On Tue, May 15, 2018 at 10:03 AM, Paul Edwards <mutazi...@gmail.com> wrote:
> On Tue, 15 May 2018 04:16:44 -0700, Ed Jaffe <edja...@phoenixsoftware.com> > wrote: > > >On 5/12/2018 2:02 PM, Ed Jaffe wrote: > > >Of course, you might have to change numerous existing LLGT instructions > >into LLGF instructions, but that's only a fraction of the effort needed > >to widen all of your pointers. > > I'm not familiar with LLGT. All my code uses > 32-bit instructions found in S/370, so there is > no LLGT to change. If you simply write your > 32-bit code sensibly (don't use the high bit > or byte in addresses for flags), it will run > AM-infinity, including AM64. > I think what Ed is getting at is to load a "32 bit" pointer, you need to insure that the high word of the register being loaded (bits 0..31) are zero. You can do this simply by somehow being sure that it is and using an L, or the LLGF will load the 32 bits into the low word (32..63) of the register and zero out the high word automatically (bits 0..31). This is the safest way, rather than using an old fashioned L instruction. Of course, if you are absolutely certain that the high word will always be zero, then this is overkill. > BFN. Paul. > > -- We all have skeletons in our closet. Mine are so old, they have osteoporosis. Maranatha! <>< John McKown ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
