Where is the GCC documentation?

The documentation for the GNU tools is provided within your tools suite installation via the IDE menu Help -> Help Contents -> Product Documentation

Alternatively you can access the documentation online at:

http://gcc.gnu.org/onlinedocs/gcc-4.5.1/gcc/index.html (compiler in Code Red IDE v4)

http://gcc.gnu.org/onlinedocs/gcc-4.3.3/gcc/ (compiler in Red Suite 3 and LPCXpresso (for Windows))

http://gcc.gnu.org/onlinedocs/gcc-4.4.1/gcc/ (compiler in LPCXpresso for Linux)

http://sourceware.org/binutils/docs-2.20/ (binutils - assembler, linker etc)