Snippet of http://www.math.utah.edu/pub/zsh/README.NONSTOP-FP: >>>>> Although IEEE 754 was not adopted until mid-1985, published drafts were available several years earlier. The first implementation was the Intel 8087 on which the original IBM PC was based in 1981. Since then, Intel IA-32 (formerly x86), i860, i960 and IA-64, Convex, HP/Compaq/DEC Alpha, HP PA-RISC, IBM Power and PowerPC, Motorola 68K and 88K, SGI MIPS, Sun SPARC, and most other CPUs (even on embedded systems) with floating-point point support adhere to at least part of the IEEE 754 specification. All Cray supercomputers manufactured since the early 1990s have used IEEE 754 arithmetic. The only non-IEEE-754 desktop (and larger) CPUs built since the mid-1980s have been the Compaq/DEC VAX (now obsolete), and the venerable IBM S/360 architecture first introduced in 1964. However, in 1998, IBM added the G5 processor boards on System/390 (Z series) with full IEEE 754 support (including 128-bit quadruple precision in hardware), and GNU/Linux on that system uses only IEEE 754 arithmetic (even though the S/360 arithmetic is available, the GNU/Linux compilers and library don't support it). In addition to CPUs, the Java Virtual Machine specification mandates a subset of IEEE 754 arithmetic. <<<<< In conclusion, GRAS don't bother testing whether the architecture is IEEE compliant. It may change when I encounter such a beast, but I'm not sure it will ever happen.