BL Branch with Link Branch with Link branches to a PC-relative offset, setting the register X30 to PC+4. It provides a hint that this is a subroutine call. 1 0 0 1 0 1 BL <label> BranchType branch_type = if op == '1' then BranchType_DIRCALL else BranchType_DIR; bits(64) offset = SignExtend(imm26:'00', 64); <label> Is the program label to be unconditionally branched to. Its offset from the address of this instruction, in the range +/-128MB, is encoded as "imm26" times 4. if branch_type == BranchType_DIRCALL then if HaveGCS() && GCSPCREnabled(PSTATE.EL) then AddGCSRecord(PC[] + 4); X[30, 64] = PC[] + 4; boolean branch_conditional = FALSE; BranchTo(PC[] + offset, branch_type, branch_conditional);