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|Home > Linker Optimization Features > Optimization with RW data compression > Options available to override the compression algorithm used by the linker|
The linker has options to disable compression or to specify a compression algorithm to be used.
You can override the compression algorithm used by the linker by either:
--datacompressor off option to turn off
Specifying a compression algorithm.
To specify a compression algorithm, use the number of the required compressor on the linker command line, for example:
armlink --datacompressor 2 …
Use the command-line option
--datacompressor list to get a list of
compression algorithms available in the linker:
armlink --datacompressor list … Num Compression algorithm ======================================================== 0 Run-length encoding 1 Run-length encoding, with LZ77 on small-repeats 2 Complex LZ77 compression
When choosing a compression algorithm be aware that:
Compressor 0 performs well on data with large areas of zero-bytes but few nonzero bytes.
Compressor 1 performs well on data where the nonzero bytes are repeating.
Compressor 2 performs well on data that contains repeated values.
The linker prefers compressor 0 or 1 where the data contains mostly zero-bytes (>75%). Compressor 2 is chosen where the data contains few zero-bytes (<10%). If the image is made up only of ARM code, then ARM decompressors are used automatically. If the image contains any Thumb code, Thumb decompressors are used. If there is no clear preference, all compressors are tested to produce the best overall size.