Quiz submission record for quiz3-2-1 at Wed Jul  7 07:42:58 2004:

Your Answer for Question 1:
Someone could exploit this because if everything is data then good instructions and bad instructions such as viruses are very hard to tell apart. 

Part of the solution is not to receive or transfer data to a unknown/untrusted source with a firewall or use constantly updated fivrus removal software.

Your Answer for Question 2:
Subnormal numbers fill the gap around zero in floating point arithmetic. Any non-zero number which is smaller than the smallest normal number is considered to be subnormal.

Some implementations of a floating point unit do not directly support subnormal numbers in hardware, but rather trap to some kind of software support. While this may be transparent to the user, it can result in calculations which produce or consume denormal numbers to be much slower than similar calculations on normal numbers.

Your Answer for Question 3:
It was to compensate for the lack of a guard digit.

Your Answer for Question 4:
For IEEE 754 would be that it is a widely implemented standard with a common floating-point format, it requires minimum accuracy to one-half ulp in the least significant bit, and that uperations must be commutative.

Against IEEE 754 would be that the community has been slow to make IEEE 754's unusual features available to the applications programmer such as directed rounding.


Your unique submission ID is quiz3-2-1-cs61c-ec-1089211378-3300.