Add PowerPC64 ld --tls-get-addr-optimize.

Sometimes it may be of benefit to force use of the __tls_get_addr_opt
call stub even when the glibc being used during linking does not
advertise __tls_get_addr_opt.

bfd/
	* elf64-ppc.h (struct ppc64_elf_params <tls_get_addr_opt>): Rename
	from no_tls_get_addr_opt.
	* elf64-ppc.c: Update for rename and inversion of tls_get_addr_opt.
	(ppc64_elf_tls_setup): Set tls_get_addr_opt to 0 only when at
	default of -1.
ld/
	* emultempl/ppc64elf.em (params): Init tls_get_addr_opt field to -1.
	(OPTION_TLS_GET_ADDR_OPT): Define.
	(PARSE_AND_LIST_LONGOPTS): Handle --tls-get-addr-opt.
	(PARSE_AND_LIST_OPTIONS, PARSE_AND_LIST_ARGS_CASES): Likewise.
	* ld.texinfo: Document --tls-get-addr-optimize and
	--no-tls-get-addr-optimize.

3 files changed, 17 insertions, 9 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 26a0537..3e0c7b8 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,11 @@
+2015-09-18  Alan Modra  <amodra@gmail.com>
+
+	* elf64-ppc.h (struct ppc64_elf_params <tls_get_addr_opt>): Rename
+	from no_tls_get_addr_opt.
+	* elf64-ppc.c: Update for rename and inversion of tls_get_addr_opt.
+	(ppc64_elf_tls_setup): Set tls_get_addr_opt to 0 only when at
+	default of -1.
+
 2015-09-17  Alan Modra  <amodra@gmail.com>
 
 	PR 18867
diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index f179f6d..5ad5f48 100644
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -8136,7 +8136,7 @@ ppc64_elf_tls_setup (struct bfd_link_info *info)
   htab->tls_get_addr_fd = ((struct ppc_link_hash_entry *)
 			   elf_link_hash_lookup (&htab->elf, "__tls_get_addr",
 						 FALSE, FALSE, TRUE));
-  if (!htab->params->no_tls_get_addr_opt)
+  if (htab->params->tls_get_addr_opt)
     {
       struct elf_link_hash_entry *opt, *opt_fd, *tga, *tga_fd;
 
@@ -8203,8 +8203,8 @@ ppc64_elf_tls_setup (struct bfd_link_info *info)
 		}
 	    }
 	}
-      else
-	htab->params->no_tls_get_addr_opt = TRUE;
+      else if (htab->params->tls_get_addr_opt < 0)
+	htab->params->tls_get_addr_opt = 0;
     }
   return _bfd_elf_tls_setup (info->output_bfd, info);
 }
@@ -10125,7 +10125,7 @@ ppc64_elf_size_dynamic_sections (bfd *output_bfd,
 	    return FALSE;
 	}
 
-      tls_opt = (!htab->params->no_tls_get_addr_opt
+      tls_opt = (htab->params->tls_get_addr_opt
 		 && htab->tls_get_addr_fd != NULL
 		 && htab->tls_get_addr_fd->elf.plt.plist != NULL);
       if (tls_opt || !htab->opd_abi)
@@ -10310,7 +10310,7 @@ plt_stub_size (struct ppc_link_hash_table *htab,
   if (stub_entry->h != NULL
       && (stub_entry->h == htab->tls_get_addr_fd
 	  || stub_entry->h == htab->tls_get_addr)
-      && !htab->params->no_tls_get_addr_opt)
+      && htab->params->tls_get_addr_opt)
     size += 13 * 4;
   return size;
 }
@@ -10354,7 +10354,7 @@ build_plt_stub (struct ppc_link_hash_table *htab,
       && plt_thread_safe
       && !((stub_entry->h == htab->tls_get_addr_fd
 	    || stub_entry->h == htab->tls_get_addr)
-	   && !htab->params->no_tls_get_addr_opt))
+	   && htab->params->tls_get_addr_opt))
     {
       bfd_vma pltoff = stub_entry->plt_ent->plt.offset & ~1;
       bfd_vma pltindex = ((pltoff - PLT_INITIAL_ENTRY_SIZE (htab))
@@ -11005,7 +11005,7 @@ ppc_build_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
       if (stub_entry->h != NULL
 	  && (stub_entry->h == htab->tls_get_addr_fd
 	      || stub_entry->h == htab->tls_get_addr)
-	  && !htab->params->no_tls_get_addr_opt)
+	  && htab->params->tls_get_addr_opt)
 	p = build_tls_get_addr_stub (htab, stub_entry, loc, off, r);
       else
 	p = build_plt_stub (htab, stub_entry, loc, off, r);
@@ -13911,7 +13911,7 @@ ppc64_elf_relocate_section (bfd *output_bfd,
 			  if (h != NULL
 			      && (h == htab->tls_get_addr_fd
 				  || h == htab->tls_get_addr)
-			      && !htab->params->no_tls_get_addr_opt)
+			      && htab->params->tls_get_addr_opt)
 			    {
 			      /* Special stub used, leave nop alone.  */
 			    }
diff --git a/bfd/elf64-ppc.h b/bfd/elf64-ppc.h
index 19f72b5..d035ffc 100644
--- a/bfd/elf64-ppc.h
+++ b/bfd/elf64-ppc.h
@@ -34,7 +34,7 @@ struct ppc64_elf_params
   bfd_signed_vma group_size;
 
   /* Whether to use a special call stub for __tls_get_addr.  */
-  int no_tls_get_addr_opt;
+  int tls_get_addr_opt;
 
   /* Whether to allow multiple toc sections.  */
   int no_multi_toc;