[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

@@ -141,33 +141,6 @@ int bdd_anodecountpp(const bdd *r, int num)
    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

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 *}