On Mon, 3 Aug 2015, Michael Meissner wrote: > The intention of theese changes (currently unwritten) is to change the > existing > problematical names that use TF in their name to be something else, and > provide > via a weak reference an alias for the old name. So if for example, we change > the default in GCC 7.0, code compiled by GCC 6.0 would work because it uses > say > __gcc_ltoq to call convert a 64-bit integer to IBM extended double instead of > __floatditf. Older code that refers to __floatditf would still work fine.
But as those names are in the implementation namespace and aren't user-visible, I don't see the point in such a change (other than as part of a complete new incompatible ABI which gets its own copies of libgcc, libstdc++, libc, libm and other affected libraries). Of course it *can* be done via symbol versioning to keep working with existing binaries / shared libraries using the existing symbols from libgcc, but the libgcc build system doesn't make that sort of target-specific symbol versioning particularly convenient. And as usual with symbol versioning, you'd break compatibility with existing static libraries / .o files. -- Joseph S. Myers jos...@codesourcery.com
