Commit bfa22eca authored by Dean Camera's avatar Dean Camera
Browse files

Split out compiler specific helper macros into a new CompilerSpecific.h header...

Split out compiler specific helper macros into a new CompilerSpecific.h header file inside the library, for future expansion.
parent 7932ce86
......@@ -29,19 +29,19 @@
*/
/** \file
* \brief GCC special function/variable attribute macros.
* \brief Special function/variable attribute macros.
*
* \copydetails Group_GCCAttributes
* \copydetails Group_FuncVarAttributes
*
* \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_GCCAttributes Function/Variable Attributes
* \brief GCC special function/variable attribute macros.
* \defgroup Group_FuncVarAttributes Function/Variable Attributes
* \brief Special function/variable attribute macros.
*
* This module contains macros for applying GCC specific attributes to functions and variables to control various
* This module contains macros for applying specific attributes to functions and variables to control various
* optimizer and code generation features of the compiler. Attributes may be placed in the function prototype
* or variable declaration in any order, and multiple attributes can be specified for a single item via a space
* separated list.
......
......@@ -71,6 +71,7 @@
#include "LUFAConfig.h"
#endif
#include "CompilerSpecific.h"
#include "Architectures.h"
#include "Attributes.h"
#include "BoardTypes.h"
......@@ -228,31 +229,6 @@
#define pgm_read_ptr(Address) (void*)pgm_read_word(Address)
#endif
#endif
/** 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");
/** Evaluates to boolean true 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 true if the given value is known to be a compile time constant.
*/
#define GCC_IS_COMPILE_CONST(x) __builtin_constant_p(x)
#if !defined(ISR) || defined(__DOXYGEN__)
/** Macro for the definition of interrupt service routines, so that the compiler can insert the required
......
/*
LUFA Library
Copyright (C) Dean Camera, 2011.
dean [at] fourwalledcubicle [dot] com
www.lufa-lib.org
*/
/*
Copyright 2011 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 disclaim 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 macros 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 Macros
* \brief Compiler specific macros for code optimization and correctness.
*
* Compiler specific macros 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");
/** Evaluates to boolean true 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 true if the given value is known to be a compile time constant.
*/
#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
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