[PPL-devel] [GIT] ppl/ppl(master): New constructor Bit_Row::Bit_Row(const Bit_Row& y, const Bit_Row& z).

[Roberto Bagnara]

Module: ppl/ppl
Branch: master
Commit: 03552e3fe4336c7c194c8b8decd092794e0977c8
URL:    http://www.cs.unipr.it/git/gitweb.cgi?p=ppl/ppl.git;a=commit;h=03552e3fe4336c7c194c8b8decd092794e0977c8

Author: Roberto Bagnara <bagnara at cs.unipr.it>
Date:   Mon Apr 20 14:43:58 2009 +0200

New constructor Bit_Row::Bit_Row(const Bit_Row& y, const Bit_Row& z).
Constructs an object containing the set-union of y and z.

---

 src/Bit_Row.cc         |   26 ++++++++++++++++++++++++++
 src/Bit_Row.defs.hh    |   13 +++++++++++++
 src/Bit_Row.inlines.hh |   14 ++++++++++++++
 3 files changed, 53 insertions(+), 0 deletions(-)

diff --git a/src/Bit_Row.cc b/src/Bit_Row.cc
index eee1cbf..e1d2e0f 100644
--- a/src/Bit_Row.cc
+++ b/src/Bit_Row.cc
@@ -376,3 +376,29 @@ PPL::Bit_Row::OK() const {
     && vec_alloc >= vec_size
     && (vec_size == 0 || mpz_getlimbn(vec, vec_size-1) != 0);
 }
+
+void
+PPL::Bit_Row::union_helper(const Bit_Row& y, const Bit_Row& z) {
+  mp_size_t y_size = y.vec->_mp_size;
+  mp_size_t z_size = z.vec->_mp_size;
+  assert(y_size <= z.size);
+  assert(vec->_mp_alloc >= z.size);
+  vec->_mp_size = z_size;
+  mp_srcptr yp = y.vec->_mp_d;
+  mp_srcptr zp = z.vec->_mp_d;
+  mp_ptr p = vec->_mp_d;
+  z_size -= y_size;
+  while (y_size > 0) {
+    *p = *yp | * zp;
+    ++yp;
+    ++zp;
+    ++p;
+    --y_size;
+  }
+  while (z_size > 0) {
+    *p = *zp;
+    ++zp;
+    ++p;
+    --z_size;
+  }
+}
diff --git a/src/Bit_Row.defs.hh b/src/Bit_Row.defs.hh
index 613046e..ce278c9 100644
--- a/src/Bit_Row.defs.hh
+++ b/src/Bit_Row.defs.hh
@@ -116,6 +116,12 @@ public:
   //! Copy-constructor.
   Bit_Row(const Bit_Row& y);
 
+  //! Set-union constructor.
+  /*!
+    Constructs an object containing the set-union of \p y and \p z.
+  */
+  Bit_Row(const Bit_Row& y, const Bit_Row& z);
+
   //! Destructor.
   ~Bit_Row();
 
@@ -191,6 +197,13 @@ private:
   //! Bit-vector representing the row.
   mpz_t vec;
 
+  //! Assigns to \p *this the union of \p y and \p z.
+  /*!
+    The size of \p y must be be less than or equal to the size of \p z.
+    Upon entry, \p vec must have allocated enough space to contain the result.
+  */
+  void union_helper(const Bit_Row& x, const Bit_Row& y);
+
   //! Assuming \p w is nonzero, returns the index of the first set bit in \p w.
   static unsigned int first_one(mp_limb_t w);
 
diff --git a/src/Bit_Row.inlines.hh b/src/Bit_Row.inlines.hh
index 6fc36f7..5321f41 100644
--- a/src/Bit_Row.inlines.hh
+++ b/src/Bit_Row.inlines.hh
@@ -46,6 +46,20 @@ Bit_Row::Bit_Row(const Bit_Row& y) {
 }
 
 inline
+Bit_Row::Bit_Row(const Bit_Row& y, const Bit_Row& z) {
+  const mp_size_t y_size = y.vec->_mp_size;
+  const mp_size_t z_size = z.vec->_mp_size;
+  if (y_size < z_size) {
+    mpz_init2(vec, z_size);
+    union_helper(y, z);
+  }
+  else {
+    mpz_init2(vec, y_size);
+    union_helper(z, y);
+  }
+}
+
+inline
 Bit_Row::~Bit_Row() {
   mpz_clear(vec);
 }