Hi Guys, I am applying the attached patch to add support for position independent data to the RX backend. When this mode is enabled constant data is referenced via an offset from a base address held in a fixed register. This allows the position of this data to be determined at run-time, rather than link-time, and without the overhead of storing relocations in the executable image.
The code was written by DJ Delorie for Renesas and it is now being
contributed back to the FSF.
Cheers
Nick
gcc/ChangeLog
2011-10-05 DJ Delorie <d...@redhat.com>
Nick Clifton <ni...@redhat.com>
* config/rx/rx.opt (mpid): Define.
* config/rx/t-rx (MULTILIB_OPTIONS): Add -mpid
(MULTILIB_DIRNAMES): Add pid.
* config/rx/rx.c (rx_gp_base_regnum_val, rx_pid_base_regnum_val)
(rx_num_interrupt_regs): New variable.
(rx_gp_base_regnum): New function. Returns the number of the
small data area register.
(rx_pid_base_regnum): New function. Returns the number of the pid
base register.
(rx_decl_for_addr): New function. Returns the symbolic part of a
MEM.
(rx_pid_data_operand): New function. Returns whether an object is
in the position independent data area.
(rx_legitimize_address): New function. Puts undecided PID
objects in the PID data area.
(rx_is_legitimate_address): Add support for PID operands.
(rx_print_operand_address): Likewise.
(rx_print_operand): Likewise.
(rx_maybe_pidify_operand): New function. Determine if an operand
is suitable for PID addressing.
(rx_gen_move_template): Add PID support.
(rx_conditional_register_usage): Likewise.
(rx_option_override): Initialise rx_num_interrupt_regs.
(rx_is_legitimate_constant): Add support for PID constants.
(TARGET_LEGITIMIZE_ADDRESS): Define.
* config/rx/constraints.md (Rpid): Define.
(Rpda): Define.
* config/rx/rx.md (UNSPEC_PID_ADDR): Define.
(tablejump): Add PID support.
(mov<>): Likewise.
(mov<>_internal): Likewise.
(addsi3): Convert to an expander. Add PID support.
(pid_addr): New pattern.
* config/rx/rx.h (CPP_SPEC): Define.
(ASM_SPEC): Pass -mpid and -mint-register on to assembler.
(CASE_VECTOR_PC_RELATIVE): Define.
(JUMP_TABLES_IN_TEXT_SECTION): Enable for PID mode.
* config/rx/rx-protos.h (rx_maybe_pidify_operand): Prototype.
* doc/invoke.texi (RX Options): Document -mpid command line
option.
rx.gcc.pid.patch.bz2
Description: BZip2 compressed data
