diff options
Diffstat (limited to 'LUFA/Common/Common.h')
| -rw-r--r-- | LUFA/Common/Common.h | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/LUFA/Common/Common.h b/LUFA/Common/Common.h index 9d64403bc..6a9356bbb 100644 --- a/LUFA/Common/Common.h +++ b/LUFA/Common/Common.h @@ -232,6 +232,15 @@ * 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 @@ -273,10 +282,11 @@ * * \param[in] Milliseconds Number of milliseconds to delay */ + static inline void Delay_MS(uint8_t Milliseconds) ATTR_ALWAYS_INLINE; static inline void Delay_MS(uint8_t Milliseconds) { #if (ARCH == ARCH_AVR8) - if (__builtin_constant_p(Milliseconds)) + if (GCC_IS_COMPILE_CONST(Milliseconds)) { _delay_ms(Milliseconds); } |