PL.8 is a dialect of PL/I developed by IBM Research in the 1970s by compiler group, under Martin Hopkins, within a major research program that led to the IBM RISC architecture.[1] It was so-called because it was about 80% of PL/I.[1][clarification needed] 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.[2] 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,[3][4] and POWER/PowerPC.[citation needed]
Use
A version was used on IBM mainframes as a development tool for software that was being designed for the IBM AS/400, as well as to write the "i370" internal code for the "Capitol" chipset used in the IBM 9377 processor and some ES/9370 models[5][6] and the millicode for S/390 and z/Architecture processors.[7]
^The compiler is described in: George Radin (May 1983). "The 801 Minicomputer". IBM Journal of Research and Development. 27 (3): 237–246. doi:10.1147/rd.273.0237.
^Gellerich, W.; Hendel, T.; Land, R.; Lehmann, H.; Mueller, M.; Oden, P.H.; Penner, H. (May 2004). "The GNU 64-bit PL8 compiler: Toward an open standard environment for firmware development". IBM Journal of Research and Development. 48 (3.4): 543–556. doi:10.1147/rd.483.0543.