Add --hash-size switch to the linker

bfd/ChangeLog

@@ -1,3 +1,15 @@
+2004-05-21  Andy Chittenden  <achittenden@bluearc.com>
+
+	* hash.c (bfd_default_hash_table_size): New variable.
+	(bfd_hash_table_init): Use new variable instead of DEFAULT_SIZE.
+	(bfd_hash_set_default_size): New function.  Set the default size
+	to a selected prime number close to the argument.  Document new
+	function.
+	* bfd-in.h: Add prototype for  bfd_hash_set_default_size.
+	* bfd-in2.h: Regenerate.
+	* Makefile.am (hash.lo): Add dependency upon libiberty.h.
+	* Makefile.in: Regenerate.
+
 2004-05-21  Mark Kettenis  <kettenis@gnu.org>
 
 	* libaout.h (machine_type): Add M_88K_OPENBSD and M_HPPA_OPENBSD.

bfd/Makefile.am

@@ -894,7 +894,7 @@ syms.lo: syms.c $(INCDIR)/filenames.h $(INCDIR)/safe-ctype.h \
   $(INCDIR)/bfdlink.h $(INCDIR)/aout/stab_gnu.h $(INCDIR)/aout/stab.def
 targets.lo: targets.c $(INCDIR)/filenames.h $(INCDIR)/fnmatch.h \
   targmatch.h
-hash.lo: hash.c $(INCDIR)/filenames.h $(INCDIR)/objalloc.h
+hash.lo: hash.c $(INCDIR)/filenames.h $(INCDIR)/objalloc.h $(INCDIR)/libiberty.h
 linker.lo: linker.c $(INCDIR)/filenames.h $(INCDIR)/bfdlink.h \
   genlink.h
 srec.lo: srec.c $(INCDIR)/filenames.h $(INCDIR)/libiberty.h \

bfd/Makefile.in

@@ -1431,7 +1431,7 @@ syms.lo: syms.c $(INCDIR)/filenames.h $(INCDIR)/safe-ctype.h \
   $(INCDIR)/bfdlink.h $(INCDIR)/aout/stab_gnu.h $(INCDIR)/aout/stab.def
 targets.lo: targets.c $(INCDIR)/filenames.h $(INCDIR)/fnmatch.h \
   targmatch.h
-hash.lo: hash.c $(INCDIR)/filenames.h $(INCDIR)/objalloc.h
+hash.lo: hash.c $(INCDIR)/filenames.h $(INCDIR)/objalloc.h $(INCDIR)/libiberty.h
 linker.lo: linker.c $(INCDIR)/filenames.h $(INCDIR)/bfdlink.h \
   genlink.h
 srec.lo: srec.c $(INCDIR)/filenames.h $(INCDIR)/libiberty.h \

bfd/bfd-in.h

@@ -433,6 +433,11 @@ extern void bfd_hash_traverse
    bfd_boolean (*) (struct bfd_hash_entry *, void *),
    void *info);
 
+/* Allows the default size of a hash table to be configured. New hash
+   tables allocated using bfd_hash_table_init will be created with
+   this size.  */
+extern void bfd_hash_set_default_size (bfd_size_type);
+
 #define COFF_SWAP_TABLE (void *) &bfd_coff_std_swap_table
 
 /* User program access to BFD facilities.  */

bfd/bfd-in2.h

@@ -440,6 +440,11 @@ extern void bfd_hash_traverse
    bfd_boolean (*) (struct bfd_hash_entry *, void *),
    void *info);
 
+/* Allows the default size of a hash table to be configured. New hash
+   tables allocated using bfd_hash_table_init will be created with
+   this size.  */
+extern void bfd_hash_set_default_size (bfd_size_type);
+
 #define COFF_SWAP_TABLE (void *) &bfd_coff_std_swap_table
 
 /* User program access to BFD facilities.  */

bfd/hash.c

@@ -1,28 +1,29 @@
 /* hash.c -- hash table routines for BFD
-   Copyright 1993, 1994, 1995, 1997, 1999, 2001, 2002, 2003
+   Copyright 1993, 1994, 1995, 1997, 1999, 2001, 2002, 2003, 2004
    Free Software Foundation, Inc.
    Written by Steve Chamberlain <sac@cygnus.com>
 
-This file is part of BFD, the Binary File Descriptor library.
+   This file is part of BFD, the Binary File Descriptor library.
 
-This program is free software; you can redistribute it and/or modify
+   This program is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
+   it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2 of the License, or
+   the Free Software Foundation; either version 2 of the License, or
-(at your option) any later version.
+   (at your option) any later version.
 
-This program is distributed in the hope that it will be useful,
+   This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
+   GNU General Public License for more details.
 
-You should have received a copy of the GNU General Public License
+   You should have received a copy of the GNU General Public License
-along with this program; if not, write to the Free Software
+   along with this program; if not, write to the Free Software
-Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
 
 #include "bfd.h"
 #include "sysdep.h"
 #include "libbfd.h"
 #include "objalloc.h"
+#include "libiberty.h"
 
 /*
 SECTION
@@ -53,6 +54,7 @@ SECTION
 @* Looking Up or Entering a String::
 @* Traversing a Hash Table::
 @* Deriving a New Hash Table Type::
+@* Changing the default Hash Table Size::
 @end menu
 
 INODE
@@ -87,6 +89,10 @@ SUBSECTION
 	been allocated for a hash table.  This will not free up the
 	<<struct bfd_hash_table>> itself, which you must provide.
 
+@findex bfd_hash_set_default_size
+	Use <<bfd_hash_set_default_size>> to set the default size of
+	hash table to use.
+
 INODE
 Looking Up or Entering a String, Traversing a Hash Table, Creating and Freeing a Hash Table, Hash Tables
 SUBSECTION
@@ -295,7 +301,8 @@ SUBSUBSECTION
 */
 
 /* The default number of entries to use when creating a hash table.  */
-#define DEFAULT_SIZE (4051)
+#define DEFAULT_SIZE 4051
+static size_t bfd_default_hash_table_size = DEFAULT_SIZE;
 
 /* Create a new hash table, given a number of entries.  */
 
@@ -339,7 +346,7 @@ bfd_hash_table_init (table, newfunc)
 						struct bfd_hash_table *,
 						const char *));
 {
-  return bfd_hash_table_init_n (table, newfunc, DEFAULT_SIZE);
+  return bfd_hash_table_init_n (table, newfunc, bfd_default_hash_table_size);
 }
 
 /* Free a hash table.  */
@@ -495,6 +502,24 @@ bfd_hash_traverse (table, func, info)
     }
 }
 
+void
+bfd_hash_set_default_size (bfd_size_type hash_size)
+{
+  int index;
+  /* Extend this prime list if you want more granularity of hash table size.  */
+  static bfd_size_type hash_size_primes[] =
+    {
+      1021, 4051, 8599, 16699
+    };
+
+  /* Work out best prime number near the hash_size.  */
+  for (index = 0; index < ARRAY_SIZE (hash_size_primes) - 1; ++index)
+    if (hash_size <= hash_size_primes[index])
+      break;
+
+  bfd_default_hash_table_size = hash_size_primes[index];
+}
+
 /* A few different object file formats (a.out, COFF, ELF) use a string
    table.  These functions support adding strings to a string table,
    returning the byte offset, and writing out the table.

ld/ChangeLog

@@ -1,3 +1,18 @@
+2004-05-21  Andy Chittenden  <achittenden@bluearc.com>
+
+	* ld.h (ld_config_type): Add new field: hash_table_size.
+	* ldmain.c: Initialise the new field to zero.  If it is non-zero
+	after parsing the linker's command line call
+	bfd_hash_set_default_size.
+	* lexsup.c (option_values): Add OPTION_HASH_SIZE.
+	(ld_options): Add hash-size.
+	(parse_args): Parse --hash-size option.  Allow
+	--reduce-memory-overheads to set the default hash table size as
+	well.
+	* ld.texinfo: Document the new switch.  Also mention that
+	--reduce-memory-overheads can affect the hash table size.
+	* NEWS: Mention the new feature.
+
 2004-05-19  J"orn Rennecke <joern.rennecke@superh.com>
 
 	* NEWS: Mention new linker map file generation and the

ld/NEWS

@@ -1,11 +1,19 @@
 -*- text -*-
 
+* A new linker command line switch has been added which allows the hash table
+  size to be set to a suitable prime value near to its argument.  This switch
+  is --hash-size=<NUMBER>.  Also if the switch --reduce-memory-overheads is
+  used, and --hash-size has not been used, then the default value will be set
+  to 1021.
+
 * Linker map files are now generated with an O(N) algorithm for finding symbols
   that are defined in each section.  This uses about 40% more memory for
   symbols than the old O(N^2) algorithm.  You can use the new
   --reduce-memory-overheads option to select the old algorithm; this option
   might also be used in the future to select similar tradeoffs.
 
+Changes in 2.15:
+  
 * New PE --large-address-aware option to indicate executables support virtual
   addresses greater than 2 gigabytes.
 

ld/ld.h

@@ -1,5 +1,5 @@
 /* ld.h -- general linker header file
-   Copyright 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2002
+   Copyright 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2002, 2004
    Free Software Foundation, Inc.
 
    This file is part of GLD, the Gnu Linker.
@@ -241,6 +241,9 @@ typedef struct {
   /* If set, only search library directories explicitly selected
      on the command line.  */
   bfd_boolean only_cmd_line_lib_dirs;
+
+  /* The size of the hash table to use.  */
+  bfd_size_type hash_table_size;
 } ld_config_type;
 
 extern ld_config_type config;

ld/ld.texinfo

@@ -1734,13 +1734,27 @@ If you specify @option{--disable-new-dtags}, no new dynamic tags will be
 created. By default, the new dynamic tags are not created. Note that
 those options are only available for ELF systems.
 
+@kindex --hash-size=@var{number}
+Set the default size of the linker's hash tables to a prime number
+close to @var{number}.  Increasing this value can reduce the length of
+time it takes the linker to perform its tasks, at the expense of
+increasing the linker's memory requirements.  Similarly reducing this
+value can reduce the memory requirements at the expense of speed.
+
 @kindex --reduce-memory-overheads
 @item --reduce-memory-overheads
 This option reduces memory requirements at ld runtime, at the expense of
 linking speed.  This was introduced to to select the old O(n^2) algorithm
 for link map file generation, rather than the new O(n) algorithm which uses
-about 40% more memory for symbol storage.  It may be also be used for
+about 40% more memory for symbol storage.
-similar such tradeoffs in the future.
+
+Another affect of the switch is to set the default hash table size to
+1021, which again saves memory at the cost of lengthening the linker's
+run time.  This is not done however if the *option{--hash-size} switch
+has been used.
+
+The @option{--reduce-memory-overheads} switch may be also be used to
+enable other tradeoffs in future versions of the linker.
 
 @end table
 

ld/ldmain.c

@@ -267,6 +267,7 @@ main (int argc, char **argv)
   config.has_shared = FALSE;
   config.split_by_reloc = (unsigned) -1;
   config.split_by_file = (bfd_size_type) -1;
+  config.hash_table_size = 0;
   command_line.force_common_definition = FALSE;
   command_line.inhibit_common_definition = FALSE;
   command_line.interpreter = NULL;
@@ -344,6 +345,9 @@ main (int argc, char **argv)
   lang_has_input_file = FALSE;
   parse_args (argc, argv);
 
+  if (config.hash_table_size != 0)
+    bfd_hash_set_default_size (config.hash_table_size);
+
   ldemul_set_symbols ();
 
   if (link_info.relocatable)

ld/lexsup.c

@@ -118,6 +118,7 @@ enum option_values
   OPTION_FORCE_EXE_SUFFIX,
   OPTION_GC_SECTIONS,
   OPTION_NO_GC_SECTIONS,
+  OPTION_HASH_SIZE,
   OPTION_CHECK_SECTIONS,
   OPTION_NO_CHECK_SECTIONS,
   OPTION_NO_UNDEFINED,
@@ -328,6 +329,8 @@ static const struct ld_option ld_options[] =
   { {"no-gc-sections", no_argument, NULL, OPTION_NO_GC_SECTIONS},
       '\0', NULL, N_("Don't remove unused sections (default)"),
       TWO_DASHES },
+  { {"hash-size=<NUMBER>", required_argument, NULL, OPTION_HASH_SIZE},
+      '\0', NULL, N_("Set default hash table size close to <NUMBER>"), TWO_DASHES },
   { {"help", no_argument, NULL, OPTION_HELP},
       '\0', NULL, N_("Print option help"), TWO_DASHES },
   { {"init", required_argument, NULL, OPTION_INIT},
@@ -364,6 +367,8 @@ static const struct ld_option ld_options[] =
       '\0', N_("TARGET"), N_("Specify target of output file"), EXACTLY_TWO_DASHES },
   { {"qmagic", no_argument, NULL, OPTION_IGNORE},
       '\0', NULL, N_("Ignored for Linux compatibility"), ONE_DASH },
+  { {"reduce-memory-overheads", no_argument, NULL, OPTION_REDUCE_MEMORY_OVERHEADS},
+      '\0', NULL, N_("Reduce memory overheads, possibly taking much longer"), TWO_DASHES },
   { {"relax", no_argument, NULL, OPTION_RELAX},
       '\0', NULL, N_("Relax branches on certain targets"), TWO_DASHES },
   { {"retain-symbols-file", required_argument, NULL,
@@ -447,8 +452,6 @@ static const struct ld_option ld_options[] =
       '\0', NULL, N_("Always set DT_NEEDED for following dynamic libs"), TWO_DASHES },
   { {"wrap", required_argument, NULL, OPTION_WRAP},
       '\0', N_("SYMBOL"), N_("Use wrapper functions for SYMBOL"), TWO_DASHES },
-  { {"reduce-memory-overheads", no_argument, NULL, OPTION_REDUCE_MEMORY_OVERHEADS},
-      '\0', NULL, N_("reduce memory overheads, possibly taking much longer"), TWO_DASHES },
 };
 
 #define OPTION_COUNT ARRAY_SIZE (ld_options)
@@ -1224,9 +1227,24 @@ parse_args (unsigned argc, char **argv)
 	case OPTION_FINI:
 	  link_info.fini_function = optarg;
 	  break;
+
 	case OPTION_REDUCE_MEMORY_OVERHEADS:
 	  command_line.reduce_memory_overheads = TRUE;
+	  if (config.hash_table_size == 0)
+	    config.hash_table_size = 1021;
 	  break;
+
+        case OPTION_HASH_SIZE:
+	  {
+	    bfd_size_type new_size;
+
+            new_size = strtoul (optarg, NULL, 0);
+            if (new_size)
+              config.hash_table_size = new_size;
+            else
+              einfo (_("%P%X: --hash-size needs a numeric argument\n"));
+          }
+          break;
 	}
     }