Modes, Flags

It is easy to be confused on this:

1. Modes are set by the program (rounding, trap enabling)
2. Flags are set as a side effect of an operation (floating-point overflow)

An overly simplistic view is that modes are read/write variables to a program, and flags are read/clear variables. We defer fuller discussion of modes of (for example) enabling traps and flags and how they fit in to a linguistic framework to an afternoon session.

In this segment we will deal only with modes for rounding ToNEAR, ToZERO, ToPOSV, ToNEGV, and how these might be used, and how this might interact with languages.