We got next failure with OptimizeStringConcat:

% /java/re/jdk/7/latest/binaries/solaris-amd64/fastdebug/bin/java -d64 -version
java version "1.7.0-ea-fastdebug"
Java(TM) SE Runtime Environment (build 1.7.0-ea-fastdebug-b100)
Java HotSpot(TM) 64-Bit Server VM (build 19.0-b03-fastdebug, mixed mode)

% /java/re/jdk/7/latest/binaries/solaris-amd64/fastdebug/bin/java -d64 -Xcomp -XX:+OptimizeStringConcat -XX:CompileThreshold=100 -XX:+AggressiveOpts -XX:+UseCompressedOops -XX:+CompileTheWorld -XX:CompileTheWorldStartAt=2001 -XX:CompileTheWorldStopAt=3000 -XX:MaxPermSize=384M -Xmx512M -Xbootclasspath/p:/java/re/jdk/7/latest/binaries/solaris-amd64/jre/lib/rt.jar

CompileTheWorld (2150) : com/sun/jndi/ldap/LdapCtx$SearchArgs
CompileTheWorld (2151) : com/sun/jndi/ldap/LdapCtx
#
# A fatal error has been detected by the Java Runtime Environment:
#
# SIGSEGV (0xb) at pc=0xfffffd7f2f45a30c, pid=23223, tid=50
#
# JRE version: 7.0
# Java VM: Java HotSpot(TM) 64-Bit Server VM (19.0-b03-fastdebug compiled mode solaris-amd64 compressed oops)
# Problematic frame:
# V [libjvm.so+0x18ba30c]
#
# An error report file with more information is saved as:
# /export/kvn/VM/hs_err_pid23223.log
#
# If you would like to submit a bug report, please visit:
# http://java.sun.com/webapps/bugreport/crash.jsp
#
 
--------------- T H R E A D ---------------
 
Current thread (0x0000000003290800): JavaThread "CompilerThread0" daemon [_thread_in_native, id=50, stack(0xfffffd7ff80cc000,0xfffffd7ff81cc000)]
 
siginfo:si_signo=SIGSEGV: si_errno=0, si_code=1 (SEGV_MAPERR), si_addr=0x0000000000000020
 
Registers:
RAX=0x0000000000000000, RBX=0x0000000000000014, RCX=0x00000000fffffffe, RDX=0x0000000000000040
RSP=0xfffffd7ff81c2f40, RBP=0xfffffd7ff81c2fc0, RSI=0x000000000426e5f8, RDI=0xfffffd7ff81c4490
R8=0x0000000000000000, R9=0x00000000037a38b0, R10=0x000000000431aa58, R11=0x000000000431aa58
R12=0x0000000003b1dfa8, R13=0xfffffd7ff81c4490, R14=0x00000000037a3950, R15=0x000000000426e5f8
RIP=0xfffffd7f2f45a30c, RFLAGS=0x0000000000010282
 
Top of Stack: (sp=0xfffffd7ff81c2f40)
0xfffffd7ff81c2f40: fffffd7ff81c4490 0000000000000001
0xfffffd7ff81c2f50: fffffd7ff81c2fc0 fffffd7f2f459196
0xfffffd7ff81c2f60: 00000000037a3858 fffffd7f2f7655dc
0xfffffd7ff81c2f70: 000000000426d9b8 fffffd7f30007eb8
0xfffffd7ff81c2f80: 000000043000b5a2 fffffd7f30009239
0xfffffd7ff81c2f90: 000000000361a558 00000000032aaf78
0xfffffd7ff81c2fa0: 00000000000001e7 fffffd7ff81c4490
0xfffffd7ff81c2fb0: 00000000037a3950 0000000000000001
0xfffffd7ff81c2fc0: fffffd7ff81c30e0 fffffd7f2f768fd7
0xfffffd7ff81c2fd0: 0000000003290800 fffffd7f301da000
0xfffffd7ff81c2fe0: fffffd7f2f459170 fffffd7f30009239
0xfffffd7ff81c2ff0: 0000000000000001 fffffd7f30007eb8
0xfffffd7ff81c3000: fffffd7f00000002 fffffd7f30009221
0xfffffd7ff81c3010: 0000000000000000 fffffd7ff81c4e28
0xfffffd7ff81c3020: 00000000037e4768 fffffd7f30007eb8
0xfffffd7ff81c3030: fffffd7f30009c13 fffffd7f30009bfb
0xfffffd7ff81c3040: fffffd7f30007ec8 fffffd7f301bc6ce
0xfffffd7ff81c3050: fffffd7f30009bc7 fffffd7f30009b90
0xfffffd7ff81c3060: fffffd7f30009b60 fffffd7f30210a07
0xfffffd7ff81c3070: fffffd7f30008f38 fffffd7f30008efe
0xfffffd7ff81c3080: fffffd7f30008ef0 fffffd7f30008fa3
0xfffffd7ff81c3090: fffffd7f30008f7f fffffd7f30008f71
0xfffffd7ff81c30a0: fffffd7f300098f1 fffffd7f300098a4
0xfffffd7ff81c30b0: fffffd7f300098a3 00000000032aaf78
0xfffffd7ff81c30c0: fffffd7f302818c8 fffffd7ff81c4490
0xfffffd7ff81c30d0: 00000000037a3950 00000000037b84f0
0xfffffd7ff81c30e0: fffffd7ff81c3ef0 fffffd7f2f767564
0xfffffd7ff81c30f0: fffffd7ff81c31e0 fffffd7ff81c4ec0
0xfffffd7ff81c3100: fffffd7f3000993b fffffd7f30009925
0xfffffd7ff81c3110: fffffd7f30007ec4 fffffd7f3021087f
0xfffffd7ff81c3120: fffffd7f302109fb fffffd7f3000ae3c
0xfffffd7ff81c3130: fffffd7f300094a0 fffffd7f3000948a
 
Instructions: (pc=0xfffffd7f2f45a30c)
0xfffffd7f2f45a2fc: c1 f5 83 f9 03 49 c7 c0 00 00 00 00 49 0f 47 c0
0xfffffd7f2f45a30c: 48 8b 78 20 e8 fb a7 f0 fe 48 8b f8 8b f3 e8 41
 
Stack: [0xfffffd7ff80cc000,0xfffffd7ff81cc000], sp=0xfffffd7ff81c2f40, free space=3db0000000000000001k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.so+0x18ba30c] const Type*LoadNode::Value(PhaseTransform*)const + 0x40c
V [libjvm.so+0x1bc8fd7] Node*PhaseIterGVN::transform_old(Node*) + 0x887
V [libjvm.so+0x1bc7564] void PhaseIterGVN::optimize() + 0x694
V [libjvm.so+0x17cfc7c] void PhaseIdealLoop::build_and_optimize(bool,bool) + 0x103c
V [libjvm.so+0x98d9fe] void Compile::Optimize() + 0x3ae
V [libjvm.so+0x986376] Compile::Compile(ciEnv*,C2Compiler*,ciMethod*,int,bool,bool) + 0x1676
V [libjvm.so+0x73962b] void C2Compiler::compile_method(ciEnv*,ciMethod*,int) + 0x10b
V [libjvm.so+0x9a5de9] void CompileBroker::invoke_compiler_on_method(CompileTask*) + 0x11e9
V [libjvm.so+0x9a3f08] void CompileBroker::compiler_thread_loop() + 0xdb8
V [libjvm.so+0x1f90a14] void JavaThread::thread_main_inner() + 0x1b4
V [libjvm.so+0x1f90651] void JavaThread::run() + 0x621
V [libjvm.so+0x1af1daa] java_start + 0x66a
C [libc.so.1+0x114ad4] _thrp_setup+0xbc _thrp_setup + 0xbc
C [libc.so.1+0x114d90] _lwp_start+0x0 _lwp_start + 0x0
 
 
Current CompileTask:
C2:7239 !b com.sun.jndi.ldap.LdapCtx.connect(Z)V (500 bytes)