Asko Kauppi <askok@dnainternet.net> writes:
I've been revising the LNUM patch (more of that later) and spend
several
hours today trying to understand what exactly -ffast-math does with
regard to NaN's (not-a-numbers).
Basically, it does not seem to know them. It gives nan==nan and other
no-can-dos that I regard as Completely Evil as to Lua compatibility.
There's a list of what exactly -ffast-math does in the gcc manual (see
Taj Khattra's followup for a quote), but I just wanted to note that
you
can tune it by following the -ffast-math option with finer-grained
options that reverse parts of its effect.
E.g., in my proggie, I use:
-ffast-math -fno-finite-math-only -ftrapping-math -fno-associative-
math
"-fno-finite-math-only" and "-ftrapping-math" reverse some of the
usual
effect of -ffast-math (-fno-associative-math is just to silence a
warning, as -ftrapping-math automatically implies that anyway).
-Miles
--
o The existentialist, not having a pillow, goes everywhere with the
book by
Sullivan, _I am going to spit on your graves_.
