--- gforth/engine/threaded.h	1999/05/04 12:51:35	1.4
+++ gforth/engine/threaded.h	2002/12/28 17:18:27	1.18
@@ -1,6 +1,6 @@
 /* This file defines a number of threading schemes.
 
-  Copyright (C) 1995, 1996,1997 Free Software Foundation, Inc.
+  Copyright (C) 1995, 1996,1997,1999 Free Software Foundation, Inc.
 
   This file is part of Gforth.
 
@@ -16,7 +16,7 @@
 
   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., 675 Mass Ave, Cambridge, MA 02139, USA.
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
 
 
   This files defines macros for threading. Many sets of macros are
@@ -91,31 +91,61 @@
 
 */
 
-/* CFA_NEXT: a more appropriate name would be CFA_LIVE, i.e., cfa is live after NEXT */
-
 #ifdef DOUBLY_INDIRECT
-#  define CFA_NEXT
 #  define NEXT_P0	({cfa=*ip;})
 #  define IP		(ip)
 #  define SET_IP(p)	({ip=(p); NEXT_P0;})
 #  define NEXT_INST	(cfa)
 #  define INC_IP(const_inc)	({cfa=IP[const_inc]; ip+=(const_inc);})
 #  define DEF_CA	Label ca;
-#  define NEXT_P1	({ip++; ca=**cfa;})
+#  define NEXT_P1	({\
+  if ((cfa<=vm_prims+DOESJUMP || cfa>=vm_prims+npriminfos)) \
+    fprintf(stderr,"NEXT encountered prim %p at ip=%p [%p .. %p]\n", cfa, ip, vm_prims+DOESJUMP, vm_prims+npriminfos); \
+  ip++; ca=**cfa;})
 #  define NEXT_P2	({goto *ca;})
-#  define EXEC(XT)	({DEF_CA cfa=(XT); ca=**cfa; goto *ca;})
-#  define NEXT1_P1 ({ca = **cfa;})
-#  define NEXT1_P2 ({goto *ca;})
+#  define EXEC(XT)	({DEF_CA cfa=(XT);\
+  if ((cfa>vm_prims+DOESJUMP && cfa<vm_prims+npriminfos)) \
+    fprintf(stderr,"EXEC encountered xt %p at ip=%p, vm_prims=%p, xts=%p\n", cfa, ip, vm_prims, xts); \
+ ca=**cfa; goto *ca;})
+
+#elif defined(NO_IP)
+
+#define NEXT_P0
+#define SET_IP(target)	assert(0)
+#define INC_IP(n)	((void)0)
+#define DEF_CA
+#define NEXT_P1
+#define NEXT_P2		({goto *next_code;})
+/* set next_code to the return address before performing EXEC */
+#define EXEC(XT)	({cfa=(XT); goto **cfa;})
 
-#else /* !defined(DOUBLY_INDIRECT) */
+#else  /* !defined(DOUBLY_INDIRECT) && !defined(NO_IP) */
 
 #if defined(DIRECT_THREADED)
 
-/* note that the "cfa dead" versions only work if GETCFA exists and works */
+/* This lets the compiler know that cfa is dead before; we place it at
+   "goto *"s that perform direct threaded dispatch (i.e., not EXECUTE
+   etc.), and thus do not reach doers, which would use cfa; the only
+   way to a doer is through EXECUTE etc., which set the cfa
+   themselves.
+
+   Some of these direct threaded schemes use "cfa" to hold the code
+   address in normal direct threaded code.  Of course we cannot use
+   KILLS there.
+
+   KILLS works by having an empty asm instruction, and claiming to the
+   compiler that it writes to cfa.
+
+   KILLS is optional.  You can write
+
+#define KILLS
+
+   and lose just a little performance.
+*/
+#define KILLS asm("":"=X"(cfa));
 
 #if THREADING_SCHEME==1
 #warning direct threading scheme 1: autoinc, long latency, cfa live
-#  define CFA_NEXT
 #  define NEXT_P0	({cfa=*ip++;})
 #  define IP		(ip-1)
 #  define SET_IP(p)	({ip=(p); NEXT_P0;})
@@ -124,14 +154,11 @@
 #  define DEF_CA
 #  define NEXT_P1
 #  define NEXT_P2	({goto *cfa;})
-#  define EXEC(XT)	({cfa=(XT); goto *cfa;})
+#  define EXEC(XT)	({cfa=(XT); goto **cfa;})
 #endif
 
 #if THREADING_SCHEME==2
 #warning direct threading scheme 2: autoinc, long latency, cfa dead
-#ifndef GETCFA
-#error GETCFA must be defined for cfa dead threading
-#endif
 #  define NEXT_P0	(ip++)
 #  define IP		(ip-1)
 #  define SET_IP(p)	({ip=(p); NEXT_P0;})
@@ -139,14 +166,13 @@
 #  define INC_IP(const_inc)	({ ip+=(const_inc);})
 #  define DEF_CA
 #  define NEXT_P1
-#  define NEXT_P2	({goto **(ip-1);})
-#  define EXEC(XT)	({goto *(XT);})
+#  define NEXT_P2	({KILLS goto **(ip-1);})
+#  define EXEC(XT)	({cfa=(XT); goto **cfa;})
 #endif
 
 
 #if THREADING_SCHEME==3
 #warning direct threading scheme 3: autoinc, low latency, cfa live
-#  define CFA_NEXT
 #  define NEXT_P0
 #  define IP		(ip)
 #  define SET_IP(p)	({ip=(p); NEXT_P0;})
@@ -155,14 +181,11 @@
 #  define DEF_CA
 #  define NEXT_P1	({cfa=*ip++;})
 #  define NEXT_P2	({goto *cfa;})
-#  define EXEC(XT)	({cfa=(XT); goto *cfa;})
+#  define EXEC(XT)	({cfa=(XT); goto **cfa;})
 #endif
 
 #if THREADING_SCHEME==4
 #warning direct threading scheme 4: autoinc, low latency, cfa dead
-#ifndef GETCFA
-#error GETCFA must be defined for cfa dead threading
-#endif
 #  define NEXT_P0
 #  define IP		(ip)
 #  define SET_IP(p)	({ip=(p); NEXT_P0;})
@@ -170,13 +193,12 @@
 #  define INC_IP(const_inc)	({ ip+=(const_inc);})
 #  define DEF_CA
 #  define NEXT_P1
-#  define NEXT_P2	({goto **(ip++);})
-#  define EXEC(XT)	({goto *(XT);})
+#  define NEXT_P2	({KILLS goto **(ip++);})
+#  define EXEC(XT)	({cfa=(XT); goto **cfa;})
 #endif
 
 #if THREADING_SCHEME==5
 #warning direct threading scheme 5: long latency, cfa live
-#  define CFA_NEXT
 #  define NEXT_P0	({cfa=*ip;})
 #  define IP		(ip)
 #  define SET_IP(p)	({ip=(p); NEXT_P0;})
@@ -185,14 +207,11 @@
 #  define DEF_CA
 #  define NEXT_P1	(ip++)
 #  define NEXT_P2	({goto *cfa;})
-#  define EXEC(XT)	({cfa=(XT); goto *cfa;})
+#  define EXEC(XT)	({cfa=(XT); goto **cfa;})
 #endif
 
 #if THREADING_SCHEME==6
 #warning direct threading scheme 6: long latency, cfa dead
-#ifndef GETCFA
-#error GETCFA must be defined for cfa dead threading
-#endif
 #  define NEXT_P0
 #  define IP		(ip)
 #  define SET_IP(p)	({ip=(p); NEXT_P0;})
@@ -200,14 +219,13 @@
 #  define INC_IP(const_inc)	({ip+=(const_inc);})
 #  define DEF_CA
 #  define NEXT_P1	(ip++)
-#  define NEXT_P2	({goto **(ip-1);})
-#  define EXEC(XT)	({goto *(XT);})
+#  define NEXT_P2	({KILLS goto **(ip-1);})
+#  define EXEC(XT)	({cfa=(XT); goto **cfa;})
 #endif
 
 
 #if THREADING_SCHEME==7
 #warning direct threading scheme 7: low latency, cfa live
-#  define CFA_NEXT
 #  define NEXT_P0
 #  define IP		(ip)
 #  define SET_IP(p)	({ip=(p); NEXT_P0;})
@@ -216,14 +234,11 @@
 #  define DEF_CA
 #  define NEXT_P1	({cfa=*ip++;})
 #  define NEXT_P2	({goto *cfa;})
-#  define EXEC(XT)	({cfa=(XT); goto *cfa;})
+#  define EXEC(XT)	({cfa=(XT); goto **cfa;})
 #endif
 
 #if THREADING_SCHEME==8
 #warning direct threading scheme 8: cfa dead, i386 hack
-#ifndef GETCFA
-#error GETCFA must be defined for cfa dead threading
-#endif
 #  define NEXT_P0
 #  define IP		(ip)
 #  define SET_IP(p)	({ip=(p); NEXT_P0;})
@@ -231,8 +246,8 @@
 #  define INC_IP(const_inc)	({ ip+=(const_inc);})
 #  define DEF_CA
 #  define NEXT_P1	(ip++)
-#  define NEXT_P2	({goto **(ip-1);})
-#  define EXEC(XT)	({goto *(XT);})
+#  define NEXT_P2	({KILLS goto **(ip-1);})
+#  define EXEC(XT)	({cfa=(XT); goto **cfa;})
 #endif
 
 #if THREADING_SCHEME==9
@@ -240,22 +255,20 @@
 /* Power uses a prepare-to-branch instruction, and the latency between
    this inst and the branch is 5 cycles on a PPC604; so we utilize this
    to do some prefetching in between */
-#  define CFA_NEXT
 #  define NEXT_P0
 #  define IP		ip
 #  define SET_IP(p)	({ip=(p); next_cfa=*ip; NEXT_P0;})
 #  define NEXT_INST	(next_cfa)
 #  define INC_IP(const_inc)	({next_cfa=IP[const_inc]; ip+=(const_inc);})
-#  define DEF_CA	Label ca;
-#  define NEXT_P1	({ca=next_cfa; cfa=next_cfa; ip++; next_cfa=*ip;})
-#  define NEXT_P2	({goto *ca;})
-#  define EXEC(XT)	({cfa=(XT); goto *cfa;})
+#  define DEF_CA	
+#  define NEXT_P1	({cfa=next_cfa; ip++; next_cfa=*ip;})
+#  define NEXT_P2	({goto *cfa;})
+#  define EXEC(XT)	({cfa=(XT); goto **cfa;})
 #  define MORE_VARS	Xt next_cfa;
 #endif
 
 #if THREADING_SCHEME==10
 #warning direct threading scheme 10: plain (no attempt at scheduling)
-#  define CFA_NEXT
 #  define NEXT_P0
 #  define IP		(ip)
 #  define SET_IP(p)	({ip=(p); NEXT_P0;})
@@ -264,7 +277,7 @@
 #  define DEF_CA
 #  define NEXT_P1
 #  define NEXT_P2	({cfa=*ip++; goto *cfa;})
-#  define EXEC(XT)	({cfa=(XT); goto *cfa;})
+#  define EXEC(XT)	({cfa=(XT); goto **cfa;})
 #endif
 
 /* direct threaded */
@@ -273,7 +286,6 @@
 
 #if THREADING_SCHEME==1
 #warning indirect threading scheme 1: autoinc, long latency, cisc
-#  define CFA_NEXT
 #  define NEXT_P0	({cfa=*ip++;})
 #  define IP		(ip-1)
 #  define SET_IP(p)	({ip=(p); NEXT_P0;})
@@ -287,7 +299,6 @@
 
 #if THREADING_SCHEME==2
 #warning indirect threading scheme 2: autoinc, long latency
-#  define CFA_NEXT
 #  define NEXT_P0	({cfa=*ip++;})
 #  define IP		(ip-1)
 #  define SET_IP(p)	({ip=(p); NEXT_P0;})
@@ -302,7 +313,6 @@
 
 #if THREADING_SCHEME==3
 #warning indirect threading scheme 3: autoinc, low latency, cisc
-#  define CFA_NEXT
 #  define NEXT_P0
 #  define IP		(ip)
 #  define SET_IP(p)	({ip=(p); NEXT_P0;})
@@ -316,7 +326,6 @@
 
 #if THREADING_SCHEME==4
 #warning indirect threading scheme 4: autoinc, low latency
-#  define CFA_NEXT
 #  define NEXT_P0	({cfa=*ip++;})
 #  define IP		(ip-1)
 #  define SET_IP(p)	({ip=(p); NEXT_P0;})
@@ -331,7 +340,6 @@
 
 #if THREADING_SCHEME==5
 #warning indirect threading scheme 5: long latency, cisc
-#  define CFA_NEXT
 #  define NEXT_P0	({cfa=*ip;})
 #  define IP		(ip)
 #  define SET_IP(p)	({ip=(p); NEXT_P0;})
@@ -345,7 +353,6 @@
 
 #if THREADING_SCHEME==6
 #warning indirect threading scheme 6: long latency
-#  define CFA_NEXT
 #  define NEXT_P0	({cfa=*ip;})
 #  define IP		(ip)
 #  define SET_IP(p)	({ip=(p); NEXT_P0;})
@@ -359,7 +366,6 @@
 
 #if THREADING_SCHEME==7
 #warning indirect threading scheme 7: low latency
-#  define CFA_NEXT
 #  define NEXT_P0	({cfa=*ip;})
 #  define IP		(ip)
 #  define SET_IP(p)	({ip=(p); NEXT_P0;})
@@ -373,7 +379,6 @@
 
 #if THREADING_SCHEME==8
 #warning indirect threading scheme 8: low latency,cisc
-#  define CFA_NEXT
 #  define NEXT_P0
 #  define IP		(ip)
 #  define SET_IP(p)	({ip=(p); NEXT_P0;})
@@ -388,7 +393,7 @@
 /* indirect threaded */
 #endif
 
-#endif /* !defined(DOUBLY_INDIRECT) */
+#endif /* !defined(DOUBLY_INDIRECT) && !defined(NO_IP) */
 
 #define NEXT ({DEF_CA NEXT_P1; NEXT_P2;})
-
+#define IPTOS NEXT_INST