Use ARCH to selectively target code generation of your program for execution either on POWER7® processors, or on all supported POWER® processors including POWER7.
Default is: ARCH(POWERPC)
Abbreviations are: ARCH(PPC|PWR7)
ARCH(POWERPC) provides code generation that is balanced among all supported POWER systems. The code does not exploit the unique hardware features of POWER7 processors.
ARCH(POWER7) specializes code generation for execution on POWER7 processors, and can provide improved performance on them.
It is recommended that you not compile using ARCH(POWER7) if you will run your program on POWER processors that are earlier than POWER7.