* Fangrui Song: > Hi, I filed https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98112 which > proposes -fdirect-access-external-data to address some x86-64 > GCC/binutils pain[1] and also benefit non-x86 architectures (also see [1] > it can prevent copy relocations). > > [1] Mentioned in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98112#c2 > > Since I am going to add this option to Clang and I hope (once GCC decides to > implement this option the two compilers can use the same option name), I bring > it to your attention.
One worry I have is that people start building shared objects with direct data access, expecting the main program to be built with indirect access. We already see this today with Qt. It's not really supported well by the toolchain and causes frequent issues. Depending on the ELF ABI in question, the new pair of -f options might not actually be meaningful. It really depends on whether you have reasonably-sized displacements available. I think there are some ABIs where the optimization is theoretically possible, but impractical because the ilimit it imposes on data segment (think AArch64 without adrp).
