JTC1/SC22/WG14
N724
ISO/IEC JTC1/SC22/WG14 N724
Minor alteration to representations of types
Clive D.W. Feather
Abstract
========
N691 defines the meaning of the sign bit as being either a negation
flag or a large negative constant. At the time I was writing the
original paper I was over-generous in the latter case. This proposal
restricts implementations to the three cases of sign-and-magnitude,
twos-complement, and ones-complement.
Proposal
========
In 6.1.2.7.2 paragraph 2 (added in N691), change:
If the sign bit is one, then the value shall be modified in
one of the following ways:
- the corresponding value with sign bit 0 is negated;
- the sign bit has some value between -1 and -2**N inclusive.
to:
If the sign bit is one, then the value shall be modified in
one of the following ways:
- the corresponding value with sign bit 0 is negated;
| - the sign bit has the value -2**N;
| - the sign bit has the value 1-2**N.