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Unit test TestPureJavaCRC32 warmup code warms up the not-so-important loop in PureJavaCRC32.update()
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Key: HADOOP-7401
URL: https://issues.apache.org/jira/browse/HADOOP-7401
Project: Hadoop Common
Issue Type: Improvement
Components: test
Affects Versions: 0.21.0
Environment: Solaris-Sparcv9; Solaris-AMD64
Reporter: monica beckwith
Priority: Minor


When the warmup code sequence in TestPureJavaCRC32.java is executed, it sends size=len=2 and due to the value of 'trials' in for loop in doBench(), the crc.update() gets run > compile threshold, thus providing the information that 'while 0>len<7' is a hot loop and 'while len>7' is a cold loop. This brings the MB/s number for len > 7 in PureJavaCRC32.update() way down (e.g. ~28.5% for size=len=65536) .

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postedJun 17, '11 at 3:23p
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