https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100236
Richard Earnshaw <rearnsha at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Ever confirmed|0 |1 Last reconfirmed| |2021-04-26 Status|UNCONFIRMED |NEW --- Comment #2 from Richard Earnshaw <rearnsha at gcc dot gnu.org> --- Confirmed. The macro THUMB2_WORK_REGS expands to (0xff & ~( (1 << THUMB_HARD_FRAME_POINTER_REGNUM) \ | (1 << SP_REGNUM) | (1 << PC_REGNUM) \ | (1 << PIC_OFFSET_TABLE_REGNUM))) But PIC_OFFSET_TABLE_REGNUM in turn expands to arm_pic_register which may be INVALID_REGNUM (~0) in some circumstances.