https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110908
--- Comment #6 from zach-gcc at cs dot stanford.edu --- I've resumed using GCC for this project, where I am instrumenting assembly and require that x30 only ever contain addresses (not arbitrary data). I ran into a case where GCC was storing data in x30 while compiling libgcc. The patch listed above appears to have solved the problem. If possible, it would be great for the patch to be merged into mainline. Thanks!
