source: libcfa/src/bitmanip.hfa @ dd46fd3

ADTast-experimental
Last change on this file since dd46fd3 was 95bda0a, checked in by Peter A. Buhr <pabuhr@…>, 2 years ago

add attribute always_inline to many CFA-library cover-routines to force inlining

  • Property mode set to 100644
File size: 8.0 KB
Line 
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 : Sat Oct  8 08:28:15 2022
14// Update Count     : 142
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#define __bitsizeof( n ) (sizeof(n) * __CHAR_BIT__)
24
25static inline __attribute__((always_inline)) {
26        // Count leading 0 bits.
27        unsigned int leading0s( unsigned char n ) { return n != 0 ? __builtin_clz( n ) - (__bitsizeof(unsigned int) - __bitsizeof(n)) : __bitsizeof(n); }
28        unsigned int leading0s( unsigned short int n ) { return n != 0 ? __builtin_clz( n ) - (__bitsizeof(unsigned int) - __bitsizeof(n)) : __bitsizeof(n); }
29        unsigned int leading0s( unsigned int n ) { return n != 0 ? __builtin_clz( n ) : __bitsizeof(n); }
30        unsigned int leading0s( unsigned long int n ) { return n != 0 ? __builtin_clzl( n ) : __bitsizeof(n); }
31        unsigned int leading0s( unsigned long long int n ) { return n != 0 ? __builtin_clzll( n ) : __bitsizeof(n); }
32
33        // Count trailing 0 bits.
34        unsigned int trailing0s( unsigned char n ) { return n != 0 ? __builtin_ctz( n ) : __bitsizeof(n); }
35        unsigned int trailing0s( unsigned short int n ) { return n != 0 ? __builtin_ctz( n ) : __bitsizeof(n); }
36        unsigned int trailing0s( unsigned int n ) { return n != 0 ? __builtin_ctz( n ) : __bitsizeof(n); }
37        unsigned int trailing0s( unsigned long int n ) { return n != 0 ? __builtin_ctzl( n ) : __bitsizeof(n); }
38        unsigned int trailing0s( unsigned long long int n ) { return n != 0 ? __builtin_ctzll( n ) : __bitsizeof(n); }
39
40        // Count all 1 bits.
41        unsigned int all1s( unsigned char n ) { return __builtin_popcount( n ); }
42        unsigned int all1s( unsigned short int n ) { return __builtin_popcount( n ); }
43        unsigned int all1s( unsigned int n ) { return __builtin_popcount( n ); }
44        unsigned int all1s( unsigned long int n ) { return __builtin_popcountl( n ); }
45        unsigned int all1s( unsigned long long int n ) { return __builtin_popcountll( n ); }
46
47        // Count all 0 bits.
48        unsigned int all0s( unsigned char n ) { return __builtin_popcount( (typeof(n))~n ); }
49        unsigned int all0s( unsigned short int n ) { return __builtin_popcount( (typeof(n))~n ); }
50        unsigned int all0s( unsigned int n ) { return __builtin_popcount( ~n ); }
51        unsigned int all0s( unsigned long int n ) { return __builtin_popcountl( ~n ); }
52        unsigned int all0s( unsigned long long int n ) { return __builtin_popcountll( ~n ); }
53
54        // Find least significiant zero bit. (ffs)
55        unsigned int low0( unsigned char n ) { return __builtin_ffs( (typeof(n))~n ); }
56        unsigned int low0( unsigned short int n ) { return __builtin_ffs( (typeof(n))~n ); }
57        unsigned int low0( unsigned int n ) { return __builtin_ffs( ~n ); }
58        unsigned int low0( unsigned long int n ) { return __builtin_ffsl( ~n ); }
59        unsigned int low0( unsigned long long int n ) { return __builtin_ffsll( ~n ); }
60
61        // Find least significiant one bit.
62        unsigned int low1( unsigned int n ) { return __builtin_ffs( n ); }
63        unsigned int low1( unsigned long int n ) { return __builtin_ffsl( n ); }
64        unsigned int low1( unsigned long long int n ) { return __builtin_ffsll( n ); }
65
66        // Find most significiant zero bit.
67        unsigned int high0( unsigned char n ) { return n == (typeof(n))-1 ? 0 : __bitsizeof(unsigned int) - __builtin_clz( (typeof(n))~n ); }
68        unsigned int high0( unsigned short int n ) { return n == (typeof(n))-1 ? 0 : __bitsizeof(unsigned int) - __builtin_clz( (typeof(n))~n ); }
69        unsigned int high0( unsigned int n ) { return n == -1 ? 0 : __bitsizeof(n) - __builtin_clz( ~n ); }
70        unsigned int high0( unsigned long int n ) { return n == -1 ? 0 : __bitsizeof(n) - __builtin_clzl( ~n ); }
71        unsigned int high0( unsigned long long int n ) { return n == -1 ? 0 : __bitsizeof(n) - __builtin_clzll( ~n ); }
72
73        // Find most significiant one bit.
74        unsigned int high1( unsigned char n ) { return n == 0 ? 0 : __bitsizeof(unsigned int) - __builtin_clz( n ); }
75        unsigned int high1( unsigned short int n ) { return n == 0 ? 0 : __bitsizeof(unsigned int) - __builtin_clz( n ); }
76        unsigned int high1( unsigned int n ) { return n == 0 ? 0 : __bitsizeof(n) - __builtin_clz( n ); }
77        unsigned int high1( unsigned long int n ) { return n == 0 ? 0 : __bitsizeof(n) - __builtin_clzl( n ); }
78        unsigned int high1( unsigned long long int n ) { return n == 0 ? 0 : __bitsizeof(n) - __builtin_clzll( n ); }
79
80        // 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
81        // but this computation returns true because of the two's complement, so it is a special case.
82        bool is_pow2( unsigned char n ) { return n == 0 ? false : (n & (n - 1)) == 0; }
83        bool is_pow2( unsigned short int n ) { return n == 0 ? false : (n & (n - 1)) == 0; }
84        bool is_pow2( unsigned int n ) { return n == 0 ? false : (n & (n - 1)) == 0; }
85        bool is_pow2( unsigned long int n ) { return n == 0 ? false : (n & (n - 1)) == 0; }
86        bool is_pow2( unsigned long long int n ) { return n == 0 ? false : (n & (n - 1)) == 0; }
87
88        // Returns n aligned at the floor of align, clear bits above or equal to align, giving n % align.
89        signed char floor2( signed char n, signed char align ) { verify( is_pow2( align ) ); return n & -align; }
90        unsigned char floor2( unsigned char n, unsigned char align ) { verify( is_pow2( align ) ); return n & -align; }
91        short int floor2( short int n, short int align ) { verify( is_pow2( align ) ); return n & -align; }
92        unsigned short int floor2( unsigned short int n, unsigned short int align ) { verify( is_pow2( align ) ); return n & -align; }
93        int floor2( int n, int align ) { verify( is_pow2( align ) ); return n & -align; }
94        unsigned int floor2( unsigned int n, unsigned int align ) { verify( is_pow2( align ) ); return n & -align; }
95        long int floor2( long int n, long int align ) { verify( is_pow2( align ) ); return n & -align; }
96        unsigned long int floor2( unsigned long int n, unsigned long int align ) { verify( is_pow2( align ) ); return n & -align; }
97        long long int floor2( long long int n, long long int align ) { verify( is_pow2( align ) ); return n & -align; }
98        unsigned long long int floor2( unsigned long long int n, unsigned long long int align ) { verify( is_pow2( align ) ); return n & -align; }
99
100        // forall( T | { T ?&?( T, T ); T -?( T ); } )
101        // T floor2( T n, T align ) { verify( is_pow2( align ) ); return n & -align; }
102
103        // Returns n aligned at the ceiling of align, negate, round down, negate is the same as round up.
104        signed char ceiling2( signed char n, signed char align ) { verify( is_pow2( align ) ); return -floor2( -n, align ); }
105        unsigned char ceiling2( unsigned char n, unsigned char align ) { verify( is_pow2( align ) ); return -floor2( -n, align ); }
106        short int ceiling2( short int n, short int align ) { verify( is_pow2( align ) ); return -floor2( -n, align ); }
107        unsigned short int ceiling2( unsigned short int n, unsigned short int align ) { verify( is_pow2( align ) ); return -floor2( -n, align ); }
108        int ceiling2( int n, int align ) { verify( is_pow2( align ) ); return -floor2( -n, align ); }
109        unsigned int ceiling2( unsigned int n, unsigned int align ) { verify( is_pow2( align ) ); return -floor2( -n, align ); }
110        long int ceiling2( long int n, long int align ) { verify( is_pow2( align ) ); return -floor2( -n, align ); }
111        unsigned long int ceiling2( unsigned long int n, unsigned long int align ) { verify( is_pow2( align ) ); return -floor2( -n, align ); }
112        long long int ceiling2( long long int n, long long int align ) { verify( is_pow2( align ) ); return -floor2( -n, align ); }
113        unsigned long long int ceiling2( unsigned long long int n, unsigned long long int align ) { verify( is_pow2( align ) ); return -floor2( -n, align ); }
114
115        // forall( T | { T floor2( T, T ); T -?( T ); } )
116        // T ceiling2( T n, T align ) { verify( is_pow2( align ) ); return -floor2( -n, align ); }
117} // distribution
118
119// Local Variables: //
120// tab-width: 4 //
121// End: //
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