source: libcfa/src/bitmanip.hfa @ 76bf23c

arm-ehjacob/cs343-translationnew-astnew-ast-unique-expr
Last change on this file since 76bf23c was 76bf23c, checked in by Peter A. Buhr <pabuhr@…>, 19 months ago

second attempt at bit manipulation operations

  • Property mode set to 100644
File size: 6.3 KB
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1//                               -*- Mode: C -*-
2//
3// Cforall Version 1.0.0 Copyright (C) 2020 University of Waterloo
4//
5// The contents of this file are covered under the licence agreement in the
6// file "LICENCE" distributed with Cforall.
7//
8// bitmanip.hfa --
9//
10// Author           : Peter A. Buhr
11// Created On       : Sat Mar 14 18:12:27 2020
12// Last Modified By : Peter A. Buhr
13// Last Modified On : Mon Apr  6 22:17:19 2020
14// Update Count     : 78
15//
16
17#pragma once
18
19// Reference: Bit Twiddling Hacks: http://graphics.stanford.edu/%7Eseander/bithacks.html#CountBitsSetNaive
20
21// Bits are numbered 1-N.
22
23#include <assert.h>
24
25#define __bitsizeof( n ) (sizeof(n) * __CHAR_BIT__)
26
27static inline {
28    // Count leading 0 bits.
29    unsigned int leading0s( unsigned char n ) { return n != 0 ? __builtin_clz( n ) - (__bitsizeof(unsigned int) - __bitsizeof(n)) : __bitsizeof(n); }
30    unsigned int leading0s( unsigned short int n ) { return n != 0 ? __builtin_clz( n ) - (__bitsizeof(unsigned int) - __bitsizeof(n)) : __bitsizeof(n); }
31    unsigned int leading0s( unsigned int n ) { return n != 0 ? __builtin_clz( n ) : __bitsizeof(n); }
32    unsigned int leading0s( unsigned long int n ) { return n != 0 ? __builtin_clzl( n ) : __bitsizeof(n); }
33    unsigned int leading0s( unsigned long long int n ) { return n != 0 ? __builtin_clzll( n ) : __bitsizeof(n); }
34
35    // Count trailing 0 bits.
36    unsigned int trailing0s( unsigned char n ) { return n != 0 ? __builtin_ctz( n ) : __bitsizeof(n); }
37    unsigned int trailing0s( unsigned short int n ) { return n != 0 ? __builtin_ctz( n ) : __bitsizeof(n); }
38    unsigned int trailing0s( unsigned int n ) { return n != 0 ? __builtin_ctz( n ) : __bitsizeof(n); }
39    unsigned int trailing0s( unsigned long int n ) { return n != 0 ? __builtin_ctzl( n ) : __bitsizeof(n); }
40    unsigned int trailing0s( unsigned long long int n ) { return n != 0 ? __builtin_ctzll( n ) : __bitsizeof(n); }
41
42    // Count all 1 bits.
43    unsigned int all1s( unsigned char n ) { return __builtin_popcount( n ); }
44    unsigned int all1s( unsigned short int n ) { return __builtin_popcount( n ); }
45    unsigned int all1s( unsigned int n ) { return __builtin_popcount( n ); }
46    unsigned int all1s( unsigned long int n ) { return __builtin_popcountl( n ); }
47    unsigned int all1s( unsigned long long int n ) { return __builtin_popcountll( n ); }
48
49    // Count all 0 bits.
50    unsigned int all0s( unsigned char n ) { return __bitsizeof(n) - __builtin_popcount( n ); }
51    unsigned int all0s( unsigned short int n ) { return __bitsizeof(n) - __builtin_popcount( n ); }
52    unsigned int all0s( unsigned int n ) { return __bitsizeof(n) - __builtin_popcount( n ); }
53    unsigned int all0s( unsigned long int n ) { return __bitsizeof(n) - __builtin_popcountl( n ); }
54    unsigned int all0s( unsigned long long int n ) { return __bitsizeof(n) - __builtin_popcountll( n ); }
55
56    // Find least significiant zero bit. (ffs)
57    unsigned int low0( unsigned char n ) { return __builtin_ffs( (typeof(n))~n ); }
58    unsigned int low0( unsigned short int n ) { return __builtin_ffs( (typeof(n))~n ); }
59    unsigned int low0( unsigned int n ) { return __builtin_ffs( ~n ); }
60    unsigned int low0( unsigned long int n ) { return __builtin_ffsl( ~n ); }
61    unsigned int low0( unsigned long long int n ) { return __builtin_ffsll( ~n ); }
62
63    // Find least significiant one bit.
64    unsigned int low1( unsigned int n ) { return __builtin_ffs( n ); }
65    unsigned int low1( unsigned long int n ) { return __builtin_ffsl( n ); }
66    unsigned int low1( unsigned long long int n ) { return __builtin_ffsll( n ); }
67
68    // Find most significiant zero bit.
69    unsigned int high0( unsigned char n ) { return n != (typeof(n))-1 ? __bitsizeof(unsigned int) - __builtin_clz( (typeof(n))~n ) : 0; }
70    unsigned int high0( unsigned short int n ) { return n != (typeof(n))-1 ? __bitsizeof(unsigned int) - __builtin_clz( (typeof(n))~n ) : 0; }
71    unsigned int high0( unsigned int n ) { return n != -1 ? __bitsizeof(n) - __builtin_clz( ~n ) : 0; }
72    unsigned int high0( unsigned long int n ) { return n != -1 ? __bitsizeof(n) - __builtin_clzl( ~n ) : 0; }
73    unsigned int high0( unsigned long long int n ) { return n != -1 ? __bitsizeof(n) - __builtin_clzll( ~n ) : 0; }
74
75    // Find most significiant one bit.
76    unsigned int high1( unsigned char n ) { return n != 0 ? __bitsizeof(unsigned int) - __builtin_clz( n ) : 0; }
77    unsigned int high1( unsigned short int n ) { return n != 0 ? __bitsizeof(unsigned int) - __builtin_clz( n ) : 0; }
78    unsigned int high1( unsigned int n ) { return n != 0 ? __bitsizeof(n) - __builtin_clz( n ) : 0; }
79    unsigned int high1( unsigned long int n ) { return n != 0 ? __bitsizeof(n) - __builtin_clzl( n ) : 0; }
80    unsigned int high1( unsigned long long int n ) { return n != 0 ? __bitsizeof(n) - __builtin_clzll( n ) : 0; }
81
82    // Check for power of 2, clears bits below value, rounding down to the next lower multiple of value.
83    bool is_pow2( int value ) { return (value & (value - 1)) == 0; }
84    bool is_pow2( unsigned long long int value ) { return (value & (value - 1)) == 0; }
85
86    // Returns value aligned at the floor of align, clear bits above or equal to align, giving value % align.
87    unsigned int floor2( unsigned int value, unsigned int align ) { assert( is_pow2( align ) ); return value & -align; }
88    unsigned long long int floor2( unsigned long long int value, unsigned long long int align ) { assert( is_pow2( align ) ); return value & -align; }
89
90    unsigned int floor( unsigned int value, unsigned int align ) { return value / align * align; }
91    unsigned long long int floor( unsigned long long int value, unsigned long long int align ) { return value / align * align; }
92
93    // Returns value aligned at the ceiling of align, negate, round down, negate is the same as round up.
94    unsigned int ceiling2( unsigned int value, unsigned int align ) { assert( is_pow2( align ) ); return -floor2( -value, align ); }
95    unsigned long long int ceiling2( unsigned long long int value, unsigned long long int align ) { assert( is_pow2( align ) ); return -floor2( -value, align ); }
96
97    unsigned int ceiling( unsigned int value, unsigned int align ) { return (value + (align - 1)) / align; }
98    unsigned long long int ceiling( unsigned long long int value, unsigned long long int align ) { return (value + (align - 1)) / align; }
99} // distribution
100
101// Local Variables: //
102// tab-width: 4 //
103// End: //
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