[MicroBlaze] PIC data text relative

Andrew Sadek <andrew.sadek.se@gmail.com>

A new implemented feature in GCC Microblaze that allows Position
Independent Code to run using Data Text Relative addressing instead
of using Global Offset Table.

Its aim was to make 'PIC' more efficient and flexible as elf size
excess performance overhead were noticed when using GOT due to the
indirect addressing.

include/ChangeLog:
	* bfdlink.h (Add flag): Add new flag @ 'bfd_link_info' struct.
	* elf/microblaze.h (Add 3 new relocations):
	R_MICROBLAZE_TEXTPCREL_64, R_MICROBLAZE_TEXTREL_64
	and R_MICROBLAZE_TEXTREL_32_LO for relax function.
bfd/ChangeLog:
	* bfd/reloc.c (2 new BFD relocations):
	BFD_RELOC_MICROBLAZE_64_TEXTPCREL &
	BFD_RELOC_MICROBLAZE_64_TEXTPCREL
	* bfd/bfd-in2.h: Regenerate
	* bfd/libbfd.h: Regenerate
	* bfd/elf32-microblaze.c (Handle new relocs): define 'HOWTO' of 3
	new relocs and handle them in both relocate and relax functions.
	(microblaze_elf_reloc_type_lookup): add mapping between for new
	bfd relocs.
	(microblaze_elf_relocate_section): Handle new relocs in case of
	elf relocation.
	(microblaze_elf_relax_section): Handle new relocs for elf relaxation.
gas/ChangeLog:
	* gas/config/tc-microblaze.c (Handle new relocs directives in
	assembler): Handle new relocs from compiler output.
	(imm_types): add new imm types for data text relative addressing
	TEXT_OFFSET, TEXT_PC_OFFSET
	(md_convert_frag): conversion for BFD_RELOC_MICROBLAZE_64_TEXTPCREL,
	BFD_RELOC_MICROBLAZE_64_TEXTPCREL
	(md_apply_fix): apply fix for BFD_RELOC_MICROBLAZE_64_TEXTPCREL,
	BFD_RELOC_MICROBLAZE_64_TEXTPCREL
	(md_estimate_size_before_relax): estimate size for
	BFD_RELOC_MICROBLAZE_64_TEXTPCREL,
	BFD_RELOC_MICROBLAZE_64_TEXTPCREL
	(tc_gen_reloc): generate relocations for
	BFD_RELOC_MICROBLAZE_64_TEXTPCREL,
	BFD_RELOC_MICROBLAZE_64_TEXTPCREL
ld/ChangeLog:
	* ld/lexsup.c (Add 2 ld options):
	(ld_options): add disable-multiple-abs-defs @ 'ld_options' array
	(parse_args): parse new option and pass flag to 'link_info' struct.
	* ld/ldlex.h (Add enum): add new enum @ 'option_values' enum.
	* ld/ld.texinfo (Add new option): Add description for
	'disable-multiple-abs-defs'
	* ld/main.c: Initialize flags with false @ 'main'. Handle
	disable-multiple-abs-defs @ 'mutiple_definition'.

1 files changed, 8 insertions, 6 deletions

diff --git a/ld/ldmain.c b/ld/ldmain.c
index 43602fe..f31eeb2 100644
--- a/ld/ldmain.c
+++ b/ld/ldmain.c
@@ -280,6 +280,7 @@ main (int argc, char **argv)
   link_info.keep_memory = TRUE;
   link_info.combreloc = TRUE;
   link_info.strip_discarded = TRUE;
+  link_info.prohibit_multiple_definition_absolute = FALSE;
   link_info.emit_hash = DEFAULT_EMIT_SYSV_HASH;
   link_info.emit_gnu_hash = DEFAULT_EMIT_GNU_HASH;
   link_info.callbacks = &link_callbacks;
@@ -968,12 +969,13 @@ multiple_definition (struct bfd_link_info *info,
      discarded, and this is not really a multiple definition at all.
      FIXME: It would be cleaner to somehow ignore symbols defined in
      sections which are being discarded.  */
-  if ((osec->output_section != NULL
-       && !bfd_is_abs_section (osec)
-       && bfd_is_abs_section (osec->output_section))
-      || (nsec->output_section != NULL
-	  && !bfd_is_abs_section (nsec)
-	  && bfd_is_abs_section (nsec->output_section)))
+  if (!info->prohibit_multiple_definition_absolute
+      && ((osec->output_section != NULL
+	   && ! bfd_is_abs_section (osec)
+	   && bfd_is_abs_section (osec->output_section))
+	  || (nsec->output_section != NULL
+	      && !bfd_is_abs_section (nsec)
+	      && bfd_is_abs_section (nsec->output_section))))
     return;
 
   name = h->root.string;