Qian Cai <cai@xxxxxx> wrote: > Fix it by moving almost all of this multi-line macro into a proper > function __get_order(), and leave get_order() as a single-line macro in > order to avoid compilation errors. The idea was that you could compile-time initialise a global variable with get_order(): int a = get_order(SOME_MACRO); This is the same reason that ilog2() is a macro: int a = ilog2(SOME_MACRO); See the banner comment on get_order(): * This function may be used to initialise variables with compile time * evaluations of constants. If you're moving the constant branch into __get_order(), an inline function, then we'll no longer be able to do this and you need to modify the comment too. In fact, would there still be a point in having the get_order() macro? Also, IIRC, older versions of gcc see __builtin_constant_p(n) == 0 inside an function, inline or otherwise, even if the passed-in argument *is* constant. David
