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[PATCH] Use binary search instead of linear search in corefile.c of gprof
- From: Dongsheng Xing <homer dot xing at yahoo dot com>
- To: binutils at sourceware dot org
- Date: Mon, 15 Jun 2009 06:11:36 -0700 (PDT)
- Subject: [PATCH] Use binary search instead of linear search in corefile.c of gprof
Hi!
This patch replace linear search by binary search in core_create_syms_from().
This is implemented by qsort(symbol_map) in read_function_mappings() by function name, thus we can do binary search in core_create_function_syms() based on function name.
But in the original version, core_create_function_syms() need to know whether a symbol is the first symbol in object file. It did this by check whether symbol_map[j].file_name==symbol_map[j-1].file_name. Since symbol_map is sorted, this method does not work. So a field `is_first:1' is added into struct function_map.
qsort() is added into cg_print_file_ordering(), since cg_print_file_ordering() requires that symbol_map is sorted by file_name.
Cheers,
Homer
diff -rup binutils-2.19.51.origin/gprof/cg_print.c binutils-2.19.51/gprof/cg_print.c
--- binutils-2.19.51.origin/gprof/cg_print.c 2009-06-14 21:00:29.000000000 +0800
+++ binutils-2.19.51/gprof/cg_print.c 2009-06-15 20:45:35.000000000 +0800
@@ -1212,6 +1212,16 @@ order_and_dump_functions_by_arcs (the_ar
}
}
+/* Compare two function_map struct based on file name.
+ We want to sort in ascending order. */
+
+static int
+cmp_symbol_map (const PTR left, const PTR right)
+{
+ return strcmp ( ((const struct function_map *) left )->file_name,
+ ((const struct function_map *) right)->file_name);
+}
+
/* Print a suggested .o ordering for files on a link line based
on profiling information. This uses the function placement
code for the bulk of its work. */
@@ -1245,6 +1255,7 @@ cg_print_file_ordering ()
}
/* Now output any .o's that didn't have any text symbols. */
+ qsort (symbol_map, symbol_map_count, sizeof (struct function_map), cmp_symbol_map);
last = NULL;
for (index = 0; index < symbol_map_count; index++)
{
@@ -1259,7 +1270,6 @@ cg_print_file_ordering ()
{
if (! symtab.base[index2].mapped)
continue;
-
if (!strcmp (symtab.base[index2].name, symbol_map[index].file_name))
break;
}
diff -rup binutils-2.19.51.origin/gprof/corefile.c binutils-2.19.51/gprof/corefile.c
--- binutils-2.19.51.origin/gprof/corefile.c 2009-06-15 19:03:48.000000000 +0800
+++ binutils-2.19.51/gprof/corefile.c 2009-06-15 20:53:44.000000000 +0800
@@ -61,12 +61,23 @@ parse_error (const char *filename)
done (1);
}
+/* Compare two function_map struct based on function name.
+ We want to sort in ascending order. */
+
+static int
+cmp_symbol_map (const PTR left, const PTR right)
+{
+ return strcmp ( ((const struct function_map *) left )->function_name,
+ ((const struct function_map *) right)->function_name);
+}
+
static void
read_function_mappings (const char *filename)
{
FILE *file = fopen (filename, "r");
char dummy[1024];
int count = 0;
+ unsigned int i;
if (!file)
{
@@ -144,6 +155,14 @@ read_function_mappings (const char *file
/* Record the size of the map table for future reference. */
symbol_map_count = count;
+
+ for (i = 0; i < symbol_map_count; ++i)
+ {
+ if (i == 0 || strcmp (symbol_map[i].file_name, symbol_map[i - 1].file_name))
+ symbol_map[i].is_first = 1;
+ }
+
+ qsort (symbol_map, symbol_map_count, sizeof (struct function_map), cmp_symbol_map);
}
@@ -532,6 +551,26 @@ core_create_syms_from (const char * sym_
free (name);
}
+static int
+search_mapped_symbol(const char *name)
+{
+ int low, high, mid, t;
+ low = 0;
+ high = symbol_map_count - 1;
+ while (low <= high)
+ {
+ mid = (low + high) / 2;
+ t = strcmp (name, symbol_map[mid].function_name);
+ if (!t)
+ return mid;
+ else if (t < 0)
+ high = mid - 1;
+ else
+ low = mid + 1;
+ }
+ return -1;
+}
+
/* Read in symbol table from core.
One symbol per function is entered. */
@@ -541,8 +580,7 @@ core_create_function_syms ()
bfd_vma min_vma = ~(bfd_vma) 0;
bfd_vma max_vma = 0;
int class;
- long i, found, skip;
- unsigned int j;
+ long i, found;
/* Pass 1 - determine upper bound on number of function names. */
symtab.len = 0;
@@ -552,23 +590,11 @@ core_create_function_syms ()
if (!core_sym_class (core_syms[i]))
continue;
- /* This should be replaced with a binary search or hashed
- search. Gross.
-
- Don't create a symtab entry for a function that has
+ /* Don't create a symtab entry for a function that has
a mapping to a file, unless it's the first function
in the file. */
- skip = 0;
- for (j = 0; j < symbol_map_count; j++)
- if (!strcmp (core_syms[i]->name, symbol_map[j].function_name))
- {
- if (j > 0 && ! strcmp (symbol_map [j].file_name,
- symbol_map [j - 1].file_name))
- skip = 1;
- break;
- }
-
- if (!skip)
+ found = search_mapped_symbol (core_syms[i]->name);
+ if (found == -1 || symbol_map[found].is_first)
++symtab.len;
}
@@ -598,23 +624,8 @@ core_create_function_syms ()
continue;
}
- /* This should be replaced with a binary search or hashed
- search. Gross. */
- skip = 0;
- found = 0;
-
- for (j = 0; j < symbol_map_count; j++)
- if (!strcmp (core_syms[i]->name, symbol_map[j].function_name))
- {
- if (j > 0 && ! strcmp (symbol_map [j].file_name,
- symbol_map [j - 1].file_name))
- skip = 1;
- else
- found = j;
- break;
- }
-
- if (skip)
+ found = search_mapped_symbol (core_syms[i]->name);
+ if (found != -1 && symbol_map[found].is_first == 0)
continue;
sym_init (symtab.limit);
@@ -625,8 +636,7 @@ core_create_function_syms ()
if (sym_sec)
symtab.limit->addr += bfd_get_section_vma (sym_sec->owner, sym_sec);
- if (symbol_map_count
- && !strcmp (core_syms[i]->name, symbol_map[found].function_name))
+ if (symbol_map_count && found != -1)
{
symtab.limit->name = symbol_map[found].file_name;
symtab.limit->mapped = 1;
diff -rup binutils-2.19.51.origin/gprof/corefile.h binutils-2.19.51/gprof/corefile.h
--- binutils-2.19.51.origin/gprof/corefile.h 2009-06-14 21:00:29.000000000 +0800
+++ binutils-2.19.51/gprof/corefile.h 2009-06-15 19:11:24.000000000 +0800
@@ -26,6 +26,7 @@ struct function_map
{
char *function_name;
char *file_name;
+ unsigned int is_first:1; /* Is this the first symbol in an object file? */
};
extern struct function_map * symbol_map;