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from gperf.texi on 2 January 2017 -->
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<TITLE>Perfect Hash Function Generator - 6 Known Bugs and Limitations with gperf</TITLE>
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Go to the first, previous, next, last section, table of contents.
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The following are some limitations with the current release of
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gperf:
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The gperf utility is tuned to execute quickly, and works quickly
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for small to medium size data sets (around 1000 keywords). It is
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extremely useful for maintaining perfect hash functions for compiler
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keyword sets. Several recent enhancements now enable gperf to
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work efficiently on much larger keyword sets (over 15,000 keywords).
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When processing large keyword sets it helps greatly to have over 8 megs
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of RAM.
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The size of the generate static keyword array can get extremely
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large if the input keyword file is large or if the keywords are quite
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similar. This tends to slow down the compilation of the generated C
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code, and greatly inflates the object code size. If this
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situation occurs, consider using the <SAMP>‘-S’</SAMP> option to reduce data
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size, potentially increasing keyword recognition time a negligible
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amount. Since many C compilers cannot correctly generate code for
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large switch statements it is important to qualify the -S option
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with an appropriate numerical argument that controls the number of
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switch statements generated.
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The maximum number of selected byte positions has an
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arbitrary limit of 255. This restriction should be removed, and if
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anyone considers this a problem write me and let me know so I can remove
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the constraint.
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Go to the first, previous, next, last section, table of contents.
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