rcb@rti-sel.UUCP (09/05/84)
It is true that the floating point on the VAX is a little strange looking at first. However, it makes perfect sense when you look at what you can do with it. The 32 and 64 bit floating point formats are identical in the first 32 bits. The 64 bit format just adds more precision bits. This allows a user to reference a 64 bit floating point value as if it were a 32 bit one without any conversion. It also allows a user to reference a 32 bit floating point value as if it were a 64 bit floating point one without any conversion. In the second case, there is a slight error starting at the 7'th digit of precision. But, if the current operation does not need that much precision, it does not matter. If the error matters, it is to handle because the error will always cause the number to be larger than it should be. Once you know that, the algorithm can be modified to take that into account. I still maintain that the VAX architecture is the most consistant and logical one that I have ever seen. Randy Buckland Research Triangle Institute ...!mcnc!rti!rcb