[GOLD] ppc64 out-of-line register save/restore functions
authorAlan Modra <amodra@gmail.com>
Wed, 2 Sep 2015 06:21:59 +0000 (15:51 +0930)
committerAlan Modra <amodra@gmail.com>
Wed, 2 Sep 2015 06:37:02 +0000 (16:07 +0930)
Gold version of a4b6fadd.  Don't emit long branch or plt branch stubs
to save/restore functions.  Copy them instead.

PR 18878
* powerpc.cc (Target_powerpc): Add savres_section_ and accessor.
(Target_powerpc::Branch_info::make_stub): Determine whether long
branch stub is for save/restore function.
(Branch_stub_ent): Add save_res_, and extra parm to constructor.
(Stub_table): Add need_save_res_.
(Stub_table:clear_stubs): Clear need_save_res_.
(Stub_table:set_address_and_size): Add save/restore section size.
(Stub_table::add_long_branch_entry): Add save_res param.  Set
need_save_res_, but don't add space for save/restore stubs.
(Stub_table::find_long_branch_entry): Return offset to local copy
of save/restore func.
(Stub_table::do_write): Don't output save/restore stubs.  Instead
copy the save/restore functions.
(Output_data_save_res:contents): New accessor.
(Target_powerpc::define_save_restore_funcs): Set savres_section_.

gold/ChangeLog
gold/powerpc.cc

index 5d0a764d0e6e2f20eba3ec3984630e48006e8fd7..5194fd5db1826a816b87bdf32941ed7a7c9bb790 100644 (file)
@@ -1,3 +1,22 @@
+2015-09-02  Alan Modra  <amodra@gmail.com>
+
+       PR 18878
+       * powerpc.cc (Target_powerpc): Add savres_section_ and accessor.
+       (Target_powerpc::Branch_info::make_stub): Determine whether long
+       branch stub is for save/restore function.
+       (Branch_stub_ent): Add save_res_, and extra parm to constructor.
+       (Stub_table): Add need_save_res_.
+       (Stub_table:clear_stubs): Clear need_save_res_.
+       (Stub_table:set_address_and_size): Add save/restore section size.
+       (Stub_table::add_long_branch_entry): Add save_res param.  Set
+       need_save_res_, but don't add space for save/restore stubs.
+       (Stub_table::find_long_branch_entry): Return offset to local copy
+       of save/restore func.
+       (Stub_table::do_write): Don't output save/restore stubs.  Instead
+       copy the save/restore functions.
+       (Output_data_save_res:contents): New accessor.
+       (Target_powerpc::define_save_restore_funcs): Set savres_section_.
+
 2015-08-25  Cary Coutant  <ccoutant@gmail.com>
 
        PR gold/18847
index 3311a1d51261b9d6777c8834f494e1471474c80d..80f9e336c16987c025a52dc508e69d4ce3bac726 100644 (file)
@@ -62,6 +62,9 @@ class Output_data_glink;
 template<int size, bool big_endian>
 class Stub_table;
 
+template<int size, bool big_endian>
+class Output_data_save_res;
+
 template<int size, bool big_endian>
 class Target_powerpc;
 
@@ -510,7 +513,7 @@ class Target_powerpc : public Sized_target<size, big_endian>
       tlsld_got_offset_(-1U),
       stub_tables_(), branch_lookup_table_(), branch_info_(),
       plt_thread_safe_(false), relax_failed_(false), relax_fail_count_(0),
-      stub_group_size_(0)
+      stub_group_size_(0), savres_section_(0)
   {
   }
 
@@ -775,6 +778,12 @@ class Target_powerpc : public Sized_target<size, big_endian>
     return 24;
   }
 
+  Output_data_save_res<size, big_endian>*
+  savres_section() const
+  {
+    return this->savres_section_;
+  }
+
   // Add any special sections for this symbol to the gc work list.
   // For powerpc64, this adds the code section of a function
   // descriptor.
@@ -1315,6 +1324,8 @@ class Target_powerpc : public Sized_target<size, big_endian>
   bool relax_failed_;
   int relax_fail_count_;
   int32_t stub_group_size_;
+
+  Output_data_save_res<size, big_endian> *savres_section_;
 };
 
 template<>
@@ -2740,8 +2751,13 @@ Target_powerpc<size, big_endian>::Branch_info::make_stub(
                           this->object_->section_name(this->shndx_).c_str());
              return true;
            }
+         bool save_res = (size == 64
+                          && gsym != NULL
+                          && gsym->source() == Symbol::IN_OUTPUT_DATA
+                          && gsym->output_data() == target->savres_section());
          return stub_table->add_long_branch_entry(this->object_,
-                                                  this->r_type_, from, to);
+                                                  this->r_type_,
+                                                  from, to, save_res);
        }
     }
   return true;
@@ -3581,7 +3597,8 @@ class Stub_table : public Output_relaxed_input_section
       targ_(targ), plt_call_stubs_(), long_branch_stubs_(),
       orig_data_size_(owner->current_data_size()),
       plt_size_(0), last_plt_size_(0),
-      branch_size_(0), last_branch_size_(0), eh_frame_added_(false)
+      branch_size_(0), last_branch_size_(0), eh_frame_added_(false),
+      need_save_res_(false)
   {
     this->set_output_section(output_section);
 
@@ -3628,7 +3645,7 @@ class Stub_table : public Output_relaxed_input_section
   // Add a long branch stub.
   bool
   add_long_branch_entry(const Powerpc_relobj<size, big_endian>*,
-                       unsigned int, Address, Address);
+                       unsigned int, Address, Address, bool);
 
   Address
   find_long_branch_entry(const Powerpc_relobj<size, big_endian>*,
@@ -3652,6 +3669,7 @@ class Stub_table : public Output_relaxed_input_section
     this->plt_size_ = 0;
     this->long_branch_stubs_.clear();
     this->branch_size_ = 0;
+    this->need_save_res_ = false;
     if (all)
       {
        this->last_plt_size_ = 0;
@@ -3665,6 +3683,8 @@ class Stub_table : public Output_relaxed_input_section
     Address start_off = off;
     off += this->orig_data_size_;
     Address my_size = this->plt_size_ + this->branch_size_;
+    if (this->need_save_res_)
+      my_size += this->targ_->savres_section()->data_size();
     if (my_size != 0)
       off = align_address(off, this->stub_align());
     // Include original section size and alignment padding in size
@@ -3919,8 +3939,9 @@ class Stub_table : public Output_relaxed_input_section
   class Branch_stub_ent
   {
   public:
-    Branch_stub_ent(const Powerpc_relobj<size, big_endian>* obj, Address to)
-      : dest_(to), toc_base_off_(0)
+    Branch_stub_ent(const Powerpc_relobj<size, big_endian>* obj,
+                   Address to, bool save_res)
+      : dest_(to), toc_base_off_(0), save_res_(save_res)
     {
       if (size == 64)
        toc_base_off_ = obj->toc_base_offset();
@@ -3935,6 +3956,7 @@ class Stub_table : public Output_relaxed_input_section
 
     Address dest_;
     unsigned int toc_base_off_;
+    bool save_res_;
   };
 
   class Branch_stub_ent_hash
@@ -3958,6 +3980,9 @@ class Stub_table : public Output_relaxed_input_section
   section_size_type plt_size_, last_plt_size_, branch_size_, last_branch_size_;
   // Whether .eh_frame info has been created for this stub section.
   bool eh_frame_added_;
+  // Set if this stub group needs a copy of out-of-line register
+  // save/restore functions.
+  bool need_save_res_;
 };
 
 // Add a plt call stub, if we do not already have one for this
@@ -4056,21 +4081,27 @@ Stub_table<size, big_endian>::add_long_branch_entry(
     const Powerpc_relobj<size, big_endian>* object,
     unsigned int r_type,
     Address from,
-    Address to)
+    Address to,
+    bool save_res)
 {
-  Branch_stub_ent ent(object, to);
+  Branch_stub_ent ent(object, to, save_res);
   Address off = this->branch_size_;
   if (this->long_branch_stubs_.insert(std::make_pair(ent, off)).second)
     {
-      unsigned int stub_size = this->branch_stub_size(to);
-      this->branch_size_ = off + stub_size;
-      if (size == 64 && stub_size != 4)
-       this->targ_->add_branch_lookup_table(to);
+      if (save_res)
+       this->need_save_res_ = true;
+      else
+       {
+         unsigned int stub_size = this->branch_stub_size(to);
+         this->branch_size_ = off + stub_size;
+         if (size == 64 && stub_size != 4)
+           this->targ_->add_branch_lookup_table(to);
+       }
     }
   return this->can_reach_stub(from, off, r_type);
 }
 
-// Find long branch stub.
+// Find long branch stub offset.
 
 template<int size, bool big_endian>
 typename Stub_table<size, big_endian>::Address
@@ -4078,10 +4109,14 @@ Stub_table<size, big_endian>::find_long_branch_entry(
     const Powerpc_relobj<size, big_endian>* object,
     Address to) const
 {
-  Branch_stub_ent ent(object, to);
+  Branch_stub_ent ent(object, to, false);
   typename Branch_stub_entries::const_iterator p
     = this->long_branch_stubs_.find(ent);
-  return p == this->long_branch_stubs_.end() ? invalid_address : p->second;
+  if (p == this->long_branch_stubs_.end())
+    return invalid_address;
+  if (p->first.save_res_)
+    return to - this->targ_->savres_section()->address() + this->branch_size_;
+  return p->second;
 }
 
 // A class to handle .glink.
@@ -4420,6 +4455,8 @@ Stub_table<size, big_endian>::do_write(Output_file* of)
           bs != this->long_branch_stubs_.end();
           ++bs)
        {
+         if (bs->first.save_res_)
+           continue;
          p = oview + this->plt_size_ + bs->second;
          Address loc = this->stub_address() + this->plt_size_ + bs->second;
          Address delta = bs->first.dest_ - loc;
@@ -4531,6 +4568,8 @@ Stub_table<size, big_endian>::do_write(Output_file* of)
           bs != this->long_branch_stubs_.end();
           ++bs)
        {
+         if (bs->first.save_res_)
+           continue;
          p = oview + this->plt_size_ + bs->second;
          Address loc = this->stub_address() + this->plt_size_ + bs->second;
          Address delta = bs->first.dest_ - loc;
@@ -4557,6 +4596,12 @@ Stub_table<size, big_endian>::do_write(Output_file* of)
            }
        }
     }
+  if (this->need_save_res_)
+    {
+      p = oview + this->plt_size_ + this->branch_size_;
+      memcpy (p, this->targ_->savres_section()->contents(),
+             this->targ_->savres_section()->data_size());
+    }
 }
 
 // Write out .glink.
@@ -4767,6 +4812,12 @@ class Output_data_save_res : public Output_section_data_build
  public:
   Output_data_save_res(Symbol_table* symtab);
 
+  const unsigned char*
+  contents() const
+  {
+    return contents_;
+  }
+
  protected:
   // Write to a map file.
   void
@@ -6685,8 +6736,9 @@ Target_powerpc<size, big_endian>::define_save_restore_funcs(
 {
   if (size == 64)
     {
-      Output_data_save_res<64, big_endian>* savres
-       = new Output_data_save_res<64, big_endian>(symtab);
+      Output_data_save_res<size, big_endian>* savres
+       = new Output_data_save_res<size, big_endian>(symtab);
+      this->savres_section_ = savres;
       layout->add_output_section_data(".text", elfcpp::SHT_PROGBITS,
                                      elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR,
                                      savres, ORDER_TEXT, false);