From feeec2952c876ab3519a02f03f6fe134c4ce144e Mon Sep 17 00:00:00 2001
From: zeroflag <amagyar@hortonworks.com>
Date: Sun, 4 Jul 2021 21:09:47 +0200
Subject: [PATCH] temp lookup words are no longer inlined but compiled to a
 temp scratch area

---
 src/main/java/com/vectron/fcl/Fcl.java |  1 +
 src/main/res/raw/locals.forth          | 13 +++++++++++--
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/main/java/com/vectron/fcl/Fcl.java b/src/main/java/com/vectron/fcl/Fcl.java
index b4a967c..2623c58 100644
--- a/src/main/java/com/vectron/fcl/Fcl.java
+++ b/src/main/java/com/vectron/fcl/Fcl.java
@@ -384,6 +384,7 @@ public class Fcl {
         addPrimitive("false", () -> stack.push(Bool.FALSE));
         addPrimitive("nil", () -> stack.push(Nil.INSTANCE));
         addPrimitive("here", () -> stack.push(new Num(dp)));
+        addPrimitive("dp!", () -> dp = stack.pop().intValue() );
         addPrimitive("interpret", () -> mode = Mode.INTERPRET);
         addPrimitive("trace", () -> trace = stack.pop().boolValue());
         addPrimitive("lit", () -> stack.push((Obj)heap[ip++]));
diff --git a/src/main/res/raw/locals.forth b/src/main/res/raw/locals.forth
index 110151c..9ee32d4 100644
--- a/src/main/res/raw/locals.forth
+++ b/src/main/res/raw/locals.forth
@@ -17,12 +17,17 @@ var: psp                        ( top of the parameter stack, each allocation ad
 var: qpsp                       ( parameter stack pointer used by quotations )
 var: frame.allocated            ( compile time variable for checking if a frame was already allocated )
 var: q.count                    ( compile time counter for quotations, nested into each other )
+var: ldp
 
+6    val:   look-word-size      ( compiled size of one lookup word )
 8    val:   max#loc             ( maximum number of local variables per word )
 1024 val:   ps.size             ( max pstack size )
 ps.size     allot val: pstack   ( parameter stack for storing the locals )
 max#loc     allot val: names    ( names of the local variables )
 
+max#loc look-word-size *
+allot val: scratch              ( scratch area for compiling temporary lookup words )
+
 0     q.count !
 false frame.allocated !
 
@@ -68,19 +73,23 @@ false frame.allocated !
     frame.allocated @ not if        ( is this the first local? )
         true frame.allocated !
         ['] frame.alloc ,           ( alloc new stack frame for max#loc )
+        scratch ldp !
     then
     (frame.top)
     ['] lit       ,  #loc @  ,      ( local index )
     ['] -         ,  ['] !   ,      ( move local to from data stack to the stack frame )
-    ['] jmp       ,  (dummy)        ( bypass the lookup word )
+    here                            ( save this dp and restore it after the lookup word is compiled to the scratch area )
     word dup >names                 ( store lookup word name )
+    ldp @ dp!                       ( set dp to scratch area )
     create postpone: immediate      ( compile immediate lookup word  )
         ['] lit       ,  swap ,     ( type 1=val 0=var )
         ['] lit       ,  #loc @  ,  ( local index within the frame )
         ['] lookup    ,
         ['] exit      ,
+    here ldp @ - look-word-size != if 'Invalid lookup word size' abort then
     #loc inc
-    resolve ;
+    here ldp !
+    dp! ;
 
 : -> immediate 1 local ;
 : => immediate 0 local ;