Change random seeds to 64bit and drop re-crcing

I had some trouble with random build failures in a large LTO project
and it turned out to be random seed collisions in a highly parallel build
(thanks to Honza for suggesting that)

There were multiple problems:
- The way to generate the random seed is not very random (milliseconds time plus pid)
and prone to collisions on highly parallel builds
- It's only 32bit
- Several users take the existing ascii seed and re-CRC32 it again, which
doesn't exactly improve it.

This patch changes that to:
- Always use 64bit seeds as numbers (no re-crcing)
- Change all users to use HOST_WIDE_INT
- When the user specifies a random seed it's still crc32ed, but only in
this case.

Passes bootstrap + testsuite on x86_64-linux.

gcc/cp:

2011-09-26   Andi Kleen <ak@linux.intel.com>

	* repo.c (finish_repo): Use HOST_WIDE_INT_PRINT_HEX_PURE.

gcc/:

2011-09-26   Andi Kleen <ak@linux.intel.com>

	* hwint.h (HOST_WIDE_INT_PRINT_HEX_PURE): Add.
	* lto-streamer.c (lto_get_section_name): Remove crc32_string.
 	Handle numerical random seed.
	* lto-streamer.h (lto_file_decl_data): Change id to unsigned HOST_WIDE_INT.
	* toplev.c (random_seed): Add.
	(init_random_seed): Change for numerical random seed.
	(get_random_seed): Return as HOST_WIDE_INT.
	(set_random_seed): Crc32 existing string.
	* toplev.h (get_random_seed): Change to numercal return.
	* tree.c (get_file_function_name): Remove CRC. Handle numerical random seed.

gcc/lto/:

2011-09-26   Andi Kleen <ak@linux.intel.com>

	* lto.c (lto_resolution_read): Remove id dumping.
	(lto_section_with_id): Turn id HOST_WIDE_ID.
	(create_subid_section_table): Dito.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@179347 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 4 insertions, 7 deletions

diff --git a/gcc/lto/lto.c b/gcc/lto/lto.c
index 0b1dcb9c8b5..77eb1a15188 100644
--- a/gcc/lto/lto.c
+++ b/gcc/lto/lto.c
@@ -976,9 +976,6 @@ lto_resolution_read (splay_tree file_ids, FILE *resolution, lto_file *file)
 	}
 
       file_data = (struct lto_file_decl_data *)nd->value;
-      if (cgraph_dump_file)
-	fprintf (cgraph_dump_file, "Adding resolution %u %u to id %x\n",
-		 index, r, file_data->id);
       VEC_safe_grow_cleared (ld_plugin_symbol_resolution_t, heap, 
 			     file_data->resolutions,
 			     max_index + 1);
@@ -990,14 +987,14 @@ lto_resolution_read (splay_tree file_ids, FILE *resolution, lto_file *file)
 /* Is the name for a id'ed LTO section? */
 
 static int 
-lto_section_with_id (const char *name, unsigned *id)
+lto_section_with_id (const char *name, unsigned HOST_WIDE_INT *id)
 {
   const char *s;
 
   if (strncmp (name, LTO_SECTION_NAME_PREFIX, strlen (LTO_SECTION_NAME_PREFIX)))
     return 0;
   s = strrchr (name, '.');
-  return s && sscanf (s, ".%x", id) == 1;
+  return s && sscanf (s, "." HOST_WIDE_INT_PRINT_HEX_PURE, id) == 1;
 }
 
 /* Create file_data of each sub file id */
@@ -1008,7 +1005,7 @@ create_subid_section_table (void **slot, void *data)
   struct lto_section_slot s_slot, *new_slot;
   struct lto_section_slot *ls = *(struct lto_section_slot **)slot;
   splay_tree file_ids = (splay_tree)data;
-  unsigned id;
+  unsigned HOST_WIDE_INT id;
   splay_tree_node nd;
   void **hash_slot;
   char *new_name;
@@ -1080,7 +1077,7 @@ static int lto_create_files_from_ids (splay_tree_node node, void *data)
 
   lto_file_finalize (file_data, lw->file);
   if (cgraph_dump_file)
-    fprintf (cgraph_dump_file, "Creating file %s with sub id %x\n", 
+    fprintf (cgraph_dump_file, "Creating file %s with sub id " HOST_WIDE_INT_PRINT_HEX "\n", 
 	     file_data->file_name, file_data->id);
   file_data->next = *lw->file_data;
   *lw->file_data = file_data;