source: libcfa/src/bitmanip.hfa

Last change on this file was fd54fef, checked in by Michael Brooks <mlbrooks@…>, 11 months ago

Converting the project to use the new syntax for otype, dtype and ttytpe.

Changed prelude (gen), libcfa and test suite to use it. Added a simple deprecation rule of the old syntax to the parser; we might wish to support both syntaxes "officially," like with an extra CLI switch, but this measure should serve as a simple reminder for our team to try the new syntax.

  • Property mode set to 100644
File size: 8.0 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 : Sun Aug 23 21:39:28 2020
14// Update Count     : 140
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 __builtin_popcount( (typeof(n))~n ); }
51        unsigned int all0s( unsigned short int n ) { return __builtin_popcount( (typeof(n))~n ); }
52        unsigned int all0s( unsigned int n ) { return __builtin_popcount( ~n ); }
53        unsigned int all0s( unsigned long int n ) { return __builtin_popcountl( ~n ); }
54        unsigned int all0s( unsigned long long int n ) { return __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 ? 0 : __bitsizeof(unsigned int) - __builtin_clz( (typeof(n))~n ); }
70        unsigned int high0( unsigned short int n ) { return n == (typeof(n))-1 ? 0 : __bitsizeof(unsigned int) - __builtin_clz( (typeof(n))~n ); }
71        unsigned int high0( unsigned int n ) { return n == -1 ? 0 : __bitsizeof(n) - __builtin_clz( ~n ); }
72        unsigned int high0( unsigned long int n ) { return n == -1 ? 0 : __bitsizeof(n) - __builtin_clzl( ~n ); }
73        unsigned int high0( unsigned long long int n ) { return n == -1 ? 0 : __bitsizeof(n) - __builtin_clzll( ~n ); }
74
75        // Find most significiant one bit.
76        unsigned int high1( unsigned char n ) { return n == 0 ? 0 : __bitsizeof(unsigned int) - __builtin_clz( n ); }
77        unsigned int high1( unsigned short int n ) { return n == 0 ? 0 : __bitsizeof(unsigned int) - __builtin_clz( n ); }
78        unsigned int high1( unsigned int n ) { return n == 0 ? 0 : __bitsizeof(n) - __builtin_clz( n ); }
79        unsigned int high1( unsigned long int n ) { return n == 0 ? 0 : __bitsizeof(n) - __builtin_clzl( n ); }
80        unsigned int high1( unsigned long long int n ) { return n == 0 ? 0 : __bitsizeof(n) - __builtin_clzll( n ); }
81
82        // Check for power of 2, clears bits below n, rounding down to the next lower multiple of n.  0 is not a power of 2
83        // but this computation returns true because of the two's complement, so it is a special case.
84        bool is_pow2( unsigned char n ) { return n == 0 ? false : (n & (n - 1)) == 0; }
85        bool is_pow2( unsigned short int n ) { return n == 0 ? false : (n & (n - 1)) == 0; }
86        bool is_pow2( unsigned int n ) { return n == 0 ? false : (n & (n - 1)) == 0; }
87        bool is_pow2( unsigned long int n ) { return n == 0 ? false : (n & (n - 1)) == 0; }
88        bool is_pow2( unsigned long long int n ) { return n == 0 ? false : (n & (n - 1)) == 0; }
89
90        // Returns n aligned at the floor of align, clear bits above or equal to align, giving n % align.
91        signed char floor2( signed char n, signed char align ) { verify( is_pow2( align ) ); return n & -align; }
92        unsigned char floor2( unsigned char n, unsigned char align ) { verify( is_pow2( align ) ); return n & -align; }
93        short int floor2( short int n, short int align ) { verify( is_pow2( align ) ); return n & -align; }
94        unsigned short int floor2( unsigned short int n, unsigned short int align ) { verify( is_pow2( align ) ); return n & -align; }
95        int floor2( int n, int align ) { verify( is_pow2( align ) ); return n & -align; }
96        unsigned int floor2( unsigned int n, unsigned int align ) { verify( is_pow2( align ) ); return n & -align; }
97        long int floor2( long int n, long int align ) { verify( is_pow2( align ) ); return n & -align; }
98        unsigned long int floor2( unsigned long int n, unsigned long int align ) { verify( is_pow2( align ) ); return n & -align; }
99        long long int floor2( long long int n, long long int align ) { verify( is_pow2( align ) ); return n & -align; }
100        unsigned long long int floor2( unsigned long long int n, unsigned long long int align ) { verify( is_pow2( align ) ); return n & -align; }
101
102        // forall( T | { T ?&?( T, T ); T -?( T ); } )
103        // T floor2( T n, T align ) { verify( is_pow2( align ) ); return n & -align; }
104
105        // Returns n aligned at the ceiling of align, negate, round down, negate is the same as round up.
106        signed char ceiling2( signed char n, signed char align ) { verify( is_pow2( align ) ); return -floor2( -n, align ); }
107        unsigned char ceiling2( unsigned char n, unsigned char align ) { verify( is_pow2( align ) ); return -floor2( -n, align ); }
108        short int ceiling2( short int n, short int align ) { verify( is_pow2( align ) ); return -floor2( -n, align ); }
109        unsigned short int ceiling2( unsigned short int n, unsigned short int align ) { verify( is_pow2( align ) ); return -floor2( -n, align ); }
110        int ceiling2( int n, int align ) { verify( is_pow2( align ) ); return -floor2( -n, align ); }
111        unsigned int ceiling2( unsigned int n, unsigned int align ) { verify( is_pow2( align ) ); return -floor2( -n, align ); }
112        long int ceiling2( long int n, long int align ) { verify( is_pow2( align ) ); return -floor2( -n, align ); }
113        unsigned long int ceiling2( unsigned long int n, unsigned long int align ) { verify( is_pow2( align ) ); return -floor2( -n, align ); }
114        long long int ceiling2( long long int n, long long int align ) { verify( is_pow2( align ) ); return -floor2( -n, align ); }
115        unsigned long long int ceiling2( unsigned long long int n, unsigned long long int align ) { verify( is_pow2( align ) ); return -floor2( -n, align ); }
116
117        // forall( T | { T floor2( T, T ); T -?( T ); } )
118        // T ceiling2( T n, T align ) { verify( is_pow2( align ) ); return -floor2( -n, align ); }
119} // distribution
120
121// Local Variables: //
122// tab-width: 4 //
123// End: //
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