Wikipedia
Vbcc
vbcc is the name of a portable and retargetable ISO/ ANSI C compiler. It supports ISO C according to ISO/IEC 9899:1989 and a subset of the new standard ISO/IEC 9899:1999.
It is divided into two parts. One is target-independent and the other is target-dependent. vbcc provides complete abstraction of host-arithmetic and target-arithmetic. It fully supports cross-compiling for 8-bit, 16-bit, 32-bit and 64-bit architectures.
Embedded systems are supported by features like different pointer-sizes, ROM-able code, inline-assembly, bit-types, interrupt-handlers, section-attributes, stack-calculation and many others (depending on the backend).