[Xsb-commits] CVS: XSB/emu builtin.c,1.141,1.142 builtin.h,1.44,1.45 complete_local.h,1.5,1.6 complete_xsb_i.h,1.18,1.19 debug_xsb.c,1.16,1.17 emudef.h,1.32,1.33 inst_xsb.c,1.13,1.14 io_builtins_xsb.c,1.23,1.24 io_builtins_xsb.h,1.1,1.2 remove_unf.c,1.1,1.2 subinst.h,1.3,1.4 subp.c,1.60,1.61

[Terrance S. <ts...@us...>]

Update of /cvsroot/xsb/XSB/emu
In directory usw-pr-cvs1:/tmp/cvs-serv741

Modified Files:
	builtin.c builtin.h complete_local.h complete_xsb_i.h 
	debug_xsb.c emudef.h inst_xsb.c io_builtins_xsb.c 
	io_builtins_xsb.h remove_unf.c subinst.h subp.c 
Log Message:

Changes for profiling routine: spitOutGraph(), some changes for
remove_unf_set pre-implementation, and a little documentation here and
there.



Index: builtin.c
===================================================================
RCS file: /cvsroot/xsb/XSB/emu/builtin.c,v
retrieving revision 1.141
retrieving revision 1.142
diff -u -r1.141 -r1.142
--- builtin.c	13 Mar 2002 22:40:13 -0000	1.141
+++ builtin.c	20 May 2002 17:47:09 -0000	1.142
@@ -906,88 +906,6 @@
 }
 #endif
 
-/*----------------------- write_quotedname/2 ---------------------------*/
-
-static xsbBool no_quotes_needed(char *string)
-{
-  int nextchar;
-  int ctr, flag;
-
-  ctr = 0;
-  nextchar = (int) string[0];
-  flag = 0;
-  if (nextchar >= 97 && nextchar <= 122) {    /* 0'a=97, 0'z=122  */
-    while (nextchar != '\0' && !flag) {
-      if (nextchar < 48 
-	  || (nextchar > 57 && nextchar < 65)
-	  || ((nextchar > 90 && nextchar < 97) && nextchar != 95)
-	  || (nextchar > 122))
-	flag = 1;
-      ctr++;
-      nextchar = (int) string[ctr];
-    }
-    if (!flag) return FALSE;
-  }
-
-  if (string[1] == '\0') {
-    if ((int) string[0] == 33 /*--- || (int) string[0] == 59 ---*/)
-      return FALSE;
-    if ((int) string[0] == 46) return TRUE;
-  }
-
-  nextchar = (int) string[0];
-  ctr = 0; 
-  while (nextchar != '\0' && !flag) {
-    switch(nextchar) {
-    case 35: case 36: case 38: case 42: case 43: case 45: case 46:
-    case 47: case 58: case 60: case 61: case 62: case 63: case 64: 
-    case 92: case 94: case 96: case 126:
-      nextchar++;
-      break;
-    default: 
-      flag = 1;
-    }
-    ctr++;
-    nextchar = (int) string[ctr];
-  }
-  return flag;
-}
-
-static void double_quotes(char *string, char *new_string)
-{
-  int ctr = 0, nctr = 0;
-
-  while (string[ctr] != '\0') {
-    if (string[ctr] == 39) {
-      new_string[nctr] = 39;
-      nctr++;
-    }
-    new_string[nctr] = string[ctr];
-    nctr++; ctr++;
-  }
-  new_string[nctr] = '\0';
-}
-
-static void write_quotedname(FILE *file, char *string)
-{
-  char* new_string;
-
-  new_string  = (char *)malloc(2*(strlen(string))+1);
-
-  if (*string == '\0') 
-    fprintf(file,"''");
-  else {
-    if (!no_quotes_needed(string)) {
-      fprintf(file,"%s",string);
-    }
-    else {
-      double_quotes(string,new_string);
-      fprintf(file,"\'%s\'",new_string);
-    }
-  }
-
-  free(new_string);
-}
 
 /*----------------------------------------------------------------------*/
 

Index: builtin.h
===================================================================
RCS file: /cvsroot/xsb/XSB/emu/builtin.h,v
retrieving revision 1.44
retrieving revision 1.45
diff -u -r1.44 -r1.45
--- builtin.h	13 Mar 2002 22:40:13 -0000	1.44
+++ builtin.h	20 May 2002 17:47:09 -0000	1.45
@@ -226,6 +226,7 @@
 #define UNWIND_STACK            233
 #define CLEAN_UP_BLOCK          234
 
+#define DUMMY                   235
 /* added by Bart Demoen & Kostis Sagonas for debugging and convenience */
 #define PRINT_LS                240
 #define PRINT_TR                241
@@ -245,3 +246,36 @@
 
 /* This hook is for Interprolog */
 #define INTERPROLOG_CALLBACK    255
+
+#define PLUS_FUNCT 1
+#define MINUS_FUNCT 2
+#define TIMES_FUNCT 3
+#define DIV_FUNCT 4
+#define BITAND_FUNCT 5
+#define BITOR_FUNCT 6
+
+#define BITNOT_FUNCT 7
+#define IDIV_FUNCT 8
+
+#define SIN_FUNCT 9
+#define COS_FUNCT 10
+#define TAN_FUNCT 11
+
+#define FLOAT_FUNCT 13
+#define FLOOR_FUNCT 14
+#define EXP_FUNCT 15
+#define LOG_FUNCT 16
+#define LOG10_FUNCT 17
+#define SQRT_FUNCT 18
+#define ASIN_FUNCT 19
+#define ACOS_FUNCT 20
+#define ATAN_FUNCT 21
+#define ABS_FUNCT 22
+#define TRUNC_FUNCT 23
+#define ROUND_FUNCT 24
+#define CEIL_FUNCT 25
+
+#define BITSHIFTL_FUNCT 26
+#define BITSHIFTR_FUNCT 27
+#define UMINUS_FUNCT 28
+

Index: complete_local.h
===================================================================
RCS file: /cvsroot/xsb/XSB/emu/complete_local.h,v
retrieving revision 1.5
retrieving revision 1.6
diff -u -r1.5 -r1.6
--- complete_local.h	12 Mar 2002 17:31:21 -0000	1.5
+++ complete_local.h	20 May 2002 17:47:09 -0000	1.6
@@ -88,6 +88,86 @@
 #define ProfileLeader
 #endif
 
+
+
+/* The following function writes the SDG to stddbg.  The SDG is
+written every "std_sample_rate" times the computation determines that
+it is checking completion for a leader.  If so, the opentable stack is
+traversed along with the various lists hanging off of the subgoal
+frames.  For each edge in the SDG a Prolog-readible fact is written
+
+edge(sdg_check_num,Type,Root_subgoal,Selected_tabled_subgoal)
+
+sdg_check_num is the number of the check.  Using sdg_check_num one can
+get a somewhat dynamic view of how the SDG changes over the
+computation.
+
+Type = 1 if it is a positive link (consumer choice point)
+Type = -1 if it is a negative link to a completion suspension choice point
+Type = 2 if it is the first call (generator cp is used here).  
+
+Right now, there isnt a good way of determining whether the first call
+of a tabled predicate is positive or negative.  So its best to table
+tnot/1 in tables.P if you want to keep full track of signs */
+
+#ifdef PROFILE
+void print_sdg_edge(int check_num,int sign,VariantSF fromsf,VariantSF tosf)
+{
+  fprintf(stddbg,"edge(%d,%d,",check_num,sign);   
+  print_subgoal(stddbg,fromsf); fprintf(stddbg,",");
+  print_subgoal(stddbg,tosf); fprintf(stddbg,").\n");
+}
+
+void SpitOutGraph(CPtr cs_ptr)
+{ 
+  CPtr tmp_openreg = cs_ptr;
+  CPtr nsf;
+  int num_subgoals = 0; 
+  VariantSF prof_compl_subg; 
+  
+  sdg_check_num++; 
+  if (sdg_sample_rate > 0 && (sdg_check_num % sdg_sample_rate == 0)) { 
+    printf(" /* now checking: %d */ \n",sdg_check_num);
+    while (tmp_openreg < COMPLSTACKBOTTOM) {
+      num_subgoals++;
+      prof_compl_subg = compl_subgoal_ptr(tmp_openreg);
+
+      fprintf(stddbg,"   /* ");
+      print_subgoal(stddbg, prof_compl_subg); 
+      fprintf(stddbg," */ \n");
+
+      if (tcp_ptcp(subg_cp_ptr(prof_compl_subg)) != NULL ) {
+      print_sdg_edge(sdg_check_num,2,
+		     tcp_ptcp(subg_cp_ptr(prof_compl_subg)),
+		     prof_compl_subg);
+      } else {
+      }
+
+      nsf = subg_asf_list_ptr(prof_compl_subg); 
+      while (nsf != NULL) {
+
+	print_sdg_edge(sdg_check_num,1,nlcp_ptcp(nsf),prof_compl_subg);
+
+	nsf = nlcp_prevlookup(nsf); 
+      }
+
+      nsf = subg_compl_susp_ptr(prof_compl_subg); 
+      while (nsf != NULL) {
+
+	print_sdg_edge(sdg_check_num,-1,csf_ptcp(nsf),prof_compl_subg);
+
+	nsf = csf_prevcsf(nsf); 
+      }
+
+      tmp_openreg = prev_compl_frame(tmp_openreg);
+    }
+    /*    printf("doing checking %d %d \n",sdg_check_num,num_subgoals); */
+  } 
+}
+#else
+#define SpitOutGraph
+#endif
+
 #ifdef LOCAL_EVAL
 #define DisposeOfComplSusp(subgoal) \
         subg_compl_susp_ptr(subgoal) = NULL
@@ -188,6 +268,12 @@
     ComplStkFrame = next_compl_frame(ComplStkFrame);
   } /* while */
   
+  /* TLS: placemarker while I develop it.  This function should happen
+   *after* simplification and *before* removal of answer lists, which
+   is useful for traversing dependency graphs. */
+
+  /*  remove_unfounded_set(cs_ptr); */
+      
   /* reclaim all answer lists, but the one for the leader */
   ComplStkFrame = next_compl_frame(cs_ptr);
   while (ComplStkFrame >= openreg) {

Index: complete_xsb_i.h
===================================================================
RCS file: /cvsroot/xsb/XSB/emu/complete_xsb_i.h,v
retrieving revision 1.18
retrieving revision 1.19
diff -u -r1.18 -r1.19
--- complete_xsb_i.h	12 Mar 2002 17:31:21 -0000	1.18
+++ complete_xsb_i.h	20 May 2002 17:47:09 -0000	1.19
@@ -73,8 +73,8 @@
     /* The following code is only done in profile mode; it keeps track
      * of characteristics of SCCs */
 
-    ProfileLeader;
-
+    /* ProfileLeader; */
+    /* SpitOutGraph(cs_ptr); */
     /* check if fixpoint has been reached, otherwise schedule any
      * unresolved answers */
     FailIfAnswersFound(check_fixpoint(subgoal,breg));
@@ -91,8 +91,6 @@
       
       CompleteSimplifyAndReclaim(cs_ptr);
 
-      remove_unfounded_set(cs_ptr);
-      
       /* leader has non-returned answers? */
       if (has_answer_code(subgoal) && (subg_answers(subgoal) > COND_ANSWERS)) {
 	reclaim_incomplete_table_structs(subgoal);

Index: debug_xsb.c
===================================================================
RCS file: /cvsroot/xsb/XSB/emu/debug_xsb.c,v
retrieving revision 1.16
retrieving revision 1.17
diff -u -r1.16 -r1.17
--- debug_xsb.c	12 Mar 2002 17:31:21 -0000	1.16
+++ debug_xsb.c	20 May 2002 17:47:09 -0000	1.17
@@ -28,6 +28,7 @@
 #include "xsb_debug.h"
 
 #include <stdio.h>
+#include <string.h>
 
 #include "auxlry.h"
 #include "cell_xsb.h"
@@ -42,6 +43,12 @@
 #include "choice.h"
 #include "macro_xsb.h"
 #include "inst_xsb.h"
+#include "debug_xsb.h"
+#include "token_xsb.h"
+#include "varstring_xsb.h"
+#include "cinterf.h"
+#include "io_defs_xsb.h"
+#include "io_builtins_xsb.h"
 
 #ifdef DEBUG
 #include "subp.h"
@@ -67,21 +74,6 @@
 
 /*----------------------------------------------------------------------*/
 
-#ifdef DEBUG
-#define STRIDESIZE     30
-
-#define EOS	"--------------------BOTTOM_OF_STACK--------------------\n"
-#define EOFR	"--------------------------------------------\n"
-#define EOSUBG	"------------------------------------------------------------\n"
-
-#define print_subg_header(SUBG) { \
-    fprintf(stddbg, "=== Frame for "); print_subgoal(stddbg, SUBG); \
-    if (is_completed(SUBG)) fprintf(stddbg, " (completed) ===\n"); \
-    else fprintf(stddbg, " (incomplete) ===\n"); }
-#endif
-
-/*----------------------------------------------------------------------*/
-
 static int count_producer_subgoals(void)
 {
   int i;
@@ -434,6 +426,7 @@
 
 static Cell cell_array[500];
 
+
 static void print_term_of_subgoal(FILE *fp, int *i)
 {
   Cell term;
@@ -446,7 +439,8 @@
     break;
   case XSB_STRUCT:
     args = get_arity((Psc)cs_val(term));
-    fprintf(fp, "%s", get_name((Psc)cs_val(term)));
+    write_quotedname(fp,     get_name((Psc)cs_val(term)));
+    /*    fprintf(fp, "%s", get_name((Psc)cs_val(term))); */
     if (args > 0) fprintf(fp, "(");
     for (j = args; j > 0; j--) {
       (*i)--;
@@ -473,7 +467,8 @@
     fprintf(fp, "]");
     break;
   case XSB_STRING:
-    fprintf(fp, "%s", string_val(term));
+    write_quotedname(fp,string_val(term));
+  /*    fprintf(fp, "%s", string_val(term));*/
     break;
   case XSB_INT:
     fprintf(fp, "%d", int_val(term));
@@ -499,7 +494,8 @@
   for (leaf = subg_leaf_ptr(subg); leaf != NULL; leaf = Parent(leaf)) {
     cell_array[i++] = BTN_Symbol(leaf);
   }
-  fprintf(fp, "%s", get_name(psc));
+  write_quotedname(fp,     get_name(psc));
+  /*  fprintf(fp, "%s", get_name(psc)); */
   if (get_arity(psc) > 0) {
     fprintf(fp, "(");
     for (i = i-2; i >= 0 ; i--) {
@@ -1006,7 +1002,7 @@
 /*----------------------------------------------------------------------*/ 
 
 /* Needs to change when new xwam stacks are introduced.  */
-static void print_heap(int overlap)	/* Heap grows up */
+ void terry_print_heap(int overlap)	/* Heap grows up */
 {
   int i, offset = 0;
   char ans = 'y';
@@ -1034,13 +1030,6 @@
   }
 }
 
-/*----- For table debugging --------------------------------------------*/ 
-
-static char *compl_stk_frame_field[] = {
-  "subgoal_ptr", "level_num",
-  "del_ret_list", "visited", "DG_edges", "DGT_edges"
-};
-
 /*----------------------------------------------------------------------*/
 
 void print_completion_stack(void)
@@ -1400,7 +1389,7 @@
   case 'H':
     scanf("%d", &num);
     skip_to_nl();
-    print_heap(num);
+    terry_print_heap(num);
     goto again;
   case 'k':
     scanf("%d", &num);

Index: emudef.h
===================================================================
RCS file: /cvsroot/xsb/XSB/emu/emudef.h,v
retrieving revision 1.32
retrieving revision 1.33
diff -u -r1.32 -r1.33
--- emudef.h	13 Mar 2002 22:40:13 -0000	1.32
+++ emudef.h	20 May 2002 17:47:09 -0000	1.33
@@ -54,7 +54,7 @@
 CPtr openreg;
 CPtr root_address;
 
-CPtr ptcpreg;
+CPtr ptcpreg = NULL;
 CPtr delayreg;
 
 #ifdef DEMAND

Index: inst_xsb.c
===================================================================
RCS file: /cvsroot/xsb/XSB/emu/inst_xsb.c,v
retrieving revision 1.13
retrieving revision 1.14
diff -u -r1.13 -r1.14
--- inst_xsb.c	21 Sep 2001 15:01:15 -0000	1.13
+++ inst_xsb.c	20 May 2002 17:47:09 -0000	1.14
@@ -35,16 +35,20 @@
 extern void init_builtin_table(void);
 
 #ifdef PROFILE
+
+/* Initialize this stuff for profiling.  In profiling, the number of
+   occurrences of each instruction can be counted, as well as
+   operations that happen within instructions, such as switch_envs,
+   and others.  Thus the instruction tables have an added field, to
+   keep the count.  In addition, statistics on SCCs can be derived and
+   the SDGs themselves printed out, if you like. */
+
 Cell inst_table[BUILTIN_TBL_SZ][6];
+
 unsigned long num_switch_envs;
 unsigned long num_switch_envs_iter;
 
 Cell subinst_table[BUILTIN_TBL_SZ][2];
-int max_subgoals = 0;
-int max_completed = 0;
-int max_consumers_in_ascc = 0;
-int max_compl_susps_in_ascc = 0;
-int trapped_prolog_cps = 0;
 
 #define XSB_INST(inum, inst, label, op1type, op2type, op3type, op4type) \
         inst_table[inst][0] = (Cell)( #inst ); \
@@ -60,6 +64,18 @@
 #define set_subinst_table(inst,instr) \
         subinst_table[inst][0] = (Cell)(instr); \
 	subinst_table[inst][1] = 0
+
+/* ProfileLeader */
+int max_subgoals = 0;
+int max_completed = 0;
+int max_consumers_in_ascc = 0;
+int max_compl_susps_in_ascc = 0;
+int trapped_prolog_cps = 0;
+
+/* SpitOutGraph */
+int sdg_sample_rate = 2000;
+int sdg_check_num = 0;
+
 #else
 Cell inst_table[BUILTIN_TBL_SZ][5];
 

Index: io_builtins_xsb.c
===================================================================
RCS file: /cvsroot/xsb/XSB/emu/io_builtins_xsb.c,v
retrieving revision 1.23
retrieving revision 1.24
diff -u -r1.23 -r1.24
--- io_builtins_xsb.c	23 Jan 2002 17:08:09 -0000	1.23
+++ io_builtins_xsb.c	20 May 2002 17:47:09 -0000	1.24
@@ -1309,3 +1309,87 @@
   return i;
 }
 
+
+/*----------------------- write_quotedname/2 ---------------------------*/
+
+xsbBool no_quotes_needed(char *string)
+{
+  int nextchar;
+  int ctr, flag;
+
+  ctr = 0;
+  nextchar = (int) string[0];
+  flag = 0;
+  if (nextchar >= 97 && nextchar <= 122) {    /* 0'a=97, 0'z=122  */
+    while (nextchar != '\0' && !flag) {
+      if (nextchar < 48 
+	  || (nextchar > 57 && nextchar < 65)
+	  || ((nextchar > 90 && nextchar < 97) && nextchar != 95)
+	  || (nextchar > 122))
+	flag = 1;
+      ctr++;
+      nextchar = (int) string[ctr];
+    }
+    if (!flag) return FALSE;
+  }
+
+  if (string[1] == '\0') {
+    if ((int) string[0] == 33 /*--- || (int) string[0] == 59 ---*/)
+      return FALSE;
+    if ((int) string[0] == 46) return TRUE;
+  }
+
+  nextchar = (int) string[0];
+  ctr = 0; 
+  while (nextchar != '\0' && !flag) {
+    switch(nextchar) {
+    case 35: case 36: case 38: case 42: case 43: case 45: case 46:
+    case 47: case 58: case 60: case 61: case 62: case 63: case 64: 
+    case 92: case 94: case 96: case 126:
+      nextchar++;
+      break;
+    default: 
+      flag = 1;
+    }
+    ctr++;
+    nextchar = (int) string[ctr];
+  }
+  return flag;
+}
+
+
+void double_quotes(char *string, char *new_string)
+{
+  int ctr = 0, nctr = 0;
+
+  while (string[ctr] != '\0') {
+    if (string[ctr] == 39) {
+      new_string[nctr] = 39;
+      nctr++;
+    }
+    new_string[nctr] = string[ctr];
+    nctr++; ctr++;
+  }
+  new_string[nctr] = '\0';
+}
+
+void write_quotedname(FILE *file, char *string)
+{
+  char* new_string;
+
+  new_string  = (char *)malloc(2*(strlen(string))+1);
+
+  if (*string == '\0') 
+    fprintf(file,"''");
+  else {
+    if (!no_quotes_needed(string)) {
+      fprintf(file,"%s",string);
+    }
+    else {
+      double_quotes(string,new_string);
+      fprintf(file,"\'%s\'",new_string);
+    }
+  }
+
+  free(new_string);
+}

Index: io_builtins_xsb.h
===================================================================
RCS file: /cvsroot/xsb/XSB/emu/io_builtins_xsb.h,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -r1.1 -r1.2
--- io_builtins_xsb.h	25 Oct 1999 05:58:36 -0000	1.1
+++ io_builtins_xsb.h	20 May 2002 17:47:10 -0000	1.2
@@ -32,3 +32,7 @@
 extern FILE *open_files[];      /* Table of file pointers for open files */
 
 extern int xsb_intern_file(FILE *f, char *c);
+
+extern void write_quotedname(FILE *file, char *string);
+extern void double_quotes(char *string, char *new_string);
+extern xsbBool no_quotes_needed(char *string);

Index: remove_unf.c
===================================================================
RCS file: /cvsroot/xsb/XSB/emu/remove_unf.c,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -r1.1 -r1.2
--- remove_unf.c	5 Oct 2001 19:26:49 -0000	1.1
+++ remove_unf.c	20 May 2002 17:47:10 -0000	1.2
@@ -1,6 +1,52 @@
 
+#include <stdio.h>
+
 #include "xsb_config.h"
+#include "basictypes.h"
 #include "cell_xsb.h"
+#include "error_xsb.h"
+#include "psc_xsb.h"
+#include "tries.h"
+#include "macro_xsb.h"
+#include "debug_xsb.h"
+#include "register.h"
+
+#ifdef DEBUG
+void my_print_completion_stack(CPtr leader_ptr)
+{
+  int i = 0;
+  EPtr eptr;
+  VariantSF subg;
+  CPtr temp = openreg;
+
+  fprintf(stddbg,"openreg -> ");
+  while (temp < (leader_ptr + COMPLFRAMESIZE)) {
+    if ((i % COMPLFRAMESIZE) == 0) {
+      fprintf(stddbg,EOFR);	
+      subg = compl_subgoal_ptr(temp);
+      print_subg_header(subg);
+      printf("ans_list_ptr %x ans_list_tail %x\n",
+	     subg_ans_list_ptr(subg),
+	     subg_ans_list_tail(subg));
+    }
+    fprintf(stddbg,"Completion Stack %p: %lx\t(%s)",
+	    temp, *temp, compl_stk_frame_field[(i % COMPLFRAMESIZE)]);
+    /* only for batched
+    if ((i % COMPLFRAMESIZE) >= COMPLFRAMESIZE-2) {
+      for (eptr = (EPtr)*temp; eptr != NULL; eptr = next_edge(eptr)) {
+	fprintf(stddbg," --> %p", edge_to_node(eptr));
+	}
+    } */
+    fprintf(stddbg,"\n");
+    temp++; i++;
+  }
+  fprintf(stddbg, EOS);
+}
 
 void remove_unfounded_set(CPtr leader_ptr) {
+
+  my_print_completion_stack((CPtr) leader_ptr);
+
 }
+
+#endif

Index: subinst.h
===================================================================
RCS file: /cvsroot/xsb/XSB/emu/subinst.h,v
retrieving revision 1.3
retrieving revision 1.4
diff -u -r1.3 -r1.4
--- subinst.h	21 Sep 2001 15:01:15 -0000	1.3
+++ subinst.h	20 May 2002 17:47:10 -0000	1.4
@@ -33,12 +33,21 @@
 #define NEW_ANSWER_SIMPL_NEG_FAIL 13
 #define NEW_ANSWER_SIMPL_NEG_SUC 14
 
+/* The following global variables are used for ProfileLeader, and
+   represent summary statistics on the size and confomation of SCCs. */
+
 extern int max_subgoals;
 extern int max_completed;
 extern int max_consumers_in_ascc;
 extern int max_compl_susps_in_ascc;
 
 extern int trapped_prolog_cps;
+
+/* The following global variables are used for SpitOutGraph, which 
+   prints out the entire SDG */
+
+extern int sdg_sample_rate;
+extern int sdg_check_num;
 
 extern Cell subinst_table[256][2];
 

Index: subp.c
===================================================================
RCS file: /cvsroot/xsb/XSB/emu/subp.c,v
retrieving revision 1.60
retrieving revision 1.61
diff -u -r1.60 -r1.61
--- subp.c	12 Mar 2002 15:13:38 -0000	1.60
+++ subp.c	20 May 2002 17:47:10 -0000	1.61
@@ -311,6 +311,8 @@
 /* set interrupt code in reg 2 and return ep of interrupt handler.	*/
 /* the returned value is normally assigned to pcreg, so this is like	*/
 /* raising a trap.							*/
+/* Note that the interrupt handlers referred to by flags array values   */
+/* are set up on the Prolog side via set_inthandler/2                   */
 /*======================================================================*/
 
 Psc synint_proc(Psc psc, int intcode, byte *cur_inst)