This patch adds initial in-gas opcode relaxation for the rl78
backend. Specifically, it checks for conditional branches that
are too far and replaces them with inverted branches around longer
fixed branches.
* elf32-rl78.c (rl78_elf_howto_table): Add R_RL78_RH_RELAX.
(rl78_reloc_map): Add BFD_RELOC_RL78_RELAX.
(rl78_elf_relocate_section): Add R_RL78_RH_RELAX, R_RL78_RH_SFR,
and R_RL78_RH_SADDR.
(rl78_elf_finish_dynamic_sections): Only validate PLT section if
we didn't relax anything, as relaxing might remove a PLT reference
after we've set up the table.
(elf32_rl78_relax_delete_bytes): New.
(reloc_bubblesort): New.
(rl78_offset_for_reloc): New.
(relax_addr16): New.
(rl78_elf_relax_section): Add support for relaxing long
instructions into short ones.
[gas]
* config/rl78-defs.h (rl78_linkrelax_addr16): Add.
(rl78_linkrelax_dsp, rl78_linkrelax_imm): Remove.
* config/rl78-parse.y: Tag all addr16 and branch patterns with
relaxation markers.
* config/tc-rl78.c (rl78_linkrelax_addr16): New.
(rl78_linkrelax_branch): New.
(OPTION_RELAX): New.
(md_longopts): Add relax option.
(md_parse_option): Add OPTION_RELAX.
(rl78_frag_init): Support relaxation.
(rl78_handle_align): New.
(md_assemble): Support relaxation.
(md_apply_fix): Likewise.
(md_convert_frag): Likewise.
* config/tc-rl78.h (MAX_MEM_FOR_RS_ALIGN_CODE): New.
(HANDLE_ALIGN): New.
(rl78_handle_align): Declare.
* config/rl78-parse.y (rl78_bit_insn): New. Set it for all bit
insn patterns.
(find_bit_index): New. Strip .BIT suffix off relevent
expressions for bit insns.
(rl78_lex): Exclude bit suffixes from expression parsing.
[include/elf]
* rl78.h (R_RL78_RH_RELAX, R_RL78_RH_SFR, R_RL78_RH_SADDR): New.
(RL78_RELAXA_BRA, RL78_RELAXA_ADDR16: New.
