libecb/ecb.h

/*
 * libecb
 *
 * Copyright (©) 2009-2011 Marc Alexander Lehmann
 * Copyright (©) 2011 Emanuele Giaquinta
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modifica-
 * tion, are permitted provided that the following conditions are met:
 *
 *   1.  Redistributions of source code must retain the above copyright notice,
 *       this list of conditions and the following disclaimer.
 *
 *   2.  Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO
 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef ECB_H
#define ECB_H

#include <inttypes.h>

/* many compilers define _GNUC_ to some versions but then only implement
 * what their idiot authors think are the "more important" extensions,
 * causing enourmous grief for some better fake benchmark numbers or so.
 * we try to detect these and simply assume they are not gcc - if they have
 * an issue with that they should have done it right in the first place.
 */
#ifndef ECB_GCC_VERSION
# if defined(__INTEL_COMPILER) || defined(__SUNPRO_C) || defined(__llvm__)
#  define ECB_GCC_VERSION(major,minor) 0
# else
#  define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)))
# endif
#endif

#ifndef __cplusplus
# if __STDC_VERSION__ >= 199901L
#  define ECB_INLINE inline
typedef _Bool ecb_bool;
# else
#  define ECB_INLINE inline /* yeah! */
typedef int ecb_bool;
# endif
#endif

#define ECB_CONCAT_(a, b) a ## b
#define ECB_CONCAT(a, b) ECB_CONCAT_(a, b)
#define ECB_STRINGIFY_(a) # a
#define ECB_STRINGIFY(a) ECB_STRINGIFY_(a)

#define ECB_HEADER_INLINE static ECB_INLINE

#if ECB_GCC_VERSION(3,1)
# define ecb_attribute(attrlist)        __attribute__(attrlist)
# define ecb_is_constant(c)             __builtin_constant_p (c)
# define ecb_expect(expr,value)         __builtin_expect ((expr),(value))
# define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
#else
# define ecb_attribute(attrlist)
# define ecb_is_constant(c)             0
# define ecb_expect(expr,value)         (expr)
# define ecb_prefetch(addr,rw,locality)
#endif

/* no emulation for ecb_decltype */
#if ECB_GCC_VERSION(4,5)
# define ecb_decltype(x) __decltype(x)
#elif ECB_GCC_VERSION(3,0)
# define ecb_decltype(x) typeof(x)
#endif

#define ecb_noinline ecb_attribute ((noinline))
#define ecb_noreturn ecb_attribute ((noreturn))
#define ecb_unused   ecb_attribute ((unused))
#define ecb_const    ecb_attribute ((const))
#define ecb_pure     ecb_attribute ((pure))
#define ecb_hot      ecb_attribute ((hot))      /* 4.3 */
#define ecb_cold     ecb_attribute ((cold))     /* 4.3 */

/* put into ifs if you are very sure that the expression */
/* is mostly true or mosty false. note that these return */
/* booleans, not the expression. */
#define ecb_unlikely(expr) ecb_expect (!!(expr), 0)
#define ecb_likely(expr)   ecb_expect (!!(expr), 1)

/* try to tell the compiler that some condition is definitely true */
#define ecb_assume(cond) do { if (!(cond)) unreachable (); } while (0)

/* count trailing zero bits and count # of one bits */
#if ECB_GCC_VERSION(3,4)
#define ecb_ctz32      (x) __builtin_ctz      (x)
#define ecb_popcount32 (x) __builtin_popcount (x)
#else
ECB_HEADER_INLINE int ecb_ctz32      (uint32_t x) ecb_const;
ECB_HEADER_INLINE
ecb_ctz32 (uint32_t x)
{
  int r = 0;

  x &= -x; /* this isolates the lowest bit */

  if (x & 0xaaaaaaaa) r +=  1;
  if (x & 0xcccccccc) r +=  2;
  if (x & 0xf0f0f0f0) r +=  4;
  if (x & 0xff00ff00) r +=  8;
  if (x & 0xffff0000) r += 16;

  return r;
}

ECB_HEADER_INLINE int ecb_popcount32 (uint32_t x) ecb_const;
ECB_HEADER_INLINE
ecb_popcount32 (uint32_t x)
{
  x -=  (x >> 1) & 0x55555555;
  x  = ((x >> 2) & 0x33333333) + (x & 0x33333333);
  x  = ((x >> 4) + x) & 0x0f0f0f0f;
  x *= 0x01010101;

  return x >> 24;
}
#endif

#if ECB_GCC_VERSION(4,3)
# define ecb_bswap32(x) __builtin_bswap32 (x)
#else
ECB_HEADER_INLINE uint32_t ecb_bswap32 (uint32_t x) ecb_const;
ECB_HEADER_INLINE uint32_t
ecb_bswap32 (uint32_t x)
{
  return (x >> 24)
      | ((x >>  8) & 0x0000ff00)
      | ((x <<  8) & 0x00ff0000)
      |  (x << 24);
}
#endif

#if ECB_GCC_VERSION(4,5)
# define ecb_unreachable() __builtin_unreachable ()
#else
/* this seems to work fine, but gcc always emits a warning for it :/ */
ECB_HEADER_INLINE void ecb_unreachable (void) ecb_attribute ((noreturn));
ECB_HEADER_INLINE void ecb_unreachable (void) { }
#endif

ECB_HEADER_INLINE unsigned char ecb_byteorder_helper () ecb_const;
ECB_HEADER_INLINE unsigned char
ecb_byteorder_helper ()
{
  const uint32_t u = 0x11223344;
  return *(unsigned char *)&u;
}

ECB_HEADER_INLINE ecb_bool ecb_big_endian    () ecb_const;
ECB_HEADER_INLINE ecb_bool ecb_big_endian    () { return ecb_byteorder_helper () == 0x11; };
ECB_HEADER_INLINE ecb_bool ecb_little_endian () ecb_const;
ECB_HEADER_INLINE ecb_bool ecb_little_endian () { return ecb_byteorder_helper () == 0x44; };

#if ecb_cplusplus_does_not_suck
// does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm)
template<typename T, int N>
static inline int ecb_array_length (const T (&arr)[N])
{
  return N;
}
#else
#define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
#endif

ECB_INLINE uint32_t ecb_rotr32 (uint32_t x, unsigned int count) ecb_const;
ECB_INLINE uint32_t
ecb_rotr32 (uint32_t x, unsigned int count)
{
  return (x << (32 - count)) | (x >> count);
}

ECB_INLINE uint32_t ecb_rotl32 (uint32_t x, unsigned int count) ecb_const;
ECB_INLINE uint32_t
ecb_rotl32 (uint32_t x, unsigned int count)
{
  return (x >> (32 - count)) | (x << count);
}

#endif

Revision:	1.16
Committed:	Thu May 26 18:34:23 2011 UTC (12 years, 11 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.15:	+8 -9 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	/*
2			* libecb
3			*
4	root	1.2	* Copyright (©) 2009-2011 Marc Alexander Lehmann
5	root	1.7	* Copyright (©) 2011 Emanuele Giaquinta
6	root	1.1	* All rights reserved.
7			*
8			* Redistribution and use in source and binary forms, with or without modifica-
9			* tion, are permitted provided that the following conditions are met:
10			*
11			* 1. Redistributions of source code must retain the above copyright notice,
12			* this list of conditions and the following disclaimer.
13			*
14			* 2. Redistributions in binary form must reproduce the above copyright
15			* notice, this list of conditions and the following disclaimer in the
16			* documentation and/or other materials provided with the distribution.
17			*
18			* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
19			* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
20			* CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
21			* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
22			* CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
23			* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
24			* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
25			* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
26			* ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
27			* OF THE POSSIBILITY OF SUCH DAMAGE.
28			*/
29
30			#ifndef ECB_H
31			#define ECB_H
32
33	root	1.6	#include <inttypes.h>
34
35	root	1.12	/* many compilers define _GNUC_ to some versions but then only implement
36			* what their idiot authors think are the "more important" extensions,
37			* causing enourmous grief for some better fake benchmark numbers or so.
38			* we try to detect these and simply assume they are not gcc - if they have
39			* an issue with that they should have done it right in the first place.
40			*/
41	root	1.14	#ifndef ECB_GCC_VERSION
42			# if defined(__INTEL_COMPILER) \|\| defined(__SUNPRO_C) \|\| defined(__llvm__)
43			# define ECB_GCC_VERSION(major,minor) 0
44			# else
45			# define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) \|\| (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)))
46			# endif
47	root	1.12	#endif
48	root	1.1
49	root	1.4	#ifndef __cplusplus
50			# if __STDC_VERSION__ >= 199901L
51			# define ECB_INLINE inline
52			typedef _Bool ecb_bool;
53			# else
54			# define ECB_INLINE inline /* yeah! */
55			typedef int ecb_bool;
56			# endif
57			#endif
58
59	root	1.8	#define ECB_CONCAT_(a, b) a ## b
60			#define ECB_CONCAT(a, b) ECB_CONCAT_(a, b)
61			#define ECB_STRINGIFY_(a) # a
62			#define ECB_STRINGIFY(a) ECB_STRINGIFY_(a)
63
64	root	1.4	#define ECB_HEADER_INLINE static ECB_INLINE
65	root	1.3
66	root	1.1	#if ECB_GCC_VERSION(3,1)
67			# define ecb_attribute(attrlist) __attribute__(attrlist)
68			# define ecb_is_constant(c) __builtin_constant_p (c)
69			# define ecb_expect(expr,value) __builtin_expect ((expr),(value))
70			# define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
71			#else
72			# define ecb_attribute(attrlist)
73			# define ecb_is_constant(c) 0
74			# define ecb_expect(expr,value) (expr)
75			# define ecb_prefetch(addr,rw,locality)
76			#endif
77
78	root	1.2	/* no emulation for ecb_decltype */
79	root	1.1	#if ECB_GCC_VERSION(4,5)
80			# define ecb_decltype(x) __decltype(x)
81			#elif ECB_GCC_VERSION(3,0)
82			# define ecb_decltype(x) typeof(x)
83			#endif
84
85			#define ecb_noinline ecb_attribute ((noinline))
86			#define ecb_noreturn ecb_attribute ((noreturn))
87			#define ecb_unused ecb_attribute ((unused))
88			#define ecb_const ecb_attribute ((const))
89			#define ecb_pure ecb_attribute ((pure))
90	root	1.4	#define ecb_hot ecb_attribute ((hot)) /* 4.3 */
91			#define ecb_cold ecb_attribute ((cold)) /* 4.3 */
92	root	1.1
93	root	1.3	/* put into ifs if you are very sure that the expression */
94			/* is mostly true or mosty false. note that these return */
95			/* booleans, not the expression. */
96	root	1.11	#define ecb_unlikely(expr) ecb_expect (!!(expr), 0)
97			#define ecb_likely(expr) ecb_expect (!!(expr), 1)
98	root	1.1
99	root	1.3	/* try to tell the compiler that some condition is definitely true */
100	root	1.1	#define ecb_assume(cond) do { if (!(cond)) unreachable (); } while (0)
101
102	root	1.3	/* count trailing zero bits and count # of one bits */
103	root	1.1	#if ECB_GCC_VERSION(3,4)
104	root	1.16	#define ecb_ctz32 (x) __builtin_ctz (x)
105			#define ecb_popcount32 (x) __builtin_popcount (x)
106	root	1.1	#else
107	root	1.16	ECB_HEADER_INLINE int ecb_ctz32 (uint32_t x) ecb_const;
108	root	1.3	ECB_HEADER_INLINE
109	root	1.14	ecb_ctz32 (uint32_t x)
110	root	1.1	{
111			int r = 0;
112
113	root	1.4	x &= -x; /* this isolates the lowest bit */
114	root	1.1
115			if (x & 0xaaaaaaaa) r += 1;
116			if (x & 0xcccccccc) r += 2;
117			if (x & 0xf0f0f0f0) r += 4;
118			if (x & 0xff00ff00) r += 8;
119			if (x & 0xffff0000) r += 16;
120
121			return r;
122			}
123
124	root	1.16	ECB_HEADER_INLINE int ecb_popcount32 (uint32_t x) ecb_const;
125	root	1.3	ECB_HEADER_INLINE
126	root	1.14	ecb_popcount32 (uint32_t x)
127	root	1.1	{
128			x -= (x >> 1) & 0x55555555;
129			x = ((x >> 2) & 0x33333333) + (x & 0x33333333);
130			x = ((x >> 4) + x) & 0x0f0f0f0f;
131			x *= 0x01010101;
132
133			return x >> 24;
134			}
135			#endif
136
137	root	1.13	#if ECB_GCC_VERSION(4,3)
138	root	1.16	# define ecb_bswap32(x) __builtin_bswap32 (x)
139	root	1.13	#else
140	root	1.16	ECB_HEADER_INLINE uint32_t ecb_bswap32 (uint32_t x) ecb_const;
141	root	1.14	ECB_HEADER_INLINE uint32_t
142	root	1.13	ecb_bswap32 (uint32_t x)
143			{
144			return (x >> 24)
145			\| ((x >> 8) & 0x0000ff00)
146			\| ((x << 8) & 0x00ff0000)
147			\| (x << 24);
148			}
149			#endif
150
151			#if ECB_GCC_VERSION(4,5)
152	root	1.16	# define ecb_unreachable() __builtin_unreachable ()
153	root	1.13	#else
154			/* this seems to work fine, but gcc always emits a warning for it :/ */
155	root	1.16	ECB_HEADER_INLINE void ecb_unreachable (void) ecb_attribute ((noreturn));
156	root	1.14	ECB_HEADER_INLINE void ecb_unreachable (void) { }
157	root	1.13	#endif
158
159	root	1.14	ECB_HEADER_INLINE unsigned char ecb_byteorder_helper () ecb_const;
160	root	1.3	ECB_HEADER_INLINE unsigned char
161	root	1.14	ecb_byteorder_helper ()
162	root	1.3	{
163			const uint32_t u = 0x11223344;
164			return (unsigned char )&u;
165			}
166
167	root	1.14	ECB_HEADER_INLINE ecb_bool ecb_big_endian () ecb_const;
168			ECB_HEADER_INLINE ecb_bool ecb_big_endian () { return ecb_byteorder_helper () == 0x11; };
169			ECB_HEADER_INLINE ecb_bool ecb_little_endian () ecb_const;
170			ECB_HEADER_INLINE ecb_bool ecb_little_endian () { return ecb_byteorder_helper () == 0x44; };
171	root	1.3
172	root	1.5	#if ecb_cplusplus_does_not_suck
173			// does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm)
174			template<typename T, int N>
175	root	1.8	static inline int ecb_array_length (const T (&arr)[N])
176	root	1.5	{
177			return N;
178			}
179			#else
180			#define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
181			#endif
182
183	root	1.14	ECB_INLINE uint32_t ecb_rotr32 (uint32_t x, unsigned int count) ecb_const;
184	root	1.6	ECB_INLINE uint32_t
185	root	1.9	ecb_rotr32 (uint32_t x, unsigned int count)
186	root	1.6	{
187	root	1.9	return (x << (32 - count)) \| (x >> count);
188	root	1.6	}
189
190	root	1.14	ECB_INLINE uint32_t ecb_rotl32 (uint32_t x, unsigned int count) ecb_const;
191	root	1.6	ECB_INLINE uint32_t
192	root	1.9	ecb_rotl32 (uint32_t x, unsigned int count)
193	root	1.6	{
194	root	1.9	return (x >> (32 - count)) \| (x << count);
195	root	1.6	}
196
197	root	1.1	#endif
198