diff --git a/vvp/Makefile.in b/vvp/Makefile.in
index b704206d0..20c72e46a 100644
--- a/vvp/Makefile.in
+++ b/vvp/Makefile.in
@@ -16,7 +16,7 @@
 #    59 Temple Place - Suite 330
 #    Boston, MA 02111-1307, USA
 #
-#ident "$Id: Makefile.in,v 1.35 2002/02/03 01:01:51 steve Exp $"
+#ident "$Id: Makefile.in,v 1.36 2002/03/18 00:19:34 steve Exp $"
 #
 #
 SHELL = /bin/sh
@@ -66,8 +66,8 @@ vpi_priv.o vpi_scope.o vpi_signal.o vpi_tasks.o vpi_time.o vpi_memory.o \
 vpi_vthr_vector.o vpip_to_dec.o vvp_vpi.o
 
 O = main.o parse.o parse_misc.o lexor.o arith.o bufif.o compile.o debug.o \
-functor.o fvectors.o npmos.o resolv.o symbols.o codes.o vthread.o schedule.o \
-tables.o udp.o memory.o force.o event.o logic.o delay.o $V
+functor.o fvectors.o npmos.o resolv.o symbols.o ufunc.o codes.o vthread.o \
+schedule.o tables.o udp.o memory.o force.o event.o logic.o delay.o $V
 
 vvp: $O 
 	$(CXX) $(rdynamic) $(CXXFLAGS) $(LDFLAGS) -o vvp $O $(LIBS) $(dllib)
diff --git a/vvp/README.txt b/vvp/README.txt
index 77cb9ac01..0a941d6c1 100644
--- a/vvp/README.txt
+++ b/vvp/README.txt
@@ -1,7 +1,7 @@
 /*
  * Copyright (c) 2001 Stephen Williams (steve@icarus.com)
  *
- *  $Id: README.txt,v 1.39 2002/01/03 04:19:01 steve Exp $
+ *  $Id: README.txt,v 1.40 2002/03/18 00:19:34 steve Exp $
  */
 
 VVP SIMULATION ENGINE
@@ -476,6 +476,13 @@ number of data inputs. The first <wid> symbols in the <symbols_list>
 gives the input data. The remaining hold the shift value, lsb first.
 
 
+STRUCTURAL FUNCTION CALLS:
+
+The .ufunc statement defines a call to a user defined function.
+
+	<label> .ufunc ;
+
+
 THREAD STATEMENTS:
 
 Thread statements create the initial threads for a simulation. These
diff --git a/vvp/codes.h b/vvp/codes.h
index a7d43030c..5a992a120 100644
--- a/vvp/codes.h
+++ b/vvp/codes.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: codes.h,v 1.37 2001/11/07 03:34:42 steve Exp $"
+#ident "$Id: codes.h,v 1.38 2002/03/18 00:19:34 steve Exp $"
 #endif
 
 
@@ -93,6 +93,8 @@ extern bool of_XORR(vthread_t thr, vvp_code_t code);
 
 extern bool of_ZOMBIE(vthread_t thr, vvp_code_t code);
 
+extern bool of_CALL_UFUNC(vthread_t thr, vvp_code_t code);
+
 /*
  * This is the format of a machine code instruction.
  */
@@ -113,6 +115,7 @@ struct vvp_code_s {
 	    unsigned short bit_idx[2];
 	    vvp_ipoint_t iptr2;
 	    vvp_cpoint_t cptr2;
+	    struct ufunc_core*ufunc_core_ptr;
       };
 };
 
@@ -148,6 +151,9 @@ extern vvp_code_t codespace_index(vvp_cpoint_t ptr);
 
 /*
  * $Log: codes.h,v $
+ * Revision 1.38  2002/03/18 00:19:34  steve
+ *  Add the .ufunc statement.
+ *
  * Revision 1.37  2001/11/07 03:34:42  steve
  *  Use functor pointers where vvp_ipoint_t is unneeded.
  *
diff --git a/vvp/compile.cc b/vvp/compile.cc
index 859acc9cf..f45a9bba7 100644
--- a/vvp/compile.cc
+++ b/vvp/compile.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: compile.cc,v 1.121 2002/03/08 05:41:45 steve Exp $"
+#ident "$Id: compile.cc,v 1.122 2002/03/18 00:19:34 steve Exp $"
 #endif
 
 # include  "arith.h"
@@ -325,7 +325,6 @@ bool functor_gen_resolv_list_s::resolve(bool mes)
       return false;
 }
 
-inline static 
 void functor_ref_lookup(vvp_ipoint_t *ref, char*lab, unsigned idx)
 {
       struct functor_gen_resolv_list_s*res = 
@@ -418,7 +417,6 @@ bool code_label_resolv_list_s::resolve(bool mes)
       return false;
 }
 
-inline static
 void code_label_lookup(struct vvp_code_s *code, char *label)
 {
       struct code_label_resolv_list_s *res
@@ -578,8 +576,8 @@ void const_functor_s::set(vvp_ipoint_t p, bool, unsigned val, unsigned)
       fprintf(stderr, "              : Value is %u, trying to set %u\n",
 	      oval, val);
 
-      debug_print(p);
 #if defined(WITH_DEBUG)
+      debug_print(p);
       breakpoint();
 #else
       fprintf(stderr, "              : I'm driving functor 0x%x\n", out);
@@ -1389,6 +1387,9 @@ vvp_ipoint_t debug_lookup_functor(const char*name)
 
 /*
  * $Log: compile.cc,v $
+ * Revision 1.122  2002/03/18 00:19:34  steve
+ *  Add the .ufunc statement.
+ *
  * Revision 1.121  2002/03/08 05:41:45  steve
  *  Debug code for write to constants.
  *
diff --git a/vvp/compile.h b/vvp/compile.h
index 7018e6bdb..337b62e46 100644
--- a/vvp/compile.h
+++ b/vvp/compile.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: compile.h,v 1.40 2002/01/03 04:19:02 steve Exp $"
+#ident "$Id: compile.h,v 1.41 2002/03/18 00:19:34 steve Exp $"
 #endif
 
 # include  <stdio.h>
@@ -118,6 +118,22 @@ extern void compile_shiftr(char*label, long width,
 extern void compile_vpi_symbol(const char*label, vpiHandle obj);
 extern void compile_vpi_lookup(vpiHandle *objref, char*label);
 
+/*
+ * This function schedules a lookup of an indexed label. The ref
+ * points to the vvp_ipoint_t that receives the result. The result may
+ * be assigned later, if the symbol is defined later in the source
+ * file, so the memory that ref points to must persist.
+ */
+extern void functor_ref_lookup(vvp_ipoint_t *ref, char*lab, unsigned idx);
+
+/*
+ * This function schedules a lookup of the labeled instruction. The
+ * code points to a code structure that points to the instruction
+ * field that receives the result, and the label is the name to
+ * lookup. The lookup will free the label text when it is done.
+ */
+extern void code_label_lookup(struct vvp_code_s *code, char *label);
+
 /* 
  * The `compile_udp_def' function creates a UDP.  The `table' is a
  * NULL terminated array of char*, as assembled by `compile_udp_table'.  
@@ -151,6 +167,13 @@ extern void compile_memory_port(char *label, char *memid,
 
 extern void compile_memory_init(char *memid, unsigned idx, unsigned char val);
 
+/*
+ * Compile the .ufunc statement.
+ */
+extern void compile_ufunc(char*label, char*code, unsigned wid,
+			  unsigned argc, struct symb_s*argv,
+			  unsigned portc, struct symb_s*portv,
+			  unsigned retc, struct symb_s*retv);
 
 /*
  * The compile_event function takes the parts of the event statement
@@ -225,6 +248,9 @@ extern void compile_net(char*label, char*name,
 
 /*
  * $Log: compile.h,v $
+ * Revision 1.41  2002/03/18 00:19:34  steve
+ *  Add the .ufunc statement.
+ *
  * Revision 1.40  2002/01/03 04:19:02  steve
  *  Add structural modulus support down to vvp.
  *
diff --git a/vvp/lexor.lex b/vvp/lexor.lex
index 679c4cbcb..5d140f82f 100644
--- a/vvp/lexor.lex
+++ b/vvp/lexor.lex
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: lexor.lex,v 1.31 2002/03/01 05:42:50 steve Exp $"
+#ident "$Id: lexor.lex,v 1.32 2002/03/18 00:19:34 steve Exp $"
 #endif
 
 # include  "parse_misc.h"
@@ -87,6 +87,7 @@
 ".shift/l"  { return K_SHIFTL; }
 ".shift/r"  { return K_SHIFTR; }
 ".thread"   { return K_THREAD; }
+".ufunc"    { return K_UFUNC; }
 ".var"      { return K_VAR; }
 ".var/s"    { return K_VAR_S; }
 ".udp"         { return K_UDP; }
@@ -158,6 +159,9 @@ int yywrap()
 
 /*
  * $Log: lexor.lex,v $
+ * Revision 1.32  2002/03/18 00:19:34  steve
+ *  Add the .ufunc statement.
+ *
  * Revision 1.31  2002/03/01 05:42:50  steve
  *  out-of-memory asserts.
  *
diff --git a/vvp/parse.y b/vvp/parse.y
index 39eea1cd6..decdccde6 100644
--- a/vvp/parse.y
+++ b/vvp/parse.y
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: parse.y,v 1.43 2002/01/03 04:19:02 steve Exp $"
+#ident "$Id: parse.y,v 1.44 2002/03/18 00:19:34 steve Exp $"
 #endif
 
 # include  "parse_misc.h"
@@ -60,7 +60,7 @@ extern FILE*yyin;
 %token K_ARITH_DIV K_ARITH_MOD K_ARITH_MULT K_ARITH_SUB K_ARITH_SUM
 %token K_CMP_GE K_CMP_GT
 %token K_EVENT K_EVENT_OR K_FUNCTOR K_NET K_NET_S
-%token K_RESOLV K_SCOPE K_SHIFTL K_SHIFTR K_THREAD
+%token K_RESOLV K_SCOPE K_SHIFTL K_SHIFTR K_THREAD K_UFUNC
 %token K_UDP K_UDP_C K_UDP_S
 %token K_MEM K_MEM_P K_MEM_I
 %token K_FORCE 
@@ -159,6 +159,17 @@ statement
 	| mem_init_stmt
 
 
+  /* The .ufunc functor is for implementing user defined functions, or
+     other thread code that is automatically invoked if any of the
+     bits in the symbols list change. */
+
+	| T_LABEL K_UFUNC T_SYMBOL ',' T_NUMBER ',' symbols
+	  '(' symbols ')' symbols ';'
+		{ compile_ufunc($1, $3, $5,
+				$7.cnt, $7.vect,
+				$9.cnt, $9.vect,
+				$11.cnt, $11.vect); }
+
   /* Resolver statements are very much like functors. They are
      compiled to functors of a different mode. */
 
@@ -538,6 +549,9 @@ int compile_design(const char*path)
 
 /*
  * $Log: parse.y,v $
+ * Revision 1.44  2002/03/18 00:19:34  steve
+ *  Add the .ufunc statement.
+ *
  * Revision 1.43  2002/01/03 04:19:02  steve
  *  Add structural modulus support down to vvp.
  *
diff --git a/vvp/ufunc.cc b/vvp/ufunc.cc
new file mode 100644
index 000000000..18f694b15
--- /dev/null
+++ b/vvp/ufunc.cc
@@ -0,0 +1,222 @@
+/*
+ * Copyright (c) 2002 Stephen Williams (steve@icarus.com)
+ *
+ *    This source code is free software; you can redistribute it
+ *    and/or modify it in source code form under the terms of the GNU
+ *    General Public License as published by the Free Software
+ *    Foundation; either version 2 of the License, or (at your option)
+ *    any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    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 02111-1307, USA
+ */
+#if !defined(WINNT)
+#ident "$Id: ufunc.cc,v 1.1 2002/03/18 00:19:34 steve Exp $"
+#endif
+
+# include  "compile.h"
+# include  "symbols.h"
+# include  "codes.h"
+# include  "functor.h"
+# include  "ufunc.h"
+# include  "vthread.h"
+# include  "schedule.h"
+#ifdef HAVE_MALLOC_H
+# include  <malloc.h>
+#endif
+# include  <stdlib.h>
+# include  <string.h>
+# include  <assert.h>
+
+#ifdef __MINGW32__
+#include <windows.h>
+#endif
+
+ufunc_core::ufunc_core(unsigned ow, vvp_ipoint_t ob, vvp_ipoint_t*op,
+		       unsigned np, vvp_ipoint_t*p,
+		       vvp_cpoint_t start_address,
+		       struct __vpiScope*run_scope)
+: owid_(ow), obase_(ob), oports_(op), nports_(np), ports_(p)
+{
+      thread_ = 0;
+      scope_ = run_scope;
+      code_ = start_address;
+
+      ibits_ = new unsigned char[(nports_+3) / 4];
+      memset(ibits_, 0xaa, (nports_+3) / 4);
+}
+
+ufunc_core::~ufunc_core()
+{
+      delete[] ports_;
+}
+
+void ufunc_core::set_bit(unsigned port_idx, unsigned val)
+{
+      unsigned idx = port_idx / 4;
+      unsigned pp  = port_idx % 4;
+
+      static const unsigned char mask[4] = {0xfc, 0xf3, 0xcf, 0x3f};
+
+      ibits_[idx] &= mask[pp];
+      ibits_[idx] |= (val&3) << pp*2;
+
+      if (thread_ == 0) {
+	    thread_ = vthread_new(code_, scope_);
+	    schedule_vthread(thread_, 0);
+      }
+}
+
+static const unsigned char strong_values[4] = {St0, St1, StX, HiZ};
+
+void ufunc_core::assign_bits_to_ports(void)
+{
+      for (unsigned idx = 0 ;  idx < nports_ ;  idx += 1) {
+	    unsigned bit_val = ibits_[idx/4] >> (idx%4)*2;
+	    bit_val &= 3;
+
+	    functor_set(ports_[idx], bit_val, strong_values[bit_val], true);
+      }
+}
+
+void ufunc_core::finish_thread(vthread_t thr)
+{
+      assert(thread_ == thr);
+      thread_ = 0;
+
+      for (unsigned idx = 0 ;  idx < owid_ ;  idx += 1) {
+	    unsigned val = functor_get(oports_[idx]);
+	    vvp_ipoint_t ptr = ipoint_index(obase_, idx);
+	    functor_set(ptr, val, strong_values[val], false);
+      }
+}
+
+/*
+ * There is an instance of ufunc_output_functor_s for each output bit
+ * of the function. This is the functor that passes the output bits to
+ * the rest of the design. The functor simply puts its input to its
+ * output.
+ */
+struct ufunc_output_functor_s  : public functor_s {
+      void set(vvp_ipoint_t, bool push, unsigned val, unsigned str = 0);
+};
+
+void ufunc_output_functor_s::set(vvp_ipoint_t, bool push, unsigned
+				 val, unsigned str)
+{
+      put_oval(val, push);
+}
+
+struct ufunc_input_functor_s  : public functor_s {
+      void set(vvp_ipoint_t, bool push, unsigned val, unsigned str = 0);
+
+      unsigned core_base_;
+      ufunc_core*core_;
+};
+
+void ufunc_input_functor_s::set(vvp_ipoint_t ptr, bool,
+				unsigned val, unsigned str)
+{
+      unsigned pp = ipoint_port(ptr);
+      core_->set_bit(core_base_+pp, val);
+}
+
+/*
+ * This function compiles the .ufunc statement that is discovered in
+ * the source file. Create all the functors and the thread, and
+ * connect them all up.
+ */
+void compile_ufunc(char*label, char*code, unsigned wid,
+		   unsigned argc,  struct symb_s*argv,
+		   unsigned portc, struct symb_s*portv,
+		   unsigned retc,  struct symb_s*retv)
+{
+
+	/* Create an array of vvp_ipoint_t pointers, that point to the
+	   .var bits of the function ports. Do this for the input
+	   ports and the output port. */
+      assert(argc == portc);
+      vvp_ipoint_t* ports = new vvp_ipoint_t [portc];
+
+      for (unsigned idx = 0 ;  idx < portc ;  idx += 1) {
+	    functor_ref_lookup(ports+idx, portv[idx].text, portv[idx].idx);
+      }
+
+      assert(retc == wid);
+      vvp_ipoint_t* rets = new vvp_ipoint_t [retc];
+
+      for (unsigned idx = 0 ;  idx < retc ;  idx += 1) {
+	    functor_ref_lookup(rets+idx, retv[idx].text, retv[idx].idx);
+      }
+
+	/* Create enough output functors for the output bits of the
+	   function. */
+      vvp_ipoint_t obase = functor_allocate(wid);
+      struct ufunc_output_functor_s*fpa
+	    = new struct ufunc_output_functor_s[wid];
+
+      for (unsigned idx = 0 ;  idx < wid ;  idx += 1) {
+	    vvp_ipoint_t ptr = ipoint_index(obase,idx);
+	    functor_define(ptr, fpa+idx);
+      }
+
+      define_functor_symbol(label, obase);
+
+	/* Construct some phantom code that is the thread of the
+	   function call. The first instruction, at the start_address
+	   of the function, loads the points and calls the function.
+	   The last instruction is the usual %end. */
+      vvp_cpoint_t start_address = codespace_allocate();
+      vvp_code_t start_code = codespace_index(start_address);
+      start_code->opcode = of_CALL_UFUNC;
+      code_label_lookup(start_code, code);
+
+      { vvp_cpoint_t cur = codespace_allocate();
+        vvp_code_t codep = codespace_index(cur);
+	codep->opcode = &of_END;
+      }
+
+
+	/* Create the function core object that references the output
+	   functors and the function ports. The input functors will
+	   point to this core to deliver input. */
+      ufunc_core*core = new ufunc_core(wid, obase, rets,
+				       portc, ports,
+				       start_address,
+				       vpip_peek_current_scope());
+      start_code->ufunc_core_ptr = core;
+
+	/* create enough input functors to connect to all the input
+	   bits of the function. These are used to detect changes and
+	   trigger the function thread. */
+      unsigned icnt = (argc + 3) / 4;
+      vvp_ipoint_t ibase = functor_allocate(icnt);
+      struct ufunc_input_functor_s*ifp
+	    = new struct ufunc_input_functor_s[icnt];
+
+      for (unsigned idx = 0 ;  idx < icnt ;  idx += 1) {
+	    vvp_ipoint_t ptr = ipoint_index(ibase,idx);
+	    struct ufunc_input_functor_s*cur = ifp+idx;
+
+	    cur->core_base_ = idx*4;
+	    cur->core_ = core;
+
+	    functor_define(ptr, ifp+idx);
+      }
+
+      inputs_connect(ibase, argc, argv);
+}
+
+/*
+ * $Log: ufunc.cc,v $
+ * Revision 1.1  2002/03/18 00:19:34  steve
+ *  Add the .ufunc statement.
+ *
+ */
+
diff --git a/vvp/ufunc.h b/vvp/ufunc.h
new file mode 100644
index 000000000..893512ca3
--- /dev/null
+++ b/vvp/ufunc.h
@@ -0,0 +1,85 @@
+#ifndef __ufunc_H
+#define __ufunc_H
+/*
+ * Copyright (c) 2002 Stephen Williams (steve@icarus.com)
+ *
+ *    This source code is free software; you can redistribute it
+ *    and/or modify it in source code form under the terms of the GNU
+ *    General Public License as published by the Free Software
+ *    Foundation; either version 2 of the License, or (at your option)
+ *    any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    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 02111-1307, USA
+ */
+#if !defined(WINNT)
+#ident "$Id: ufunc.h,v 1.1 2002/03/18 00:19:34 steve Exp $"
+#endif
+
+# include  "pointers.h"
+
+/*
+ * The .ufunc statement creates functors to represent user defined
+ * functions. The function device itself is implemented as a thread
+ * with a bunch of functors for the output bits. This thread has a set
+ * of outputs, represented by output_functors and a set of inputs
+ * connected to input functors. The input functors detect that a
+ * change has occurred, and invoke the thread to process the new
+ * values. The relationships work like this:
+ *
+ *  ufunc_input_functor_s --+--> ufunc_core --+--> ufunc_output_functor_s
+ *                          |                 |
+ *  ufunc_input_functor_s --+                 +--> ufunc_output_functor_s
+ *                          |
+ *  ufunc_input_functor_s --+
+ */
+
+class ufunc_core {
+
+    public:
+      ufunc_core(unsigned ow, vvp_ipoint_t ob, vvp_ipoint_t*op,
+		 unsigned np, vvp_ipoint_t*p,
+		 vvp_cpoint_t start_address,
+		 struct __vpiScope*run_scope);
+      ~ufunc_core();
+
+      void set_bit(unsigned port_idx, unsigned val);
+
+      void assign_bits_to_ports();
+      void finish_thread(vthread_t thr);
+
+      struct __vpiScope*scope() { return scope_; }
+
+    private:
+	// The owid_ and obase_ point to the functor vector that makes
+	// up the output of the function.
+      unsigned owid_;
+      vvp_ipoint_t obase_;
+      vvp_ipoint_t*oports_;
+	// Keep an array of vvp_ipoint_t pointers that point to .var
+	// functors. These are the input ports of the function.
+      unsigned nports_;
+      vvp_ipoint_t*ports_;
+	// This is a thread to execute the behavioral portion of the
+	// function.
+      vthread_t thread_;
+      struct __vpiScope*scope_;
+      vvp_cpoint_t code_;
+
+	// Save the input bits as I receive them.
+      unsigned char*ibits_;
+};
+
+/*
+ * $Log: ufunc.h,v $
+ * Revision 1.1  2002/03/18 00:19:34  steve
+ *  Add the .ufunc statement.
+ *
+ */
+#endif
diff --git a/vvp/vthread.cc b/vvp/vthread.cc
index 51429d27f..68b65824e 100644
--- a/vvp/vthread.cc
+++ b/vvp/vthread.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: vthread.cc,v 1.66 2002/01/26 02:08:07 steve Exp $"
+#ident "$Id: vthread.cc,v 1.67 2002/03/18 00:19:34 steve Exp $"
 #endif
 
 # include  "vthread.h"
@@ -25,6 +25,7 @@
 # include  "debug.h"
 # include  "schedule.h"
 # include  "functor.h"
+# include  "ufunc.h"
 # include  "event.h"
 # include  "vpi_priv.h"
 #ifdef HAVE_MALLOC_H
@@ -1716,8 +1717,41 @@ bool of_ZOMBIE(vthread_t thr, vvp_code_t)
       return false;
 }
 
+/*
+ * This is a phantom opcode used to call user defined functions. It is
+ * used in code generated by the .ufunc statement. This instruction
+ * contains a pointer to executable code of the function, and to a
+ * ufunc_core object that has all the port information about the
+ * function.
+ */
+bool of_CALL_UFUNC(vthread_t thr, vvp_code_t cp)
+{
+	/* Copy all the inputs to the ufunc object to the port
+	   variables of the function. This copies all the values
+	   atomically. */
+      cp->ufunc_core_ptr->assign_bits_to_ports();
+
+	/* Create a temporary thread, and execute it manually. This is
+	   necessary so that the previous step (assign_bits_to_ports)
+	   and the execution of the function itself are an atomic
+	   unit. If it were not, then the inputs might change between
+	   setup and execution, causing really bad things to happen. */
+      vthread_t child = vthread_new(cp->cptr, cp->ufunc_core_ptr->scope());
+      vthread_mark_scheduled(child);
+      vthread_run(child);
+
+	/* Now copy the output from the result variable to the output
+	   ports of the .ufunc device. */
+      cp->ufunc_core_ptr->finish_thread(thr);
+
+      return true;
+}
+
 /*
  * $Log: vthread.cc,v $
+ * Revision 1.67  2002/03/18 00:19:34  steve
+ *  Add the .ufunc statement.
+ *
  * Revision 1.66  2002/01/26 02:08:07  steve
  *  Handle x in l-value of set/x
  *
@@ -1825,63 +1859,5 @@ bool of_ZOMBIE(vthread_t thr, vvp_code_t)
  *  Add strengths to functors at compile time,
  *  and Make functors pass their strengths as they
  *  propagate their output.
- *
- * Revision 1.36  2001/05/06 17:42:22  steve
- *  Add the %ix/get instruction. (Stephan Boettcher)
- *
- * Revision 1.35  2001/05/05 23:55:46  steve
- *  Add the beginnings of an interactive debugger.
- *
- * Revision 1.34  2001/05/02 23:16:50  steve
- *  Document memory related opcodes,
- *  parser uses numbv_s structures instead of the
- *  symbv_s and a mess of unions,
- *  Add the %is/sub instruction.
- *        (Stephan Boettcher)
- *
- * Revision 1.33  2001/05/02 01:57:26  steve
- *  Support behavioral subtraction.
- *
- * Revision 1.32  2001/05/02 01:37:38  steve
- *  initialize is_schedule.
- *
- * Revision 1.31  2001/05/01 05:00:02  steve
- *  Implement %ix/load.
- *
- * Revision 1.30  2001/05/01 01:09:39  steve
- *  Add support for memory objects. (Stephan Boettcher)
- *
- * Revision 1.29  2001/04/21 00:34:39  steve
- *  Working %disable and reap handling references from scheduler.
- *
- * Revision 1.28  2001/04/18 05:04:19  steve
- *  %end complete the %join for the parent.
- *
- * Revision 1.27  2001/04/18 04:21:23  steve
- *  Put threads into scopes.
- *
- * Revision 1.26  2001/04/15 16:37:48  steve
- *  add XOR support.
- *
- * Revision 1.25  2001/04/15 04:07:56  steve
- *  Add support for behavioral xnor.
- *
- * Revision 1.24  2001/04/14 05:10:05  steve
- *  Initialize the waiting_for_event member.
- *
- * Revision 1.23  2001/04/13 03:55:18  steve
- *  More complete reap of all threads.
- *
- * Revision 1.22  2001/04/05 01:12:28  steve
- *  Get signed compares working correctly in vvp.
- *
- * Revision 1.21  2001/04/03 03:18:34  steve
- *  support functor_set push for blocking assignment.
- *
- * Revision 1.20  2001/04/01 22:25:33  steve
- *  Add the reduction nor instruction.
- *
- * Revision 1.19  2001/04/01 07:22:08  steve
- *  Implement the less-then and %or instructions.
  */