variables            85 Word types
 89 Initialization sequence
 
 

blk/085

@@ -1,16 +1,15 @@
-Word routines
+Word types
 
-This is the description of all word routine you can encounter
+There are 4 word types in Collapse OS. Whenever you have a
-in this Forth implementation. That is, a wordref will always
+wordref, it's pointing to a byte with numbers 0 to 3. This
-point to a memory offset containing one of these numbers.
+number is the word type and the word's behavior depends on it.
 
-0x17: nativeWord. This words PFA contains native binary code
+0: native. This words PFA contains native binary code and is
-and is jumped to directly.
+jumped to directly.
 
-0x0e: compiledWord. This word's PFA contains an atom list and
+1: compiled. This word's PFA contains an atom list and its
-its execution is described in "EXECUTION MODEL" above.
+execution is described in "EXECUTION MODEL" above.
 
-0x0b: cellWord. This word is usually followed by a 2-byte value
+2: cell. This word is usually followed by a 2-byte value in its
-in its PFA.  Upon execution, the *address* of the PFA is pushed
+PFA. Upon execution, the address of the PFA is pushed to PS.
-to PS.
                                                         (cont.)

blk/086

@@ -1,13 +1,13 @@
-0x2b: doesWord. This word is created by "DOES>" and is followed
+3: DOES>. This word is created by "DOES>" and is followed
 by a 2-byte value as well as the address where "DOES>" was
 compiled. At that address is an atom list exactly like in a
 compiled word. Upon execution, after having pushed its cell
-addr to PSP, it execute its reference exactly like a
+addr to PSP, it executes its reference exactly like a
-compiledWord.
+compiled word.
-
+
-Also note that word routines references in wordrefs are 1b.
+
-This means that all word routine reference must live below
+
-0x100 in boot binary.
+
 
 
 

blk/243

@@ -3,14 +3,12 @@
 : BJP, BIN( @ + JPnn, ;
 : BJPcc, BIN( @ + JPccnn, ;
 
-: JPNEXT, 26 BJP, ; ( 26 == next )
+VARIABLE lblchkPS
-
+: chkPS, lblchkPS @ CALLnn, ; ( chkPS, B305 )
-: chkPS, L4 @ CALLnn, ; ( chkPS, B305 )
+CREATE lblnext 0x1a , ( stable ABI until set in B300 )
-
+: JPNEXT, lblnext @ JPnn, ;
 : CODE ( same as CREATE, but with native word )
-    (entry)
+    (entry) 0 C, ( 0 == native ) ;
-    23 C, ( 23 == nativeWord )
-;
 : ;CODE JPNEXT, ;
 
 

blk/263

@@ -2,7 +2,7 @@ VARIABLE XCURRENT
 : XCON XCURRENT CURRENT* ! ;
 : XCOFF 0x02 RAM+ CURRENT* ! ;
 : (xentry) XCON (entry) XCOFF ;
-: XCREATE (xentry) 11 C, ;
+: XCREATE (xentry) 2 C, ;
 : XCODE XCON CODE XCOFF ;
 : XIMM XCON IMMEDIATE XCOFF ;
 : _xapply ( a -- a-off )

blk/265

@@ -1,5 +1,5 @@
 : X:
-    (xentry) [ 0x0e LITN ] C,
+    (xentry) 1 ( compiled ) C,
     BEGIN WORD
     XCURRENT @ SWAP ( xcur w ) _find ( a f )
     IF   ( a )

blk/282

@@ -1,3 +1,5 @@
+VARIABLE lblofl VARIABLE lblpushRS VARIABLE lblexec
+VARIABLE lblfind
 1 53 LOADR+
 
 
@@ -9,8 +11,3 @@
 
 
 
-
-
-
-
-

blk/283

@@ -1,16 +1,14 @@
 H@ ORG !
-0 JPnn,       ( 00, main )     0 JPnn,       ( 03, find )
+0 JPnn, ( 00, main ) NOP, NOP, NOP, ( unused )
-NOP, NOP,     ( 06, unused )   NOP, NOP,     ( 08, LATEST )
+NOP, NOP, ( unused ) NOP, NOP, ( 08, LATEST )
-NOP,          ( 0a, unused )
+NOP, NOP, NOP, NOP, NOP, NOP, NOP, ( 0a, unused )
-( 0b cellWord, push PFA ) DE PUSHqq, JR, 0x0c A, ( next )
+0 JPnn, ( 11, pushRS ) 0 JPnn, ( 14, popRS )
-0 JPnn,   ( 0e, compiledWord ) 0 JPnn,       ( 11, pushRS )
+NOP, NOP, NOP, ( unused )
-0 JPnn,       ( 14, popRS )
+0 JPnn, ( 1a, next ) NOP, NOP, NOP, ( unused )
-EXDEHL, JP(HL), NOP, ( 17, nativeWord )
+NOP, NOP, NOP, NOP, ( unused )
-0 JPnn,       ( 1a, next )     0 JPnn,       ( unused )
+NOP, NOP, NOP, NOP, ( unused )
-NOP, NOP, NOP, NOP, ( 20, unused )
+0 JPnn, ( RST 28 )
-NOP, NOP, NOP, NOP, ( 24, unused )
+NOP, NOP, NOP, NOP, NOP, ( unused )
-0 JPnn,       ( RST 28 )
+0 JPnn, ( RST 30 )
-0 JPnn,       ( 2b, doesWord ) NOP, NOP,     ( 2e, unused )
+NOP, NOP, NOP, NOP, NOP, ( unused )
-0 JPnn,       ( RST 30 )
+0 JPnn, ( RST 38 )
-0 JPnn,       ( 33, execute )  NOP, NOP,     ( unused )
-0 JPnn,       ( RST 38 )

blk/284

@@ -5,7 +5,7 @@
 0 A,, ( prev )
 4 A,
 H@ XCURRENT !        ( set current tip of dict, 0x42 )
-    0x17 A,          ( nativeWord )
+    0 A, ( native )
     0x14 BCALL,      ( popRS )
     HL PUSHqq, IY POPqq, ( --> IP )
     JPNEXT,

blk/285

@@ -6,7 +6,7 @@ CODE (?br)           ( 0x67 )
     ( True, skip next 2 bytes and don't branch )
     IY INCss, IY INCss,
     JPNEXT, NOP, NOP, NOP,
-CODE (loop) ( 0x77 )
+CODE (loop) ( 0x80 )
     0 IX+ INC(IXY+), IFZ, 1 IX+ INC(IXY+), THEN, ( I++ )
     ( Jump if I <> I' )
     A 0 IX+ LDrIXY, 2 IX- CP(IXY+), JRNZ, L2 BWR ( branch )

blk/289

@@ -1,16 +0,0 @@
-( Name of BOOT word )
-L1 BSET 4 A, 'B' A, 'O' A, 'O' A, 'T' A,
-
-PC ORG @ 1 + ! ( main )
-( STACK OVERFLOW PROTECTION: See B76 )
-    SP PS_ADDR LDddnn,
-    IX RS_ADDR LDddnn,
-( HERE begins at RAMEND )
-    HL RAMSTART 0x80 + LDddnn,
-    RAMSTART 0x04 + LD(nn)HL, ( RAM+04 == HERE )
-( LATEST is a label to the latest entry of the dict. It is
-  written at offset 0x08 by the process or person building
-  Forth. )
-    BIN( @ 0x08 + LDHL(nn),
-    RAMSTART 0x02 + LD(nn)HL, ( RAM+02 == CURRENT       cont. )
-

blk/290

@@ -1,16 +0,0 @@
-    EXDEHL,
-    HL L1 @ LDddnn,
-    0x03 BCALL, ( 03 == find )
-    0x33 BJP,   ( 33 == execute )
-
-
-
-
-
-
-
-
-
-
-
-

blk/291

@@ -1,4 +1,4 @@
-PC ORG @ 4 + ! ( find )
+lblfind BSET
 ( Find the entry corresponding to word name where (HL) points
   to in dictionary having its tip at DE and sets DE to point
   to that entry. Z if found, NZ if not. )

blk/297

@@ -1,4 +1,4 @@
-L4 BSET PC ORG @ 0x12 + ! ( pushRS )
+lblpushRS BSET PC ORG @ 0x12 + ! ( pushRS )
     IX INCss,
     IX INCss,
     0 IX+ L LDIXYr,

blk/298

@@ -1,9 +1,9 @@
 6 A, '(' A, 'u' A, 'f' A, 'l' A, 'w' A, ')' A,
-L2 BSET ( abortUnderflow )
+lblofl BSET ( abortUnderflow )
     HL PC 7 - LDddnn,
     DE RAMSTART 0x02 + LDdd(nn),   ( RAM+02 == CURRENT )
-    0x03 BCALL, ( find )
+    lblfind @ CALLnn,
-    0x33 BJP,   ( 33 == execute )
+    JR, L2 FWR ( execute, B301 )
 
 
 

blk/299

@@ -0,0 +1,16 @@
+L1 BSET 4 A, 'B' A, 'O' A, 'O' A, 'T' A,
+PC ORG @ 1 + ! ( main )
+( STACK OVERFLOW PROTECTION: See B76 )
+    SP PS_ADDR LDddnn, IX RS_ADDR LDddnn,
+( HERE begins at RAMEND )
+    HL RAMSTART 0x80 + LDddnn,
+    RAMSTART 0x04 + LD(nn)HL, ( RAM+04 == HERE )
+( LATEST is a label to the latest entry of the dict. It is
+  written at offset 0x08 by the process or person building
+  Forth. )
+    BIN( @ 0x08 + LDHL(nn),
+    RAMSTART 0x02 ( CURRENT ) + LD(nn)HL,
+    EXDEHL,
+    HL L1 @ LDddnn,
+    lblfind @ CALLnn,
+    JR, L1 FWR ( execute, B301 )

blk/300

@@ -1,15 +1,15 @@
-PC ORG @ 0x1b + ! ( next )
+lblnext BSET PC ORG @ 0x1b + ! ( next )
 ( This routine is jumped to at the end of every word. In it,
   we jump to current IP, but we also take care of increasing
   it by 2 before jumping. )
 	( Before we continue: are stacks within bounds? )
     ( PS ) HL PS_ADDR LDddnn,
     SP SUBHLss,
-    JRC, L2 BWR ( abortUnderflow-B298 )
+    JRC, lblofl BWR ( abortUnderflow-B298 )
     ( RS ) IX PUSHqq, HL POPqq,
     DE RS_ADDR LDddnn,
     DE SUBHLss,
-    JRC, L2 BWR ( IX < RS_ADDR? abortUnderflow-B298 )
+    JRC, lblofl BWR ( IX < RS_ADDR? abortUnderflow-B298 )
     E 0 IY+ LDrIXY,
     D 1 IY+ LDrIXY,
     IY INCss, IY INCss,

blk/301

@@ -1,14 +1,13 @@
-L3 BSET PC ORG @ 0x34 + ! ( execute. DE -> wordref )
+lblexec BSET L1 FSET ( B299 ) L2 FSET ( B298 )
+    ( DE -> wordref )
     ( We don't apply BIN( reliably on stable ABI stuff, we
       might need to adjust addr. Ugly, but well... )
     BIN( @ [IF]
         A XORr, D ORr, IFZ, D BIN( @ 256 / LDrn, THEN,
     [THEN]
-    LDA(DE),
+    LDA(DE), DE INCss,
-    L A LDrr,
+    A ORr, IFZ, EXDEHL, JP(HL), THEN,
-    H BIN( @ 256 / LDrn,
+    A DECr, JRZ, L1 FWR ( compiled B303 )
-    DE INCss,
+    ( cell or does. push PFA ) DE PUSHqq,
-    ( DE points to PFA )
+    A DECr, JRZ, lblnext BWR ( cell )
-    JP(HL),
+    ( continue to does, B302 )
-
-

blk/302

@@ -1,11 +1,9 @@
-PC ORG @ 0x2c + ! ( doesWord )
+( does. The word was spawned from a definition word that has a
-( The word was spawned from a definition word that has a
   DOES>. PFA+2 (right after the actual cell) is a link to the
   slot right after that DOES>. Therefore, what we need to do
   push the cell addr like a regular cell, then follow the
   linkfrom the PFA, and then continue as a regular
   compiledWord. )
-    DE PUSHqq, ( like a regular cell )
     EXDEHL,
     HL INCss,
     HL INCss,

blk/303

@@ -1,16 +1,15 @@
-PC ORG @ 0x0f + ! ( compiledWord )
+( compiled word ) L1 FSET ( execute B301 )
 ( 1. Push current IP to RS
   2. Set new IP to the second atom of the list
   3. Execute the first atom of the list. )
     IY PUSHqq, HL POPqq, ( <-- IP )
-    L4 @ ( pushRS ) CALLnn,
+    lblpushRS @ ( pushRS ) CALLnn,
     EXDEHL,          ( HL points to PFA )
 ( While we inc, dereference into DE for execute call later. )
     LDDE(HL),
     HL INCss,
     HL PUSHqq, IY POPqq, ( --> IP )
-    JR, L3 BWR      ( execute-B301 )
+    JR, lblexec BWR      ( execute-B301 )
-
 
 
 

blk/305

@@ -1,4 +1,4 @@
-L4 BSET ( chkPS )
+lblchkPS BSET ( chkPS )
 ( Note that you only need to call this in words that push
   back to PSP. If they don't, calling chkPS is redundant with
   check in next )
@@ -9,7 +9,7 @@ L4 BSET ( chkPS )
     SP SUBHLss,
     EXX,
     CNC RETcc,      ( PS_ADDR >= SP? good )
-    JR, L2 BWR      ( abortUnderflow-B298 )
+    JR, lblofl BWR      ( abortUnderflow-B298 )
 
 
 

blk/306

@@ -5,7 +5,7 @@
 CODE EXECUTE
     DE POPqq,
     chkPS,
-    JR, L3 BWR      ( execute-B301 )
+    JR, lblexec BWR      ( execute-B301 )
 
 ( a b c -- b c a )
 CODE ROT

blk/310

@@ -10,7 +10,7 @@ CODE PICK
     EXDEHL,
     HL PS_ADDR LDddnn,
     DE SUBHLss,
-    CC L2 @ JPccnn,    ( abortUnderflow-B298 )
+    CC lblofl @ JPccnn,    ( abortUnderflow-B298 )
     BC PUSHqq,
 ;CODE
 

blk/330

@@ -2,8 +2,7 @@ CODE _find  ( cur w -- a f )
     HL POPqq,       ( w )
     DE POPqq,       ( cur )
     chkPS,
-    ( 3 == find )
+    lblfind @ CALLnn,
-    3 BCALL,
     IFNZ,
         ( not found )
         HL PUSHqq,

blk/371

@@ -6,7 +6,7 @@
     H@ CURRENT !
 ;
 : (entry) WORD [entry] ;
-: CREATE (entry) 11 ( 11 == cellWord ) C, ;
+: CREATE (entry) 2 ( cellWord ) C, ;
 : VARIABLE CREATE 2 ALLOT ;
 
 

blk/373

@@ -1,7 +1,6 @@
 : DOES>
     ( Overwrite cellWord in CURRENT )
-    ( 43 == doesWord )
+    3 ( does ) CURRENT @ C!
-    43 CURRENT @ C!
     ( When we have a DOES>, we forcefully place HERE to 4
       bytes after CURRENT. This allows a DOES word to use ","
       and "C," without messing everything up. )

blk/397

@@ -7,8 +7,7 @@
 ( gets its name at the very end. can't comment afterwards )
 : _ BEGIN LIT< ) WORD S= UNTIL ; IMMEDIATE
 : _ ( : will get its name almost at the very end )
-    (entry)
+    (entry) 1 ( compiled ) C,
-    [ 14 ( == compiledWord ) LITN ] C,
     BEGIN
         WORD FIND
         IF ( is word ) DUP IMMED? IF EXECUTE ELSE , THEN

blk/759

@@ -1,4 +1,3 @@
 : CODE ( same as CREATE, but with native word )
-    (entry)
+    (entry) 0 ( native ) C, ;
-    23 C, ( 23 == nativeWord ) ;
 : ;CODE JMPn, 0x1a ( next ) RPCn, ;

blk/812

@@ -1,15 +1,15 @@
 H@ ORG !
 JMPn, 0 A,,   ( 00, main )     JMPn, 0 A,,   ( 03, find )
 0 A,,         ( 06, unused )   0 A,,         ( 08, LATEST )
-0 A,          ( 0a, unused )   JMPn, 0 A,,   ( 0b, cellWord )
+0 A,          ( 0a, unused )   0 A, 0 A,,    ( 0b, unused )
-JMPn, 0 A,, ( 0e compiledWord ) JMPn, 0 A,,  ( 11, pushRS )
+0 A, 0 A,,    ( 0e, unused )   JMPn, 0 A,,  ( 11, pushRS )
 JMPn, 0 A,,   ( 14, popRS )
-DI JMPr,      ( 17, nativeWord ) 0 A,
+0 A, 0 A,,    ( 17, unused )
-JMPn, 0 A,,   ( 1a, next )     JMPn, 0 A,,   ( 1d, unused )
+JMPn, 0 A,,   ( 1a, next )     0 A, 0 A,,    ( 1d, unused )
-0 A, 0 A,     ( 20, numberWord ) 0 A, 0 A,   ( 22, litWord )
+0 A, 0 A,     ( 20, unused )   0 A, 0 A,     ( 22, unused )
-0 A, 0 A,     ( 24, addrWord ) 0 A, 0 A,     ( 26, unused )
+0 A, 0 A,     ( 24, unused )   0 A, 0 A,     ( 26, unused )
 0 A, 0 A,,    ( unused )
-JMPn, 0 A,,   ( 2b, doesWord ) 0 A, 0 A,     ( 2e, unused )
+0 A, 0 A,,    ( 2b, unused )   0 A, 0 A,     ( 2e, unused )
 0 A, 0 A,,    ( unused )
 JMPn, 0 A,,   ( 33, execute )  0 A, 0 A,     ( unused )
 0 A, 0 A,,    ( unused )

blk/813

@@ -3,7 +3,7 @@
   the "stable ABI" )
 'E' A, 'X' A, 'I' A, 'T' A, 0 A,, ( prev ) 4 A, ( len )
 H@ XCURRENT ! ( set current tip of dict, 0x42 )
-    0x17 A, ( nativeWord )
+    0 A, ( native )
     DX [BP] 0 MOVx[]+, BP DECx, BP DECx, ( popRS )
 ;CODE NOP,
 CODE (br) ( 0x53 ) L2 BSET ( used in br? )

blk/814

@@ -1,5 +1,5 @@
-PC ORG @ 0x20 + ! ( numberWord )
+ORG @ 0xb9 + HERE !
-PC ORG @ 0x24 + ! ( addrWord ) ( see B287 for comments )
+CODE (n) ( 0xbf, number literal )
     DI DX MOVxx, DI [DI] MOVx[], DI PUSHx,
     DX INCx, DX INCx,
 ;CODE

blk/815

@@ -3,11 +3,11 @@ PC 0x1d - ORG @ 0x1b + ! ( next )
     DI [DI] MOVx[], ( wordref )
     ( continue to execute )
 L1 BSET PC 0x36 - ORG @ 0x34 + ! ( execute -- DI -> wordref )
-    AH AH XORrr, AL [DI] MOVr[],
+    AL [DI] MOVr[], DI INCx, ( PFA )
-    DI INCx, ( PFA )
+    AL AL ORrr, IFZ, DI JMPr, THEN, ( native )
-    AX JMPr,
+    ( continue to compiled )
 
-PC 0x11 - ORG @ 0x0f + ! ( compiledWord -- DI -> PFA )
+PC 0x11 - ORG @ 0x0f + ! ( compiled -- DI -> PFA )
     BP INCx, BP INCx, [BP] 0 DX MOV[]+x, ( pushRS )
     DX DI MOVxx, DX INCx, DX INCx, ( --> IP )
     DI [DI] MOVx[],

blk/818

@@ -2,7 +2,7 @@ CODE BYE BEGIN, JMPs, AGAIN, ;CODE
 CODE EMIT
     AX POPx, AH 0x0e MOVri, ( print char ) 0x10 INT,
 ;CODE CODE 0 AX AX XORxx, AX PUSHx, ;CODE
-: FOO 'X' EMIT ; : BAR 0 IF FOO THEN FOO BYE ;
+: FOO 'F' EMIT ; : BAR 0 IF FOO THEN FOO BYE ;
 L3 BSET 3 A, 'B' A, 'A' A, 'R' A,
 PC 3 - ORG @ 1+ ! ( main )
     SP PS_ADDR MOVxI,