IEEE_754 logic
Peter Dalgaard BSA writes:
Thomas Hoffmann <hoffmann@ehmgs2.et.tu-dresden.de> writes: 3. The C9x draft introduces
the is*() functionality under the name of "classification MACROS". If an
implementation implements this standard, autoconf misses isnan() and isfinite().
The problem for me is, that if isnan and isfinite are the way C9x says (i.e. are MACROS), then configure concludes "not there" (AC_FUNCS misses macros (intentionally)).
From this it reasons "not IEEE 754".
Then I get back to a native finite() in Arith.h, but IEEE 754 mode was switched off. So I see two topics: 1. Maybe not to (only) check if isnan/isfinite are library functions, but also to check for working macros (I have not found a predefined macro in Autoconf for this). This seems of some importance to me, because it is not only an idiosyncracy of a singular system, but may become a more widespread problem if systems become C9x compliant someday. 2. Introduce a more bulletproof check for IEEE 754. Is there possibly a computation we can carry out and conclude from its result to IEEE 754? I just have no idea. ============================================================================= Thomas Hoffmann, Institut fuer Halbleiter- und Mikrosystemtechnik, TU Dresden E-mail: hoffmann@ehmgs2.et.tu-dresden.de -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-devel-request@stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._