Z3 sources

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>

lib/bit_util.h

@@ -0,0 +1,132 @@
+/*++
+Copyright (c) 2012 Microsoft Corporation
+
+Module Name:
+
+    bit_util.h
+
+Abstract:
+
+    Bit hacking utilities.
+
+Author:
+
+    Leonardo de Moura (leonardo) 2012-09-11.
+
+Revision History:
+
+--*/
+#ifndef _BIT_UTIL_H_
+#define _BIT_UTIL_H_
+
+/**
+   \brief Return the position of the most significant (set) bit of a
+   nonzero unsigned integer.
+*/
+unsigned msb_pos(unsigned v);
+
+/**
+   \brief Return the number of leading zeros bits in a nonzero unsigned integer.
+*/
+unsigned nlz_core(unsigned x);
+
+/**
+   \brief Return the number of leading zero bits in data (a number of sz words).
+*/
+unsigned nlz(unsigned sz, unsigned const * data);
+
+/**
+   \brief Return the number of trailing zeros in a nonzero unsigned number.
+*/
+unsigned ntz_core(unsigned x);
+
+/**
+   \brief Return the number of trailing zero bits in data (a number of sz words).
+*/
+unsigned ntz(unsigned sz, unsigned const * data);
+
+/**
+   \brief dst <- src
+   
+   Trucate if src_sz > dst_sz.
+   Fill range [src_sz, dst_sz) of dst with zeros if dst_sz > src_sz.
+*/
+void copy(unsigned src_sz, unsigned const * src, unsigned dst_sz, unsigned * dst);
+
+/**
+   \brief Return true if all words of data are zero.
+*/
+bool is_zero(unsigned sz, unsigned const * data);
+
+/**
+   \brief Set all words of data to zero.
+*/
+void reset(unsigned sz, unsigned * data);
+
+/**
+   \brief dst <- src << k
+   Store in dst the result of shifting src k bits to the left.
+   The result is truncated by dst_sz.
+
+   \pre src_sz != 0
+   \pre dst_sz != 0
+*/
+void shl(unsigned src_sz, unsigned const * src, unsigned k, unsigned dst_sz, unsigned * dst);
+
+/**
+   \brief dst <- src >> k
+   Store in dst the result of shifting src k bits to the right.
+
+   \pre dst must have size sz.
+   \pre src_sz != 0
+   \pre dst_sz != 0
+*/
+void shr(unsigned sz, unsigned const * src, unsigned k, unsigned * dst);
+
+/**
+   \brief dst <- src >> k
+   Store in dst the result of shifting src k bits to the right.
+
+   Trucate if src_sz > dst_sz.
+   Fill range [src_sz, dst_sz) of dst with zeros if dst_sz > src_sz.
+
+   \pre src_sz != 0
+   \pre dst_sz != 0
+*/
+void shr(unsigned src_sz, unsigned const * src, unsigned k, unsigned dst_sz, unsigned * dst);
+
+/**
+   \brief Return true if one of the first k bits of src is not zero.
+*/
+bool has_one_at_first_k_bits(unsigned sz, unsigned const * data, unsigned k);
+
+
+/**
+   \brief data <- data + 1
+   
+   Return true if no overflow occurred.
+*/
+bool inc(unsigned sz, unsigned * data);
+
+/**
+   \brief data <- data - 1
+   
+   Return true if no underflow occurred.
+*/
+bool dec(unsigned sz, unsigned * data);
+
+/**
+   \brief Return true if data1 < data2. 
+
+   Both must have the same size.
+*/
+bool lt(unsigned sz, unsigned * data1, unsigned * data2);
+
+
+/**
+   \brief Store in c the a+b. This procedure assumes that a,b,c are vectors of size sz.
+   Return false if a+b overflows.
+*/
+bool add(unsigned sz, unsigned const * a, unsigned const * b, unsigned * c);
+
+#endif