[PATCH] ppc64: fix semtimedop compat syscall

Paul Mackerras paulus at samba.org
Wed Mar 23 09:40:45 EST 2005

Stephen Rothwell writes:

> On Wed, 23 Mar 2005 07:19:31 +1100 Paul Mackerras <paulus at samba.org> wrote:
> > Arnd Bergmann writes:
> > 
> > > One problem is that sign extension can not be expressed in architecture
> > > independent C code.
> > 
> > On which architectures does (long)(int) x not give the desired result?
> Presumably for a u32 function argument x which has been zero extended?

Huh??  For a 64-bit architecture with 32-bit ints, (long)(int) x will
sign-extend the bottom 32 bits of x to 64 bits.  The top 32 bits don't
matter, and in particular it doesn't matter if x has previously been
zero-extended to 64 bits, or if x is a u32.


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