SDCC is a retargettable, optimizing ANSI - C compiler that targets the Intel
8051, Maxim 80DS390, Zilog Z80 and the Motorola 68HC08 based MCUs. Work is in
progress on supporting the Microchip PIC16 and PIC18 series. SDCC is Free Open
Source Software,  distributed under GNU General Public License (GPL).

By default, this will build sdcc without pic support. If you want that, install 
gputils and run the script as follows:  ENABLE_PIC=y sh ./sdcc.SlackBuild

You can download the doc tarball from:
http://downloads.sourceforge.net/project/sdcc/sdcc-doc/3.0.0/sdcc-doc-3.0.0.tar.bz2