mirror of
https://github.com/Z3Prover/z3
synced 2025-10-31 11:42:28 +00:00
130 lines
2.8 KiB
C
130 lines
2.8 KiB
C
/*++
|
|
Copyright (c) 2012 Microsoft Corporation
|
|
|
|
Module Name:
|
|
|
|
bit_util.h
|
|
|
|
Abstract:
|
|
|
|
Bit hacking utilities.
|
|
|
|
Author:
|
|
|
|
Leonardo de Moura (leonardo) 2012-09-11.
|
|
|
|
Revision History:
|
|
|
|
--*/
|
|
#pragma once
|
|
|
|
/**
|
|
\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
|
|
|
|
Truncate 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.
|
|
|
|
Truncate 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);
|
|
|