ARM Compiler toolchain v4.1 for µVision Using the Compiler

Compiler Coding Practices
5.4 Selecting the target CPU at compile time
Each new version of the ARM architecture typically supports extra instructions, extra modes of
operation, pipeline differences, and register renaming. You can often significantly improve the
performance of your C or C++ code by selecting the appropriate target processor at compile
time.
To specify a target processor at compile time:
1. Decide whether the compiled program is to run on a specific ARM architecture-based
processor or on different ARM processors.
2. Obtain the name, or names, of the target processors recognized by the compiler using the
following compiler command-line option:
--cpu=list
3. If the compiled program is to run on a specific ARM architecture-based processor, having
obtained the name of the processor with the --cpu=list option, select the target processor
using the --cpu=name compiler command-line option. For example, to compile code to run
on a Cortex-M3 processor:
armcc --cpu=Cortex-M3 myprog.c
Selecting the target processor using the --cpu=name command-line option enables the compiler
to make full use of instructions that are supported by the processor, and also to perform
processor-specific optimizations such as instruction scheduling.
--cpu=list lists all the processors supported by the compiler.
5.4.1 See also
Reference
Compiler Reference:
• --cpu=list on page 3-20
• --cpu=name on page 3-20.
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