Processor Optimization Options

The Alpha edition of Visual C++ provides a family of switches that allow you to optimize compiled code for a specific processor within a platform. Processor optimizations are accomplished by a combination of code pattern selection, code scheduling, and instruction selection. Using a processor-specific optimization switch can result in code that will not run on a different processor.

If you do not want to optimize your code for a specific processor, do not use any of these switches. The compiler will then use a blended model, resulting in code that executes well across all processors within a platform family.

For Alpha processors the compiler accepts:

Processor switch Description
/QA21064 EV4
/QA21164 EV5
/QA21164A EV56 with byte/word support
/QA21164PC EV56 with byte/word support and Motion Video Instructions (by _ _asm)
/QA21264 EV6 with byte/word support, Motion Video Instructions, and new core integer and floating-point instructions

Important   Using a processor optimization switch that enables byte/word support produces code that will not run on previous processors without byte/word support.