structure, aligment, memory

[Jeff]

Dear all,

I was reading the ISO/IEC 9899 , and see the following thing:

6.7.1

10 . An implementation may allocate any addressable storage unit large enough to hold a bit-
field. If enough space remains, a bit-field that immediately follows another bit-field in a
structure shall be packed into adjacent bits of the same unit. If insufficient space remains,
whether a bit-field that does not fit is put into the next unit or overlaps adjacent units is
implementation-defined. The order of allocation of bit-fields within a unit (high-order to
low-order or low-order to high-order) is implementation-defined. The alignment of the
addressable storage unit is unspecified.

In the last sentence, "The alignment of the addressable storage unit is unspecified."

What is the meaning of "aligment" here ? I have heard it before but I can't figure out what dose it
mean.

Thanks in advance.

 

[Greg P.]

Do a google search for "memory model boundaries". There are too many
excellent articles on memory models and memory fragmentation for me to state
it all here. =)

--

Regards,
Greg P.

Golden Rule of Open Source Programming:
"Don't whine about something unless you plan to implement it yourself"