[anthk]

Under EForth with FP done in software:

2 f 1 f 1 f f+ f- f. 0.000 ok

PFE, I think reusing the GLIBC math library:

2e0 1e0 1e0 f+ f- f. 0.000000 ok

[Dylan16807]

Every implementation of floating point can handle small to medium integers without rounding. So that example doesn't show anything we can learn from.

[anthk]

Buth for Forth you can have a totally working software floating point made from the people whose later would set the IEEE standard. Think about very small microcontrollers without FP in hardware, you can be sure that a software FP implementation will perfectly work under the standard thresolds.

[Dylan16807]

Okay, I guess? I appreciate having a well-verified library when I can't have floating point hardware, but I'm never in that situation and I really don't see how it's relevant to this discussion. Any floating point implementation is going to have rounding problems, including IEEE. The example above is IEEE.