IEEE 754 conformance on various architectures

[Kamaraju S Kusumanchi <kamaraju@bluebottle.com>]

Hi
    I am trying to understand why guile 1.8.2 FTBFS on alpha architecture.
The corresponding build log is at
http://buildd.debian.org/fetch.cgi?&pkg=guile-1.8&ver=1.8.2%2B1-2&arch=alpha&stamp=1188100514&file=log

I looked at the source guile-1.8-1.8.2+1/test-suite/standalone/test-round.c

and the lines where the build fails is 

      /* 2^DBL_MANT_DIG-1
         In the past scm_c_round had incorrectly incremented this value, due
         to the way that x+0.5 would round upwards (in the usual default
         nearest-even mode on most systems).  */
      x = ldexp (1.0, DBL_MANT_DIG) - 1.0;
      assert (x == floor (x));      /* should be an integer already */
      assert (scm_c_round (x) == x);  /* scm_c_round should return it
unchanged */

I do not have access to an alpha machine, so the only way I can debug the
problem is by looking at the source code. I gather that the above test
should not fail provided IEEE 745 standard is followed for performing
floating point arithmetic. What is the status of this on various
architectures (especially on alpha)?

thanks in advance
raju
-- 
Kamaraju S Kusumanchi
http://www.people.cornell.edu/pages/kk288/
http://malayamaarutham.blogspot.com/