From bfa22eca26b52e859d19d013a132e6e79aa4e689 Mon Sep 17 00:00:00 2001 From: Dean Camera Date: Wed, 6 Jul 2011 02:11:13 +0000 Subject: [PATCH] Split out compiler specific helper macros into a new CompilerSpecific.h header file inside the library, for future expansion. --- LUFA/Common/Attributes.h | 10 ++-- LUFA/Common/Common.h | 26 +-------- LUFA/Common/CompilerSpecific.h | 96 ++++++++++++++++++++++++++++++++++ 3 files changed, 102 insertions(+), 30 deletions(-) create mode 100644 LUFA/Common/CompilerSpecific.h diff --git a/LUFA/Common/Attributes.h b/LUFA/Common/Attributes.h index bb07417299..d6722a28d5 100644 --- a/LUFA/Common/Attributes.h +++ b/LUFA/Common/Attributes.h @@ -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. diff --git a/LUFA/Common/Common.h b/LUFA/Common/Common.h index 02fc98fdcc..87fc08cb1c 100644 --- a/LUFA/Common/Common.h +++ b/LUFA/Common/Common.h @@ -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 diff --git a/LUFA/Common/CompilerSpecific.h b/LUFA/Common/CompilerSpecific.h new file mode 100644 index 0000000000..ee6db461bb --- /dev/null +++ b/LUFA/Common/CompilerSpecific.h @@ -0,0 +1,96 @@ +/* + 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 +