4.4 Selecting the target processor at compile time
You can often significantly improve the performance of your C or C++ code by selecting the appropriate target processor at compile time.
Each new version of the ARM architecture typically supports extra instructions, extra modes
of operation, pipeline differences, and register renaming.
Decide whether the compiled program is to run on a specific ARM architecture-based
processor or on different ARM processors.
Obtain the name, or names, of the target processors recognized by the compiler using
the following compiler command-line option:
If the compiled program is to run on a specific ARM architecture-based processor,
having obtained the name of the processor with the
select the target processor using the
--cpu=compiler command-line option.
For example, to compile code to run on a Cortex-A9 processor:
armcc --cpu=Cortex-A9 myprog.c
Alternatively, if the compiled program is to run on different ARM processors, choose
the lowest common denominator architecture appropriate for the application and then
specify that architecture in place of the processor name. For example, to compile code
for processors supporting the ARMv6 architecture:
armcc --cpu=6 myprog.c
Selecting the target processor using the
command-line option lets the compiler:
--cpu=list lists all the processors and architectures that the compiler