https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87871
--- Comment #24 from Peter Bergner <bergner at gcc dot gnu.org> ---
So improve_allocation() initially looks at using r0, but disregards it because
check_hard_reg_p() returns false for r0, and that is because we fail this test:
/* Checking only profitable hard regs. */
if (! TEST_HARD_REG_BIT (profitable_regs, hard_regno))
return false;
I don't know why r0 isn't in profitable_regs for pseudo 116.
