Dear all,

While testing my code under cygwin I'm observing the following error that might
indicate some problems with llvm libraries shipped. I narrowed down the test
code to a single cpp file, that if compiled and run against a GL-enabled XWin
server, fails to execute a GL request that in turn executes a compiled GLSL
code. 

The error displayed by the test code is this:

LLVM ERROR: Program used external function '___chkstk_ms' which could not be resolved!

Googling and experimenting seems to hint that under certain conditions the
underlying GLSL compiler creates assembly that relies on the ___chkstk_ms
symbol, that is unavailable for one or another reason.

Please find attached the test code in cygwin-llvm.cpp, its strace output,
cygcheck.out, gcc -v output, and XWin.0.log. I would be glad to produce more
information if needed.

PS: my X server doesn't use hardware rendering (libGL says 'Screen is not
Windows-DRI capable').  Also lines 1429-1430 in the strace output show dlsym()
failure, and suggest that this is not a X server error.




-- 
Sincerely,
	Dmitry Karasik