How to build newlib for ARM/thumb, sp -fshort-double is supporte d??

[Jepsen Hans Peter]

Hello 

To get better performance, we want to use the -fshort-double option.
We are using eCos as RTOS.

To us it seems, that the toolchain and eCos supports this. But that
there is one  problem, newlib is not supporting it with the build
instructions on 
http://ecos.sourceware.org/build-toolchain.html. 

Is this correct? 

If yes, how to build newlib, so that -fshort-double works? 

If possible, we would like a multilib build of newlib, so that it
selects 
the correct version of newlib, if -fshort-double is used. 

regards 

Hans Peter