From 61195a987d86ea08ddd0688f596def59ed1847fc Mon Sep 17 00:00:00 2001
From: Virgil Dupras <hsoft@hardcoded.net>
Date: Mon, 30 Mar 2020 15:11:23 -0400
Subject: [PATCH] forth: Forth-ify "HERE", "CURRENT" and "JTBL"

---
 emul/forth/z80c.bin | Bin 1388 -> 1436 bytes
 forth/forth.asm     |  34 +++++-----------------------------
 forth/icore.fs      |  28 ++++++++++++++++++++--------
 3 files changed, 25 insertions(+), 37 deletions(-)

diff --git a/emul/forth/z80c.bin b/emul/forth/z80c.bin
index ecf78e012944815ac0d55edeb7cc27fa07f6e75c..bbe9626267d5b3343b1a3af5d28b2e80f9347ee4 100644
GIT binary patch
delta 363
zcmaFEHHUk{119;aB85C(xjC2}nY==re1sTS_!txzI2at6+<Y9}gLx-^V3IWEdf~|A
z;Tq)11CeC`a-Bnif?WMV_!-zi>Y0EdfuWuuPz4MO9+Rb+RT;Y{J2HziZk`;;>}7D5
zb2BGUn~e+u6G#Woiv#Q(Kueu<_&@?#oCnx1vx7(l21W*FAZzkvW_4Cou0*zw$^V(<
z1oOEjv#p0pLPYggBojdz`nZx<U>bwj6WOvj*RwaU1%nN%0m=unb1<86fmGB0WgMA2
z{X$%W0)kva>=`)u82Y$sSne}P0A0k$-~p8HU{+uNIv>cYXX0Rpp1guZi7|TeX%-8u
ze_W1CKAs_dfuKOJ;8b9c0J@Wd85D9>f((s(412f~82A`CnENK{vP!c@11;=eZk_DU
GDhmKP8BSXO

delta 315
zcmbQk{f2A9115n65gDEZ+#Jk~Om04o?!m&7|1(Jn8UAu)3JmoO;bCCmV^CmVV6dF*
z&8*58J-LusoUwUwC$pEqTFz!pM<!<*83rbh5}p?a*gJrRIP36%1TL~3V86@`A{7`I
z8JvNv$;>S3tY0}3*;FR$v&aeBb4_Mj50!+7#<55yf;7Z&C9%LX2D2x!U1VL)-oO?N
zHtar7KA4?@nT-pi;yzHuk;&69#5E`&$Th^Cfs>CRj;n^{K9dB{MT`uVoa=#Z0y`hb
zs%PS0@R@vrMTya8@^2Okt#e$COg^3=et{rA9%EHtkN~=qgBcVOR)P$Td<;EY3JiP<
W9L#Z(V_BuyeK<iL44quhDhmLcP)L9P

diff --git a/forth/forth.asm b/forth/forth.asm
index db20979..01309da 100644
--- a/forth/forth.asm
+++ b/forth/forth.asm
@@ -131,6 +131,8 @@ LIT:
 	.dw	FLAGS
 ; 46
 	.dw	PARSEPTR
+	.dw	HERE
+	.dw	CURRENT
 
 ; *** Code ***
 forthMain:
@@ -161,7 +163,7 @@ forthMain:
 .bootName:
 	.db	"BOOT", 0
 
-.fill 105
+.fill 101
 
 ; STABLE ABI
 ; Offset: 00cd
@@ -784,36 +786,10 @@ PARSED:
 	jp	next
 
 
-.fill 96
-
-	.db	"JTBL"
-	.dw	$-PARSED
-	.db	4
-JTBL:
-	.dw	sysvarWord
-	.dw	JUMPTBL
-
-; STABLE ABI (every sysvars)
-; Offset: 05ca
-.out $
-	.db "HERE"
-	.dw $-JTBL
-	.db 4
-HERE_:	; Caution: conflicts with actual variable name
-	.dw sysvarWord
-	.dw HERE
-
-	.db "CURRENT"
-	.dw $-HERE_
-	.db 7
-CURRENT_:
-	.dw sysvarWord
-	.dw CURRENT
-
-.fill 92
+.fill 224
 
 	.db	"_bend"
-	.dw	$-CURRENT_
+	.dw	$-PARSED
 	.db	5
 ; Offset: 0647
 .out $
diff --git a/forth/icore.fs b/forth/icore.fs
index 1461b4a..1b0b4dd 100644
--- a/forth/icore.fs
+++ b/forth/icore.fs
@@ -55,6 +55,8 @@
     ,           ( write! )
 ; IMMEDIATE
 
+: JTBL 0x08 ;
+
 : FLAGS
     ( JTBL+44 == FLAGS )
     [ JTBL 44 + @ LITN ]
@@ -65,6 +67,16 @@
     [ JTBL 46 + @ LITN ]
 ;
 
+: HERE
+    ( JTBL+48 == HERE )
+    [ JTBL 48 + @ LITN ]
+;
+
+: CURRENT
+    ( JTBL+50 == CURRENT )
+    [ JTBL 50 + @ LITN ]
+;
+
 : QUIT
     0 _c FLAGS _c ! _c (resRS)
     LIT< INTERPRET (find) _c DROP EXECUTE
@@ -100,8 +112,8 @@
 ;
 
 : C,
-    HERE _c @ _c C!
-    HERE _c @ 1 _c + HERE _c !
+    _c HERE _c @ _c C!
+    _c HERE _c @ 1 _c + _c HERE _c !
 ;
 
 ( The NOT is to normalize the negative/positive numbers to 1
@@ -136,18 +148,18 @@
 ;
 
 : (entry)
-    HERE _c @       ( h )
+    _c HERE _c @       ( h )
     _c WORD         ( h s )
     SCPY            ( h )
     ( Adjust HERE -1 because SCPY copies the null )
-    HERE _c @ 1 _c - ( h h' )
-    _c DUP HERE _c ! ( h h' )
+    _c HERE _c @ 1 _c - ( h h' )
+    _c DUP _c HERE _c ! ( h h' )
     _c SWAP _c -       ( sz )
     ( write prev value )
-    HERE _c @ CURRENT _c @ _c - ,
+    _c HERE _c @ _c CURRENT _c @ _c - ,
     ( write size )
     _c C,
-    HERE _c @ CURRENT _c !
+    _c HERE _c @ _c CURRENT _c !
 ;
 
 : INTERPRET
@@ -177,7 +189,7 @@
   it to avoid bootstrapping issues )
 : LITN
     ( JTBL+24 == NUMBER )
-    JTBL 24 _c + ,
+    _c JTBL 24 _c + ,
     ,
 ;