Greatly improve the speed if looking up DWARF line number information.

* dwarf2.c (comp_unit): Add new fields 'lookup_funcinfo_table' and
	'number_of_functions' to keep lookup table and number of entries in
	the table.
	(line_sequence): Add new fields 'line_info_lookup' and 'num_lines'
	to keep lookup table and number of entries in the table.
	(lookup_funcinfo): New structure for lookup table for function
	references.
	(build_line_info_table): New function to create and build the lookup
	table for line information.
	(lookup_address_in_line_info_table): Use the lookup table instead of
	traverse a linked list.
	(compare_lookup_funcinfos): New compare fuction used in sorting of
	lookup table for function references.
	(build_lookup_funcinfo_table): New function to create, build and
	sort the lookup table for functions references.
	(lookup_address_in_function_table): Use the table instead of
	traverse a linked list.
	(_bfd_dwarf2_cleanup_debug_info): Free memory from function references
	lookup table.

bfd/ChangeLog

@@ -1,3 +1,25 @@
+2016-11-08  Igor Tsimbalist  <tigor.tools@gmail.com>
+
+	* dwarf2.c (comp_unit): Add new fields 'lookup_funcinfo_table' and
+	'number_of_functions' to keep lookup table and number of entries in
+	the table.
+	(line_sequence): Add new fields 'line_info_lookup' and 'num_lines'
+	to keep lookup table and number of entries in the table.
+	(lookup_funcinfo): New structure for lookup table for function
+	references.
+	(build_line_info_table): New function to create and build the lookup
+	table for line information.
+	(lookup_address_in_line_info_table): Use the lookup table instead of
+	traverse a linked list.
+	(compare_lookup_funcinfos): New compare fuction used in sorting of
+	lookup table for function references.
+	(build_lookup_funcinfo_table): New function to create, build and
+	sort the lookup table for functions references.
+	(lookup_address_in_function_table): Use the table instead of
+	traverse a linked list.
+	(_bfd_dwarf2_cleanup_debug_info): Free memory from function references
+	lookup table.
+
 2016-11-04  Nick Clifton  <nickc@redhat.com>
 
 	* targets.c (bfd_target_vector): Only add riscv_elf32_vec target

bfd/dwarf2.c

@@ -256,6 +256,12 @@ struct comp_unit
   /* A list of the functions found in this comp. unit.  */
   struct funcinfo *function_table;
 
+  /* A table of function information references searchable by address.  */
+  struct lookup_funcinfo *lookup_funcinfo_table;
+
+  /* Number of functions in the function_table and sorted_function_table.  */
+  bfd_size_type number_of_functions;
+
   /* A list of the variables found in this comp. unit.  */
   struct varinfo *variable_table;
 
@@ -1237,6 +1243,8 @@ struct line_sequence
   bfd_vma               low_pc;
   struct line_sequence* prev_sequence;
   struct line_info*     last_line;  /* Largest VMA.  */
+  struct line_info**    line_info_lookup;
+  bfd_size_type		num_lines;
 };
 
 struct line_info_table
@@ -1272,13 +1280,27 @@ struct funcinfo
   /* Source location line number.  */
   int			line;
   int			tag;
-  bfd_boolean is_linkage;
+  bfd			boolean is_linkage;
   const char *		name;
   struct arange		arange;
   /* Where the symbol is defined.  */
   asection *		sec;
 };
 
+struct lookup_funcinfo
+{
+  /* Function information corresponding to this lookup table entry.  */
+  struct funcinfo *	funcinfo;
+
+  /* The lowest address for this specific function.  */
+  bfd_vma 		low_addr;
+
+  /* The highest address of this function before the lookup table is sorted.
+     The highest address of all prior functions after the lookup table is
+     sorted, which is used for binary search.  */
+  bfd_vma 		high_addr;
+};
+
 struct varinfo
 {
   /* Pointer to previous variable in list of all variables */
@@ -1579,6 +1601,51 @@ compare_sequences (const void* a, const void* b)
   return 0;
 }
 
+/* Construct the line information table for quick lookup.  */
+
+static bfd_boolean
+build_line_info_table (struct line_info_table *  table,
+		       struct line_sequence *    seq)
+{
+  bfd_size_type      amt;
+  struct line_info** line_info_lookup;
+  struct line_info*  each_line;
+  unsigned int       num_lines;
+  unsigned int       index;
+
+  if (seq->line_info_lookup != NULL)
+    return TRUE;
+
+  /* Count the number of line information entries.  We could do this while
+     scanning the debug information, but some entries may be added via
+     lcl_head without having a sequence handy to increment the number of
+     lines.  */
+  num_lines = 0;
+  for (each_line = seq->last_line; each_line; each_line = each_line->prev_line)
+    num_lines++;
+
+  if (num_lines == 0)
+    return TRUE;
+
+  /* Allocate space for the line information lookup table.  */
+  amt = sizeof (struct line_info*) * num_lines;
+  line_info_lookup = (struct line_info**) bfd_alloc (table->abfd, amt);
+  if (line_info_lookup == NULL)
+    return FALSE;
+
+  /* Create the line information lookup table.  */
+  index = num_lines;
+  for (each_line = seq->last_line; each_line; each_line = each_line->prev_line)
+    line_info_lookup[--index] = each_line;
+
+  BFD_ASSERT (index == 0);
+
+  seq->num_lines = num_lines;
+  seq->line_info_lookup = line_info_lookup;
+
+  return TRUE;
+}
+
 /* Sort the line sequences for quick lookup.  */
 
 static bfd_boolean
@@ -1610,6 +1677,8 @@ sort_line_sequences (struct line_info_table* table)
       sequences[n].low_pc = seq->low_pc;
       sequences[n].prev_sequence = NULL;
       sequences[n].last_line = seq->last_line;
+      sequences[n].line_info_lookup = NULL;
+      sequences[n].num_lines = 0;
       seq = seq->prev_sequence;
       free (last_seq);
     }
@@ -2091,7 +2160,7 @@ lookup_address_in_line_info_table (struct line_info_table *table,
 				   unsigned int *discriminator_ptr)
 {
   struct line_sequence *seq = NULL;
-  struct line_info *each_line;
+  struct line_info *info;
   int low, high, mid;
 
   /* Binary search the array of sequences.  */
@@ -2109,26 +2178,43 @@ lookup_address_in_line_info_table (struct line_info_table *table,
 	break;
     }
 
-  if (seq && addr >= seq->low_pc && addr < seq->last_line->address)
+  /* Check for a valid sequence.  */
-    {
+  if (!seq || addr < seq->low_pc || addr >= seq->last_line->address)
-      /* Note: seq->last_line should be a descendingly sorted list.  */
+    goto fail;
-      for (each_line = seq->last_line;
-	   each_line;
-	   each_line = each_line->prev_line)
-	if (addr >= each_line->address)
-	  break;
 
-      if (each_line
+  if (!build_line_info_table (table, seq))
-	  && !(each_line->end_sequence || each_line == seq->last_line))
+    goto fail;
+
+  /* Binary search the array of line information.  */
+  low = 0;
+  high = seq->num_lines;
+  info = NULL;
+  while (low < high)
     {
-	  *filename_ptr = each_line->filename;
+      mid = (low + high) / 2;
-	  *linenumber_ptr = each_line->line;
+      info = seq->line_info_lookup[mid];
+      if (addr < info->address)
+	high = mid;
+      else if (addr >= seq->line_info_lookup[mid + 1]->address)
+	low = mid + 1;
+      else
+	break;
+    }
+
+  /* Check for a valid line information entry.  */
+  if (info
+      && addr >= info->address
+      && addr < seq->line_info_lookup[mid + 1]->address
+      && !(info->end_sequence || info == seq->last_line))
+    {
+      *filename_ptr = info->filename;
+      *linenumber_ptr = info->line;
       if (discriminator_ptr)
-	    *discriminator_ptr = each_line->discriminator;
+	*discriminator_ptr = info->discriminator;
       return seq->last_line->address - seq->low_pc;
     }
-    }
 
+fail:
   *filename_ptr = NULL;
   return 0;
 }
@@ -2139,13 +2225,99 @@ static bfd_boolean
 read_debug_ranges (struct comp_unit * unit)
 {
   struct dwarf2_debug * stash = unit->stash;
+
   return read_section (unit->abfd, &stash->debug_sections[debug_ranges],
 		       stash->syms, 0,
-		       &stash->dwarf_ranges_buffer, &stash->dwarf_ranges_size);
+		       &stash->dwarf_ranges_buffer,
+		       &stash->dwarf_ranges_size);
 }
 
 /* Function table functions.  */
 
+static int
+compare_lookup_funcinfos (const void * a, const void * b)
+{
+  const struct lookup_funcinfo * lookup1 = a;
+  const struct lookup_funcinfo * lookup2 = b;
+
+  if (lookup1->low_addr < lookup2->low_addr)
+    return -1;
+  if (lookup1->low_addr > lookup2->low_addr)
+    return 1;
+  if (lookup1->high_addr < lookup2->high_addr)
+    return -1;
+  if (lookup1->high_addr > lookup2->high_addr)
+    return 1;
+
+  return 0;
+}
+
+static bfd_boolean
+build_lookup_funcinfo_table (struct comp_unit * unit)
+{
+  struct lookup_funcinfo *lookup_funcinfo_table = unit->lookup_funcinfo_table;
+  unsigned int number_of_functions = unit->number_of_functions;
+  struct funcinfo *each;
+  struct lookup_funcinfo *entry;
+  size_t index;
+  struct arange *range;
+  bfd_vma low_addr, high_addr;
+
+  if (lookup_funcinfo_table || number_of_functions == 0)
+    return TRUE;
+
+  /* Create the function info lookup table.  */
+  lookup_funcinfo_table = (struct lookup_funcinfo *)
+    bfd_malloc (number_of_functions * sizeof (struct lookup_funcinfo));
+  if (lookup_funcinfo_table == NULL)
+    return FALSE;
+
+  /* Populate the function info lookup table.  */
+  index = number_of_functions;
+  for (each = unit->function_table; each; each = each->prev_func)
+    {
+      entry = &lookup_funcinfo_table[--index];
+      entry->funcinfo = each;
+
+      /* Calculate the lowest and highest address for this function entry.  */
+      low_addr  = entry->funcinfo->arange.low;
+      high_addr = entry->funcinfo->arange.high;
+
+      for (range = entry->funcinfo->arange.next; range; range = range->next)
+	{
+	  if (range->low < low_addr)
+	    low_addr = range->low;
+	  if (range->high > high_addr)
+	    high_addr = range->high;
+	}
+
+      entry->low_addr = low_addr;
+      entry->high_addr = high_addr;
+    }
+
+  BFD_ASSERT (index == 0);
+
+  /* Sort the function by address.  */
+  qsort (lookup_funcinfo_table,
+	 number_of_functions,
+	 sizeof (struct lookup_funcinfo),
+	 compare_lookup_funcinfos);
+
+  /* Calculate the high watermark for each function in the lookup table.  */
+  high_addr = lookup_funcinfo_table[0].high_addr;
+  for (index = 1; index < number_of_functions; index++)
+    {
+      entry = &lookup_funcinfo_table[index];
+      if (entry->high_addr > high_addr)
+	high_addr = entry->high_addr;
+      else
+	entry->high_addr = high_addr;
+    }
+
+  unit->lookup_funcinfo_table = lookup_funcinfo_table;
+  return TRUE;
+}
+
 /* If ADDR is within UNIT's function tables, set FUNCTION_PTR, and return
    TRUE.  Note that we need to find the function that has the smallest range
    that contains ADDR, to handle inlined functions without depending upon
@@ -2156,38 +2328,72 @@ lookup_address_in_function_table (struct comp_unit *unit,
 				  bfd_vma addr,
 				  struct funcinfo **function_ptr)
 {
-  struct funcinfo* each_func;
+  unsigned int number_of_functions = unit->number_of_functions;
+  struct lookup_funcinfo* lookup_funcinfo = NULL;
+  struct funcinfo* funcinfo = NULL;
   struct funcinfo* best_fit = NULL;
   bfd_vma best_fit_len = 0;
+  bfd_size_type low, high, mid, first;
   struct arange *arange;
 
-  for (each_func = unit->function_table;
+  if (!build_lookup_funcinfo_table (unit))
-       each_func;
+    return FALSE;
-       each_func = each_func->prev_func)
+
+  /* Find the first function in the lookup table which may contain the
+     specified address.  */
+  low = 0;
+  high = number_of_functions;
+  first = high;
+  while (low < high)
     {
-      for (arange = &each_func->arange;
+      mid = (low + high) / 2;
-	   arange;
+      lookup_funcinfo = &unit->lookup_funcinfo_table[mid];
-	   arange = arange->next)
+      if (addr < lookup_funcinfo->low_addr)
+	high = mid;
+      else if (addr >= lookup_funcinfo->high_addr)
+	low = mid + 1;
+      else
+	high = first = mid;
+    }
+
+  /* Find the 'best' match for the address.  The prior algorithm defined the
+     best match as the function with the smallest address range containing
+     the specified address.  This definition should probably be changed to the
+     innermost inline routine containing the address, but right now we want
+     to get the same results we did before.  */
+  while (first < number_of_functions)
     {
-	  if (addr >= arange->low && addr < arange->high)
+      if (addr < unit->lookup_funcinfo_table[first].low_addr)
+	break;
+      funcinfo = unit->lookup_funcinfo_table[first].funcinfo;
+
+      for (arange = &funcinfo->arange; arange; arange = arange->next)
 	{
+	  if (addr < arange->low || addr >= arange->high)
+	    continue;
+
 	  if (!best_fit
-		  || arange->high - arange->low < best_fit_len)
+	      || arange->high - arange->low < best_fit_len
+	      /* The following comparison is designed to return the same
+		 match as the previous algorithm for routines which have the
+		 same best fit length.  */
+	      || (arange->high - arange->low == best_fit_len
+		  && funcinfo > best_fit))
 	    {
-		  best_fit = each_func;
+	      best_fit = funcinfo;
 	      best_fit_len = arange->high - arange->low;
 	    }
 	}
-	}
+
+      first++;
     }
 
-  if (best_fit)
+  if (!best_fit)
-    {
+    return FALSE;
+
   *function_ptr = best_fit;
   return TRUE;
 }
-  return FALSE;
-}
 
 /* If SYM at ADDR is within function table of UNIT, set FILENAME_PTR
    and LINENUMBER_PTR, and return TRUE.  */
@@ -2271,7 +2477,7 @@ lookup_symbol_in_variable_table (struct comp_unit *unit,
       *linenumber_ptr = each->line;
       return TRUE;
     }
-  else
+
   return FALSE;
 }
 
@@ -2515,6 +2721,7 @@ scan_unit_for_symbols (struct comp_unit *unit)
 	  func->tag = abbrev->tag;
 	  func->prev_func = unit->function_table;
 	  unit->function_table = func;
+      unit->number_of_functions++;
 	  BFD_ASSERT (!unit->cached);
 
 	  if (func->tag == DW_TAG_inlined_subroutine)
@@ -4244,6 +4451,12 @@ _bfd_dwarf2_cleanup_debug_info (bfd *abfd, void **pinfo)
 	  function_table = function_table->prev_func;
 	}
 
+      if (each->lookup_funcinfo_table)
+	{
+	  free (each->lookup_funcinfo_table);
+	  each->lookup_funcinfo_table = NULL;
+	}
+
       while (variable_table)
 	{
 	  if (variable_table->file)