The compiler is based on the original Portable C Compiler by Stephen
C. Johnson, written in the late 70's. Even though much of the
compiler has been rewritten, some of the basics still remain.
PCC debuted in Unix Version 7 and replaced the DMR compiler (Dennis
Ritchie's original C compiler) in both System V and the BSD 4.x
releases. Some history about pcc is in the A History of UNIX before
Berkeley: UNIX Evolution: 1975-1984 and in the Evolution of C.
About 50% of the front-end code and 80% of the back-end code has been
rewritten. Most stuff is written by Anders Magnusson, with the
exception of the data-flow analysis part and the SSA conversion code
which is written by Peter A. Jonsson, and the Mips port that were
written as part of a project by undergraduate students at Luleå
University of Technology (LTU).