adding fixed size bit-vectors

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
2025-05-06 15:25:46 +00:00 · 2014-09-15 20:00:45 -07:00 · 2014-09-15 20:00:45 -07:00 · cd12fa8461
commit cd12fa8461
parent c09903288f
4 changed files with 388 additions and 0 deletions
--- a/src/util/fixed_bit_vector.h
+++ b/src/util/fixed_bit_vector.h
@ -0,0 +1,118 @@
+/*++
+Copyright (c) 2014 Microsoft Corporation
+
+Module Name:
+
+    fixed_bit_vector.h
+
+Abstract:
+
+    Simple bitvector implementation for fixed size bit-vectors.
+
+Author:
+
+    Nikolaj Bjorner (nbjorner) 2014-9-15.
+
+Revision History:
+
+    Related to bit_vector, but is based on a manager.
+
+--*/
+#ifndef _FIXED_BIT_VECTOR_H_
+#define _FIXED_BIT_VECTOR_H_
+
+#include<string.h>
+#include"debug.h"
+#include"small_object_allocator.h"
+
+class fixed_bit_vector;
+class fixed_bit_vector_manager {
+    friend class fixed_bit_vector;
+    small_object_allocator m_alloc;
+    unsigned               m_num_bits;
+    unsigned               m_num_bytes;
+    unsigned               m_num_words;
+    unsigned               m_mask;
+    unsigned num_bytes() const { return m_num_bytes; }
+
+    static unsigned num_words(unsigned num_bits) { 
+        return (num_bits + 31) / 32;
+    }    
+
+public:
+    fixed_bit_vector_manager(unsigned num_bits);
+
+    fixed_bit_vector* allocate();
+    fixed_bit_vector* allocate1();
+    fixed_bit_vector* allocate0();
+    fixed_bit_vector* allocate(fixed_bit_vector& bv);
+    void deallocate(fixed_bit_vector* bv);
+
+    void copy(fixed_bit_vector& dst, fixed_bit_vector const& src) const;
+    unsigned num_words() const { return m_num_words; }
+    unsigned num_bits() const { return m_num_bits; }
+    fixed_bit_vector& reset(fixed_bit_vector& bv) const { return fill0(bv); }
+    fixed_bit_vector& fill0(fixed_bit_vector& bv) const;
+    fixed_bit_vector& fill1(fixed_bit_vector& bv) const;
+    fixed_bit_vector& set_and(fixed_bit_vector& dst, fixed_bit_vector const& src) const;
+    fixed_bit_vector& set_or(fixed_bit_vector& dst,  fixed_bit_vector const& src) const;
+    fixed_bit_vector& set_neg(fixed_bit_vector& dst) const;
+    unsigned last_word(fixed_bit_vector const& bv) const;
+    bool equals(fixed_bit_vector const& a, fixed_bit_vector const& b) const;
+    unsigned hash(fixed_bit_vector const& src) const;
+    bool contains(fixed_bit_vector const& a, fixed_bit_vector const& b) const;
+    std::ostream& display(std::ostream& out, fixed_bit_vector const& b) const;    
+};
+
+class fixed_bit_vector {
+    friend class fixed_bit_vector_manager;
+    unsigned    m_data[1];
+
+    static unsigned get_pos_mask(unsigned bit_idx) {
+        return 1 << (bit_idx % 32);
+    }
+
+
+    unsigned get_bit_word(unsigned bit_idx) const {
+        return m_data[bit_idx / 32];
+    }
+
+    unsigned & get_bit_word(unsigned bit_idx) {
+        return m_data[bit_idx / 32];
+    }
+
+public:
+
+    fixed_bit_vector() {}
+    
+    ~fixed_bit_vector() {}
+    
+    unsigned get_word(unsigned word_idx) const { return m_data[word_idx]; }
+
+    bool operator[](unsigned bit_idx) const {
+        return get(bit_idx);
+    }
+    
+    bool get(unsigned bit_idx) const {
+        return (get_bit_word(bit_idx) & get_pos_mask(bit_idx)) != 0;
+    }
+    
+    void set(unsigned bit_idx) {
+        get_bit_word(bit_idx) |= get_pos_mask(bit_idx);
+    }
+
+    void unset(unsigned bit_idx) {
+        get_bit_word(bit_idx) &= ~get_pos_mask(bit_idx);
+    }
+    
+    void set(unsigned bit_idx, bool val) {
+        int _val = static_cast<int>(val);
+        get_bit_word(bit_idx) ^= (-_val ^ get_bit_word(bit_idx)) & get_pos_mask(bit_idx);
+    }
+
+};
+
+
+
+#endif /* _FIXED_BIT_VECTOR_H_ */
+