I have seen more than 40% performance regression on a maptest benchmark
(HashMap Test) for build 75.

To reproduce:

% uname -a

SunOS vispro 5.7 Generic_106541-16 sun4u sparc SUNW,Ultra-30

% cd /home/zzhang/bugs

% jdk1.4_b75/bin/java -version
java version "1.4.0-beta_refresh"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0-beta_refresh-b75)
Java HotSpot(TM) Client VM (build 1.4.0-beta_refresh-b75, mixed mode)

% jdk1.4_b75/bin/java -client -ms256m -mx256m -cp . perfteam.jetstream.JetStream -r 5 -testfile MapTests.txt

******** Starting run #1 ********
Hashtable Test: 3028
HashMap Test: 3903
TreeMap Test: 3171
******** Starting run #2 ********
Hashtable Test: 2842
HashMap Test: 3969
TreeMap Test: 3127
******** Starting run #3 ********
Hashtable Test: 2861
HashMap Test: 3866
TreeMap Test: 3072
******** Starting run #4 ********
Hashtable Test: 2842
HashMap Test: 4023
TreeMap Test: 3073
******** Starting run #5 ********
Hashtable Test: 2861
HashMap Test: 3867
TreeMap Test: 3062
Overall Score: 75546

% jdk1.3/bin/java -version
java version "1.3.0"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.0)
Java HotSpot(TM) Client VM (build 1.3.0, mixed mode)

 
% jdk1.3/bin/java -client -ms256m -mx256m -cp . perfteam.jetstream.JetStream -r 5 -testfile MapTests.txt

******** Starting run #1 ********
Hashtable Test: 3137
HashMap Test: 2865
TreeMap Test: 3324
******** Starting run #2 ********
Hashtable Test: 2968
HashMap Test: 2818
TreeMap Test: 3209
******** Starting run #3 ********
Hashtable Test: 3165
HashMap Test: 2815
TreeMap Test: 3209
******** Starting run #4 ********
Hashtable Test: 3178
HashMap Test: 2814
TreeMap Test: 3250
******** Starting run #5 ********
Hashtable Test: 2997
HashMap Test: 3131
TreeMap Test: 3238
Overall Score: 71434


% jdk1.4_b74/bin/java -version
java version "1.4.0-beta_refresh"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0-beta_refresh-b74)
Java HotSpot(TM) Client VM (build 1.4.0-beta_refresh-b74, mixed mode)

% jdk1.4_b74/bin/java -client -ms256m -mx256m -cp . perfteam.jetstream.JetStream -r 5 -testfile MapTests.txt

******** Starting run #1 ********
Hashtable Test: 3041
HashMap Test: 2808
TreeMap Test: 3220
******** Starting run #2 ********
Hashtable Test: 2851
HashMap Test: 2788
TreeMap Test: 2979
******** Starting run #3 ********
Hashtable Test: 2831
HashMap Test: 2764
TreeMap Test: 3050
******** Starting run #4 ********
Hashtable Test: 2833
HashMap Test: 2783
TreeMap Test: 3086
******** Starting run #5 ********
Hashtable Test: 2852
HashMap Test: 2818
TreeMap Test: 3053
Overall Score: 69818

You would see the regression on HashMap sub-test.