[ARM] VFP11 denorm erratum workaround in linker

[Nick Clifton]

Hi Julian,

> OK now?

Yes - thanks for taking the time to rework the patch.

>     bfd/
>     * bfd-in2.h: Regenerate.
>     * bfd-in.h (bfd_arm_vfp11_fix): New enum. Specify how VFP11
>     instruction scanning should be done.
>     (bfd_elf32_arm_init_maps, bfd_elf32_arm_vfp11_erratum_scan)
>     (bfd_elf32_arm_vfp11_fix_veneer_locations): Add prototypes.
>     (bfd_elf32_arm_set_target_relocs): Add vfp11 fix type argument to
>     prototype.
>     * elf-bfd.h (elf_backend_write_section): Add struct bfd_link_info
>     argument.
>     * elf32-arm.c (VFP11_ERRATUM_VENEER_SECTION_NAME)
>     (VFP11_ERRATUM_VENEER_ENTRY_NAME): Define macros.
>     (elf32_vfp11_erratum_type): New enum.
>     (elf32_vfp11_erratum_list): New struct. List of veneers or jumps to
>     veneers.
>     (_arm_elf_section_data): Add mapsize, erratumcount, erratumlist.
>     (elf32_arm_link_hash_table): Add vfp11_erratum_glue_size,
>     vfp11_fix and num_vfp11_fixes fields.
>     (elf32_arm_link_hash_table_create): Initialise vfp11_fix,
>     vfp11_erratum_glue_size, num_vfp11_fixes fields.
>     (VFP11_ERRATUM_VENEER_SIZE): Define. Size of an (ARM) veneer.
>     (bfd_elf32_arm_allocate_interworking_sections): Initialise erratum
>     glue section.
>     (elf32_arm_section_map_add): Add an code/data mapping symbol entry
>     to a section's map.
>     (record_vfp11_erratum_veneer): Create a single veneer, and its
>     associated symbols.
>     (bfd_elf32_arm_add_glue_sections_to_bfd): Add vfp11 erratum glue.
>     (bfd_elf32_arm_init_maps): Initialise mapping symbol table for input
>     BFDs.
>     (bfd_elf32_arm_set_vfp11_fix): Set the type of erratum workaround
>     required.
>     (bfd_arm_vfp11_pipe): Define VFP11 instruction pipes.
>     (bfd_arm_vfp11_regno): Recode a register number from a VFP11 insn.
>     (bfd_arm_vfp11_write_mask): Update write mask according to coded
>     register number.
>     (bfd_arm_vfp11_antidependency): New function.
>     (bfd_arm_vfp11_insn_decode): Decode a VFP11 insn.
>     (elf32_arm_compare_mapping): Declare.
>     (bfd_elf32_arm_vfp11_erratum_scan): Scan the sections of an input
>     BFD for potential erratum-triggering insns. Record results.
>     (bfd_elf32_arm_vfp11_fix_veneer_locations): Find out where veneers
>     and branches to veneers have been placed in virtual memory after
>     layout.
>     (bfd_elf32_arm_set_target_relocs): Set vfp11_fix field in global
>     hash table.
>     (elf32_arm_output_symbol_hook): Remove.
>     (elf32_arm_write_section): Output veneers, and branches to veneers.
>     Use maps from input sections, not output sections, for code
>     byte-swapping.
>     * elf32-ppc.c (ppc_elf_write_section): Add dummy link_info argument.
>     * elf32-score.c (_bfd_score_elf_write_section): Likewise.
>     * elfxx-mips.c (_bfd_mips_elf_write_section): Likewise.
>     * elfxx-mips.h (_bfd_mips_elf_write_section): Likewise.
> 
>     ld/
>     * NEWS: Mention --vfp11-denorm-fix option.
>     * ld.texinfo: Document above.
>     * emulparams/armelf_linux.sh (OTHER_TEXT_SECTIONS): Add
>     .vfp11_veneer section.
>     * emulparams/armelf.sh (OTHER_TEXT_SECTIONS): Likewise.
>     * emultempl/armelf.em (vfp11_denorm_fix): New static variable.
>     (arm_elf_before_allocation): Call bfd_elf32_arm_set_vfp11_fix,
>     bfd_elf32_arm_init_maps and bfd_elf32_arm_vfp11_erratum_scan.
>     (arm_elf_after_allocation): New function. Call
>     bfd_elf32_arm_vfp11_fix_veneer_locations for all input statements.
>     (arm_elf_create_output_section_statements): Pass vfp11 fix command
>     line option to BFD.
>     (OPTION_VFP11_DENORM_FIX): New option.
>     (PARSE_AND_LIST_LONGOPTS): Handle new option.
>     (PARSE_AND_LIST_OPTIONS): Likewise.
>     (PARSE_AND_LIST_ARGS_CASES): Likewise.
>     (LDEMUL_AFTER_ALLOCATION): Define.
> 
>     ld/testsuite/
>     * ld-arm/arm-elf.exp: Add VFP11 tests.
>     * ld-arm/vfp11-fix-none.s: New file.
>     * ld-arm/vfp11-fix-none.d: Expected disassembly of above.
>     * ld-arm/vfp11-fix-scalar.s: New file.
>     * ld-arm/vfp11-fix-scalar.d: Expected disassembly of above.
>     * ld-arm/vfp11-fix-vector.s: New file.
>     * ld-arm/vfp11-fix-vector.d: Expected disassembly of above.

Approved - please apply.

Cheers
   Nick