Where can I find -arch options doc for mac gcc?

The link here Apple's gcc, what's the difference between -arch i386 and -m32? is not valid any more.

And searching on apple site is astoundingly difficult: I c开发者_开发问答ouldn't find it.

How about the gcc man page? % man gcc

Most (all?) man pages are available at Apple’s Web site, too: gcc man page

-arch is an Apple GCC-specific option that tells the compiler to generate code for all architectures specified with -arch, e.g. -arch i386 -arch x86_64 will produce fat binaries targeted at both 32-bit and 64-bit Intel, whereas only one of -m32, -m64 is used by the compiler.