adding fixed size bit-vectors

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/util/fixed_bit_vector.cpp

@@ -0,0 +1,151 @@
+/*++
+Copyright (c) 2014 Microsoft Corporation
+
+Module Name:
+
+    fixed_bit_vector.cpp
+
+Abstract:
+
+    Simple bitvector implementation for fixed size bit-vectors.
+
+Author:
+
+    Nikolaj Bjorner (nbjorner) 2014-9-15.
+    Leonardo de Moura (leonardo) 2006-10-03.
+
+Revision History:
+    Based on bit_vector.cpp
+
+--*/
+
+#include<limits.h>
+#include"fixed_bit_vector.h"
+#include"trace.h"
+#include"hash.h"
+
+
+fixed_bit_vector_manager::fixed_bit_vector_manager(unsigned num_bits):
+    m_alloc("fixed_bit_vector") {
+    m_num_bits = num_bits;
+    m_num_words = num_words(num_bits);
+    m_num_bytes = m_num_words * sizeof(unsigned);
+    unsigned bit_rest = m_num_bits % 32;
+    m_mask = (1U << bit_rest) - 1;
+    if (m_mask == 0) m_mask = UINT_MAX;
+}
+
+
+fixed_bit_vector* fixed_bit_vector_manager::allocate() {
+    return static_cast<fixed_bit_vector*>(m_alloc.allocate(m_num_bytes));
+}
+
+fixed_bit_vector* fixed_bit_vector_manager::allocate0() {
+    fixed_bit_vector* result = allocate();
+    fill0(*result);
+    return result;
+}
+
+fixed_bit_vector* fixed_bit_vector_manager::allocate1() {
+    fixed_bit_vector* result = allocate();
+    fill1(*result);
+    return result;
+}
+
+fixed_bit_vector* fixed_bit_vector_manager::allocate(fixed_bit_vector& bv) {
+    fixed_bit_vector* result = allocate();
+    copy(*result, bv);
+    return result;
+}
+
+void fixed_bit_vector_manager::deallocate(fixed_bit_vector* bv) {
+    m_alloc.deallocate(m_num_bytes, bv);
+}
+
+
+void fixed_bit_vector_manager::copy(fixed_bit_vector& dst, fixed_bit_vector const& src) const {
+    memcpy(dst.m_data, src.m_data, num_bytes());
+}
+
+
+fixed_bit_vector& 
+fixed_bit_vector_manager::fill0(fixed_bit_vector& bv) const {
+    memset(bv.m_data, 0, num_bytes());
+    return bv;
+}
+
+fixed_bit_vector& 
+fixed_bit_vector_manager::fill1(fixed_bit_vector& bv) const {
+    memset(bv.m_data, 0xFF, num_bytes());
+    return bv;
+}
+
+fixed_bit_vector& 
+fixed_bit_vector_manager::set_and(fixed_bit_vector& dst, fixed_bit_vector const& src) const {
+    for (unsigned i = 0; i < m_num_words; i++) 
+        dst.m_data[i] &= src.m_data[i];
+    return dst;
+}
+
+fixed_bit_vector& 
+fixed_bit_vector_manager::set_or(fixed_bit_vector& dst,  fixed_bit_vector const& src) const {
+    for (unsigned i = 0; i < m_num_words; i++) 
+        dst.m_data[i] |= src.m_data[i];
+    return dst;
+}
+
+fixed_bit_vector& 
+fixed_bit_vector_manager::set_neg(fixed_bit_vector& dst) const {
+    for (unsigned i = 0; i < m_num_words; i++) 
+        dst.m_data[i] = ~dst.m_data[i];
+    return dst;
+}
+
+unsigned fixed_bit_vector_manager::last_word(fixed_bit_vector const& bv) const {
+    unsigned n = num_words();
+    if (n == 0) return 0;
+    return bv.m_data[n-1] & m_mask;
+}
+
+bool fixed_bit_vector_manager::equals(fixed_bit_vector const& a, fixed_bit_vector const& b) const {
+    if (&a == &b) return true;
+    unsigned n = num_words();
+    if (n == 0)
+        return true;
+    for (unsigned i = 0; i < n - 1; i++) {
+        if (a.m_data[i] != b.m_data[i])
+            return false;
+    }
+    return last_word(a) == last_word(b);
+}
+unsigned fixed_bit_vector_manager::hash(fixed_bit_vector const& src) const {
+    return string_hash(reinterpret_cast<char const* const>(src.m_data), num_bits()/8, num_bits());
+}
+
+bool fixed_bit_vector_manager::contains(fixed_bit_vector const& a, fixed_bit_vector const& b) const {
+    unsigned n = num_words();
+    if (n == 0)
+        return true;
+    
+    for (unsigned i = 0; i < n - 1; ++i) {
+        if ((a.m_data[i] & b.m_data[i]) != b.m_data[i])
+            return false;
+    }
+    unsigned b_data = last_word(b);
+    return (last_word(a) & b_data) == b_data;
+}
+
+std::ostream& fixed_bit_vector_manager::display(std::ostream& out, fixed_bit_vector const& b) const {
+    unsigned i = num_bits();
+    while (i > 0) {
+        --i;
+        if (b.get(i))
+            out << "1";
+        else
+            out << "0";
+    }
+    return out;
+}
+
+
+