Introduction to SDCC: Small Device C Compiler

SDCCis a Freeware, retargettable, optimizing ANSI - C compiler that targets the Intel 8051, Maxim 5962-0051101NXD , Zilog Z80 and the Motorola 68HC08 based MCUs. Work is in progress on supporting the Microchip PIC16 and PIC18 series. AVR and gbz80 ports are no longer maintained. The entire source code for the compiler is distributed under GPL.
Some of the features include:
ASXXXX and ASLINK, a Freeware, retargettable assembler and linker.
extensive MCU specific language extensions, allowing effective use of the underlying hardware.
a host of standard optimizations such as global sub expression elimination, loop optimizations (loop invariant, strength reduction of induction variables and loop reversing ), constant folding and propagation, copy propagation, dead code elimination and jump tables for 'switch' statements.
MCU specific optimisations, including a global register allocator.
adaptable MCU specific backend that should be well suited for other 8 bit MCUs
independent rule based peep hole optimizer.
a full range of data types: char (8 bits, 1 byte), short (16 bits, 2 bytes), int (16 bits, 2 bytes), long (32 bit, 4 bytes) and float (4 byte IEEE).
the ability to add inline assembler code anywhere in a function.
the ability to report on the complexity of a function to help decide what should be re-written in assembler.
a good selection of automated regression tests.
SDCC also comes with the source level debugger 5962-0051201QHA , using the current version of Daniel's s51 simulator. (Currently not available on Win32 platforms).
SDCC was written by Sandeep Dutta and released under a GPL license. Since its initial release there have been numerous bug fixes and improvements. As of December 1999, the code was moved to SourceForge where all the "users turned developers" can access the same source tree. SDCC is constantly being updated with all the users' and developers' input.