------- Comment #6 from bjoern dot m dot haase at web dot de 2006-09-06 16:51 ------- To clear up the issues.
1.) libgcc provides a fp emulation based on compiled c functions that is to my very best knowledge untested for avr and extremely inefficient. 2.) avr-libc provides fp emulation that is hand-tuned assembly and on a less restrictive license than GPL. IIRC, the person who wrote them is no longer active in the field. 3.) the functions supplied by avr-libc are as basic as "single float add 3", "single float multiply 3", "single float convert to integer 2" ... 4.) the hand-tuned assembly routines should really replace the libgcc ones, but that's not easily feasible. Partly due to licensing issues (modified free bsd for avr-libc), partly because it is very very difficult for us developers to get code integrated into mainline gcc. 5.) the externally supplied functions in libm need the hand-tuned assembly versions in order to operate properly and will failed with the untested libgcc variants. 5.) There is only one single libc and libm implementation available for avr that cooperates with gcc: avr-libc. The suggestion of Joerg Wunsch is, thus, in line with the needs of gcc users for the avr target. Bjoern. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28718
