An issue I raised on IBM-MAIN led to discussing how to round an address to
a 16-byte (quad-word) boundary. The C example included the expression
<code>p &= -16;</code>. I suggested that the NILL & NILF instructions
could handle this, but probably wouldn't. So...
<quote>
Re specification of rounding mask: I do think -16, -8, etc. are an elegant
way to specify these, particularly as they correlate to 16-byte, 8-byte,
etc. boundaries. I sure wish they were usable with NILL and NILF.
Well, I decided to check before complaining... and (surprise!):
0000028C 0000 0000 00000000 481 NILL
R15,-4
** ASMA031E Invalid immediate or mask field
00000290 C0FB FFFF FFF0 00000000 482 NILF
R15,-16
483
*
Sigh.
</quote>
Given what J. Scott has said before, I guess this is yet another
consequence of how HLASM handles numbers.
--
sas
