Ph. Abbott et al., Architecture and software support in IBM S/390 parallel enterprise sewers for IEEE floating-point arithmetic, IBM J RES, 43(5-6), 1999, pp. 723-760
IEEE Binary Floating-Point is an industry-standard architecture. The IBM Sy
stem/360(TM) hexadecimal floating-point architecture predates the IEEE stan
dard and has been carried forward through the System/370(TM) to current Sys
tem/390(R) processors, The growing importance of industry standards and flo
ating-point combined to produce a need for IEEE Floating-Point on System/39
0. At the same time, customer investment in IBM floating-point had to be pr
eserved. This paper describes the architecture, hardware, and software effo
rts that combined to produce a conforming implementation of IEEE Floating-P
oint on System/390 while retaining compatibility with the original IBM arch
itecture.