[binutils-gdb] xtensa: optimize removed_by_actions

[Max Filippov <jcmvbkbc at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=071aa5c98a31c966f5fbfc573fcee61350fd1936

commit 071aa5c98a31c966f5fbfc573fcee61350fd1936
Author: Max Filippov <jcmvbkbc@gmail.com>
Date:   Sat Mar 28 08:46:28 2015 +0300

    xtensa: optimize removed_by_actions
    
    The function removed_by_actions iterates through text actions to
    calculate an offset applied by text actions to a given VMA. Although it
    has a parameter p_start_action that allows for incremental offset
    calculation, in many places it's used with p_start_action explicitly set
    to the first action. After the first relaxation pass when the list of
    text actions is finalized, an array of offsets sorted by VMA may be used
    to speed up this function.
    
    Original profile:
    
    % time    self  children    called     name
    -----------------------------------------
              0.35    0.00   33872/4808961     relax_section_symbols
              3.32    0.00  326022/4808961     relax_property_section
             12.83    0.00 1259379/4808961     offset_with_removed_text
             32.50    0.00 3189688/4808961     translate_reloc
      71.5   49.00    0.00 4808961         removed_by_actions
    -----------------------------------------
    
    Same data, after optimization:
    
    % time    self  children    called     name
    -----------------------------------------
              0.00    0.00   33872/4808537     relax_section_symbols
              0.01    0.00  326022/4808537     relax_property_section
              0.05    0.00 1258955/4808537     offset_with_removed_text_map
              0.13    0.00 3189688/4808537     translate_reloc
       1.0    0.20    0.00 4808537         removed_by_actions_map
              0.00    0.00     120/120         map_removal_by_action
    -----------------------------------------
    
    2015-04-01  Max Filippov  <jcmvbkbc@gmail.com>
    bfd/
    	* elf32-xtensa.c (removal_by_action_entry_struct,
    	removal_by_action_map_struct): new structures.
    	(removal_by_action_entry, removal_by_action_map): new typedefs.
    	(text_action_list_struct): add new field: map.
    	(map_removal_by_action, removed_by_actions_map,
    	offset_with_removed_text_map): new functions.
    	(relax_section): replace offset_with_removed_text with
    	offset_with_removed_text_map.
    	(translate_reloc, relax_property_section, relax_section_symbols):
    	replace removed_by_actions with removed_by_actions_map.

Diff:
---
 bfd/elf32-xtensa.c | 181 +++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 156 insertions(+), 25 deletions(-)

diff --git a/bfd/elf32-xtensa.c b/bfd/elf32-xtensa.c
index 872370b..21b2871 100644
--- a/bfd/elf32-xtensa.c
+++ b/bfd/elf32-xtensa.c
@@ -5420,11 +5420,28 @@ struct text_action_struct
   text_action *next;
 };
 
+struct removal_by_action_entry_struct
+{
+  bfd_vma offset;
+  int removed;
+  int eq_removed;
+  int eq_removed_before_fill;
+};
+typedef struct removal_by_action_entry_struct removal_by_action_entry;
+
+struct removal_by_action_map_struct
+{
+  unsigned n_entries;
+  removal_by_action_entry *entry;
+};
+typedef struct removal_by_action_map_struct removal_by_action_map;
+
 
 /* List of all of the actions taken on a text section.  */
 struct text_action_list_struct
 {
   text_action *head;
+  removal_by_action_map map;
 };
 
 
@@ -5636,6 +5653,101 @@ action_list_count (text_action_list *action_list)
   return count;
 }
 
+static void
+map_removal_by_action (text_action_list *action_list)
+{
+  text_action *r;
+  int removed = 0;
+  removal_by_action_map map;
+  bfd_boolean eq_complete;
+
+  map.n_entries = 0;
+  map.entry = bfd_malloc (action_list_count (action_list) *
+			  sizeof (removal_by_action_entry));
+  eq_complete = FALSE;
+
+  for (r = action_list->head; r;)
+    {
+      removal_by_action_entry *ientry = map.entry + map.n_entries;
+
+      if (map.n_entries && (ientry - 1)->offset == r->offset)
+	{
+	  --ientry;
+	}
+      else
+	{
+	  ++map.n_entries;
+	  eq_complete = FALSE;
+	  ientry->offset = r->offset;
+	  ientry->eq_removed_before_fill = removed;
+	}
+
+      if (!eq_complete)
+	{
+	  if (r->action != ta_fill || r->removed_bytes >= 0)
+	    {
+	      ientry->eq_removed = removed;
+	      eq_complete = TRUE;
+	    }
+	  else
+	    ientry->eq_removed = removed + r->removed_bytes;
+	}
+
+      removed += r->removed_bytes;
+      ientry->removed = removed;
+      r = r->next;
+    }
+  action_list->map = map;
+}
+
+static int
+removed_by_actions_map (text_action_list *action_list, bfd_vma offset,
+			bfd_boolean before_fill)
+{
+  unsigned a, b;
+
+  if (!action_list->map.entry)
+    map_removal_by_action (action_list);
+
+  if (!action_list->map.n_entries)
+    return 0;
+
+  a = 0;
+  b = action_list->map.n_entries;
+
+  while (b - a > 1)
+    {
+      unsigned c = (a + b) / 2;
+
+      if (action_list->map.entry[c].offset <= offset)
+	a = c;
+      else
+	b = c;
+    }
+
+  if (action_list->map.entry[a].offset < offset)
+    {
+      return action_list->map.entry[a].removed;
+    }
+  else if (action_list->map.entry[a].offset == offset)
+    {
+      return before_fill ?
+	action_list->map.entry[a].eq_removed_before_fill :
+	action_list->map.entry[a].eq_removed;
+    }
+  else
+    {
+      return 0;
+    }
+}
+
+static bfd_vma
+offset_with_removed_text_map (text_action_list *action_list, bfd_vma offset)
+{
+  int removed = removed_by_actions_map (action_list, offset, FALSE);
+  return offset - removed;
+}
+
 
 /* The find_insn_action routine will only find non-fill actions.  */
 
@@ -5909,6 +6021,9 @@ init_xtensa_relax_info (asection *sec)
 
   relax_info->action_list.head = NULL;
 
+  relax_info->action_list.map.n_entries = 0;
+  relax_info->action_list.map.entry = NULL;
+
   relax_info->fix_list = NULL;
   relax_info->fix_array = NULL;
   relax_info->fix_array_count = 0;
@@ -9218,7 +9333,7 @@ relax_section (bfd *abfd, asection *sec, struct bfd_link_info *link_info)
 		  if (elf_hash_table (link_info)->dynamic_sections_created)
 		    shrink_dynamic_reloc_sections (link_info, abfd, sec, irel);
 		  irel->r_info = ELF32_R_INFO (0, R_XTENSA_NONE);
-		  irel->r_offset = offset_with_removed_text
+		  irel->r_offset = offset_with_removed_text_map
 		    (&relax_info->action_list, irel->r_offset);
 		  continue;
 		}
@@ -9255,7 +9370,7 @@ relax_section (bfd *abfd, asection *sec, struct bfd_link_info *link_info)
 		    }
 		}
 
-	      source_offset = offset_with_removed_text
+	      source_offset = offset_with_removed_text_map
 		(&relax_info->action_list, irel->r_offset);
 	      irel->r_offset = source_offset;
 	    }
@@ -9352,7 +9467,7 @@ relax_section (bfd *abfd, asection *sec, struct bfd_link_info *link_info)
 		      break;
 		    }
 
-		  new_end_offset = offset_with_removed_text
+		  new_end_offset = offset_with_removed_text_map
 		    (&target_relax_info->action_list,
 		     r_rel.target_offset + diff_value);
 		  diff_value = new_end_offset - new_reloc.target_offset;
@@ -9750,7 +9865,6 @@ translate_reloc (const r_reloc *orig_rel, r_reloc *new_rel, asection *sec)
   xtensa_relax_info *relax_info;
   removed_literal *removed;
   bfd_vma target_offset, base_offset;
-  text_action *act;
 
   *new_rel = *orig_rel;
 
@@ -9803,19 +9917,26 @@ translate_reloc (const r_reloc *orig_rel, r_reloc *new_rel, asection *sec)
      offset.  */
 
   base_offset = r_reloc_get_target_offset (new_rel) - new_rel->rela.r_addend;
-  act = relax_info->action_list.head;
   if (base_offset <= target_offset)
     {
-      int base_removed = removed_by_actions (&act, base_offset, FALSE);
-      int addend_removed = removed_by_actions (&act, target_offset, FALSE);
+      int base_removed = removed_by_actions_map (&relax_info->action_list,
+						 base_offset, FALSE);
+      int addend_removed = removed_by_actions_map (&relax_info->action_list,
+						   target_offset, FALSE) -
+	base_removed;
+
       new_rel->target_offset = target_offset - base_removed - addend_removed;
       new_rel->rela.r_addend -= addend_removed;
     }
   else
     {
       /* Handle a negative addend.  The base offset comes first.  */
-      int tgt_removed = removed_by_actions (&act, target_offset, FALSE);
-      int addend_removed = removed_by_actions (&act, base_offset, FALSE);
+      int tgt_removed = removed_by_actions_map (&relax_info->action_list,
+						target_offset, FALSE);
+      int addend_removed = removed_by_actions_map (&relax_info->action_list,
+						   base_offset, FALSE) -
+	tgt_removed;
+
       new_rel->target_offset = target_offset - tgt_removed;
       new_rel->rela.r_addend += addend_removed;
     }
@@ -10138,9 +10259,10 @@ relax_property_section (bfd *abfd,
 	      bfd_vma old_offset = val.r_rel.target_offset;
 	      bfd_vma new_offset;
 	      long old_size, new_size;
-	      text_action *act = target_relax_info->action_list.head;
-	      new_offset = old_offset -
-		removed_by_actions (&act, old_offset, FALSE);
+	      int removed_by_old_offset =
+		removed_by_actions_map (&target_relax_info->action_list,
+					old_offset, FALSE);
+	      new_offset = old_offset - removed_by_old_offset;
 
 	      /* Assert that we are not out of bounds.  */
 	      old_size = bfd_get_32 (abfd, size_p);
@@ -10164,9 +10286,10 @@ relax_property_section (bfd *abfd,
 
 		      /* Recompute the new_offset, but this time don't
 			 include any fill inserted by relaxation.  */
-		      act = target_relax_info->action_list.head;
-		      new_offset = old_offset -
-			removed_by_actions (&act, old_offset, TRUE);
+		      removed_by_old_offset =
+			removed_by_actions_map (&target_relax_info->action_list,
+						old_offset, TRUE);
+		      new_offset = old_offset - removed_by_old_offset;
 
 		      /* If it is not unreachable and we have not yet
 			 seen an unreachable at this address, place it
@@ -10182,8 +10305,12 @@ relax_property_section (bfd *abfd,
 		    }
 		}
 	      else
-		new_size -=
-		    removed_by_actions (&act, old_offset + old_size, TRUE);
+		{
+		  int removed_by_old_offset_size =
+		    removed_by_actions_map (&target_relax_info->action_list,
+					    old_offset + old_size, TRUE);
+		  new_size -= removed_by_old_offset_size - removed_by_old_offset;
+		}
 
 	      if (new_size != old_size)
 		{
@@ -10441,14 +10568,16 @@ relax_section_symbols (bfd *abfd, asection *sec)
 
       if (isym->st_shndx == sec_shndx)
 	{
-	  text_action *act = relax_info->action_list.head;
 	  bfd_vma orig_addr = isym->st_value;
+	  int removed = removed_by_actions_map (&relax_info->action_list,
+						orig_addr, FALSE);
 
-	  isym->st_value -= removed_by_actions (&act, orig_addr, FALSE);
-
+	  isym->st_value -= removed;
 	  if (ELF32_ST_TYPE (isym->st_info) == STT_FUNC)
 	    isym->st_size -=
-	      removed_by_actions (&act, orig_addr + isym->st_size, FALSE);
+	      removed_by_actions_map (&relax_info->action_list,
+				      orig_addr + isym->st_size, FALSE) -
+	      removed;
 	}
     }
 
@@ -10466,15 +10595,17 @@ relax_section_symbols (bfd *abfd, asection *sec)
 	   || sym_hash->root.type == bfd_link_hash_defweak)
 	  && sym_hash->root.u.def.section == sec)
 	{
-	  text_action *act = relax_info->action_list.head;
 	  bfd_vma orig_addr = sym_hash->root.u.def.value;
+	  int removed = removed_by_actions_map (&relax_info->action_list,
+						orig_addr, FALSE);
 
-	  sym_hash->root.u.def.value -=
-	    removed_by_actions (&act, orig_addr, FALSE);
+	  sym_hash->root.u.def.value -= removed;
 
 	  if (sym_hash->type == STT_FUNC)
 	    sym_hash->size -=
-	      removed_by_actions (&act, orig_addr + sym_hash->size, FALSE);
+	      removed_by_actions_map (&relax_info->action_list,
+				      orig_addr + sym_hash->size, FALSE) -
+	      removed;
 	}
     }