Fix slowdown about partial linking (#14)

debian/changelog

@@ -1,3 +1,9 @@
+binutils (2.41-6deepin7) unstable; urgency=medium
+
+  * Fix slowdown about partial linking.
+
+ -- Xin Wang <[email protected]>  Tue, 16 Jan 2025 15:33 +0800
+
 binutils (2.41-6deepin6) unstable; urgency=medium
 
   * Disable gold linker for MIPS targets as they are broken as of 2.41.

debian/patches/PR32238-ld-r-slowdown-since-21401fc7bf.patch

@@ -0,0 +1,144 @@
+From 8455910b34f9fbf0bc43915418617641db55f883 Mon Sep 17 00:00:00 2001
+From: Alan Modra <[email protected]>
+Date: Sat, 4 Jan 2025 11:33:27 +1030
+Subject: [PATCH] PR32238, ld -r slowdown since 21401fc7bf
+
+	PR 32238
+	* ldlang.c (struct out_section_hash_entry): Add "tail".
+	(output_section_statement_newfunc_1): New, extracted from..
+	(output_section_statement_newfunc): ..here.  Init tail.
+	(lang_output_section_statement_lookup): Use tail to avoid
+	list traversal.
+---
+ ld/ldlang.c | 66 ++++++++++++++++++++++++++++++++++++-----------------
+ 1 file changed, 45 insertions(+), 21 deletions(-)
+
+diff --git a/ld/ldlang.c b/ld/ldlang.c
+index a357f80235f..3b6b8563c49 100644
+--- a/ld/ldlang.c
++++ b/ld/ldlang.c
+@@ -1246,6 +1246,7 @@ struct out_section_hash_entry
+ {
+   struct bfd_hash_entry root;
+   lang_statement_union_type s;
++  struct out_section_hash_entry *tail;
+ };
+
+ /* The hash table.  */
+@@ -1255,10 +1256,10 @@ static struct bfd_hash_table output_section_statement_table;
+ /* Support routines for the hash table used by lang_output_section_find,
+    initialize the table, fill in an entry and remove the table.  */
+
+-static struct bfd_hash_entry *
+-output_section_statement_newfunc (struct bfd_hash_entry *entry,
+-				  struct bfd_hash_table *table,
+-				  const char *string)
++static struct out_section_hash_entry *
++output_section_statement_newfunc_1 (struct bfd_hash_entry *entry,
++				    struct bfd_hash_table *table,
++				    const char *string)
+ {
+   lang_output_section_statement_type **nextp;
+   struct out_section_hash_entry *ret;
+@@ -1268,12 +1269,12 @@ output_section_statement_newfunc (struct bfd_hash_entry *entry,
+       entry = (struct bfd_hash_entry *) bfd_hash_allocate (table,
+ 							   sizeof (*ret));
+       if (entry == NULL)
+-	return entry;
++	return NULL;
+     }
+
+   entry = bfd_hash_newfunc (entry, table, string);
+   if (entry == NULL)
+-    return entry;
++    return NULL;
+
+   ret = (struct out_section_hash_entry *) entry;
+   memset (&ret->s, 0, sizeof (ret->s));
+@@ -1298,6 +1299,20 @@ output_section_statement_newfunc (struct bfd_hash_entry *entry,
+      instead.  */
+   nextp = &ret->s.output_section_statement.next;
+   lang_statement_append (&lang_os_list, &ret->s, nextp);
++  return ret;
++}
++
++static struct bfd_hash_entry *
++output_section_statement_newfunc (struct bfd_hash_entry *entry,
++				  struct bfd_hash_table *table,
++				  const char *string)
++{
++  struct out_section_hash_entry *ret;
++
++  ret = output_section_statement_newfunc_1 (entry, table, string);
++  if (ret == NULL)
++    return NULL;
++  ret->tail = ret;
+   return &ret->root;
+ }
+
+@@ -1523,31 +1538,39 @@ lang_output_section_statement_lookup (const char *name,
+     {
+       /* We have a section of this name, but it might not have the correct
+ 	 constraint.  */
++      struct out_section_hash_entry *first_ent = entry;
+       struct out_section_hash_entry *last_ent;
+
+       name = entry->s.output_section_statement.name;
+-      do
++      if (create != 2
++	  && !(create && constraint == SPECIAL))
+ 	{
+-	  if (create != 2
+-	      && !(create && constraint == SPECIAL)
+-	      && (constraint == entry->s.output_section_statement.constraint
++	  do
++	    {
++	      if (constraint == entry->s.output_section_statement.constraint
+ 		  || (constraint == 0
+-		      && entry->s.output_section_statement.constraint >= 0)))
+-	    return &entry->s.output_section_statement;
+-	  last_ent = entry;
+-	  entry = (struct out_section_hash_entry *) entry->root.next;
++		      && entry->s.output_section_statement.constraint >= 0))
++		return &entry->s.output_section_statement;
++	      last_ent = entry;
++	      entry = (struct out_section_hash_entry *) entry->root.next;
++	    }
++	  while (entry != NULL
++		 && name == entry->s.output_section_statement.name);
+ 	}
+-      while (entry != NULL
+-	     && name == entry->s.output_section_statement.name);
++      else
++	last_ent = first_ent->tail;
+
+       if (!create)
+ 	return NULL;
+
+-      entry
+-	= ((struct out_section_hash_entry *)
+-	   output_section_statement_newfunc (NULL,
+-					     &output_section_statement_table,
+-					     name));
++      /* Only the first entry needs the tail pointer.  */
++      entry = bfd_hash_allocate (&output_section_statement_table,
++				 offsetof (struct out_section_hash_entry, tail));
++      if (entry != NULL)
++	entry
++	  = output_section_statement_newfunc_1 (&entry->root,
++						&output_section_statement_table,
++						name);
+       if (entry == NULL)
+ 	{
+ 	  einfo (_("%F%P: failed creating section `%s': %E\n"), name);
+@@ -1555,6 +1578,7 @@ lang_output_section_statement_lookup (const char *name,
+ 	}
+       entry->root = last_ent->root;
+       last_ent->root.next = &entry->root;
++      first_ent->tail = entry;
+     }
+
+   entry->s.output_section_statement.name = name;
+-- 
+2.45.2
+

debian/patches/series

@@ -173,3 +173,4 @@ remove-file-produced-by-bison.patch
 replace-space-with-tab.patch
 LoongArch-binutils-compatible-with-older-gcc.diff
 LoongArch-remove-test-cases-for-compatibility.patch
+PR32238-ld-r-slowdown-since-21401fc7bf.patch