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The function pointer to the __attribute __ ((const)) function?
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The function pointer to the __attribute __ ((const)) function?
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How (in GCC/"GNU C") do you declare a function pointer which points to an __attribute__((const)) function? The idea being that I want the compiler to avoid generating multiple calls to the function called through the function pointer when it can cache the return value from a previous call.
typedef void (*t_const_function)(void) __attribute__((const));
static __attribute__((const)) void A(void) {
}
static void B(void) {
}
int main(int argc, const char* argv[]) {
t_const_function a = A;
// warning: initialization makes qualified
// function pointer from unqualified:
t_const_function b = B;
return 0;
}
Or just:
__attribute__((const)) void(*a)(void) = A;
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