Now that the avr backend can support 64-bit floats by means of
configure-options --with-double= and --with-long-double=, this patch
series adds some routines to support it.
It's an ad-hoc, avr-specific implementation in assembly and GNU-C which
is added as a new subfolder in libgcc/config/avr/libf7.
Patch 1/3 is the GCC changes: Documentation and new avr-specific
configure options:
--with-libf7 selects to which level double support from libf7 is added
to libgcc.
--with-double-comparison select what FLOAT_LIB_COMPARE_RETURNS_BOOL returns.
I wrote the libf7 code from scratch and put it under GPL v3 + library
exception, so it should be no problem to have it as part of libgcc.
Patch 2/3 is the libgcc additions:
--with-libf7 selects which makefile-snips from libf7 to use.
Patch 3/3 is the actual libf7 implementation. A great deal of which is
assembly, together with C + inline assembly for higher routines.
Ok for trunk?
Johann
