On 1/8/19 4:46 PM, Cao jin wrote: > One more question: in compressed/, for mem*(), it seems we both use the > macros of boot/string.h, and the functions of compressed/string.c. Is > that what we want? > > compressed/ is compiled with -O2, so it cannot be told by objdump -d, > but still can be confirmed by nm <*.o>, for example: > > $nm arch/x86/boot/compressed/eboot.o > U memcpy > U memset > > $nm arch/x86/boot/compressed/pgtable_64.o > # No entry of mem*() > > both of eboot.c and pgtable_64.c #include "../string.h", and use some of > mem*(), it is counter-intuitive to me. Very appreciate it someone can > leave a hint. >
Well, I think HPA's previous answer is also suitable for this question, with -O2, sometimes __builtin_mem*() is optimized as inline code, while sometimes just emit a call to corresponding self-defined mem*() functions. -- Sincerely, Cao jin
