kernel vm question

[Dag-Erling Smørgrav]

des at des.no (Dag-Erling Smørgrav) writes:
> David Schultz <das at FreeBSD.ORG> writes:
> > When the line is there, the compiler is probably smart enough to
> > realize that 'x=y; y=x' is (usually) a no-op, so it optimizes away
> > both statements.
> Wrong.  The compiler is free to optimize away the second statement
> provided that neither x nor y is declared volatile, but it cannot
> optimize away the first statement.

I should add: unless it can determine with absolute certainty that x
is not referenced later.

DES
-- 
Dag-Erling Smørgrav - des at des.no