libgmp-3.dll missing from windows binary release

[js.mdnq]

I'm trying to test gdc for Win/x64, I too get the same errors 
about missing dll's.

This was my process:

1. Install tdm64-gcc-4.7.1-3.exe
2. Extract gcc-4.6.1-tdm64-1-gdc-20121117-D2.060.7z to the 
MinGW64 install dir.

Tried running gdc.exe and x86_64-w64-mingw32-gdc.exe and both 
complain about missing dlls. The dlls files exist

\MinGW64\libexec\gcc\x86_64-w64-mingw32\4.7.1\

(gdc is in the MinGW64\bin dir)

Copying the dlls to the gdc allows it to find them(So obviously 
there is a path issue. Someone is making an assuming where the 
libs should be found but hasn't told the rest of us).

The new error is

/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/4.6.1/../../../../x86_64-w64-mingw32/bin/ld.exe: 
cannot find -lgcc

I've tried copying the root bin to this bin's dir but no luck.

Also, when I run gdc under visual D I get the original missing 
dll's errors.

So there seems to be a huge issue with how mingw-gdc is using 
paths. (Does a LIB environmental variable need to be set?)

As far as the last error, I'm not sure. I've never really used 
gcc and there is virtually no info on that error on google. I can 
compile the d code but cannot link it.