Building Xerces 3.1.2 with cl-clang in VS2010/2013 is very very slow and fails

Versions:
   Xerces C++ 3.1.2 release (svn co asf - Revision 1903652: /xerces/c/tags/Xerces-C_3_1_2)
   LLVM-3.7.0-r239299-win32.exe (from 9.6.2015-13:30)
   VS2013 (Update 4)

Bulding Debug/Release:
c:\temp\Xerces-C_3_1_2\projects\Win32\VC12\xerces-all\xerces-all.sln

gives:

Output:
1> PHI node entries do not match predecessors!
1> %cast.result74 = phi %"class.xercesc_3_1::DOMNode"* [ %9, %cast.notnull.71 ], [ null, %entry ], !dbg !957
1> label %entry
1>CL : fatal error : error in backend: Broken function found, compilation aborted!
1>clang-cl.exe : error : clang frontend command failed with exit code 70 (use -v to see invocation)
1> clang version 3.7.0 (trunk)
1> Target: i686-pc-windows-msvc
1> Thread model: posix
1> clang-cl.exe: note: diagnostic msg: PLEASE submit a bug report to http://llvm.org/bugs/ and include the crash backtrace, preprocessed source, and associated run script.
1> clang-cl.exe: note: diagnostic msg:

Error-List:
Error 190 error : error in backend: Broken function found, compilation aborted! c:\temp\Xerces-C_3_1_2\projects\Win32\VC12\xerces-all\XercesLib\CL
Error 191 error : clang frontend command failed with exit code 70 (use -v to see invocation) c:\temp\Xerces-C_3_1_2\projects\Win32\VC12\xerces-all\XercesLib\clang-cl.exe

the microsoft cl-VS2010/VS2013 (without threaded compile and /MP) compiles in this szenario serveral (5 or more) times faster then cl-clang

anything (how to use the -v switch?) i can do to reduce the bug information further?

Try disabling C++ exceptions. The implementation suffers from problems like these and needs LLVM IR changes to support it.

I should really disconnect the /EHs flag and add some /EHexperimental-cxx-exceptions flag to clang-cl, honestly.

Try disabling C++ exceptions.

Xerces uses try/catch all over the place

I should really disconnect
the /EHs flag and add some
/EHexperimental-cxx-exceptions
flag to clang-cl, honestly.

yupp that would be great - most of the "bugs" i found can be removed by disabling exceptions
- and even the try/catch user can the be then checked if buildable

Circling back around, I recently disabled C++ EH by default on Windows.

The slowness is probably not having /MP.

as stated serveral times before VS2010 still beats clang-cl (by the nearly same factor) if /MP is disabled and the number of concurrent builds is set to 1

i will try again later next week

FWIW, I also see slowdowns like this on our buildbot:
http://lab.llvm.org:8011/builders/clang-x86-win2008-selfhost/builds/1962
The stage 1 incremental build is 2.5m and the stage 2 build takes 26m. This
is an optimized build with assertions enabled, though, so it's not an
apples-to-apples comparision.