On Thu, Feb 13, 2003 at 12:07:57PM -0800, Long Li wrote: > Hi, > > I am using a gcc 3.0.4 MIPS crosscompiler on Redhat. I > found something interesting: when I use specifly -O1 > for compilation, and I can use memcpy function even I > did not tell the compiler where I declard it or define > it. However, when I specify -O0, then the compiler > tells me undefined reference to this memcpy function. > So my questions are: > > 1. Is memcpy a built-in function for gcc? But why not > for optimization level 0? Because using it is an optimization. > 2. Besides memcpy, is there any other functions built > in too? Lots. The list varies depending on the GCC version; see the manual. -- Daniel Jacobowitz MontaVista Software Debian GNU/Linux Developer
