Important Notice: Our web hosting provider recently started charging us for additional visits, which was unexpected. In response, we're seeking donations. Depending on the situation, we may explore different monetization options for our Community and Expert Contributors. It's crucial to provide more returns for their expertise and offer more Expert Validated Answers or AI Validated Answers. Learn more about our hosting issue here.

subsets?

April 26, 2017subsets

0

Posted

subsets?

1 Answer

0

Posted

The Alpha architecture is upward- and downward- compatible, and newer instructions are emulated on older platforms, for those cases where the compiler is explicitly requested to generate the newer Alpha instructions. 14-35 Hardware Information In particular, OpenVMS Alpha V7.1 and later include the instruction emulation capabilities necessary for the execution of newer Alpha instructions on older Alpha microprocessors. (Instruction emulation capabilities are available for user-mode application code, and are not available to device drivers or other similar kernel-mode code.) Alpha instructions are available in groups (or subsets). Obviously, there is the base instruction set that is available on all Alpha microprocessors. Then, the following are the current instruction extension groups (or subsets) that are available on some of various recent Alpha microprocessors: o byte/word extension (BWX): LDBU, LDWU, SEXTB, SEXTW, STB, and STW. o floating-point and square root extension (FIX): FTOI