[buddy] Inline the "is bdd constant" check performed in copies/constructors.

This avoids a library call to bdd_addref or bdd_delref.

* src/kernel.c (bdd_delref_nc, bdd_addref_nc): New function,
that work only on BDD that are not constant.
* src/cpext.cxx (bdd::operator=): Move...
* src/bdd.hh (bdd::operator=): ... here.
(bdd::bdd, bdd::~bdd, bdd::operator=): Inline the "is bdd constant"
check and call bdd_delref_nc/bdd_addref_nc only otherwise.

buddy/ChangeLog

@@ -1,3 +1,16 @@
+2011-04-30  Alexandre Duret-Lutz  <adl@lrde.epita.fr>
+
+	Inline the "is bdd constant" check performed in copies/constructors.
+
+	This avoids a library call to bdd_addref or bdd_delref.
+
+	* src/kernel.c (bdd_delref_nc, bdd_addref_nc): New function,
+	that work only on BDD that are not constant.
+	* src/cpext.cxx (bdd::operator=): Move...
+	* src/bdd.hh (bdd::operator=): ... here.
+	(bdd::bdd, bdd::~bdd, bdd::operator=): Inline the "is bdd constant"
+	check and call bdd_delref_nc/bdd_addref_nc only otherwise.
+
 2011-04-30  Alexandre Duret-Lutz  <adl@lrde.epita.fr>
 
 	Hint gcc about likely/unlikely branches.

buddy/src/bdd.h

@@ -272,7 +272,9 @@ extern int      bdd_var(BDD) __purefn;
 extern BDD      bdd_low(BDD) __purefn;
 extern BDD      bdd_high(BDD) __purefn;
 extern int      bdd_varlevel(int) __purefn;
+extern BDD      bdd_addref_nc(BDD);
 extern BDD      bdd_addref(BDD);
+extern BDD      bdd_delref_nc(BDD);
 extern BDD      bdd_delref(BDD);
 extern void     bdd_gbc(void);
 extern int      bdd_scanset(BDD, int**, int*);
@@ -453,8 +455,8 @@ class bdd
  public:
 
    bdd(void)         { root=0; }
-   bdd(const bdd &r) { bdd_addref(root=r.root); }
+   bdd(const bdd &r) { root=r.root; if (root > 1) bdd_addref_nc(root); }
-   ~bdd(void)        { bdd_delref(root); }
+   ~bdd(void)        { if (root > 1) bdd_delref_nc(root); }
 
    int id(void) const;
 
@@ -481,7 +483,7 @@ class bdd
 private:
    BDD root;
 
-   bdd(BDD r) { bdd_addref(root=r); }
+   bdd(BDD r) { root=r; if (root > 1) bdd_addref_nc(root); }
    bdd operator=(BDD r);
 
    friend int      bdd_init(int, int);
@@ -849,6 +851,32 @@ inline int bdd::operator==(const bdd &r) const
 inline int bdd::operator!=(const bdd &r) const
 { return r.root!=root; }
 
+inline bdd bdd::operator=(const bdd &r)
+{
+  if (__likely(root != r.root))
+    {
+      if (root > 1)
+	bdd_delref_nc(root);
+      root = r.root;
+      if (root > 1)
+	bdd_addref_nc(root);
+    }
+  return *this;
+}
+
+inline bdd bdd::operator=(int r)
+{
+  if (__likely(root != r))
+    {
+      if (root > 1)
+	bdd_delref_nc(root);
+      root = r;
+      if (root > 1)
+	bdd_addref_nc(root);
+    }
+  return *this;
+}
+
 inline bdd bdd_true(void)
 { return 1; }
 

buddy/src/cppext.cxx

@@ -81,7 +81,7 @@ static bddstrmhandler strmhandler_fdd;
 int bdd_cpp_init(int n, int c)
 {
    int ok = bdd_init(n,c);
-   
+
    strmhandler_bdd = NULL;
    strmhandler_fdd = NULL;
 
@@ -115,11 +115,11 @@ int bdd_setbddpairs(bddPair *pair, int *oldvar, const bdd *newvar, int size)
 {
    if (pair == NULL)
       return 0;
-   
+
    for (int n=0,e=0 ; n<size ; n++)
       if ((e=bdd_setbddpair(pair, oldvar[n], newvar[n].root)) < 0)
 	 return e;
-   
+
    return 0;
 }
 
@@ -135,39 +135,12 @@ int bdd_anodecountpp(const bdd *r, int num)
       cpr[n] = r[n].root;
 
    cou = bdd_anodecount(cpr,num);
-   
+
    free(cpr);
 
    return cou;
 }
 
-/*************************************************************************
-  BDD class functions
-*************************************************************************/
-
-bdd bdd::operator=(const bdd &r)
-{
-   if (root != r.root)
-   {
-      bdd_delref(root);
-      root = r.root;
-      bdd_addref(root);
-   }
-   return *this;
-}
-
-
-bdd bdd::operator=(int r)
-{
-   if (root != r)
-   {
-      bdd_delref(root);
-      root = r;
-      bdd_addref(root);
-   }
-   return *this;
-}
-
 
 /*************************************************************************
   C++ iostream operators
@@ -216,14 +189,14 @@ ostream &operator<<(ostream &o, const bdd &r)
 	 o << (r.root == 0 ? "F" : "T");
 	 return o;
       }
-      
+
       int *set = new int[bddvarnum];
       if (set == NULL)
       {
 	 bdd_error(BDD_MEMORY);
 	 return o;
       }
-      
+
       memset(set, 0, sizeof(int) * bddvarnum);
       bdd_printset_rec(o, r.root, set);
       delete[] set;
@@ -234,7 +207,7 @@ ostream &operator<<(ostream &o, const bdd &r)
       o << "ROOT: " << r.root << "\n";
       if (r.root < 2)
 	 return o;
-      
+
       bdd_mark(r.root);
 
       for (int n=0 ; n<bddnodesize ; n++)
@@ -242,7 +215,7 @@ ostream &operator<<(ostream &o, const bdd &r)
 	 if (LEVEL(n) & MARKON)
 	 {
 	    BddNode *node = &bddnodes[n];
-	 
+
 	    LEVELp(node) &= MARKOFF;
 
 	    o << "[" << setw(5) << n << "] ";
@@ -263,9 +236,9 @@ ostream &operator<<(ostream &o, const bdd &r)
       o << "digraph G {\n";
       o << "0 [shape=box, label=\"0\", style=filled, shape=box, height=0.3, width=0.3];\n";
       o << "1 [shape=box, label=\"1\", style=filled, shape=box, height=0.3, width=0.3];\n";
-      
+
       bdd_printdot_rec(o, r.root);
-      
+
       o << "}\n";
 
       bdd_unmark(r.root);
@@ -278,19 +251,19 @@ ostream &operator<<(ostream &o, const bdd &r)
 	 o << (r == 0 ? "F" : "T");
 	 return o;
       }
-      
+
       int *set = new int[bddvarnum];
       if (set == NULL)
       {
 	 bdd_error(BDD_MEMORY);
 	 return o;
       }
-      
+
       memset(set, 0, sizeof(int) * bddvarnum);
       fdd_printset_rec(o, r.root, set);
       delete[] set;
    }
-   
+
    return o;
 }
 
@@ -333,7 +306,7 @@ ostream &operator<<(ostream &o, const bdd_ioformat &f)
       for (int n=0 ; n<bddnodesize ; n++)
       {
 	 const BddNode *node = &bddnodes[n];
-	 
+
 	 if (LOWp(node) != -1)
 	 {
 	    o << "[" << setw(5) << n << "] ";
@@ -347,7 +320,7 @@ ostream &operator<<(ostream &o, const bdd_ioformat &f)
 	 }
       }
    }
-   
+
    return o;
 }
 
@@ -356,7 +329,7 @@ static void bdd_printset_rec(ostream& o, int r, int* set)
 {
    int n;
    int first;
-   
+
    if (r == 0)
       return;
    else
@@ -364,7 +337,7 @@ static void bdd_printset_rec(ostream& o, int r, int* set)
    {
       o << "<";
       first = 1;
-      
+
       for (n=0 ; n<bddvarnum ; n++)
       {
 	 if (set[n] > 0)
@@ -386,10 +359,10 @@ static void bdd_printset_rec(ostream& o, int r, int* set)
    {
       set[LEVEL(r)] = 1;
       bdd_printset_rec(o, LOW(r), set);
-      
+
       set[LEVEL(r)] = 2;
       bdd_printset_rec(o, HIGH(r), set);
-      
+
       set[LEVEL(r)] = 0;
    }
 }
@@ -410,7 +383,7 @@ static void bdd_printdot_rec(ostream& o, int r)
    o << r << " -> " << HIGH(r) << "[style=filled];\n";
 
    SETMARK(r);
-   
+
    bdd_printdot_rec(o, LOW(r));
    bdd_printdot_rec(o, HIGH(r));
 }
@@ -422,7 +395,7 @@ static void fdd_printset_rec(ostream &o, int r, int *set)
    int used = 0;
    int *binval;
    int ok, first;
-   
+
    if (r == 0)
       return;
    else
@@ -431,18 +404,18 @@ static void fdd_printset_rec(ostream &o, int r, int *set)
       o << "<";
       first=1;
       int fdvarnum = fdd_domainnum();
-	 
+
       for (n=0 ; n<fdvarnum ; n++)
       {
 	 int firstval=1;
 	 used = 0;
 	 int binsize = fdd_varnum(n);
 	 int *vars = fdd_vars(n);
-	 
+
 	 for (m=0 ; m<binsize ; m++)
 	    if (set[vars[m]] != 0)
 	       used = 1;
-	 
+
 	 if (used)
 	 {
 	    if (!first)
@@ -458,7 +431,7 @@ static void fdd_printset_rec(ostream &o, int r, int *set)
 	    {
 	       binval = fdddec2bin(n, m);
 	       ok=1;
-	       
+
 	       for (i=0 ; i<binsize && ok ; i++)
 		  if (set[vars[i]] == 1  &&  binval[i] != 0)
 		     ok = 0;
@@ -486,10 +459,10 @@ static void fdd_printset_rec(ostream &o, int r, int *set)
    {
       set[bddlevel2var[LEVEL(r)]] = 1;
       fdd_printset_rec(o, LOW(r), set);
-      
+
       set[bddlevel2var[LEVEL(r)]] = 2;
       fdd_printset_rec(o, HIGH(r), set);
-      
+
       set[bddlevel2var[LEVEL(r)]] = 0;
    }
 }
@@ -581,7 +554,7 @@ bvec bvec_map2(const bvec &a, const bvec &b,
       bdd_error(BVEC_SIZE);
       return res;
    }
-   
+
    res = bvec_false(a.bitnum());
    for (n=0 ; n < a.bitnum() ; n++)
       res.set(n, fun(a[n], b[n]));
@@ -601,7 +574,7 @@ bvec bvec_map3(const bvec &a, const bvec &b, const bvec &c,
       bdd_error(BVEC_SIZE);
       return res;
    }
-   
+
    res = bvec_false(a.bitnum());
    for (n=0 ; n < a.bitnum() ; n++)
       res.set(n, fun(a[n], b[n], c[n]) );

buddy/src/kernel.c

@@ -1102,6 +1102,20 @@ void bdd_gbc(void)
 }
 
 
+BDD bdd_addref_nc(BDD root)
+{
+#ifndef NDEBUG
+   if (!bddrunning)
+      return root;
+   if (root < 2 || root >= bddnodesize)
+      return bdd_error(BDD_ILLBDD);
+   if (LOW(root) == -1)
+      return bdd_error(BDD_ILLBDD);
+#endif
+   INCREF(root);
+   return root;
+}
+
 /*
 NAME    {* bdd\_addref *}
 SECTION {* kernel *}
@@ -1131,6 +1145,23 @@ BDD bdd_addref(BDD root)
    return root;
 }
 
+// Non constant version
+BDD bdd_delref_nc(BDD root)
+{
+#ifndef NDEBUG
+   if (root < 2  ||  !bddrunning)
+      return root;
+   if (root >= bddnodesize)
+      return bdd_error(BDD_ILLBDD);
+   if (LOW(root) == -1)
+      return bdd_error(BDD_ILLBDD);
+
+   /* if the following line is present, fails there much earlier */
+   if (!HASREF(root)) bdd_error(BDD_BREAK); /* distinctive */
+#endif
+   DECREF(root);
+   return root;
+}
 
 /*
 NAME    {* bdd\_delref *}