On 11/24/2015 06:44 PM, Segher Boessenkool wrote: > On Tue, Nov 24, 2015 at 04:44:23PM +0100, Florian Weimer wrote: >> It seems that GCC has an optimization that turns >> >> static int a = 0; >> >> into >> >> static int a; >> >> and puts the symbol into .bss instead of .data (on GNU/Linux). >> >> Is this correct? Would it make sense for glibc to rely on this >> optimization (purely as an optimization)? > > See -fzero-initialized-in-bss. Thanks, this settles it. It's available since GCC 4. However, there is still a subtle difference for non-static objects. Adding the initializer turns a tentative definition into a definite one, and it seems that this can't go into .bss. Florian
