add the fast dispatch option/feature

git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk@7950 626c5289-ae23-0410-ae9c-e8d60b6d4f22

SWIG/Source/Modules/main.cxx

@@ -59,6 +59,7 @@ static const char *usage1 = (const char*)"\
                        -features directors,autodoc=1      \n\
                        if not explicit value is given to the feature, a '1' is used \n\
      -fvirtual       - Compile in virtual elimination mode\n\
+     -fdispatch      - Use fast dispatch mode, which produces faster overload dispatcher code\n\
      -Fstandard      - Display error/warning messages in commonly used format\n\
      -Fmicrosoft     - Display error/warning messages in Microsoft format\n\
      -help           - This output\n\
@@ -388,6 +389,9 @@ void SWIG_getoptions(int argc, char *argv[])
 	  } else if (strcmp(argv[i],"-fvirtual") == 0) {
 	    Wrapper_virtual_elimination_mode_set(1);
 	    Swig_mark_arg(i);
+	  } else if (strcmp(argv[i],"-fdispatch") == 0) {
+	    Wrapper_fast_dispatch_mode_set(1);
+	    Swig_mark_arg(i);
 	  } else if (strcmp(argv[i],"-directors") == 0) {
 	    Hash *features_hash = Swig_cparse_features();
 	    String *name = NewString("");

SWIG/Source/Modules/overload.cxx

@@ -28,6 +28,13 @@ struct Overloaded {
   int        error;      /* Ambiguity error                    */
 };
 
+static int fast_dispatch_mode = 0;
+
+/* Set fast_dispatch_mode */
+void Wrapper_fast_dispatch_mode_set(int flag) {
+  fast_dispatch_mode = flag;
+}
+
 /* -----------------------------------------------------------------------------
  * Swig_overload_rank()
  *
@@ -290,9 +297,9 @@ Swig_overload_rank(Node *n, bool script_lang_wrapping) {
   return result;
 }
 
-/* -----------------------------------------------------------------------------
- * print_typecheck()
- * ----------------------------------------------------------------------------- */
+// /* -----------------------------------------------------------------------------
+//  * print_typecheck()
+//  * ----------------------------------------------------------------------------- */
 
 static bool
 print_typecheck(String *f, int j, Parm *pj) {
@@ -347,8 +354,159 @@ ReplaceFormat (const String_or_char *fmt, int j) {
  * the regular function arguments.
  * ----------------------------------------------------------------------------- */
 
+/*
+  Fast dispatch mechanism, provided by  Salvador Fandi~no Garc'ia (#930586).
+*/
+String *
+Swig_overload_dispatch_fast(Node *n, const String_or_char *fmt, int *maxargs) {
+  int i,j;
+  
+  *maxargs = 1;
+
+  String *f = NewString("");
+
+  /* Get a list of methods ranked by precedence values and argument count */
+  List *dispatch = Swig_overload_rank(n, true);
+  int   nfunc = Len(dispatch);
+
+  /* Loop over the functions */
+
+  for (i = 0; i < nfunc; i++) {
+    Node *ni = Getitem(dispatch,i);
+    Parm *pi = Getattr(ni,"wrap:parms");
+    int num_required = emit_num_required(pi);
+    int num_arguments = emit_num_arguments(pi);
+    if (num_arguments > *maxargs) *maxargs = num_arguments;
+    int varargs = emit_isvarargs(pi);    
+    
+    if (!varargs) {
+      if (num_required == num_arguments) {
+	Printf(f,"if (%s == %d) {\n", argc_template_string, num_required);
+      } else {
+	Printf(f,"if ((%s >= %d) && (%s <= %d)) {\n", 
+	       argc_template_string, num_required, 
+	       argc_template_string, num_arguments);
+      }
+    } else {
+      Printf(f,"if (%s >= %d) {\n", argc_template_string, num_required);
+    }
+
+    /* create a list with the wrappers that collide with the
+       current one based on argument number */
+    List *coll=NewList();
+    for (int k=i+1; k<nfunc; k++) {
+      Node *nk = Getitem(dispatch,k);
+      Parm *pk = Getattr(nk,"wrap:parms");
+      int nrk = emit_num_required(pk);
+      int nak = emit_num_arguments(pk);
+      if ((nrk>=num_required && nrk<=num_arguments) ||
+	  (nak>=num_required && nak<=num_arguments) ||
+	  (nrk<=num_required && nak>=num_arguments))
+	Append(coll, nk);
+    }
+
+    // printf("overload: %s coll=%d\n", Char(Getattr(n, "sym:name")), Len(coll));
+
+    int num_braces = 0;
+    bool test=(Len(coll)>0 && num_arguments);
+    if (test) {
+      Printf(f,"int _v=1;\n");
+    
+      j = 0;
+      Parm *pj = pi;
+      while (pj) {
+	if (checkAttribute(pj,"tmap:in:numinputs","0")) {
+	  pj = Getattr(pj,"tmap:in:next");
+	  continue;
+	}
+
+	String *tm = Getattr(pj,"tmap:typecheck");
+	if (tm) {
+	  /* normalise for comparison later */ 
+	  Replaceid(tm,Getattr(pj,"lname"),"_v");
+
+	  /* if all the wrappers have the same type check on this
+	     argument we can optimize it out */
+	  bool emitcheck=0;
+	  for (int k=0; k<Len(coll) && !emitcheck; k++) {
+	    Node *nk = Getitem(coll, k);
+	    Parm *pk = Getattr(nk,"wrap:parms");
+	    int nak=emit_num_arguments(pk);
+	    if (nak<=j)  continue;
+	    int l=0;
+	    Parm *pl=pk;
+	    /* finds arg j on the collider wrapper */
+	    while(pl && l<=j) {
+	      if (checkAttribute(pl,"tmap:in:numinputs","0")) {
+		pl = Getattr(pl,"tmap:in:next");
+		continue;
+	      }
+	      if (l==j) {
+		/* we are at arg j, so we compare the tmaps now */
+		String *tml = Getattr(pl, "tmap:typecheck");
+		/* normalise it before comparing */
+		if (tml) Replaceid(tml,Getattr(pl,"lname"),"_v");
+		if (!tml || Cmp(tm, tml)) emitcheck=1;
+		//printf("tmap: %s[%d] (%d) => %s\n\n",
+		//       Char(Getattr(nk, "sym:name")),
+		//       l, emitcheck, tml?Char(tml):0);
+	      }
+	      Parm *pl1 = Getattr(pl,"tmap:in:next");
+	      if (pl1) pl = pl1;
+	      else pl = nextSibling(pl);
+	      l++;
+	    }
+	  }
+
+	  if (emitcheck) {
+	    if (j >= num_required) {
+	      Printf(f, "if (%s > %d) {\n", argc_template_string, j);
+	      num_braces++;
+	    }
+	    String *tmp=NewStringf(argv_template_string, j);
+	    Replaceall(tm,"$input", tmp);
+	    Printv(f,"{\n",tm,"}\n",NIL);
+	    Printf(f, "if (!_v) goto fail_%s;\n", Getattr(ni, "wrap:name"));
+	  }
+	}
+	if (!Getattr(pj,"tmap:in:SWIGTYPE") && Getattr(pj,"tmap:typecheck:SWIGTYPE")) {
+	  /* we emit  a warning if the argument defines the 'in' typemap, but not the 'typecheck' one */
+	  Swig_warning(WARN_TYPEMAP_TYPECHECK_UNDEF, Getfile(ni), Getline(ni),
+		       "Overloaded %s(%s) with no explicit typecheck typemap for arg %d of type '%s'\n", 
+		       Getattr(n,"name"),ParmList_str_defaultargs(pi),
+		       j+1, SwigType_str(Getattr(pj,"type"),0));
+	}
+	Parm *pj1 = Getattr(pj,"tmap:in:next");
+	if (pj1) pj = pj1;
+	else pj = nextSibling(pj);
+	j++;
+      }
+    }
+
+    /* close braces */
+    for (/* empty */; num_braces > 0; num_braces--) Printf(f, "}\n");
+
+
+    String *lfmt = ReplaceFormat (fmt, num_arguments);
+    Printf(f, Char(lfmt),Getattr(ni,"wrap:name"));
+
+    Printf(f,"}\n"); /* braces closes "if" for this method */
+    Printf(f, "fail_%s:\n\n", Getattr(ni,"wrap:name"));
+
+    Delete (lfmt);
+    Delete(coll);
+  }
+  Delete(dispatch);
+  return f;
+}
+
 String *
 Swig_overload_dispatch(Node *n, const String_or_char *fmt, int *maxargs) {
+
+  if (fast_dispatch_mode  || GetFlag(n,"feature:fastdispatch")) {
+    return Swig_overload_dispatch_fast(n, fmt, maxargs);
+  }
+  
   int i,j;
   
   *maxargs = 1;
@@ -423,7 +581,6 @@ Swig_overload_dispatch(Node *n, const String_or_char *fmt, int *maxargs) {
     for (/* empty */; num_braces > 0; num_braces--)
       Printf(f, "}\n");
     Printf(f,"}\n"); /* braces closes "if" for this method */
-    Delattr(ni,"wrap:parms");
   }
   Delete(dispatch);
   return f;

SWIG/Source/Modules/swigmod.h

@@ -350,6 +350,7 @@ int is_member_director(Node* member);
 void Wrapper_virtual_elimination_mode_set(int);
 void Wrapper_director_mode_set(int);
 void Wrapper_director_protected_mode_set(int);
+void Wrapper_fast_dispatch_mode_set(int);
 
 void clean_overloaded(Node *n);