Various changes with focus to startup speedup

The startup timeout on Win32 is reduced to 80% without assembler and to 50% with assembler usage (which is optional)
proto.c
 - do not look up in filed tree and inserts in two steps but do it at once
 - next few small speedups
 - some often called elementary functions can be optionally implemented in assembler
 - dispart some functions to see more exact result from profiling
packet-tpnc.c
 - do not reallocate memory for each filed

svn path=/trunk/; revision=23643

9 files changed, 360 insertions, 48 deletions

diff --git a/Makefile.nmake b/Makefile.nmake
index 6983f5997d..1a993d341b 100644
--- a/Makefile.nmake
+++ b/Makefile.nmake
@@ -592,6 +592,7 @@ REQUIRED_TOOLS=\
 	/usr/bin/find	\
 	$(PERL)	\
 	$(PYTHON)	\
+	$(NASM)	\
 	sed	\
 	unzip	\
 	wget
diff --git a/config.nmake b/config.nmake
index 709500696d..fe02e279b4 100644
--- a/config.nmake
+++ b/config.nmake
@@ -80,6 +80,15 @@ MSVC_VARIANT=MSVC6
 # Visual C++ 8.0, _MSC_VER 1400, msvcr80.dll
 #MSVC_VARIANT=DOTNET20
 
+#
+# Optional: To compile some time critical code from assembler instead of C
+#
+# If you have the NASM compiler, set this to the NASM executable.
+#
+# If you don't have NASM, comment this line out, so that NASM
+# isn't defined.
+#
+#NASM=c:\progs\nasm\nasm.exe
 
 
 ##### Libraries #####
diff --git a/epan/Makefile.am b/epan/Makefile.am
index 902c76b40f..a566f076d9 100644
--- a/epan/Makefile.am
+++ b/epan/Makefile.am
@@ -74,7 +74,9 @@ EXTRA_libwireshark_la_SOURCES =	\
 	g_ascii_strtoull.c	\
 	g_ascii_strtoull.h	\
 	inet_aton.c		\
-	inet_aton.h
+	inet_aton.h		\
+	asm_utils.c		\
+	asm_utils.h
 
 EXTRA_DIST = \
 	diam_dict.l		\
diff --git a/epan/Makefile.nmake b/epan/Makefile.nmake
index fd8772c1e7..7951a54179 100644
--- a/epan/Makefile.nmake
+++ b/epan/Makefile.nmake
@@ -55,7 +55,13 @@ EXTRA_OBJECTS = \
 	inet_pton.obj	\
 	inet_ntop.obj	\
 	mkstemp.obj	\
-	strptime.obj
+	strptime.obj	\
+!IFDEF NASM
+	asm_utils_win32_x86.obj
+!ELSE
+	asm_utils.obj
+!ENDIF
+
 
 
 !IFDEF DOXYGEN
@@ -245,6 +251,14 @@ reassemble_test_install:
 	if exist reassemble_test.exe          xcopy reassemble_test.exe          $(INSTALL_DIR) /d
 
 
+#
+# Compile some time crtical code from assembler if NASM available
+#
+!IFDEF NASM
+asm_utils_win32_x86.obj: asm_utils_win32_x86.asm
+	$(NASM) -f win32 -o $@ $?
+!ENDIF
+
 # (Windows only) Copy some sources from /trunk to /trunk/epan.
 # It is a cleaner to compile these sources seperately with this makefile than
 # using the object code compiled by the makefile in /trunk for both dynamically
diff --git a/epan/asm_utils.c b/epan/asm_utils.c
new file mode 100644
index 0000000000..98044c14bc
--- /dev/null
+++ b/epan/asm_utils.c
@@ -0,0 +1,67 @@
+/* asm_utils.c
+ * Functions optionally implemented in assembler
+ *
+ * $Id$
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * 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 the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#include <string.h>
+#include <ctype.h>
+#include <glib.h>
+
+#include "asm_utils.h"
+
+/* String comparison func for dfilter_token GTree */
+int
+wrs_strcmp(gconstpointer a, gconstpointer b)
+{
+    return strcmp((const char*)a, (const char*)b);
+}
+
+int 
+wrs_strcmp_with_data(gconstpointer a, gconstpointer b, gpointer user_data _U_)
+{
+    return strcmp((const char*)a, (const char*)b);
+}
+
+guchar 
+wrs_check_charset(const guchar table[256], const char *str)
+{
+    const char *p = str;
+    guchar c;
+
+    do {
+      c = *(p++);
+    } while (table[c]);
+    return c;
+}
+
+guint
+wrs_str_hash(gconstpointer v)
+{
+  /* 31 bit hash function */
+  const signed char *p = v;
+  guint32 h = *p;
+  if (h)
+    for (p += 1; *p != '\0'; p++)
+      h = (h << 5) - h + *p;
+  return h;
+}
+
diff --git a/epan/asm_utils.h b/epan/asm_utils.h
new file mode 100644
index 0000000000..21a2ef55eb
--- /dev/null
+++ b/epan/asm_utils.h
@@ -0,0 +1,37 @@
+/* asm_utils.h
+ * Functions optionally implemented in assembler
+ *
+ * $Id$
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * 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 the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#ifndef __ASM_UTILS_H__
+#define __ASM_UTILS_H__
+
+int wrs_strcmp(gconstpointer a, gconstpointer b);
+int wrs_strcmp_with_data(gconstpointer a, gconstpointer b, gpointer user_data);
+
+guchar wrs_check_charset(const guchar table[256], const char *str);
+
+guint wrs_str_hash(gconstpointer v);
+
+/* int wrs_count_bitshift(guint32 bitmask); */
+
+#endif  /* __ASM_UTILS_H__ */
diff --git a/epan/asm_utils_win32_x86.asm b/epan/asm_utils_win32_x86.asm
new file mode 100644
index 0000000000..767d303994
--- /dev/null
+++ b/epan/asm_utils_win32_x86.asm
@@ -0,0 +1,147 @@
+; asm_utils_win32_x86.c
+; Functions optionally implemented in assembler
+;
+; $Id$
+;
+; Wireshark - Network traffic analyzer
+; By Gerald Combs <gerald@wireshark.org>
+; Copyright 1998 Gerald Combs
+;
+; 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 the Free Software Foundation; either version 2
+; of the License, or (at your option) any later version.
+;
+; This program is distributed in the hope that it will be useful,
+; but WITHOUT ANY WARRANTY; without even the implied warranty of
+; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+; GNU General Public License for more details.
+;
+; You should have received a copy of the GNU General Public License
+; along with this program; if not, write to the Free Software
+; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+;
+
+SECTION .text
+
+GLOBAL _wrs_strcmp
+GLOBAL _wrs_strcmp_with_data
+GLOBAL _wrs_check_charset
+GLOBAL _wrs_str_hash
+
+    align 16
+_wrs_strcmp
+_wrs_strcmp_with_data
+    mov ecx, dword [esp + 4]  ; a
+    mov edx, dword [esp + 8]  ; b
+    push ebx
+CMP_LOOP:
+    mov eax, dword [ecx]
+    mov ebx, dword [edx]
+    cmp al, bl
+    jne CMP_NEQ_END
+    or al, al
+    jz CMP_EQ_END
+    cmp ah, bh
+    jne CMP_NEQ_END
+    or ah, ah
+    jz CMP_EQ_END
+    shr eax, 16
+    shr ebx, 16
+    add ecx, byte 4
+    add edx, byte 4
+    cmp al, bl
+    jne CMP_NEQ_END
+    or al, al
+    jz CMP_EQ_END
+    cmp ah, bh
+    jne CMP_NEQ_END
+    or ah, ah
+    jnz CMP_LOOP
+CMP_EQ_END:
+    pop ebx
+    xor eax, eax
+    retn
+CMP_NEQ_END:  
+    ; returns 1 or -1 based on CF flag from the last comparision
+    sbb eax, eax
+    pop ebx
+    shl eax, 1
+    inc eax
+    retn
+
+    align 16
+_wrs_check_charset:
+    mov edx, dword [esp + 4]  ; table
+    mov ecx, dword [esp + 8]  ; str
+    push edi
+    push ebx
+    mov edi, edx
+    mov bl, byte 0xFF
+CHK_LOOP:
+    mov eax, dword [ecx]
+    movzx edx, al
+    test bl, byte [edi+edx]
+    jz CHK_AL_END
+    movzx edx, ah
+    test bl, byte [edi+edx]
+    jz CHK_AH_END
+    shr eax, 16
+    add ecx, byte 4
+    movzx edx, al
+    test bl, byte [edi+edx]
+    jz CHK_AL_END
+    movzx edx, ah
+    test bl, byte [edi+edx]
+    jnz CHK_LOOP
+CHK_AH_END
+    movzx eax, ah
+    pop ebx
+    pop edi
+    retn
+CHK_AL_END
+    movzx eax, al
+    pop ebx
+    pop edi
+    retn
+
+    align 16
+_wrs_str_hash:
+    mov edx, dword [esp + 4]  ; v
+    push ebx
+    xor eax, eax
+    mov ecx, dword [edx]
+    or cl, cl
+    movzx ebx, cl
+    jz HASH_END
+HASH_LOOP:
+    sub ebx, eax
+    shl eax, 5
+    add eax, ebx
+    or ch, ch
+    movzx ebx, ch
+    jz HASH_END
+    sub ebx, eax
+    shl eax, 5
+    add eax, ebx
+    shr ecx, 16
+    add edx, byte 4
+    or cl, cl
+    movzx ebx, cl
+    jz HASH_END
+    sub ebx, eax
+    shl eax, 5
+    add eax, ebx
+    or ch, ch
+    movzx ebx, ch
+    jz HASH_END
+    sub ebx, eax
+    shl eax, 5
+    add eax, ebx
+    mov ecx, dword [edx]
+    or cl, cl
+    movzx ebx, cl
+    jnz HASH_LOOP
+HASH_END:
+    pop ebx
+    retn
diff --git a/epan/dissectors/packet-tpncp.c b/epan/dissectors/packet-tpncp.c
index b696a5e9db..acc3398068 100644
--- a/epan/dissectors/packet-tpncp.c
+++ b/epan/dissectors/packet-tpncp.c
@@ -123,6 +123,7 @@ static value_string tpncp_enums_id_vals[MAX_ENUMS_NUM][MAX_ENUM_ENTRIES];
 static gchar *tpncp_enums_name_vals[MAX_ENUMS_NUM];
 
 static gint hf_size = 1;
+static gint hf_allocated = 0; 
 static hf_register_info *hf = NULL;
 static hf_register_info hf_tpncp[] = {
     {
@@ -575,9 +576,10 @@ static gint init_tpncp_data_fields_info(tpncp_data_field_info *data_fields_info,
 
     if (!was_registered) {
         /* Register non-standard data should be done only once. */
+        hf_allocated = hf_size+array_length(hf_tpncp)-1;
+        if ((hf = (hf_register_info *)g_realloc(hf, hf_allocated * sizeof(hf_register_info))) == NULL)
+            return (-1);
         for (index = 0; index < array_length(hf_tpncp); index++) {
-            if ((hf = (hf_register_info *)realloc(hf, hf_size*sizeof(hf_register_info))) == NULL)
-                return (-1);
             memcpy(hf + (hf_size - 1), hf_tpncp + index, sizeof(hf_register_info));
             hf_size++;
         }
@@ -616,8 +618,8 @@ static gint init_tpncp_data_fields_info(tpncp_data_field_info *data_fields_info,
             current_data_id = data_id;
         }
         else {
-            if ((current_tpncp_data_field_info->p_next =
-                (tpncp_data_field_info *)calloc(1, sizeof(tpncp_data_field_info)))
+            if ((current_tpncp_data_field_info->p_next = 
+                (tpncp_data_field_info *)g_malloc0(sizeof(tpncp_data_field_info))) 
                 == NULL)
                 return (-1);
             current_tpncp_data_field_info = current_tpncp_data_field_info->p_next;
@@ -655,8 +657,11 @@ static gint init_tpncp_data_fields_info(tpncp_data_field_info *data_fields_info,
                 break;
         }
         /* Register initialized hf_register_info in global database. */
-        if ((hf = (hf_register_info *)realloc(hf, hf_size*sizeof(hf_register_info))) == NULL)
-            return (-1);
+        if (hf_size > hf_allocated) {
+            hf_allocated += 1024;
+            if ((hf = (hf_register_info *)g_realloc(hf, hf_allocated * sizeof(hf_register_info))) == NULL)
+                return (-1);
+        }
         memcpy(hf + hf_size - 1, &hf_entr, sizeof(hf_register_info));
         hf_size++;
         current_tpncp_data_field_info->tpncp_data_field_sign = tpncp_data_field_sign;
diff --git a/epan/proto.c b/epan/proto.c
index 48d567c447..bce9b59082 100644
--- a/epan/proto.c
+++ b/epan/proto.c
@@ -44,6 +44,7 @@
 #include "tvbuff.h"
 #include "emem.h"
 #include "charsets.h"
+#include "asm_utils.h"
 
 #ifdef NEED_G_ASCII_STRCASECMP_H
 #include "g_ascii_strcasecmp.h"
@@ -68,6 +69,19 @@ struct ptvcursor {
 	gint		offset;
 };
 
+/* Candidates for assembler */
+int 
+wrs_count_bitshift(guint32 bitmask)
+{
+	int bitshift = 0;
+
+	while ((bitmask & (1 << bitshift)) == 0)
+		bitshift++;
+	return bitshift;
+}
+
+
+
 #if GLIB_MAJOR_VERSION < 2
 static void *discard_const(const void *const_ptr)
 {
@@ -209,9 +223,6 @@ proto_tree_set_uint64_tvb(field_info *fi, tvbuff_t *tvb, gint start, guint lengt
 
 static int proto_register_field_init(header_field_info *hfinfo, int parent);
 
-/* Comparision function for tree insertion. A wrapper around strcmp() */
-static int g_strcmp(gconstpointer a, gconstpointer b);
-
 /* special-case header field used within proto.c */
 int hf_text_only = -1;
 
@@ -287,6 +298,12 @@ gpa_hfinfo_t gpa_hfinfo;
 
 /* Balanced tree of abbreviations and IDs */
 static GTree *gpa_name_tree = NULL;
+static header_field_info *same_name_hfinfo;
+
+static void save_same_name_hfinfo(gpointer data)
+{
+  same_name_hfinfo = (header_field_info*)data;
+}
 
 /* Points to the first element of an array of Booleans, indexed by
    a subtree item type; that array element is TRUE if subtrees of
@@ -326,8 +343,8 @@ proto_init(void (register_all_protocols)(register_cb cb, gpointer client_data),
 
 
 	proto_names = g_hash_table_new(g_int_hash, g_int_equal);
-	proto_short_names = g_hash_table_new(g_int_hash, g_int_equal);
-	proto_filter_names = g_hash_table_new(g_int_hash, g_int_equal);
+	proto_short_names = g_hash_table_new(g_str_hash, g_str_equal);
+	proto_filter_names = g_hash_table_new(g_str_hash, g_str_equal);
 
 	proto_cleanup();
 
@@ -339,7 +356,7 @@ proto_init(void (register_all_protocols)(register_cb cb, gpointer client_data),
 	gpa_hfinfo.len=0;
 	gpa_hfinfo.allocated_len=0;
 	gpa_hfinfo.hfi=NULL;
-	gpa_name_tree = g_tree_new(g_strcmp);
+	gpa_name_tree = g_tree_new_full(wrs_strcmp_with_data, NULL, NULL, save_same_name_hfinfo);
 
 	/* Initialize the ftype subsystem */
 	ftypes_initialize();
@@ -386,13 +403,6 @@ proto_init(void (register_all_protocols)(register_cb cb, gpointer client_data),
 	memset(tree_is_expanded, 0, num_tree_types*sizeof (gboolean));
 }
 
-/* String comparison func for dfilter_token GTree */
-static int
-g_strcmp(gconstpointer a, gconstpointer b)
-{
-	return strcmp((const char*)a, (const char*)b);
-}
-
 void
 proto_cleanup(void)
 {
@@ -3498,14 +3508,12 @@ proto_register_protocol(const char *name, const char *short_name, const char *fi
     }
     g_hash_table_insert(proto_names, key, (gpointer)name);
 
-    key = g_malloc (sizeof(gint));
-    *key = g_str_hash(short_name);
-    existing_name = g_hash_table_lookup(proto_short_names, key);
+    existing_name = g_hash_table_lookup(proto_short_names, (gpointer)short_name);
     if (existing_name != NULL) {
         g_error("Duplicate protocol short_name \"%s\"!"
             " This might be caused by an inappropriate plugin or a development error.", short_name);
     }
-    g_hash_table_insert(proto_short_names, key, (gpointer)short_name);
+    g_hash_table_insert(proto_short_names, (gpointer)short_name, (gpointer)short_name);
 
     found_invalid = FALSE;
     for (i = 0; i < strlen(filter_name); i++) {
@@ -3519,14 +3527,12 @@ proto_register_protocol(const char *name, const char *short_name, const char *fi
             " Allowed are lower characters, digits, '-', '_' and '.'."
             " This might be caused by an inappropriate plugin or a development error.", filter_name);
     }
-    key = g_malloc (sizeof(gint));
-    *key = g_str_hash(filter_name);
-    existing_name = g_hash_table_lookup(proto_filter_names, key);
+    existing_name = g_hash_table_lookup(proto_filter_names, (gpointer)filter_name);
     if (existing_name != NULL) {
         g_error("Duplicate protocol filter_name \"%s\"!"
             " This might be caused by an inappropriate plugin or a development error.", filter_name);
     }
-    g_hash_table_insert(proto_filter_names, key, (gpointer)filter_name);
+    g_hash_table_insert(proto_filter_names, (gpointer)filter_name, (gpointer)filter_name);
 
     /* Add this protocol to the list of known protocols; the list
        is sorted by protocol short name. */
@@ -3765,9 +3771,29 @@ proto_register_field_array(int parent, hf_register_info *hf, int num_records)
 	}
 }
 
-static int
-proto_register_field_init(header_field_info *hfinfo, int parent)
-{
+/* chars allowed in field abbrev */
+static 
+const guchar fld_abbrev_chars[256] = {
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0x00-0x0F */
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0x10-0x1F */
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, /* 0x20-0x2F '-', '.'     */
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, /* 0x30-0x3F '0'-'9'      */
+ 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0x40-0x4F 'A'-'O'      */
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, /* 0x50-0x5F 'P'-'Z', '_' */
+ 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0x60-0x6F 'a'-'o'      */
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, /* 0x70-0x7F 'p'-'z'      */
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0x80-0x8F */
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0x90-0x9F */
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0xA0-0xAF */
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0xB0-0xBF */
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0xC0-0xCF */
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0xD0-0xDF */
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0xE0-0xEF */
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0xF0-0xFF */
+};                                                         
+
+/* temporary function containing assert part for easier profiling */
+static void tmp_fld_check_assert(header_field_info *hfinfo) {
 	/* The field must have a name (with length > 0) */
 	DISSECTOR_ASSERT(hfinfo->name && hfinfo->name[0]);
 
@@ -3812,10 +3838,17 @@ proto_register_field_init(header_field_info *hfinfo, int parent)
 	default:
 		break;
 	}
+}
+
+static int
+proto_register_field_init(header_field_info *hfinfo, int parent)
+{
+
+	tmp_fld_check_assert(hfinfo);
+
 	/* if this is a bitfield, compute bitshift */
 	if (hfinfo->bitmask) {
-		while ((hfinfo->bitmask & (1 << hfinfo->bitshift)) == 0)
-			hfinfo->bitshift++;
+		hfinfo->bitshift = wrs_count_bitshift(hfinfo->bitmask);
 	}
 
 	hfinfo->parent = parent;
@@ -3839,19 +3872,17 @@ proto_register_field_init(header_field_info *hfinfo, int parent)
 	/* if we have real names, enter this field in the name tree */
 	if ((hfinfo->name[0] != 0) && (hfinfo->abbrev[0] != 0 )) {
 
-		header_field_info *same_name_hfinfo, *same_name_next_hfinfo;
-		const char *p;
+		header_field_info *same_name_next_hfinfo;
 		guchar c;
 
 		/* Check that the filter name (abbreviation) is legal;
 		 * it must contain only alphanumerics, '-', "_", and ".". */
-		for (p = hfinfo->abbrev; (c = *p) != '\0'; p++) {
-			if (!(isalnum(c) || c == '-' || c == '_' || c == '.')) {
-				fprintf(stderr, "OOPS: '%c' in '%s'\n", c, hfinfo->abbrev);
-				DISSECTOR_ASSERT(isalnum(c) || c == '-' || c == '_' ||
-			    		c == '.');
-			}
+		c = wrs_check_charset(fld_abbrev_chars, hfinfo->abbrev);
+		if (c) {
+			fprintf(stderr, "OOPS: '%c' in '%s'\n", c, hfinfo->abbrev);
+			DISSECTOR_ASSERT(!c);
 		}
+
 		/* We allow multiple hfinfo's to be registered under the same
 		 * abbreviation. This was done for X.25, as, depending
 		 * on whether it's modulo-8 or modulo-128 operation,
@@ -3859,11 +3890,11 @@ proto_register_field_init(header_field_info *hfinfo, int parent)
 		 * a byte, and we want to be able to refer to that field
 		 * with one name regardless of whether the packets
 		 * are modulo-8 or modulo-128 packets. */
-#if GLIB_MAJOR_VERSION < 2
-		same_name_hfinfo = g_tree_lookup(gpa_name_tree, discard_const(hfinfo->abbrev));
-#else
-		same_name_hfinfo = g_tree_lookup(gpa_name_tree, hfinfo->abbrev);
-#endif
+		same_name_hfinfo = NULL;
+		g_tree_insert(gpa_name_tree, (gpointer) (hfinfo->abbrev), hfinfo);
+		/* if it is already present 
+         * the previous hfinfo with the same name is saved 
+         * to same_name_hfinfo by value destroy callback */
 		if (same_name_hfinfo) {
 			/* There's already a field with this name.
 			 * Put it after that field in the list of
@@ -3882,7 +3913,6 @@ proto_register_field_init(header_field_info *hfinfo, int parent)
 			same_name_hfinfo->same_name_next = hfinfo;
 			hfinfo->same_name_prev = same_name_hfinfo;
 		}
-		g_tree_insert(gpa_name_tree, (gpointer) (hfinfo->abbrev), hfinfo);
 	}
 
 	return hfinfo->id;