A Thought on the Discussion of DEC Alphas

Phil Bourne system at CUHHCA.HHMI.COLUMBIA.EDU
Sat Mar 12 12:51:16 EST 1994


In response to an article I wrote some time ago on items to consider
in optimizing code for use on Alpha's I received this note re the
use of IEEE arithmetic. Given the current discussion I thought I 
would pass it on.. if you would like code to test this problem
please let me know.. 
         /Phil Bourne

============ Note from Layne ==================
	A real service to the DEC user community would be to point out that
the AXP does NOT support fully the IEEE 754 Standard for floating point
arithmetic.  In particular, programs using IEEE arithmetic on a DECstation,
when ported to an Alpha (either via mx or via recompiling), do NOT produce
the same results as on the DECstation!  If you want, I can send you a
program which illustrates the different results on the MIPS RISC and the
AXP.

Layne T. Watson
Departments of Computer Science and Mathematics
Virginia Polytechnic Institute & State University





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