https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87984
--- Comment #14 from Alexander Monakov <amonakov at gcc dot gnu.org> --- With -fno-tree-fre it's still broken. How long will GCC play this sort of whack-a-mole with ad-hoc restrictions to gimple optimizations (PR 29877, PR 42491, PR 61572)? And this: > for fixed registers there is no need to specify them in clobbers, but users > might still use those fixed registers in asm) as possibly modifying content > of local or global register vars. is not true, we do require inline asm to properly inform the compiler about accessing global register variables by mentioning them in constraints.
