John Gilmore wrote:
> I prefer to use 'null' for pointer values that point nowhere, either
> x'00000000' or x'0000000000000000' and 'nul' for the byte/character
> x'00'. This issue is not, however, a very important one.
What I was talking about is perhaps better illustrated by example:
NUL EQU 0
* Sensible (IMO):
LA Rx,STRING(Ry) Address next character
CLI 0(Rx),NUL Is it a null?
* Not sensible (IMO):
CHSI ReturnCode,NUL Did that CALL work OK?
> About the construction
>
> | DC AL1(64) A byte containing the number 64
>
> I am even less enthusiastic; z/Architecture now supports loading and
> storing single-byte signed binary integers in the same way that it
> supports halfword ones, and "containing the number 64" is thus at best
> ambiguous.
This is copy/paste from an assembly:
000000 40 2 DC AL1(64)
000001 C0 3 DC AL1(-64)
In what sense are either of these "ambiguous"? My contention is that the
style (in this case, using decimal notation for a number) enhances
readability. As a counter example,I have actually seen:
N Rx,=F'16777215'
which strikes me as perverse, verging on deliberate obfuscation.
Best regards, Steve Hobson
Je me presse de rire de tout, de peur d'être obligé d'en pleurer
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