Merge pull request #155 from TG9541/fix-pick

fixes #154 PICK is off by one

forth.asm

@@ -1988,6 +1988,7 @@ ZEQUAL:
         HEADER  PICK "PICK"
 PICK:
         CALLR   DOXCODE
+        INCW    X
         SLAW    X
         ADDW    X,YTEMP
         LDW     X,(X)
@@ -3997,7 +3998,6 @@ DOTS:
         CALL    TOR             ; start count down loop
         JRA     DOTS2           ; skip first pass
 DOTS1:  CALL    RAT
-        CALL    ONEP
         CALL    PICK
         CALL    DOT             ; index stack, display contents
 DOTS2:  CALL    DONXT

lib/2OVER

@@ -1,4 +1,4 @@
 \ STM8 eForth 2OVER   double utility word                TG9541
 \ refer to github.com/TG9541/stm8ef/blob/master/LICENSE.md
 
-: 2OVER  ( d1 d2 -- d1 d2 d1 ) [ $AD00 , ( CALLR 0 ) ] 4 PICK ;
+: 2OVER  ( d1 d2 -- d1 d2 d1 ) [ $AD00 , ( CALLR 0 ) ] 3 PICK ;

lib/@inter

@@ -14,7 +14,7 @@
   : @inter ( n a -- n )
     \ compile time: consumes xt of 2cell+ and @dif
     DUP @ 1- >R 2+ DUP BEGIN
-      3 PICK OVER @ < NOT WHILE NIP [ ROT ( 2cell+ ) CALL, ] NEXT
+      2 PICK OVER @ < NOT WHILE NIP [ ROT ( 2cell+ ) CALL, ] NEXT
         DROP DUP
       ELSE R> DROP THEN
     OVER = IF

lib/DSQRT

@@ -7,7 +7,7 @@
   $8000 ( d c ) $8000 ( d c g )
   BEGIN
     DUP DUP UM* ( d c g g^2)
-    6 PICK 6 PICK ( d c g g^2 d )
+    5 PICK 5 PICK ( d c g g^2 d )
     D> IF ( d c g )
       OVER XOR
     THEN ( d c g )
@@ -19,3 +19,10 @@
     THEN
   UNTIL
 ;
+
+
+\\ Example:
+
+0 16 DSQRT .S    \ 1024 <sp ok
+0 1 DSQRT .S     \ 256 <sp  ok
+16 0 DSQRT .S    \ 4 <sp  ok

test/board.fs

@@ -17,6 +17,16 @@ T{e -11 5 .R e-> 5 207 }T
 T{e -11 4 U.R e-> 5 263 }T
 T{e 11 4 U.R e-> 4 162 }T
 
+\ core: stack manipulation
+T{ 1 2   OVER -> 1 2 1 }T
+T{ 1 2   SWAP -> 2 1 }T
+T{ 1 2 3 ROT  -> 2 3 1 }T
+T{ 1 2 3 NIP  -> 1 3 }T
+T{ 1 2 3 0 PICK -> 1 2 3 3 }T
+T{ 1 2 3 2 PICK -> 1 2 3 1 }T
+T{ 1 2 2DUP -> 1 2 1 2 }T
+T{ 1 2 3 4 2DROP -> 1 2 }T
+
 \ core: compare operations
 T{ 10 -500 = -> 0 }T
 T{ -500 -500 = -> -1 }T