[ViewVC] Diff of: cvs/libecb/ecb.pod

Comparing libecb/ecb.pod (file contents):
Revision 1.50 by root, Thu Jun 28 20:20:27 2012 UTC vs.
Revision 1.90 by root, Tue Jun 22 00:01:15 2021 UTC

…		…
10		10
11	Its homepage can be found here:	11	Its homepage can be found here:
12		12
13	http://software.schmorp.de/pkg/libecb	13	http://software.schmorp.de/pkg/libecb
14		14
15	It mainly provides a number of wrappers around GCC built-ins, together	15	It mainly provides a number of wrappers around many compiler built-ins,
16	with replacement functions for other compilers. In addition to this,	16	together with replacement functions for other compilers. In addition
17	it provides a number of other lowlevel C utilities, such as endianness	17	to this, it provides a number of other lowlevel C utilities, such as
18	detection, byte swapping or bit rotations.	18	endianness detection, byte swapping or bit rotations.
19		19
20	Or in other words, things that should be built into any standard C system,	20	Or in other words, things that should be built into any standard C
21	but aren't, implemented as efficient as possible with GCC, and still	21	system, but aren't, implemented as efficient as possible with GCC (clang,
22	correct with other compilers.	22	msvc...), and still correct with other compilers.
23		23
24	More might come.	24	More might come.
25		25
26	=head2 ABOUT THE HEADER	26	=head2 ABOUT THE HEADER
27		27
…		…
58		58
59	=head2 TYPES / TYPE SUPPORT	59	=head2 TYPES / TYPE SUPPORT
60		60
61	ecb.h makes sure that the following types are defined (in the expected way):	61	ecb.h makes sure that the following types are defined (in the expected way):
62		62
63	int8_t uint8_t int16_t uint16_t	63	int8_t uint8_
64	int32_t uint32_t int64_t uint64_t	64	int16_t uint16_t
		65	int32_t uint32_
		66	int64_t uint64_t
		67	int_fast8_t uint_fast8_t
		68	int_fast16_t uint_fast16_t
		69	int_fast32_t uint_fast32_t
		70	int_fast64_t uint_fast64_t
65	intptr_t uintptr_t	71	intptr_t uintptr_t
66		72
67	The macro C<ECB_PTRSIZE> is defined to the size of a pointer on this	73	The macro C<ECB_PTRSIZE> is defined to the size of a pointer on this
68	platform (currently C<4> or C<8>) and can be used in preprocessor	74	platform (currently C<4> or C<8>) and can be used in preprocessor
69	expressions.	75	expressions.
70		76
71	For C<ptrdiff_t> and C<size_t> use C<stddef.h>.	77	For C<ptrdiff_t> and C<size_t> use C<stddef.h>/C<cstddef>.
72		78
73	=head2 LANGUAGE/COMPILER VERSIONS	79	=head2 LANGUAGE/ENVIRONMENT/COMPILER VERSIONS
74		80
75	All the following symbols expand to an expression that can be tested in	81	All the following symbols expand to an expression that can be tested in
76	preprocessor instructions as well as treated as a boolean (use C<!!> to	82	preprocessor instructions as well as treated as a boolean (use C<!!> to
77	ensure it's either C<0> or C<1> if you need that).	83	ensure it's either C<0> or C<1> if you need that).
78		84
79	=over 4	85	=over
80		86
81	=item ECB_C	87	=item ECB_C
82		88
83	True if the implementation defines the C<__STDC__> macro to a true value,	89	True if the implementation defines the C<__STDC__> macro to a true value,
84	which is typically true for both C and C++ compilers.	90	while not claiming to be C++, i..e C, but not C++.
85		91
86	=item ECB_C99	92	=item ECB_C99
87		93
88	True if the implementation claims to be compliant to C99 (ISO/IEC	94	True if the implementation claims to be compliant to C99 (ISO/IEC
89	9899:1999) or any later version.	95	9899:1999) or any later version, while not claiming to be C++.
90		96
91	Note that later versions (ECB_C11) remove core features again (for	97	Note that later versions (ECB_C11) remove core features again (for
92	example, variable length arrays).	98	example, variable length arrays).
93		99
94	=item ECB_C11	100	=item ECB_C11, ECB_C17
95		101
96	True if the implementation claims to be compliant to C11 (ISO/IEC	102	True if the implementation claims to be compliant to C11/C17 (ISO/IEC
97	9899:2011) or any later version.	103	9899:2011, :20187) or any later version, while not claiming to be C++.
98		104
99	=item ECB_CPP	105	=item ECB_CPP
100		106
101	True if the implementation defines the C<__cplusplus__> macro to a true	107	True if the implementation defines the C<__cplusplus__> macro to a true
102	value, which is typically true for C++ compilers.	108	value, which is typically true for C++ compilers.
103		109
104	=item ECB_CPP11	110	=item ECB_CPP11, ECB_CPP14, ECB_CPP17
105		111
106	True if the implementation claims to be compliant to ISO/IEC 14882:2011	112	True if the implementation claims to be compliant to C++11/C++14/C++17
107	(C++11) or any later version.	113	(ISO/IEC 14882:2011, :2014, :2017) or any later version.
108		114
		115	Note that many C++20 features will likely have their own feature test
		116	macros (see e.g. L<http://eel.is/c++draft/cpp.predefined#1.8>).
		117
		118	=item ECB_OPTIMIZE_SIZE
		119
		120	Is C<1> when the compiler optimizes for size, C<0> otherwise. This symbol
		121	can also be defined before including F<ecb.h>, in which case it will be
		122	unchanged.
		123
109	=item ECB_GCC_VERSION(major,minor)	124	=item ECB_GCC_VERSION (major, minor)
110		125
111	Expands to a true value (suitable for testing in by the preprocessor)	126	Expands to a true value (suitable for testing by the preprocessor) if the
112	if the compiler used is GNU C and the version is the given version, or	127	compiler used is GNU C and the version is the given version, or higher.
113	higher.
114		128
115	This macro tries to return false on compilers that claim to be GCC	129	This macro tries to return false on compilers that claim to be GCC
116	compatible but aren't.	130	compatible but aren't.
117		131
118	=item ECB_EXTERN_C	132	=item ECB_EXTERN_C
…		…
137		151
138	ECB_EXTERN_C_END	152	ECB_EXTERN_C_END
139		153
140	=item ECB_STDFP	154	=item ECB_STDFP
141		155
142	If this evaluates to a true value (suitable for testing in by the	156	If this evaluates to a true value (suitable for testing by the
143	preprocessor), then C<float> and C<double> use IEEE 754 single/binary32	157	preprocessor), then C<float> and C<double> use IEEE 754 single/binary32
144	and double/binary64 representations internally I<and> the endianness of	158	and double/binary64 representations internally I<and> the endianness of
145	both types match the endianness of C<uint32_t> and C<uint64_t>.	159	both types match the endianness of C<uint32_t> and C<uint64_t>.
146		160
147	This means you can just copy the bits of a C<float> (or C<double>) to an	161	This means you can just copy the bits of a C<float> (or C<double>) to an
…		…
150		164
151	This is true for basically all modern platforms, although F<ecb.h> might	165	This is true for basically all modern platforms, although F<ecb.h> might
152	not be able to deduce this correctly everywhere and might err on the safe	166	not be able to deduce this correctly everywhere and might err on the safe
153	side.	167	side.
154		168
155	=back	169	=item ECB_64BIT_NATIVE
156		170
		171	Evaluates to a true value (suitable for both preprocessor and C code
		172	testing) if 64 bit integer types on this architecture are evaluated
		173	"natively", that is, with similar speeds as 32 bit integerss. While 64 bit
		174	integer support is very common (and in fatc required by libecb), 32 bit
		175	cpus have to emulate operations on them, so you might want to avoid them.
		176
		177	=item ECB_AMD64, ECB_AMD64_X32
		178
		179	These two macros are defined to C<1> on the x86_64/amd64 ABI and the X32
		180	ABI, respectively, and undefined elsewhere.
		181
		182	The designers of the new X32 ABI for some inexplicable reason decided to
		183	make it look exactly like amd64, even though it's completely incompatible
		184	to that ABI, breaking about every piece of software that assumed that
		185	C<__x86_64> stands for, well, the x86-64 ABI, making these macros
		186	necessary.
		187
		188	=back
		189
		190	=head2 MACRO TRICKERY
		191
		192	=over
		193
		194	=item ECB_CONCAT (a, b)
		195
		196	Expands any macros in C<a> and C<b>, then concatenates the result to form
		197	a single token. This is mainly useful to form identifiers from components,
		198	e.g.:
		199
		200	#define S1 str
		201	#define S2 cpy
		202
		203	ECB_CONCAT (S1, S2)(dst, src); // == strcpy (dst, src);
		204
		205	=item ECB_STRINGIFY (arg)
		206
		207	Expands any macros in C<arg> and returns the stringified version of
		208	it. This is mainly useful to get the contents of a macro in string form,
		209	e.g.:
		210
		211	#define SQL_LIMIT 100
		212	sql_exec ("select * from table limit " ECB_STRINGIFY (SQL_LIMIT));
		213
		214	=item ECB_STRINGIFY_EXPR (expr)
		215
		216	Like C<ECB_STRINGIFY>, but additionally evaluates C<expr> to make sure it
		217	is a valid expression. This is useful to catch typos or cases where the
		218	macro isn't available:
		219
		220	#include <errno.h>
		221
		222	ECB_STRINGIFY (EDOM); // "33" (on my system at least)
		223	ECB_STRINGIFY_EXPR (EDOM); // "33"
		224
		225	// now imagine we had a typo:
		226
		227	ECB_STRINGIFY (EDAM); // "EDAM"
		228	ECB_STRINGIFY_EXPR (EDAM); // error: EDAM undefined
		229
		230	=back
		231
157	=head2 GCC ATTRIBUTES	232	=head2 ATTRIBUTES
158		233
159	A major part of libecb deals with GCC attributes. These are additional	234	A major part of libecb deals with additional attributes that can be
160	attributes that you can assign to functions, variables and sometimes even	235	assigned to functions, variables and sometimes even types - much like
161	types - much like C<const> or C<volatile> in C.	236	C<const> or C<volatile> in C. They are implemented using either GCC
162		237	attributes or other compiler/language specific features. Attributes
163	While GCC allows declarations to show up in many surprising places,
164	but not in many expected places, the safest way is to put attribute
165	declarations before the whole declaration:	238	declarations must be put before the whole declaration:
166		239
167	ecb_const int mysqrt (int a);	240	ecb_const int mysqrt (int a);
168	ecb_unused int i;	241	ecb_unused int i;
169		242
170	For variables, it is often nicer to put the attribute after the name, and
171	avoid multiple declarations using commas:
172
173	int i ecb_unused;
174
175	=over 4	243	=over
176
177	=item ecb_attribute ((attrs...))
178
179	A simple wrapper that expands to C<__attribute__((attrs))> on GCC, and to
180	nothing on other compilers, so the effect is that only GCC sees these.
181
182	Example: use the C<deprecated> attribute on a function.
183
184	ecb_attribute((__deprecated__)) void
185	do_not_use_me_anymore (void);
186		244
187	=item ecb_unused	245	=item ecb_unused
188		246
189	Marks a function or a variable as "unused", which simply suppresses a	247	Marks a function or a variable as "unused", which simply suppresses a
190	warning by GCC when it detects it as unused. This is useful when you e.g.	248	warning by the compiler when it detects it as unused. This is useful when
191	declare a variable but do not always use it:	249	you e.g. declare a variable but do not always use it:
192		250
193	{	251	{
194	int var ecb_unused;	252	ecb_unused int var;
195		253
196	#ifdef SOMECONDITION	254	#ifdef SOMECONDITION
197	var = ...;	255	var = ...;
198	return var;	256	return var;
199	#else	257	#else
200	return 0;	258	return 0;
201	#endif	259	#endif
202	}	260	}
203		261
		262	=item ecb_deprecated
		263
		264	Similar to C<ecb_unused>, but marks a function, variable or type as
		265	deprecated. This makes some compilers warn when the type is used.
		266
		267	=item ecb_deprecated_message (message)
		268
		269	Same as C<ecb_deprecated>, but if possible, the specified diagnostic is
		270	used instead of a generic depreciation message when the object is being
		271	used.
		272
204	=item ecb_inline	273	=item ecb_inline
205		274
206	This is not actually an attribute, but you use it like one. It expands	275	Expands either to (a compiler-specific equivalent of) C<static inline> or
207	either to C<static inline> or to just C<static>, if inline isn't	276	to just C<static>, if inline isn't supported. It should be used to declare
208	supported. It should be used to declare functions that should be inlined,	277	functions that should be inlined, for code size or speed reasons.
209	for code size or speed reasons.
210		278
211	Example: inline this function, it surely will reduce codesize.	279	Example: inline this function, it surely will reduce codesize.
212		280
213	ecb_inline int	281	ecb_inline int
214	negmul (int a, int b)	282	negmul (int a, int b)
…		…
216	return - (a * b);	284	return - (a * b);
217	}	285	}
218		286
219	=item ecb_noinline	287	=item ecb_noinline
220		288
221	Prevent a function from being inlined - it might be optimised away, but	289	Prevents a function from being inlined - it might be optimised away, but
222	not inlined into other functions. This is useful if you know your function	290	not inlined into other functions. This is useful if you know your function
223	is rarely called and large enough for inlining not to be helpful.	291	is rarely called and large enough for inlining not to be helpful.
224		292
225	=item ecb_noreturn	293	=item ecb_noreturn
226		294
…		…
236	}	304	}
237		305
238	In this case, the compiler would probably be smart enough to deduce it on	306	In this case, the compiler would probably be smart enough to deduce it on
239	its own, so this is mainly useful for declarations.	307	its own, so this is mainly useful for declarations.
240		308
		309	=item ecb_restrict
		310
		311	Expands to the C<restrict> keyword or equivalent on compilers that support
		312	them, and to nothing on others. Must be specified on a pointer type or
		313	an array index to indicate that the memory doesn't alias with any other
		314	restricted pointer in the same scope.
		315
		316	Example: multiply a vector, and allow the compiler to parallelise the
		317	loop, because it knows it doesn't overwrite input values.
		318
		319	void
		320	multiply (ecb_restrict float *src,
		321	ecb_restrict float *dst,
		322	int len, float factor)
		323	{
		324	int i;
		325
		326	for (i = 0; i < len; ++i)
		327	dst [i] = src [i] * factor;
		328	}
		329
241	=item ecb_const	330	=item ecb_const
242		331
243	Declares that the function only depends on the values of its arguments,	332	Declares that the function only depends on the values of its arguments,
244	much like a mathematical function. It specifically does not read or write	333	much like a mathematical function. It specifically does not read or write
245	any memory any arguments might point to, global variables, or call any	334	any memory any arguments might point to, global variables, or call any
…		…
305	functions only called in exceptional or rare cases.	394	functions only called in exceptional or rare cases.
306		395
307	=item ecb_artificial	396	=item ecb_artificial
308		397
309	Declares the function as "artificial", in this case meaning that this	398	Declares the function as "artificial", in this case meaning that this
310	function is not really mean to be a function, but more like an accessor	399	function is not really meant to be a function, but more like an accessor
311	- many methods in C++ classes are mere accessor functions, and having a	400	- many methods in C++ classes are mere accessor functions, and having a
312	crash reported in such a method, or single-stepping through them, is not	401	crash reported in such a method, or single-stepping through them, is not
313	usually so helpful, especially when it's inlined to just a few instructions.	402	usually so helpful, especially when it's inlined to just a few instructions.
314		403
315	Marking them as artificial will instruct the debugger about just this,	404	Marking them as artificial will instruct the debugger about just this,
…		…
333		422
334	=back	423	=back
335		424
336	=head2 OPTIMISATION HINTS	425	=head2 OPTIMISATION HINTS
337		426
338	=over 4	427	=over
339		428
340	=item bool ecb_is_constant(expr)	429	=item bool ecb_is_constant (expr)
341		430
342	Returns true iff the expression can be deduced to be a compile-time	431	Returns true iff the expression can be deduced to be a compile-time
343	constant, and false otherwise.	432	constant, and false otherwise.
344		433
345	For example, when you have a C<rndm16> function that returns a 16 bit	434	For example, when you have a C<rndm16> function that returns a 16 bit
…		…
363	return is_constant (n) && !(n & (n - 1))	452	return is_constant (n) && !(n & (n - 1))
364	? rndm16 () & (num - 1)	453	? rndm16 () & (num - 1)
365	: (n * (uint32_t)rndm16 ()) >> 16;	454	: (n * (uint32_t)rndm16 ()) >> 16;
366	}	455	}
367		456
368	=item bool ecb_expect (expr, value)	457	=item ecb_expect (expr, value)
369		458
370	Evaluates C<expr> and returns it. In addition, it tells the compiler that	459	Evaluates C<expr> and returns it. In addition, it tells the compiler that
371	the C<expr> evaluates to C<value> a lot, which can be used for static	460	the C<expr> evaluates to C<value> a lot, which can be used for static
372	branch optimisations.	461	branch optimisations.
373		462
…		…
420	{	509	{
421	if (ecb_expect_false (current + size > end))	510	if (ecb_expect_false (current + size > end))
422	real_reserve_method (size); /* presumably noinline */	511	real_reserve_method (size); /* presumably noinline */
423	}	512	}
424		513
425	=item bool ecb_assume (cond)	514	=item ecb_assume (cond)
426		515
427	Try to tell the compiler that some condition is true, even if it's not	516	Tries to tell the compiler that some condition is true, even if it's not
428	obvious.	517	obvious. This is not a function, but a statement: it cannot be used in
		518	another expression.
429		519
430	This can be used to teach the compiler about invariants or other	520	This can be used to teach the compiler about invariants or other
431	conditions that might improve code generation, but which are impossible to	521	conditions that might improve code generation, but which are impossible to
432	deduce form the code itself.	522	deduce form the code itself.
433		523
…		…
450		540
451	Then the compiler I<might> be able to optimise out the second call	541	Then the compiler I<might> be able to optimise out the second call
452	completely, as it knows that C<< current + 1 > end >> is false and the	542	completely, as it knows that C<< current + 1 > end >> is false and the
453	call will never be executed.	543	call will never be executed.
454		544
455	=item bool ecb_unreachable ()	545	=item ecb_unreachable ()
456		546
457	This function does nothing itself, except tell the compiler that it will	547	This function does nothing itself, except tell the compiler that it will
458	never be executed. Apart from suppressing a warning in some cases, this	548	never be executed. Apart from suppressing a warning in some cases, this
459	function can be used to implement C<ecb_assume> or similar functions.	549	function can be used to implement C<ecb_assume> or similar functionality.
460		550
461	=item bool ecb_prefetch (addr, rw, locality)	551	=item ecb_prefetch (addr, rw, locality)
462		552
463	Tells the compiler to try to prefetch memory at the given C<addr>ess	553	Tells the compiler to try to prefetch memory at the given C<addr>ess
464	for either reading (C<rw> = 0) or writing (C<rw> = 1). A C<locality> of	554	for either reading (C<rw> = 0) or writing (C<rw> = 1). A C<locality> of
465	C<0> means that there will only be one access later, C<3> means that	555	C<0> means that there will only be one access later, C<3> means that
466	the data will likely be accessed very often, and values in between mean	556	the data will likely be accessed very often, and values in between mean
467	something... in between. The memory pointed to by the address does not	557	something... in between. The memory pointed to by the address does not
468	need to be accessible (it could be a null pointer for example), but C<rw>	558	need to be accessible (it could be a null pointer for example), but C<rw>
469	and C<locality> must be compile-time constants.	559	and C<locality> must be compile-time constants.
470		560
		561	This is a statement, not a function: you cannot use it as part of an
		562	expression.
		563
471	An obvious way to use this is to prefetch some data far away, in a big	564	An obvious way to use this is to prefetch some data far away, in a big
472	array you loop over. This prefetches memory some 128 array elements later,	565	array you loop over. This prefetches memory some 128 array elements later,
473	in the hope that it will be ready when the CPU arrives at that location.	566	in the hope that it will be ready when the CPU arrives at that location.
474		567
475	int sum = 0;	568	int sum = 0;
…		…
496		589
497	=back	590	=back
498		591
499	=head2 BIT FIDDLING / BIT WIZARDRY	592	=head2 BIT FIDDLING / BIT WIZARDRY
500		593
501	=over 4	594	=over
502		595
503	=item bool ecb_big_endian ()	596	=item bool ecb_big_endian ()
504		597
505	=item bool ecb_little_endian ()	598	=item bool ecb_little_endian ()
506		599
…		…
512		605
513	=item int ecb_ctz32 (uint32_t x)	606	=item int ecb_ctz32 (uint32_t x)
514		607
515	=item int ecb_ctz64 (uint64_t x)	608	=item int ecb_ctz64 (uint64_t x)
516		609
		610	=item int ecb_ctz (T x) [C++]
		611
517	Returns the index of the least significant bit set in C<x> (or	612	Returns the index of the least significant bit set in C<x> (or
518	equivalently the number of bits set to 0 before the least significant bit	613	equivalently the number of bits set to 0 before the least significant bit
519	set), starting from 0. If C<x> is 0 the result is undefined.	614	set), starting from 0. If C<x> is 0 the result is undefined.
520		615
521	For smaller types than C<uint32_t> you can safely use C<ecb_ctz32>.	616	For smaller types than C<uint32_t> you can safely use C<ecb_ctz32>.
522		617
		618	The overloaded C++ C<ecb_ctz> function supports C<uint8_t>, C<uint16_t>,
		619	C<uint32_t> and C<uint64_t> types.
		620
523	For example:	621	For example:
524		622
525	ecb_ctz32 (3) = 0	623	ecb_ctz32 (3) = 0
526	ecb_ctz32 (6) = 1	624	ecb_ctz32 (6) = 1
527		625
528	=item bool ecb_is_pot32 (uint32_t x)	626	=item bool ecb_is_pot32 (uint32_t x)
529		627
530	=item bool ecb_is_pot64 (uint32_t x)	628	=item bool ecb_is_pot64 (uint32_t x)
531		629
		630	=item bool ecb_is_pot (T x) [C++]
		631
532	Return true iff C<x> is a power of two or C<x == 0>.	632	Returns true iff C<x> is a power of two or C<x == 0>.
533		633
534	For smaller types then C<uint32_t> you can safely use C<ecb_is_pot32>.	634	For smaller types than C<uint32_t> you can safely use C<ecb_is_pot32>.
		635
		636	The overloaded C++ C<ecb_is_pot> function supports C<uint8_t>, C<uint16_t>,
		637	C<uint32_t> and C<uint64_t> types.
535		638
536	=item int ecb_ld32 (uint32_t x)	639	=item int ecb_ld32 (uint32_t x)
537		640
538	=item int ecb_ld64 (uint64_t x)	641	=item int ecb_ld64 (uint64_t x)
		642
		643	=item int ecb_ld64 (T x) [C++]
539		644
540	Returns the index of the most significant bit set in C<x>, or the number	645	Returns the index of the most significant bit set in C<x>, or the number
541	of digits the number requires in binary (so that C<< 2**ld <= x <	646	of digits the number requires in binary (so that C<< 2**ld <= x <
542	2**(ld+1) >>). If C<x> is 0 the result is undefined. A common use case is	647	2**(ld+1) >>). If C<x> is 0 the result is undefined. A common use case is
543	to compute the integer binary logarithm, i.e. C<floor (log2 (n))>, for	648	to compute the integer binary logarithm, i.e. C<floor (log2 (n))>, for
…		…
548	the given data type), while C<ecb_ld> returns how many bits the number	653	the given data type), while C<ecb_ld> returns how many bits the number
549	itself requires.	654	itself requires.
550		655
551	For smaller types than C<uint32_t> you can safely use C<ecb_ld32>.	656	For smaller types than C<uint32_t> you can safely use C<ecb_ld32>.
552		657
		658	The overloaded C++ C<ecb_ld> function supports C<uint8_t>, C<uint16_t>,
		659	C<uint32_t> and C<uint64_t> types.
		660
553	=item int ecb_popcount32 (uint32_t x)	661	=item int ecb_popcount32 (uint32_t x)
554		662
555	=item int ecb_popcount64 (uint64_t x)	663	=item int ecb_popcount64 (uint64_t x)
556		664
		665	=item int ecb_popcount (T x) [C++]
		666
557	Returns the number of bits set to 1 in C<x>.	667	Returns the number of bits set to 1 in C<x>.
558		668
559	For smaller types than C<uint32_t> you can safely use C<ecb_popcount32>.	669	For smaller types than C<uint32_t> you can safely use C<ecb_popcount32>.
		670
		671	The overloaded C++ C<ecb_popcount> function supports C<uint8_t>, C<uint16_t>,
		672	C<uint32_t> and C<uint64_t> types.
560		673
561	For example:	674	For example:
562		675
563	ecb_popcount32 (7) = 3	676	ecb_popcount32 (7) = 3
564	ecb_popcount32 (255) = 8	677	ecb_popcount32 (255) = 8
…		…
567		680
568	=item uint16_t ecb_bitrev16 (uint16_t x)	681	=item uint16_t ecb_bitrev16 (uint16_t x)
569		682
570	=item uint32_t ecb_bitrev32 (uint32_t x)	683	=item uint32_t ecb_bitrev32 (uint32_t x)
571		684
		685	=item T ecb_bitrev (T x) [C++]
		686
572	Reverses the bits in x, i.e. the MSB becomes the LSB, MSB-1 becomes LSB+1	687	Reverses the bits in x, i.e. the MSB becomes the LSB, MSB-1 becomes LSB+1
573	and so on.	688	and so on.
574		689
		690	The overloaded C++ C<ecb_bitrev> function supports C<uint8_t>, C<uint16_t> and C<uint32_t> types.
		691
575	Example:	692	Example:
576		693
577	ecb_bitrev8 (0xa7) = 0xea	694	ecb_bitrev8 (0xa7) = 0xea
578	ecb_bitrev32 (0xffcc4411) = 0x882233ff	695	ecb_bitrev32 (0xffcc4411) = 0x882233ff
579		696
		697	=item T ecb_bitrev (T x) [C++]
		698
		699	Overloaded C++ bitrev function.
		700
		701	C<T> must be one of C<uint8_t>, C<uint16_t> or C<uint32_t>.
		702
580	=item uint32_t ecb_bswap16 (uint32_t x)	703	=item uint32_t ecb_bswap16 (uint32_t x)
581		704
582	=item uint32_t ecb_bswap32 (uint32_t x)	705	=item uint32_t ecb_bswap32 (uint32_t x)
583		706
584	=item uint64_t ecb_bswap64 (uint64_t x)	707	=item uint64_t ecb_bswap64 (uint64_t x)
		708
		709	=item T ecb_bswap (T x)
585		710
586	These functions return the value of the 16-bit (32-bit, 64-bit) value	711	These functions return the value of the 16-bit (32-bit, 64-bit) value
587	C<x> after reversing the order of bytes (0x11223344 becomes 0x44332211 in	712	C<x> after reversing the order of bytes (0x11223344 becomes 0x44332211 in
588	C<ecb_bswap32>).	713	C<ecb_bswap32>).
589		714
		715	The overloaded C++ C<ecb_bswap> function supports C<uint8_t>, C<uint16_t>,
		716	C<uint32_t> and C<uint64_t> types.
		717
590	=item uint8_t ecb_rotl8 (uint8_t x, unsigned int count)	718	=item uint8_t ecb_rotl8 (uint8_t x, unsigned int count)
591		719
592	=item uint16_t ecb_rotl16 (uint16_t x, unsigned int count)	720	=item uint16_t ecb_rotl16 (uint16_t x, unsigned int count)
593		721
594	=item uint32_t ecb_rotl32 (uint32_t x, unsigned int count)	722	=item uint32_t ecb_rotl32 (uint32_t x, unsigned int count)
…		…
605		733
606	These two families of functions return the value of C<x> after rotating	734	These two families of functions return the value of C<x> after rotating
607	all the bits by C<count> positions to the right (C<ecb_rotr>) or left	735	all the bits by C<count> positions to the right (C<ecb_rotr>) or left
608	(C<ecb_rotl>).	736	(C<ecb_rotl>).
609		737
610	Current GCC versions understand these functions and usually compile them	738	Current GCC/clang versions understand these functions and usually compile
611	to "optimal" code (e.g. a single C<rol> or a combination of C<shld> on	739	them to "optimal" code (e.g. a single C<rol> or a combination of C<shld>
612	x86).	740	on x86).
		741
		742	=item T ecb_rotl (T x, unsigned int count) [C++]
		743
		744	=item T ecb_rotr (T x, unsigned int count) [C++]
		745
		746	Overloaded C++ rotl/rotr functions.
		747
		748	C<T> must be one of C<uint8_t>, C<uint16_t>, C<uint32_t> or C<uint64_t>.
		749
		750	=back
		751
		752	=head2 HOST ENDIANNESS CONVERSION
		753
		754	=over
		755
		756	=item uint_fast16_t ecb_be_u16_to_host (uint_fast16_t v)
		757
		758	=item uint_fast32_t ecb_be_u32_to_host (uint_fast32_t v)
		759
		760	=item uint_fast64_t ecb_be_u64_to_host (uint_fast64_t v)
		761
		762	=item uint_fast16_t ecb_le_u16_to_host (uint_fast16_t v)
		763
		764	=item uint_fast32_t ecb_le_u32_to_host (uint_fast32_t v)
		765
		766	=item uint_fast64_t ecb_le_u64_to_host (uint_fast64_t v)
		767
		768	Convert an unsigned 16, 32 or 64 bit value from big or little endian to host byte order.
		769
		770	The naming convention is C<ecb_>(C<be>\|C<le>)C<_u>C<16\|32\|64>C<_to_host>,
		771	where C<be> and C<le> stand for big endian and little endian, respectively.
		772
		773	=item uint_fast16_t ecb_host_to_be_u16 (uint_fast16_t v)
		774
		775	=item uint_fast32_t ecb_host_to_be_u32 (uint_fast32_t v)
		776
		777	=item uint_fast64_t ecb_host_to_be_u64 (uint_fast64_t v)
		778
		779	=item uint_fast16_t ecb_host_to_le_u16 (uint_fast16_t v)
		780
		781	=item uint_fast32_t ecb_host_to_le_u32 (uint_fast32_t v)
		782
		783	=item uint_fast64_t ecb_host_to_le_u64 (uint_fast64_t v)
		784
		785	Like above, but converts I<from> host byte order to the specified
		786	endianness.
		787
		788	=back
		789
		790	In C++ the following additional template functions are supported:
		791
		792	=over
		793
		794	=item T ecb_be_to_host (T v)
		795
		796	=item T ecb_le_to_host (T v)
		797
		798	=item T ecb_host_to_be (T v)
		799
		800	=item T ecb_host_to_le (T v)
		801
		802	=back
		803
		804	These functions work like their C counterparts, above, but use templates,
		805	which make them useful in generic code.
		806
		807	C<T> must be one of C<uint8_t>, C<uint16_t>, C<uint32_t> or C<uint64_t>
		808	(so unlike their C counterparts, there is a version for C<uint8_t>, which
		809	again can be useful in generic code).
		810
		811	=head2 UNALIGNED LOAD/STORE
		812
		813	These function load or store unaligned multi-byte values.
		814
		815	=over
		816
		817	=item uint_fast16_t ecb_peek_u16_u (const void *ptr)
		818
		819	=item uint_fast32_t ecb_peek_u32_u (const void *ptr)
		820
		821	=item uint_fast64_t ecb_peek_u64_u (const void *ptr)
		822
		823	These functions load an unaligned, unsigned 16, 32 or 64 bit value from
		824	memory.
		825
		826	=item uint_fast16_t ecb_peek_be_u16_u (const void *ptr)
		827
		828	=item uint_fast32_t ecb_peek_be_u32_u (const void *ptr)
		829
		830	=item uint_fast64_t ecb_peek_be_u64_u (const void *ptr)
		831
		832	=item uint_fast16_t ecb_peek_le_u16_u (const void *ptr)
		833
		834	=item uint_fast32_t ecb_peek_le_u32_u (const void *ptr)
		835
		836	=item uint_fast64_t ecb_peek_le_u64_u (const void *ptr)
		837
		838	Like above, but additionally convert from big endian (C<be>) or little
		839	endian (C<le>) byte order to host byte order while doing so.
		840
		841	=item ecb_poke_u16_u (void *ptr, uint16_t v)
		842
		843	=item ecb_poke_u32_u (void *ptr, uint32_t v)
		844
		845	=item ecb_poke_u64_u (void *ptr, uint64_t v)
		846
		847	These functions store an unaligned, unsigned 16, 32 or 64 bit value to
		848	memory.
		849
		850	=item ecb_poke_be_u16_u (void *ptr, uint_fast16_t v)
		851
		852	=item ecb_poke_be_u32_u (void *ptr, uint_fast32_t v)
		853
		854	=item ecb_poke_be_u64_u (void *ptr, uint_fast64_t v)
		855
		856	=item ecb_poke_le_u16_u (void *ptr, uint_fast16_t v)
		857
		858	=item ecb_poke_le_u32_u (void *ptr, uint_fast32_t v)
		859
		860	=item ecb_poke_le_u64_u (void *ptr, uint_fast64_t v)
		861
		862	Like above, but additionally convert from host byte order to big endian
		863	(C<be>) or little endian (C<le>) byte order while doing so.
		864
		865	=back
		866
		867	In C++ the following additional template functions are supported:
		868
		869	=over
		870
		871	=item T ecb_peek<T> (const void *ptr)
		872
		873	=item T ecb_peek_be<T> (const void *ptr)
		874
		875	=item T ecb_peek_le<T> (const void *ptr)
		876
		877	=item T ecb_peek_u<T> (const void *ptr)
		878
		879	=item T ecb_peek_be_u<T> (const void *ptr)
		880
		881	=item T ecb_peek_le_u<T> (const void *ptr)
		882
		883	Similarly to their C counterparts, these functions load an unsigned 8, 16,
		884	32 or 64 bit value from memory, with optional conversion from big/little
		885	endian.
		886
		887	Since the type cannot be deduced, it has to be specified explicitly, e.g.
		888
		889	uint_fast16_t v = ecb_peek<uint16_t> (ptr);
		890
		891	C<T> must be one of C<uint8_t>, C<uint16_t>, C<uint32_t> or C<uint64_t>.
		892
		893	Unlike their C counterparts, these functions support 8 bit quantities
		894	(C<uint8_t>) and also have an aligned version (without the C<_u> prefix),
		895	all of which hopefully makes them more useful in generic code.
		896
		897	=item ecb_poke (void *ptr, T v)
		898
		899	=item ecb_poke_be (void *ptr, T v)
		900
		901	=item ecb_poke_le (void *ptr, T v)
		902
		903	=item ecb_poke_u (void *ptr, T v)
		904
		905	=item ecb_poke_be_u (void *ptr, T v)
		906
		907	=item ecb_poke_le_u (void *ptr, T v)
		908
		909	Again, similarly to their C counterparts, these functions store an
		910	unsigned 8, 16, 32 or z64 bit value to memory, with optional conversion to
		911	big/little endian.
		912
		913	C<T> must be one of C<uint8_t>, C<uint16_t>, C<uint32_t> or C<uint64_t>.
		914
		915	Unlike their C counterparts, these functions support 8 bit quantities
		916	(C<uint8_t>) and also have an aligned version (without the C<_u> prefix),
		917	all of which hopefully makes them more useful in generic code.
		918
		919	=back
		920
		921	=head2 FAST INTEGER TO STRING
		922
		923	Libecb defines a set of very fast integer to decimal string (or integer
		924	to ascii, short C<i2a>) functions. These work by converting the integer
		925	to a fixed point representation and then successively multiplying out
		926	the topmost digits. Unlike some other, also very fast, libraries, ecb's
		927	algorithm should be completely branchless per digit, and does not rely on
		928	the presence of special cpu functions (such as clz).
		929
		930	There is a high level API that takes an C<int32_t>, C<uint32_t>,
		931	C<int64_t> or C<uint64_t> as argument, and a low-level API, which is
		932	harder to use but supports slightly more formatting options.
		933
		934	=head3 HIGH LEVEL API
		935
		936	The high level API consists of four functions, one each for C<int32_t>,
		937	C<uint32_t>, C<int64_t> and C<uint64_t>:
		938
		939	=over
		940
		941	=item ECB_I2A_I32_DIGITS (=11)
		942
		943	=item char ecb_i2a_u32 (char ptr, uint32_t value)
		944
		945	Takes an C<uint32_t> I<value> and formats it as a decimal number starting
		946	at I<ptr>, using at most C<ECB_I2A_I32_DIGITS> characters. Returns a
		947	pointer to just after the generated string, where you would normally put
		948	the temrinating C<0> character. This function outputs the minimum number
		949	of digits.
		950
		951	=item ECB_I2A_U32_DIGITS (=10)
		952
		953	=item char ecb_i2a_i32 (char ptr, int32_t value)
		954
		955	Same as C<ecb_i2a_u32>, but formats a C<int32_t> value, including a minus
		956	sign if needed.
		957
		958	=item ECB_I2A_I64_DIGITS (=20)
		959
		960	=item char ecb_i2a_u64 (char ptr, uint64_t value)
		961
		962	=item ECB_I2A_U64_DIGITS (=21)
		963
		964	=item char ecb_i2a_i64 (char ptr, int64_t value)
		965
		966	Similar to their 32 bit counterparts, these take a 64 bit argument.
		967
		968	=item ECB_I2A_MAX_DIGITS (=21)
		969
		970	Instead of using a type specific length macro, youi can just use
		971	C<ECB_I2A_MAX_DIGITS>, which is good enough for any C<ecb_i2a> function.
		972
		973	=back
		974
		975	=head3 LOW-LEVEL API
		976
		977	The functions above use a number of low-level APIs which have some strict
		978	limitaitons, but cna be used as building blocks (study of C<ecb_i2a_i32>
		979	and related cunctions is recommended).
		980
		981	There are three families of functions: functions that convert a number
		982	to a fixed number of digits with leading zeroes (C<ecb_i2a_0N>, C<0>
		983	for "leading zeroes"), functions that generate up to N digits, skipping
		984	leading zeroes (C<_N>), and functions that can generate more digits, but
		985	the leading digit has limited range (C<_xN>).
		986
		987	None of the functions deal with negative numbera.
		988
		989	=over
		990
		991	=item char ecb_i2a_02 (char ptr, uint32_t value) // 32 bit
		992
		993	=item char ecb_i2a_03 (char ptr, uint32_t value) // 32 bit
		994
		995	=item char ecb_i2a_04 (char ptr, uint32_t value) // 32 bit
		996
		997	=item char ecb_i2a_05 (char ptr, uint32_t value) // 64 bit
		998
		999	=item char ecb_i2a_06 (char ptr, uint32_t value) // 64 bit
		1000
		1001	=item char ecb_i2a_07 (char ptr, uint32_t value) // 64 bit
		1002
		1003	=item char ecb_i2a_08 (char ptr, uint32_t value) // 64 bit
		1004
		1005	=item char ecb_i2a_09 (char ptr, uint32_t value) // 64 bit
		1006
		1007	The C<< ecb_i2a_0I<N> > functions take an unsigned I<value> and convert
		1008	them to exactly I<N> digits, returning a pointer to the first character
		1009	after the digits. The I<value> must be in range. The functions marked with
		1010	I<32 bit> do their calculations internally in 32 bit, the ones marked with
		1011	I<64 bit> internally use 64 bit integers, which might be slow on 32 bit
		1012	architectures (the high level API decides on 32 vs. 64 bit versions using
		1013	C<ECB_64BIT_NATIVE>).
		1014
		1015	=item char ecb_i2a_2 (char ptr, uint32_t value) // 32 bit
		1016
		1017	=item char ecb_i2a_3 (char ptr, uint32_t value) // 32 bit
		1018
		1019	=item char ecb_i2a_4 (char ptr, uint32_t value) // 32 bit
		1020
		1021	=item char ecb_i2a_5 (char ptr, uint32_t value) // 64 bit
		1022
		1023	=item char ecb_i2a_6 (char ptr, uint32_t value) // 64 bit
		1024
		1025	=item char ecb_i2a_7 (char ptr, uint32_t value) // 64 bit
		1026
		1027	=item char ecb_i2a_8 (char ptr, uint32_t value) // 64 bit
		1028
		1029	=item char ecb_i2a_9 (char ptr, uint32_t value) // 64 bit
		1030
		1031	Similarly, the C<< ecb_i2a_I<N> > functions take an unsigned I<value>
		1032	and convert them to at most I<N> digits, suppressing leading zeroes, and
		1033	returning a pointer to the first character after the digits.
		1034
		1035	=item ECB_I2A_MAX_X5 (=59074)
		1036
		1037	=item char ecb_i2a_x5 (char ptr, uint32_t value) // 32 bit
		1038
		1039	=item ECB_I2A_MAX_X10 (=2932500665)
		1040
		1041	=item char ecb_i2a_x10 (char ptr, uint32_t value) // 64 bit
		1042
		1043	The C<< ecb_i2a_xI<N> >> functions are similar to the C<< ecb_i2a_I<N> >
		1044	functions, but they can generate one digit more, as long as the number
		1045	is within range, which is given by the symbols C<ECB_I2A_MAX_X5> (almost
		1046	16 bit range) and C<ECB_I2A_MAX_X10> (a bit more than 31 bit range),
		1047	respectively.
		1048
		1049	For example, the sigit part of a 32 bit signed integer just fits into the
		1050	C<ECB_I2A_MAX_X10> range, so while C<ecb_i2a_x10> cannot convert a 10
		1051	digit number, it can convert all 32 bit signed numbers. Sadly, it's not
		1052	good enough for 32 bit unsigned numbers.
613		1053
614	=back	1054	=back
615		1055
616	=head2 FLOATING POINT FIDDLING	1056	=head2 FLOATING POINT FIDDLING
617		1057
618	=over 4	1058	=over
		1059
		1060	=item ECB_INFINITY [-UECB_NO_LIBM]
		1061
		1062	Evaluates to positive infinity if supported by the platform, otherwise to
		1063	a truly huge number.
		1064
		1065	=item ECB_NAN [-UECB_NO_LIBM]
		1066
		1067	Evaluates to a quiet NAN if supported by the platform, otherwise to
		1068	C<ECB_INFINITY>.
		1069
		1070	=item float ecb_ldexpf (float x, int exp) [-UECB_NO_LIBM]
		1071
		1072	Same as C<ldexpf>, but always available.
		1073
		1074	=item uint32_t ecb_float_to_binary16 (float x) [-UECB_NO_LIBM]
619		1075
620	=item uint32_t ecb_float_to_binary32 (float x) [-UECB_NO_LIBM]	1076	=item uint32_t ecb_float_to_binary32 (float x) [-UECB_NO_LIBM]
621		1077
622	=item uint64_t ecb_double_to_binary64 (double x) [-UECB_NO_LIBM]	1078	=item uint64_t ecb_double_to_binary64 (double x) [-UECB_NO_LIBM]
623		1079
624	These functions each take an argument in the native C<float> or C<double>	1080	These functions each take an argument in the native C<float> or C<double>
625	type and return the IEEE 754 bit representation of it.	1081	type and return the IEEE 754 bit representation of it (binary16/half,
		1082	binary32/single or binary64/double precision).
626		1083
627	The bit representation is just as IEEE 754 defines it, i.e. the sign bit	1084	The bit representation is just as IEEE 754 defines it, i.e. the sign bit
628	will be the most significant bit, followed by exponent and mantissa.	1085	will be the most significant bit, followed by exponent and mantissa.
629		1086
630	This function should work even when the native floating point format isn't	1087	This function should work even when the native floating point format isn't
…		…
634		1091
635	On all modern platforms (where C<ECB_STDFP> is true), the compiler should	1092	On all modern platforms (where C<ECB_STDFP> is true), the compiler should
636	be able to optimise away this function completely.	1093	be able to optimise away this function completely.
637		1094
638	These functions can be helpful when serialising floats to the network - you	1095	These functions can be helpful when serialising floats to the network - you
639	can serialise the return value like a normal uint32_t/uint64_t.	1096	can serialise the return value like a normal uint16_t/uint32_t/uint64_t.
640		1097
641	Another use for these functions is to manipulate floating point values	1098	Another use for these functions is to manipulate floating point values
642	directly.	1099	directly.
643		1100
644	Silly example: toggle the sign bit of a float.	1101	Silly example: toggle the sign bit of a float.
…		…
647	/* this results in a single add instruction to toggle the bit, and 4 extra */	1104	/* this results in a single add instruction to toggle the bit, and 4 extra */
648	/* instructions to move the float value to an integer register and back. */	1105	/* instructions to move the float value to an integer register and back. */
649		1106
650	x = ecb_binary32_to_float (ecb_float_to_binary32 (x) ^ 0x80000000U)	1107	x = ecb_binary32_to_float (ecb_float_to_binary32 (x) ^ 0x80000000U)
651		1108
		1109	=item float ecb_binary16_to_float (uint16_t x) [-UECB_NO_LIBM]
		1110
652	=item float ecb_binary32_to_float (uint32_t x) [-UECB_NO_LIBM]	1111	=item float ecb_binary32_to_float (uint32_t x) [-UECB_NO_LIBM]
653		1112
654	=item double ecb_binary32_to_double (uint64_t x) [-UECB_NO_LIBM]	1113	=item double ecb_binary64_to_double (uint64_t x) [-UECB_NO_LIBM]
655		1114
656	The reverse operation of the previos function - takes the bit representation	1115	The reverse operation of the previous function - takes the bit
657	of an IEEE binary32 or binary64 number and converts it to the native C<float>	1116	representation of an IEEE binary16, binary32 or binary64 number (half,
		1117	single or double precision) and converts it to the native C<float> or
658	or C<double> format.	1118	C<double> format.
659		1119
660	This function should work even when the native floating point format isn't	1120	This function should work even when the native floating point format isn't
661	IEEE compliant, of course at a speed and code size penalty, and of course	1121	IEEE compliant, of course at a speed and code size penalty, and of course
662	also within reasonable limits (it tries to convert normals and denormals,	1122	also within reasonable limits (it tries to convert normals and denormals,
663	and might be lucky for infinities, and with extraordinary luck, also for	1123	and might be lucky for infinities, and with extraordinary luck, also for
664	negative zero).	1124	negative zero).
665		1125
666	On all modern platforms (where C<ECB_STDFP> is true), the compiler should	1126	On all modern platforms (where C<ECB_STDFP> is true), the compiler should
667	be able to optimise away this function completely.	1127	be able to optimise away this function completely.
668		1128
		1129	=item uint16_t ecb_binary32_to_binary16 (uint32_t x)
		1130
		1131	=item uint32_t ecb_binary16_to_binary32 (uint16_t x)
		1132
		1133	Convert a IEEE binary32/single precision to binary16/half format, and vice
		1134	versa, handling all details (round-to-nearest-even, subnormals, infinity
		1135	and NaNs) correctly.
		1136
		1137	These are functions are available under C<-DECB_NO_LIBM>, since
		1138	they do not rely on the platform floating point format. The
		1139	C<ecb_float_to_binary16> and C<ecb_binary16_to_float> functions are
		1140	usually what you want.
		1141
669	=back	1142	=back
670		1143
671	=head2 ARITHMETIC	1144	=head2 ARITHMETIC
672		1145
673	=over 4	1146	=over
674		1147
675	=item x = ecb_mod (m, n)	1148	=item x = ecb_mod (m, n)
676		1149
677	Returns C<m> modulo C<n>, which is the same as the positive remainder	1150	Returns C<m> modulo C<n>, which is the same as the positive remainder
678	of the division operation between C<m> and C<n>, using floored	1151	of the division operation between C<m> and C<n>, using floored
…		…
685	C<n> must be strictly positive (i.e. C<< >= 1 >>), while C<m> must be	1158	C<n> must be strictly positive (i.e. C<< >= 1 >>), while C<m> must be
686	negatable, that is, both C<m> and C<-m> must be representable in its	1159	negatable, that is, both C<m> and C<-m> must be representable in its
687	type (this typically excludes the minimum signed integer value, the same	1160	type (this typically excludes the minimum signed integer value, the same
688	limitation as for C</> and C<%> in C).	1161	limitation as for C</> and C<%> in C).
689		1162
690	Current GCC versions compile this into an efficient branchless sequence on	1163	Current GCC/clang versions compile this into an efficient branchless
691	almost all CPUs.	1164	sequence on almost all CPUs.
692		1165
693	For example, when you want to rotate forward through the members of an	1166	For example, when you want to rotate forward through the members of an
694	array for increasing C<m> (which might be negative), then you should use	1167	array for increasing C<m> (which might be negative), then you should use
695	C<ecb_mod>, as the C<%> operator might give either negative results, or	1168	C<ecb_mod>, as the C<%> operator might give either negative results, or
696	change direction for negative values:	1169	change direction for negative values:
…		…
709		1182
710	=back	1183	=back
711		1184
712	=head2 UTILITY	1185	=head2 UTILITY
713		1186
714	=over 4	1187	=over
715		1188
716	=item element_count = ecb_array_length (name)	1189	=item element_count = ecb_array_length (name)
717		1190
718	Returns the number of elements in the array C<name>. For example:	1191	Returns the number of elements in the array C<name>. For example:
719		1192
…		…
727		1200
728	=head2 SYMBOLS GOVERNING COMPILATION OF ECB.H ITSELF	1201	=head2 SYMBOLS GOVERNING COMPILATION OF ECB.H ITSELF
729		1202
730	These symbols need to be defined before including F<ecb.h> the first time.	1203	These symbols need to be defined before including F<ecb.h> the first time.
731		1204
732	=over 4	1205	=over
733		1206
734	=item ECB_NO_THRADS	1207	=item ECB_NO_THREADS
735		1208
736	If F<ecb.h> is never used from multiple threads, then this symbol can	1209	If F<ecb.h> is never used from multiple threads, then this symbol can
737	be defined, in which case memory fences (and similar constructs) are	1210	be defined, in which case memory fences (and similar constructs) are
738	completely removed, leading to more efficient code and fewer dependencies.	1211	completely removed, leading to more efficient code and fewer dependencies.
739		1212
…		…
753	dependencies on the math library (usually called F<-lm>) - these are	1226	dependencies on the math library (usually called F<-lm>) - these are
754	marked with [-UECB_NO_LIBM].	1227	marked with [-UECB_NO_LIBM].
755		1228
756	=back	1229	=back
757		1230
		1231	=head1 UNDOCUMENTED FUNCTIONALITY
758		1232
		1233	F<ecb.h> is full of undocumented functionality as well, some of which is
		1234	intended to be internal-use only, some of which we forgot to document, and
		1235	some of which we hide because we are not sure we will keep the interface
		1236	stable.
		1237
		1238	While you are welcome to rummage around and use whatever you find useful
		1239	(we can't stop you), keep in mind that we will change undocumented
		1240	functionality in incompatible ways without thinking twice, while we are
		1241	considerably more conservative with documented things.
		1242
		1243	=head1 AUTHORS
		1244
		1245	C<libecb> is designed and maintained by:
		1246
		1247	Emanuele Giaquinta <e.giaquinta@glauco.it>
		1248	Marc Alexander Lehmann <schmorp@schmorp.de>
		1249
		1250

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Comparing libecb/ecb.pod (file contents): Revision 1.50 by root, Thu Jun 28 20:20:27 2012 UTC vs. Revision 1.90 by root, Tue Jun 22 00:01:15 2021 UTC

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Comparing libecb/ecb.pod (file contents):
Revision 1.50 by root, Thu Jun 28 20:20:27 2012 UTC vs.
Revision 1.90 by root, Tue Jun 22 00:01:15 2021 UTC