After having seen Dan Greiner's presentations at SHARE, I would guess that it's to make some microcoded instruction execute in fewer cycles.
Gary Weinhold On 12/11/2010 3:05 PM, Don Higgins wrote:
John You are correct. The ALSIHN instruction does add logical immediate to high 32 bits of register and does not set condition code. I have no idea why this sigle add instruction with no cc update was added. If I had to pick just one, it seems like low order 32 bits or all 64 bit add would have been more useful for adjusting indexes etc. Don Higgins [email protected]
