[PATCH] [MIPS] Add generation of PLT entries with compact jumps for MIPS R6

[Nick Clifton]

Hi Faraz, Hi Matthew,

> Adds a new option to get the linker to emit PLTs that use compact
> branches instead of delay slot branches.
> 
> bfd/
> 	* elfxx-mips.c (LA25_BC): New macro.
> 	(mips_elf_link_hash_table)<compact_branches>: New field.
> 	(STUB_JALRC): New macro.
> 	(mipsr6_o32_exec_plt0_entry_compact): New array.
> 	(mipsr6_n32_exec_plt0_entry_compact): Likewise.
> 	(mipsr6_n64_exec_plt0_entry_compact): Likewise.
> 	(mipsr6_exec_plt_entry_compact): Likewise.
> 	(mips_elf_create_la25_stub): Use BC instead of J for stubs
> 	when compact_branches is true.
> 	(_bfd_mips_elf_finish_dynamic_symbol): Choose the compact
> 	PLT for MIPSR6 with compact_branches.  Do not reorder the
> 	compact branches PLT.  Switch the lazy stub for MIPSR6
> 	with compact_branches to use JALRC.
> 	(mips_finish_exec_plt): Choose the compact PLT0 for MIPSR6
> 	when compact_branches is true.
> 	(_bfd_mips_elf_compact_branches): New function.
> 	* elfxx-mips.h (_bfd_mips_elf_compact_branches): New prototype.
> 
> ld/
> 	* emultempl/mipself.em (compact_branches): New static variable.
> 	(mips_create_output_section_statements): Call
> 	_bfd_mips_elf_compact_branches.
> 	(PARSE_AND_LIST_PROLOGUE): Add OPTION_COMPACT_BRANCHES and
> 	OPTION_NO_COMPACT_BRANCHES.
> 	(PARSE_AND_LIST_LONGOPTS): Add compact-branches,
> 	no-compact-branches.
> 	(PARSE_AND_LIST_OPTIONS): Add --compact-branches,
> 	--no-compact-branches.
> 	(PARSE_AND_LIST_ARGS_CASES): Handle the above.
> 	* ld.texinfo: Document --compact-branches, --no-compact-branches.
> 	* testsuite/ld-mips-elf/pic-and-nonpic-1-r6.dd: New test.
> 	* testsuite/ld-mips-elf/pic-and-nonpic-1-r6.nd: New test.
> 	* testsuite/ld-mips-elf/pic-and-nonpic-3a-r6.dd: New test.
> 	* testsuite/ld-mips-elf/pic-and-nonpic-3a-r6.gd: New test.
> 	* testsuite/ld-mips-elf/pic-and-nonpic-1a-r6.s: New test source.
> 	* testsuite/ld-mips-elf/pic-and-nonpic-3a-r6.s: New test source.
> 	* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
  
Approved - please apply.

Cheers
  Nick