On Sun, Sep 15, 2002 at 05:20:05PM +0100, James Stevenson wrote: > > > > 33 - 48 = 56 > > > > 49 - 64 = 72 > > > > > > > > Can anybody please explain me , > > > > what is the reason behind this ? > > > > > > > > Why is it that only the required > > > > amount of stack is not allocated ? > > > > > > compilers tend to optimize by keeping the stack aligned > > > on certin boundries and also some machines always require > > > that say the stack point must always be on a quad word > > > boundry. Do you actually use the variable at all ? > > > a really simple compliler optimizeation is to remove anything that > > > is not referenced even when you dont use and optimizeation flags. > > > > One question remains. What are the 8 extra bytes for? > > 2 pointers are stored around there at the start of the stack > a frame pointer and a pointer to the old stack frame i think. Well, probably yes. Can be tested using --fomit-frame-pointer compiler flag. I was just puzzled by the first line, which stated it's only 4 for lengs 0 - 4. I might have as well be a typo... ------------------------------------------------------------------------------- Jan 'Bulb' Hudec <bulb@ucw.cz> -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
