--- gforth/vmgen-ex2/engine.c	2002/06/02 15:46:17	1.1
+++ gforth/vmgen-ex2/engine.c	2007/12/31 19:02:25	1.10
@@ -1,12 +1,12 @@
 /* vm interpreter wrapper
 
-  Copyright (C) 2001 Free Software Foundation, Inc.
+  Copyright (C) 2001,2002,2003,2007 Free Software Foundation, Inc.
 
   This file is part of Gforth.
 
   Gforth is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License
-  as published by the Free Software Foundation; either version 2
+  as published by the Free Software Foundation, either version 3
   of the License, or (at your option) any later version.
 
   This program is distributed in the hope that it will be useful,
@@ -15,14 +15,11 @@
   GNU General Public License for more details.
 
   You should have received a copy of the GNU General Public License
-  along with this program; if not, write to the Free Software
-  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
+  along with this program; if not, see http://www.gnu.org/licenses/.
 */
 
 #include "mini.h"
 
-#define vm_Cell2Cell(_x,_y) ((_y)=(_x))
-
 #define USE_spTOS 1
 
 #ifdef USE_spTOS
@@ -42,17 +39,16 @@
 
 /* here you select the threading scheme; I have only set this up for
    386 and generic, because I don't know what preprocessor macros to
-   test for (Gforth uses config.guess instead).
-   Anyway, it's probably best to build them all and select the fastest
-   instead of hardwiring a specific scheme for an architecture. */
+   test for (Gforth uses config.guess instead).  Anyway, it's probably
+   best to build them all and select the fastest instead of hardwiring
+   a specific scheme for an architecture.  E.g., scheme 8 is fastest
+   for Gforth "make bench" on a 486, whereas scheme 5 is fastest for
+   "mini fib.mini" on an Athlon */
 #ifndef THREADING_SCHEME
-#ifdef i386
-#define THREADING_SCHEME 8
-#else
 #define THREADING_SCHEME 5
-#endif
 #endif /* defined(THREADING_SCHEME) */
 
+#ifdef __GNUC__
 #if THREADING_SCHEME==1
 /* direct threading scheme 1: autoinc, long latency (HPPA, Sharc) */
 #  define NEXT_P0	({cfa=*ip++;})
@@ -62,7 +58,7 @@
 #  define INC_IP(const_inc)	({cfa=IP[const_inc]; ip+=(const_inc);})
 #  define DEF_CA
 #  define NEXT_P1
-#  define NEXT_P2	({goto *cfa;})
+#  define NEXT_P2	({goto *(cfa.inst);})
 #endif
 
 #if THREADING_SCHEME==3
@@ -74,20 +70,20 @@
 #  define INC_IP(const_inc)	({ip+=(const_inc);})
 #  define DEF_CA
 #  define NEXT_P1	({cfa=*ip++;})
-#  define NEXT_P2	({goto *cfa;})
+#  define NEXT_P2	({goto *(cfa.inst);})
 #endif
 
 #if THREADING_SCHEME==5
 /* direct threading scheme 5: early fetching (Alpha, MIPS) */
 #  define CFA_NEXT
 #  define NEXT_P0	({cfa=*ip;})
-#  define IP		((Cell *)ip)
+#  define IP		(ip)
 #  define SET_IP(p)	({ip=(Inst *)(p); NEXT_P0;})
-#  define NEXT_INST	((Cell)cfa)
+#  define NEXT_INST	(cfa)
 #  define INC_IP(const_inc)	({cfa=ip[const_inc]; ip+=(const_inc);})
 #  define DEF_CA
 #  define NEXT_P1	(ip++)
-#  define NEXT_P2	({goto *cfa;})
+#  define NEXT_P2	({goto *(cfa.inst);})
 #endif
 
 #if THREADING_SCHEME==8
@@ -114,8 +110,8 @@
 #  define INC_IP(const_inc)	({next_cfa=IP[const_inc]; ip+=(const_inc);})
 #  define DEF_CA	
 #  define NEXT_P1	({cfa=next_cfa; ip++; next_cfa=*ip;})
-#  define NEXT_P2	({goto *cfa;})
-#  define MORE_VARS	Inst next_cfa;
+#  define NEXT_P2	({goto *(cfa.inst);})
+#  define MORE_VARS	Cell next_cfa;
 #endif
 
 #if THREADING_SCHEME==10
@@ -127,13 +123,32 @@
 #  define INC_IP(const_inc)	({ip+=(const_inc);})
 #  define DEF_CA
 #  define NEXT_P1
-#  define NEXT_P2	({cfa=*ip++; goto *cfa;})
+#  define NEXT_P2	({cfa=*ip++; goto *(cfa.inst);})
 #endif
 
 
 #define NEXT ({DEF_CA NEXT_P1; NEXT_P2;})
-#define IPTOS ((Cell)(NEXT_INST))
-#define CASE
+#define IPTOS ((NEXT_INST))
+
+#define INST_ADDR(name) (Label)&&I_##name
+#define LABEL(name) I_##name:
+#else /* !defined(__GNUC__) */
+/* use switch dispatch */
+#define DEF_CA
+#define NEXT_P0
+#define NEXT_P1
+#define NEXT_P2 goto next_inst;
+#define SET_IP(p)	(ip=(p))
+#define IP              ip
+#define NEXT_INST	(*ip)
+#define INC_IP(const_inc)	(ip+=(const_inc))
+#define IPTOS NEXT_INST
+#define INST_ADDR(name) I_##name
+#define LABEL(name) case I_##name:
+
+#endif /* !defined(__GNUC__) */
+
+#define LABEL2(x)
 
 #ifdef VM_PROFILING
 #define SUPER_END  vm_count_block(IP)
@@ -141,15 +156,24 @@
 #define SUPER_END
 #endif
 
-#define INST_ADDR(name) (Label)&&I_##name
-#define LABEL(name) I_##name
+#ifndef __GNUC__
+enum {
+#include "mini-labels.i"
+};
+#endif
+
+#if defined(__GNUC__) && ((__GNUC__==2 && defined(__GNUC_MINOR__) && __GNUC_MINOR__>=7)||(__GNUC__>2))
+#define MAYBE_UNUSED __attribute__((unused))
+#else
+#define MAYBE_UNUSED
+#endif
 
 /* the return type can be anything you want it to */
 long engine(Cell *ip0, Cell *sp, char *fp)
 {
   /* VM registers (you may want to use gcc's "Explicit Reg Vars" here) */
   Cell * ip;
-  Cell * cfa;
+  Cell cfa;
 #ifdef USE_spTOS
   Cell   spTOS;
 #else
@@ -175,7 +199,17 @@ long engine(Cell *ip0, Cell *sp, char *f
 
   SET_IP(ip0);
   SUPER_END;  /* count the BB starting at ip0 */
-  NEXT;
 
+#ifdef __GNUC__
+  NEXT;
+#include "mini-vm.i"
+#else  
+ next_inst:
+  switch((*ip++).inst) {
 #include "mini-vm.i"
+  default:
+    fprintf(stderr,"unknown instruction %d at %p\n", ip[-1], ip-1);
+    exit(1);
+  }
+#endif
 }