[GOLD] Reduce size of class Symbol

On 64-bit targets there is a 32-bit hole in symbol->u_, and another
due to symbol flags exceeding 32 bits.  By splitting the union,
the total size of the class reduces by one 64-bit word.

	* symtab.h (Symbol): Split u_ into u1_ and u2_.  Adjust accessors
	to suit.  Move plt_offset_ before got_offsets_.
	* symtab.cc (Symbol::init_fields): Adjust for union change.
	(Symbol::init_base_output_data): Likewise.
	(Symbol::init_base_output_segment): Likewise.
	(Symbol::allocate_base_common): Likewise.
	(Symbol::output_section): Likewise.
	(Symbol::set_output_section): Likewise.
	(Symbol::set_output_segment): Likewise.
	* resolve.cc (Symbol::override_base): Likewise.
	(Symbol::override_base_with_special): Likewise.

1 files changed, 44 insertions, 44 deletions

diff --git a/gold/symtab.h b/gold/symtab.h
index c371731b5eb..88d6c2782ba 100644
--- a/gold/symtab.h
+++ b/gold/symtab.h
@@ -159,7 +159,7 @@ class Symbol
   object() const
   {
     gold_assert(this->source_ == FROM_OBJECT);
-    return this->u_.from_object.object;
+    return this->u1_.object;
   }
 
   // Return the index of the section in the input relocatable or
@@ -169,7 +169,7 @@ class Symbol
   {
     gold_assert(this->source_ == FROM_OBJECT);
     *is_ordinary = this->is_ordinary_shndx_;
-    return this->u_.from_object.shndx;
+    return this->u2_.shndx;
   }
 
   // Return the output data section with which this symbol is
@@ -179,7 +179,7 @@ class Symbol
   output_data() const
   {
     gold_assert(this->source_ == IN_OUTPUT_DATA);
-    return this->u_.in_output_data.output_data;
+    return this->u1_.output_data;
   }
 
   // If this symbol was defined with respect to an output data
@@ -188,7 +188,7 @@ class Symbol
   offset_is_from_end() const
   {
     gold_assert(this->source_ == IN_OUTPUT_DATA);
-    return this->u_.in_output_data.offset_is_from_end;
+    return this->u2_.offset_is_from_end;
   }
 
   // Return the output segment with which this symbol is associated,
@@ -198,7 +198,7 @@ class Symbol
   output_segment() const
   {
     gold_assert(this->source_ == IN_OUTPUT_SEGMENT);
-    return this->u_.in_output_segment.output_segment;
+    return this->u1_.output_segment;
   }
 
   // If this symbol was defined with respect to an output segment,
@@ -207,7 +207,7 @@ class Symbol
   offset_base() const
   {
     gold_assert(this->source_ == IN_OUTPUT_SEGMENT);
-    return this->u_.in_output_segment.offset_base;
+    return this->u2_.offset_base;
   }
 
   // Return the symbol binding.
@@ -973,38 +973,38 @@ class Symbol
 
   union
   {
-    // This struct is used if SOURCE_ == FROM_OBJECT.
-    struct
-    {
-      // Object in which symbol is defined, or in which it was first
-      // seen.
-      Object* object;
-      // Section number in object_ in which symbol is defined.
-      unsigned int shndx;
-    } from_object;
-
-    // This struct is used if SOURCE_ == IN_OUTPUT_DATA.
-    struct
-    {
-      // Output_data in which symbol is defined.  Before
-      // Layout::finalize the symbol's value is an offset within the
-      // Output_data.
-      Output_data* output_data;
-      // True if the offset is from the end, false if the offset is
-      // from the beginning.
-      bool offset_is_from_end;
-    } in_output_data;
-
-    // This struct is used if SOURCE_ == IN_OUTPUT_SEGMENT.
-    struct
-    {
-      // Output_segment in which the symbol is defined.  Before
-      // Layout::finalize the symbol's value is an offset.
-      Output_segment* output_segment;
-      // The base to use for the offset before Layout::finalize.
-      Segment_offset_base offset_base;
-    } in_output_segment;
-  } u_;
+    // This is used if SOURCE_ == FROM_OBJECT.
+    // Object in which symbol is defined, or in which it was first
+    // seen.
+    Object* object;
+
+    // This is used if SOURCE_ == IN_OUTPUT_DATA.
+    // Output_data in which symbol is defined.  Before
+    // Layout::finalize the symbol's value is an offset within the
+    // Output_data.
+    Output_data* output_data;
+
+    // This is used if SOURCE_ == IN_OUTPUT_SEGMENT.
+    // Output_segment in which the symbol is defined.  Before
+    // Layout::finalize the symbol's value is an offset.
+    Output_segment* output_segment;
+  } u1_;
+
+  union
+  {
+    // This is used if SOURCE_ == FROM_OBJECT.
+    // Section number in object in which symbol is defined.
+    unsigned int shndx;
+
+    // This is used if SOURCE_ == IN_OUTPUT_DATA.
+    // True if the offset is from the end, false if the offset is
+    // from the beginning.
+    bool offset_is_from_end;
+
+    // This is used if SOURCE_ == IN_OUTPUT_SEGMENT.
+    // The base to use for the offset before Layout::finalize.
+    Segment_offset_base offset_base;
+  } u2_;
 
   // The index of this symbol in the output file.  If the symbol is
   // not going into the output file, this value is -1U.  This field
@@ -1018,16 +1018,16 @@ class Symbol
   // non-zero value during Layout::finalize.
   unsigned int dynsym_index_;
 
-  // The GOT section entries for this symbol.  A symbol may have more
-  // than one GOT offset (e.g., when mixing modules compiled with two
-  // different TLS models), but will usually have at most one.
-  Got_offset_list got_offsets_;
-
   // If this symbol has an entry in the PLT section, then this is the
   // offset from the start of the PLT section.  This is -1U if there
   // is no PLT entry.
   unsigned int plt_offset_;
 
+  // The GOT section entries for this symbol.  A symbol may have more
+  // than one GOT offset (e.g., when mixing modules compiled with two
+  // different TLS models), but will usually have at most one.
+  Got_offset_list got_offsets_;
+
   // Symbol type (bits 0 to 3).
   elfcpp::STT type_ : 4;
   // Symbol binding (bits 4 to 7).
@@ -1069,7 +1069,7 @@ class Symbol
   // True if this symbol was forced to local visibility by a version
   // script (bit 28).
   bool is_forced_local_ : 1;
-  // True if the field u_.from_object.shndx is an ordinary section
+  // True if the field u2_.shndx is an ordinary section
   // index, not one of the special codes from SHN_LORESERVE to
   // SHN_HIRESERVE (bit 29).
   bool is_ordinary_shndx_ : 1;