PL.8

PL.8 is a dialect of PL/I (Programming Language One) developed by IBM Research in the 1970s by the compiler group, under Martin Hopkins, within a major research program that led to the IBM RISC architecture. The ".8" in the name was intended to suggest it was about 80% of PL/I. Written in PL/I and bootstrapped via the PL/I Optimizing compiler, it was an alternative to PL/S for system programming, compiling initially to an intermediate machine-independent language with symbolic registers and machine-like operations. It applied machine-independent program optimization techniques to this intermediate language to produce exceptionally good object code. The intermediate language was mapped by the back-end to the target machine's register architecture and instruction set. Back-ends were written for IBM 801, S/370, Motorola 68000, and POWER/PowerPC.