> Looks like Solaris is not happy about unaligned accesses.
Many RISC processors don't like it; in some of them, the OS catches the
unaligned access trap and simulates the access (perhaps noisily, as I
think Digital UNIX does, printing a message on the controlling tty, and
probably slowly in any case), and, in others, the OS just sends a signal
to the process, as Solaris does.
(Some C compilers might be able to conclude, in some cases, that a
possibly-misaligned pointer is being used, and generate paranoid code in
those cases, or might, as Sun C does, support an "always be paranoid"
option:
-misalign
(SPARC) Informs the compiler that data is not properly
aligned and thus very conservative loads and stores
must be used for data, that is, one byte at a time.
Using this option can cause significant performance
degradation when running the program. If you compile
and link in separate steps, this option must appear on
both the compile and link command lines.
-misalign2
(SPARC) Assumes that data is not properly aligned, but
that data is at least half-word aligned. Though conser-
vative uses of loads and stores must be used for data,
the performance degradation when running a program is
less than that seen for -misalign. If you compile and
link in separate steps, this option must appear on both
the compile and link command lines.
but it's probably best to avoid misaligned accesses.)
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