Compiling optimized release build with debug info turns off optimizations?

[Mikko Ronkainen]

I want to profile a program with a profiler (say Intel VTune). If 
I have understood correctly, the build to be profiled should be 
an optimized release version. It would be beneficial to have 
debug info in that profile build though so that the profiler can 
show correct functions names etc.

Now if I add -g to an optimized build (-O3 -release) in LDC, it 
seems that all/some optimizations are turned off. The debug (-g) 
and profile (-O3 -release -g) builds have the same performance. 
Release (-O3 -release) is noticeably faster.

The profile build works as expected in GDC.

I don't know if this something to do with this: 
http://forum.dlang.org/thread/iiqppmojezdrmnsfienq@forum.dlang.org