[GOLD] PowerPC64 tocsave

This adds support to gold for the tocsave relocs already supported by
ld.bfd.  R_PPC64_TOCSAVE relocs are part of a scheme to move r2 saves
to the prologue of a function rather than in each plt call stub.  We
don't want a compiler to always emit the r2 save, as this would be
wasted if the calls turned out to be local.  See the tocsave*.s in
ld/testsuite/ld-powerpc/.

	* powerpc.cc (Target_powerpc::tocsave_loc_): New var.
	(Target_powerpc::mark_pltcall, add_tocsave, tocsave_loc): New functions.
	(Target_powerpc::Branch_info::tocsave_): New var.
	(Target_powerpc::Branch_info::mark_pltcall): New function.
	(Target_powerpc::Branch_info::make_stub): Pass tocsave_ to
	add_plt_call_entry.
	(Stub_table::Plt_stub_ent): Make public.  Add r2save_.
	(Stub_table::add_plt_call_entry): Add bool tocsave_ param.  Set
	r2save_.
	(Stub_table::find_plt_call_entry): Return Plt_stub_ent*.  Adjust
	use throughout.
	(Stub_table::do_write): Conditionally output r2 save in plt stubs.
	(Target_powerpc::Scan::local): Handle R_PPC64_TOCSAVE.
	(Target_powerpc::Scan::global): Likewise.
	(Target_powerpc::Relocate::relocate): Skip r2 save in plt call stub
	with tocsave reloc.  Replace header tocsave nop with r2 save.
	* symtab.h (struct Symbol_location_hash): Make public.

1 files changed, 10 insertions, 10 deletions

diff --git a/gold/symtab.h b/gold/symtab.h
index 46c7fce..77552ae 100644
--- a/gold/symtab.h
+++ b/gold/symtab.h
@@ -1273,6 +1273,16 @@ struct Symbol_location
   }
 };
 
+// A map from symbol name (as a pointer into the namepool) to all
+// the locations the symbols is (weakly) defined (and certain other
+// conditions are met).  This map will be used later to detect
+// possible One Definition Rule (ODR) violations.
+struct Symbol_location_hash
+{
+  size_t operator()(const Symbol_location& loc) const
+  { return reinterpret_cast<uintptr_t>(loc.object) ^ loc.offset ^ loc.shndx; }
+};
+
 // This class manages warnings.  Warnings are a GNU extension.  When
 // we see a section named .gnu.warning.SYM in an object file, and if
 // we wind using the definition of SYM from that object file, then we
@@ -1695,16 +1705,6 @@ class Symbol_table
   typedef Unordered_map<Symbol_table_key, Symbol*, Symbol_table_hash,
 			Symbol_table_eq> Symbol_table_type;
 
-  // A map from symbol name (as a pointer into the namepool) to all
-  // the locations the symbols is (weakly) defined (and certain other
-  // conditions are met).  This map will be used later to detect
-  // possible One Definition Rule (ODR) violations.
-  struct Symbol_location_hash
-  {
-    size_t operator()(const Symbol_location& loc) const
-    { return reinterpret_cast<uintptr_t>(loc.object) ^ loc.offset ^ loc.shndx; }
-  };
-
   typedef Unordered_map<const char*,
                         Unordered_set<Symbol_location, Symbol_location_hash> >
   Odr_map;