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| author | Fabian Topfstedt <[email protected]> | 2017-07-20 08:22:44 +0200 | 
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| committer | Fabian Topfstedt <[email protected]> | 2017-07-20 08:22:44 +0200 | 
| commit | ee43856ff7ba37ea89d1a8a4700efba4e4f69571 (patch) | |
| tree | b0ed5b538396b0b2b027e69ad8ceac443c067c79 /lib/lufa/LUFA/Common/CompilerSpecific.h | |
| parent | 99b6e918eab31d4f53cabc04a995da945335ac7f (diff) | |
| parent | 14c5160b1a94d5dc416002791b3c207ba0dca789 (diff) | |
| download | qmk_firmware-ee43856ff7ba37ea89d1a8a4700efba4e4f69571.tar.gz qmk_firmware-ee43856ff7ba37ea89d1a8a4700efba4e4f69571.zip | |
Merge https://github.com/qmk/qmk_firmware
Diffstat (limited to 'lib/lufa/LUFA/Common/CompilerSpecific.h')
| -rw-r--r-- | lib/lufa/LUFA/Common/CompilerSpecific.h | 97 | 
1 files changed, 97 insertions, 0 deletions
| diff --git a/lib/lufa/LUFA/Common/CompilerSpecific.h b/lib/lufa/LUFA/Common/CompilerSpecific.h new file mode 100644 index 0000000000..41e5305b1d --- /dev/null +++ b/lib/lufa/LUFA/Common/CompilerSpecific.h @@ -0,0 +1,97 @@ +/* +             LUFA Library +     Copyright (C) Dean Camera, 2017. + +  dean [at] fourwalledcubicle [dot] com +           www.lufa-lib.org +*/ + +/* +  Copyright 2017  Dean Camera (dean [at] fourwalledcubicle [dot] com) + +  Permission to use, copy, modify, distribute, and sell this +  software and its documentation for any purpose is hereby granted +  without fee, provided that the above copyright notice appear in +  all copies and that both that the copyright notice and this +  permission notice and warranty disclaimer appear in supporting +  documentation, and that the name of the author not be used in +  advertising or publicity pertaining to distribution of the +  software without specific, written prior permission. + +  The author disclaims all warranties with regard to this +  software, including all implied warranties of merchantability +  and fitness.  In no event shall the author be liable for any +  special, indirect or consequential damages or any damages +  whatsoever resulting from loss of use, data or profits, whether +  in an action of contract, negligence or other tortious action, +  arising out of or in connection with the use or performance of +  this software. +*/ + +/** \file + *  \brief Compiler specific definitions for code optimization and correctness. + * + *  \copydetails Group_CompilerSpecific + * + *  \note Do not include this file directly, rather include the Common.h header file instead to gain this file's + *        functionality. + */ + +/** \ingroup Group_Common + *  \defgroup Group_CompilerSpecific Compiler Specific Definitions + *  \brief Compiler specific definitions for code optimization and correctness. + * + *  Compiler specific definitions to expose certain compiler features which may increase the level of code optimization + *  for a specific compiler, or correct certain issues that may be present such as memory barriers for use in conjunction + *  with atomic variable access. + * + *  Where possible, on alternative compilers, these macros will either have no effect, or default to returning a sane value + *  so that they can be used in existing code without the need for extra compiler checks in the user application code. + * + *  @{ + */ + +#ifndef __LUFA_COMPILERSPEC_H__ +#define __LUFA_COMPILERSPEC_H__ + +	/* Preprocessor Checks: */ +		#if !defined(__INCLUDE_FROM_COMMON_H) +			#error Do not include this file directly. Include LUFA/Common/Common.h instead to gain this functionality. +		#endif + +	/* Public Interface - May be used in end-application: */ +		/* Macros: */ +			#if defined(__GNUC__) || defined(__DOXYGEN__) +				/** Forces GCC to use pointer indirection (via the device's pointer register pairs) when accessing the given +				 *  struct pointer. In some cases GCC will emit non-optimal assembly code when accessing a structure through +				 *  a pointer, resulting in a larger binary. When this macro is used on a (non \c const) structure pointer before +				 *  use, it will force GCC to use pointer indirection on the elements rather than direct store and load +				 *  instructions. +				 * +				 *  \param[in, out] StructPtr  Pointer to a structure which is to be forced into indirect access mode. +				 */ +				#define GCC_FORCE_POINTER_ACCESS(StructPtr)   __asm__ __volatile__("" : "=b" (StructPtr) : "0" (StructPtr)) + +				/** Forces GCC to create a memory barrier, ensuring that memory accesses are not reordered past the barrier point. +				 *  This can be used before ordering-critical operations, to ensure that the compiler does not re-order the resulting +				 *  assembly output in an unexpected manner on sections of code that are ordering-specific. +				 */ +				#define GCC_MEMORY_BARRIER()                  __asm__ __volatile__("" ::: "memory"); + +				/** Determines if the specified value can be determined at compile-time to be a constant value when compiling under GCC. +				 * +				 *  \param[in] x  Value to check compile-time constantness of. +				 * +				 *  \return Boolean \c true if the given value is known to be a compile time constant, \c false otherwise. +				 */ +				#define GCC_IS_COMPILE_CONST(x)               __builtin_constant_p(x) +			#else +				#define GCC_FORCE_POINTER_ACCESS(StructPtr) +				#define GCC_MEMORY_BARRIER() +				#define GCC_IS_COMPILE_CONST(x)               0 +			#endif + +#endif + +/** @} */ + | 
