kristof.beyls added inline comments.
================ Comment at: docs/ReleaseNotes.rst:84 + In a future release of Clang, we intend to change the default to + ``-fno-lax-vector-conversions``. + ---------------- efriedma wrote: > rsmith wrote: > > efriedma wrote: > > > And if you want to allow your code to build with both clang-9 and > > > clang-10, you have to do version detection in your build scripts? > > I guess you'd detect whether the compiler supports > > `-flax-vector-conversions=all`, and pass that if so, and otherwise pass > > `-flax-vector-conversions`. Well, either that or you fix your code to not > > rely on lax vector conversions between int and float vectors. If your code > > builds with GCC, you did that already (they never supported lax conversions > > between float and int vectors, as far as I can tell). > > > > Do you have a preferred alternative? > All the alternatives are terrible in their own way: > > 1. This status quo, which breaks compatibility with previous versions of clang > 2. We could make -flax-vector-conversions mean the same thing as earlier > versions of clang. So the flag wouldn't have the same meaning as gcc's flag. > 3. Some mix of the previous options: we could wait until there are one or two > released versions that support -flax-vector-conversions=all , then change the > meaning of -flax-vector-conversions. But I have no idea how we would decide > on a timeline. > > I ran into this issue recently updating our compiler. That said, the code in > question was only using the implicit conversion in a couple places by > accident, so it was easy enough to just fix the source. Maybe adding an entry in the release notes about this change could help with making option 1 slightly more palatable? My guess is that option 1 is the right one for the long term (compatibility between gcc and clang so code is more portable between both compilers). Repository: rC Clang CHANGES SINCE LAST ACTION https://reviews.llvm.org/D67678/new/ https://reviews.llvm.org/D67678 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
