nightly failure after 6431242 putback:
#
# An unexpected error has been detected by Java Runtime Environment:
#
#  Internal Error (/net/prt-solx86-q1-2/PrtBuildDir/workspace/src/share/vm/opto/
matcher.cpp, 1340), pid=16889, tid=9
#
# Java VM: Java HotSpot(TM) Server VM (20061016093837.yq123930.hs-c2-debug compi
led mode)
#
# Error: assert(false,"bad AD file")
# 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 (0x081c7800):  JavaThread "CompilerThread0" daemon [_thread_in_na
tive, id=9]

Stack: [0x77e26000,0x77e66000),  sp=0x77e63f58,  free space=247k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V  [libjvm.so+0xbd0d70] void VMError::report_and_die() + 0x520
V  [libjvm.so+0x37bf77] void report_assertion_failure(const char*,int,const char*) + 0x5f
V  [libjvm.so+0x8d5f72] Node*Matcher::Label_Root(const Node*,State*,Node*,constNode*) + 0x652
V  [libjvm.so+0x8d5cea] Node*Matcher::Label_Root(const Node*,State*,Node*,constNode*) + 0x3ca
V  [libjvm.so+0x8d5cea] Node*Matcher::Label_Root(const Node*,State*,Node*,constNode*) + 0x3ca
V  [libjvm.so+0x8d5015] MachNode*Matcher::match_tree(const Node*) + 0x1ad
V  [libjvm.so+0x8d34a3] Node*Matcher::xform(Node*,int) + 0x5ef
V  [libjvm.so+0x8d08b6] void Matcher::match() + 0x716
V  [libjvm.so+0x3108d9] void Compile::Code_Gen() + 0x10d
V  [libjvm.so+0x30bb05] Compile::Compile(ciEnv*,C2Compiler*,ciMethod*,int,bool) + 0xc59
V  [libjvm.so+0x1f8a08] void C2Compiler::compile_method(ciEnv*,ciMethod*,int) + 0x68
V  [libjvm.so+0x31e50c] void CompileBroker::invoke_compiler_on_method(CompileTask*) + 0xbd0
V  [libjvm.so+0x31d010] void CompileBroker::compiler_thread_loop() + 0x798
V  [libjvm.so+0xaf7bb2] void compiler_thread_entry(JavaThread*,Thread*) + 0x2a
V  [libjvm.so+0xaf093e] void JavaThread::thread_main_inner() + 0x16e
V  [libjvm.so+0xaf067d] void JavaThread::run() + 0x359
V  [libjvm.so+0x96073b] java_start + 0xe3
C  [libc.so.1+0x9f92e] __divdi3 + 0xe
C  [libc.so.1+0x9fc10] _t_cancel + 0x10e


Current CompileTask:
C2:1846   b  sun.security.provider.ByteArrayAccess.i2bBig4
Posted Date : 2006-10-18 21:53:30.0

N/A

It is caused of the change in match_into_reg:

+   // make ReverseBytesI/ReverseBytesL match normal when there exists control
+   int n_opcode = n->Opcode();
+ 
+   if ((n_opcode  == Op_ReverseBytesI || n_opcode == Op_ReverseBytesL) && control) 
+      return false;
+ 
See Test.java of 6431242. 
The code here is to avoid generating code spilling onto stack, since load followed reverse can use loadI_reversed rule. If without this code, the generated code will first spilling the value to stack then read reversely back and cost more instruction cycles. 

I missed a check of if the code is shared, it is not shared at above condition, return false go through the normal match tree.
Posted Date : 2006-10-18 23:46:30.0

A simplified test case attached for reproduction.
Posted Date : 2006-10-18 23:56:47.0