On Tue, Apr 17, 2012 at 2:52 AM, Oleg Endo <oleg.e...@t-online.de> wrote: > On Mon, 2012-04-16 at 04:11 +0800, Chiheng Xu wrote: >> On Sat, Apr 14, 2012 at 11:47 AM, Chiheng Xu <chiheng...@gmail.com> wrote: >> > >> > And I want to say that tree/gimple/rtl are compiler's data(or state), >> > not compiler's text(or logic), the most important thing about them is >> > how to access their fields. >> > >> >> Given the above assumption, now I doubt the necessity of accessor >> macros or C++ getter/setter method. > > According to my experience, it doesn't take more time/effort to write > "tree->code ()" instead of "tree->code" and such getter functions allow > for easier refactoring etc. If you omit the getters/setters you can't > express things such as immutable objects (well you still could with > const ivars but...), and you'll always have to have the ivar... > Sorry, I don't know what is the benefit of const ivars. But if you use "tree->code" instead of "tree->code()", the compiler know very well whether you intend to read or write a piece of memory. The const-ness is clear. I doubt how the compiler optimizer can further optimize it.
>> >> Is "tree->code" more direct and efficient than "TREE_CODE(tree)" or >> "tree->get_code()" ? > > What do you mean by efficient? All of them will (most likely) end up as > the same machine code. By saying "efficient", I probably mean compile time is reduced( macro expansion + optimizing, or inlining + optimizing, are avoided). I also probably mean reduced .h file size( the definitions of accessor macros and C++ getter/setter inline methods, are avoided). -- Chiheng Xu
