RE: splitting load immediates using high and lo_sum

["Tabony, Charles" <ctabony at qualcomm dot com>]

> From: Dale Johannesen [mailto:dalej@apple.com]
> 
> On Jul 21, 2005, at 5:04 PM, Tabony, Charles wrote:
> 
> >> From: Dale Johannesen [mailto:dalej@apple.com]
> >>
> >> On Jul 21, 2005, at 4:36 PM, Tabony, Charles wrote:
> >>
> >>> Hi,
> >>>
> >>> I am working on a port for a processor that has 32 bit registers
but
> >>> can
> >>> only load 16 bit immediates.
> >>>   ""
> >>>   "%0.h = #HI(%1)")
> >>
> >> What are the semantics of this?  Low bits zeroed, or untouched?
> >> If the former, your semantics are identical to Sparc; look at that.
> >
> > The low bits are untouched.  However, I would expect the compiler to
> > always follow setting the high bits with setting the low bits.
> 
> OK, if you're willing to accept that limitation (your architecture
could
> handle putting the LO first, which Sparc can't) then Sparc is still a
> good model to look at.  What it does should work for you.

Aha!  I looked at the SPARC code and distilled it down to what I needed
and the difference is that it sets the mode of the high and lo_sum
expressions to the mode of operand 0, while I was setting it to the mode
of operand 1.  Now mine works great.

Thank you,
Charles J. Tabony