[TRIVIAL] strlen("literal string") -> (sizeof("literal string")-1)

[TRIVIAL] strlen("literal string") -> (sizeof("literal string")-1)

[junkio]

Here is a patch that does the same as what Keith Owens did in
his patch recently.

    Message-ID: <fa.iks3ohv.1flge08@ifi.uio.no>
    From: Keith Owens <kaos@ocs.com.au>
    Subject: [patch] 2.4.19 Generate better code for nfs_sillyrename
    Date: Wed, 28 Aug 2002 07:08:17 GMT

    Using strlen() generates an unnecessary inline function expansion plus
    dynamic stack adjustment.  For constant strings, strlen() == sizeof()-1
    and the object code is better.

The patch is against 2.4.19.

diff -ru 2.4.19/arch/mips/hp-lj/utils.c 2.4.19-strlen/arch/mips/hp-lj/utils.c
--- 2.4.19/arch/mips/hp-lj/utils.c	2002-08-02 10:48:43.000000000 -0700
+++ 2.4.19-strlen/arch/mips/hp-lj/utils.c	2002-08-28 01:17:20.000000000 -0700
@@ -48,7 +48,7 @@
 {
 	char* pos = strstr(cl, "reserved_buffer=");
  	if (pos) {
-		buffer_size = simple_strtol(pos+strlen("reserved_buffer="), 
+		buffer_size = simple_strtol(pos+(sizeof("reserved_buffer=")-1), 
 					    0, 10);
 		buffer_size <<= 20;
 		if (buffer_size + MIN_GEN_MEM > base_mem)
diff -ru 2.4.19/arch/mips/mips-boards/atlas/atlas_setup.c 2.4.19-strlen/arch/mips/mips-boards/atlas/atlas_setup.c
--- 2.4.19/arch/mips/mips-boards/atlas/atlas_setup.c	2002-08-02 10:48:43.000000000 -0700
+++ 2.4.19-strlen/arch/mips/mips-boards/atlas/atlas_setup.c	2002-08-28 01:17:20.000000000 -0700
@@ -92,7 +92,7 @@
 	argptr = prom_getcmdline();
 	if ((argptr = strstr(argptr, "kgdb=ttyS")) != NULL) {
 		int line;
-		argptr += strlen("kgdb=ttyS");
+		argptr += (sizeof("kgdb=ttyS")-1);
 		if (*argptr != '0' && *argptr != '1')
 			printk("KGDB: Uknown serial line /dev/ttyS%c, "
 			       "falling back to /dev/ttyS1\n", *argptr);
diff -ru 2.4.19/arch/mips/mips-boards/malta/malta_setup.c 2.4.19-strlen/arch/mips/mips-boards/malta/malta_setup.c
--- 2.4.19/arch/mips/mips-boards/malta/malta_setup.c	2002-08-02 10:48:43.000000000 -0700
+++ 2.4.19-strlen/arch/mips/mips-boards/malta/malta_setup.c	2002-08-28 01:17:20.000000000 -0700
@@ -121,7 +121,7 @@
 	argptr = prom_getcmdline();
 	if ((argptr = strstr(argptr, "kgdb=ttyS")) != NULL) {
 		int line;
-		argptr += strlen("kgdb=ttyS");
+		argptr += (sizeof("kgdb=ttyS")-1);
 		if (*argptr != '0' && *argptr != '1')
 			printk("KGDB: Uknown serial line /dev/ttyS%c, "
 			       "falling back to /dev/ttyS1\n", *argptr);
diff -ru 2.4.19/arch/mips/sgi-ip22/ip22-setup.c 2.4.19-strlen/arch/mips/sgi-ip22/ip22-setup.c
--- 2.4.19/arch/mips/sgi-ip22/ip22-setup.c	2002-08-02 10:48:43.000000000 -0700
+++ 2.4.19-strlen/arch/mips/sgi-ip22/ip22-setup.c	2002-08-28 01:17:20.000000000 -0700
@@ -173,7 +173,7 @@
 	kgdb_ttyd = prom_getcmdline();
 	if ((kgdb_ttyd = strstr(kgdb_ttyd, "kgdb=ttyd")) != NULL) {
 		int line;
-		kgdb_ttyd += strlen("kgdb=ttyd");
+		kgdb_ttyd += (sizeof("kgdb=ttyd")-1);
 		if (*kgdb_ttyd != '1' && *kgdb_ttyd != '2')
 			printk("KGDB: Uknown serial line /dev/ttyd%c, "
 			       "falling back to /dev/ttyd1\n", *kgdb_ttyd);
diff -ru 2.4.19/arch/ppc/boot/utils/mknote.c 2.4.19-strlen/arch/ppc/boot/utils/mknote.c
--- 2.4.19/arch/ppc/boot/utils/mknote.c	2001-05-24 15:02:07.000000000 -0700
+++ 2.4.19-strlen/arch/ppc/boot/utils/mknote.c	2002-08-28 01:17:21.000000000 -0700
@@ -21,7 +21,7 @@
 {
 /* header */
 	/* namesz */
-	PL(strlen("PowerPC")+1);
+	PL((sizeof("PowerPC")-1)+1);
 	/* descrsz */
 	PL(6*4);
 	/* type */
diff -ru 2.4.19/arch/ppc/boot/utils/mkprep.c 2.4.19-strlen/arch/ppc/boot/utils/mkprep.c
--- 2.4.19/arch/ppc/boot/utils/mkprep.c	2001-05-24 15:02:07.000000000 -0700
+++ 2.4.19-strlen/arch/ppc/boot/utils/mkprep.c	2002-08-28 01:17:21.000000000 -0700
@@ -250,7 +250,7 @@
   unsigned char str[256];
   
   write( out, "\t.data\n\t.globl input_data\ninput_data:\n",
-	 strlen( "\t.data\n\t.globl input_data\ninput_data:\n" ) );
+	 (sizeof("\t.data\n\t.globl input_data\ninput_data:\n")-1) );
   pos = 0;
   cksum = 0;
   while ((len = read(in, buf, sizeof(buf))) > 0)
@@ -262,7 +262,7 @@
     {
       if (cnt == 0)
       {
-	write( out, "\t.long\t", strlen( "\t.long\t" ) );
+	write( out, "\t.long\t", (sizeof("\t.long\t")-1) );
       }
       sprintf( str, "0x%02X%02X%02X%02X", lp[0], lp[1], lp[2], lp[3]);
       write( out, str, strlen(str) );
diff -ru 2.4.19/arch/ppc/kernel/pmac_feature.c 2.4.19-strlen/arch/ppc/kernel/pmac_feature.c
--- 2.4.19/arch/ppc/kernel/pmac_feature.c	2002-08-02 10:48:45.000000000 -0700
+++ 2.4.19-strlen/arch/ppc/kernel/pmac_feature.c	2002-08-28 01:17:20.000000000 -0700
@@ -1043,9 +1043,9 @@
 	prop = (char *)get_property(node, "AAPL,clock-id", NULL);
 	if (!prop)
 		return -ENODEV;
-	if (strncmp(prop, "usb0u048", strlen("usb0u048")) == 0)
+	if (strncmp(prop, "usb0u048", (sizeof("usb0u048")-1)) == 0)
 		number = 0;
-	else if (strncmp(prop, "usb1u148", strlen("usb1u148")) == 0)
+	else if (strncmp(prop, "usb1u148", (sizeof("usb1u148")-1)) == 0)
 		number = 2;
 	else
 		return -ENODEV;
diff -ru 2.4.19/arch/ppc64/boot/mknote.c 2.4.19-strlen/arch/ppc64/boot/mknote.c
--- 2.4.19/arch/ppc64/boot/mknote.c	2002-08-02 10:48:45.000000000 -0700
+++ 2.4.19-strlen/arch/ppc64/boot/mknote.c	2002-08-28 01:17:20.000000000 -0700
@@ -18,7 +18,7 @@
 {
 /* header */
 	/* namesz */
-	PL(strlen("PowerPC")+1);
+	PL((sizeof("PowerPC")-1)+1);
 	/* descrsz */
 	PL(6*4);
 	/* type */
diff -ru 2.4.19/arch/ppc64/boot/zImage.c 2.4.19-strlen/arch/ppc64/boot/zImage.c
--- 2.4.19/arch/ppc64/boot/zImage.c	2002-08-02 10:48:45.000000000 -0700
+++ 2.4.19-strlen/arch/ppc64/boot/zImage.c	2002-08-28 01:17:20.000000000 -0700
@@ -219,7 +219,7 @@
 	/* rec->data[0] = ...;	# Written below before return */
 	/* rec->data[1] = ...;	# Written below before return */
 
-	rec = bi_rec_alloc_bytes(rec, strlen("chrpboot")+1);
+	rec = bi_rec_alloc_bytes(rec, (sizeof("chrpboot")-1)+1);
 	rec->tag = BI_BOOTLOADER_ID;
 	sprintf( (char *)rec->data, "chrpboot");
 
diff -ru 2.4.19/drivers/char/ftape/zftape/zftape-vtbl.c 2.4.19-strlen/drivers/char/ftape/zftape/zftape-vtbl.c
--- 2.4.19/drivers/char/ftape/zftape/zftape-vtbl.c	2001-04-06 10:42:55.000000000 -0700
+++ 2.4.19-strlen/drivers/char/ftape/zftape/zftape-vtbl.c	2002-08-28 01:17:13.000000000 -0700
@@ -164,7 +164,7 @@
 		/* use the kernel strstr()   */
 		blocksize= strstr(label, " blocksize ");
 		if (blocksize) {
-			blocksize += strlen(" blocksize ");
+			blocksize += (sizeof(" blocksize ")-1);
 			for(*blk_sz= 0; 
 			    *blocksize >= '0' && *blocksize <= '9'; 
 			    blocksize++) {
diff -ru 2.4.19/drivers/isdn/isdn_net.c 2.4.19-strlen/drivers/isdn/isdn_net.c
--- 2.4.19/drivers/isdn/isdn_net.c	2001-12-21 09:41:54.000000000 -0800
+++ 2.4.19-strlen/drivers/isdn/isdn_net.c	2002-08-28 01:17:16.000000000 -0700
@@ -653,7 +653,7 @@
 					isdn_net_hangup(&p->dev);
 					break;
 				}
-				if (!strncmp(lp->dial->num, "LEASED", strlen("LEASED"))) {
+				if (!strncmp(lp->dial->num, "LEASED", (sizeof("LEASED")-1))) {
 					restore_flags(flags);
 					lp->dialstate = 4;
 					printk(KERN_INFO "%s: Open leased line ...\n", lp->name);
diff -ru 2.4.19/drivers/net/au1000_eth.c 2.4.19-strlen/drivers/net/au1000_eth.c
--- 2.4.19/drivers/net/au1000_eth.c	2002-08-02 10:48:50.000000000 -0700
+++ 2.4.19-strlen/drivers/net/au1000_eth.c	2002-08-28 01:17:11.000000000 -0700
@@ -707,7 +707,7 @@
 						dev->name);
 				/* use the hard coded mac addresses */
 			} else {
-				str2eaddr(ethaddr, pmac + strlen("ethaddr="));
+				str2eaddr(ethaddr, pmac + (sizeof("ethaddr=")-1));
 				memcpy(au1000_mac_addr, ethaddr, 
 						sizeof(dev->dev_addr));
 			}
diff -ru 2.4.19/drivers/s390/block/dasd.c 2.4.19-strlen/drivers/s390/block/dasd.c
--- 2.4.19/drivers/s390/block/dasd.c	2002-08-02 10:48:52.000000000 -0700
+++ 2.4.19-strlen/drivers/s390/block/dasd.c	2002-08-28 01:17:19.000000000 -0700
@@ -3830,13 +3830,13 @@
 	off += 4;
 	while (buffer[off] && !isalnum (buffer[off]))
 		off++;
-	if (!strncmp (buffer + off, "device", strlen ("device"))) {
-		off += strlen ("device");
+	if (!strncmp (buffer + off, "device", (sizeof("device")-1))) {
+		off += (sizeof("device")-1);
 		while (buffer[off] && !isalnum (buffer[off]))
 			off++;
 	}
-	if (!strncmp (buffer + off, "range=", strlen ("range="))) {
-		off += strlen ("range=");
+	if (!strncmp (buffer + off, "range=", (sizeof("range=")-1))) {
+		off += (sizeof("range=")-1);
 		while (buffer[off] && !isalnum (buffer[off]))
 			off++;
 	}
@@ -3858,15 +3858,15 @@
                         buffer);
         } else {
                 off = (long) temp - (long) buffer;
-                if (!strncmp (buffer, "add", strlen ("add"))) {
+                if (!strncmp (buffer, "add", (sizeof("add")-1))) {
                         dasd_add_range (range.from, range.to, features);
                         dasd_enable_ranges (&range, NULL, 0);
                 } else { 
                         while (buffer[off] && !isalnum (buffer[off]))
                                 off++;
-                        if (!strncmp (buffer + off, "on", strlen ("on"))) {
+                        if (!strncmp (buffer + off, "on", (sizeof("on")-1))) {
                                 dasd_enable_ranges (&range, NULL, 0);
-                        } else if (!strncmp (buffer + off, "off", strlen ("off"))) {
+                        } else if (!strncmp (buffer + off, "off", (sizeof("off")-1))) {
                                 dasd_disable_ranges (&range, NULL, 0, 1);
                         } else {
                                 printk (KERN_WARNING PRINTK_HEADER
diff -ru 2.4.19/drivers/s390/char/tape.c 2.4.19-strlen/drivers/s390/char/tape.c
--- 2.4.19/drivers/s390/char/tape.c	2001-07-25 14:12:02.000000000 -0700
+++ 2.4.19-strlen/drivers/s390/char/tape.c	2002-08-28 01:17:19.000000000 -0700
@@ -921,7 +921,7 @@
         if (tape_devices_entry) {
             memset (tape_devices_entry, 0, sizeof (struct proc_dir_entry));
             tape_devices_entry->name = "tapedevices";
-            tape_devices_entry->namelen = strlen ("tapedevices");
+            tape_devices_entry->namelen = (sizeof("tapedevices")-1);
             tape_devices_entry->low_ino = 0;
             tape_devices_entry->mode = (S_IFREG | S_IRUGO | S_IWUSR);
             tape_devices_entry->nlink = 1;
diff -ru 2.4.19/drivers/scsi/53c7xx.c 2.4.19-strlen/drivers/scsi/53c7xx.c
--- 2.4.19/drivers/scsi/53c7xx.c	2002-02-08 23:39:18.000000000 -0800
+++ 2.4.19-strlen/drivers/scsi/53c7xx.c	2002-08-28 01:17:14.000000000 -0700
@@ -409,7 +409,7 @@
          continue;
       if (!strncmp(setup_strings[x], key, strlen(key)))
          break;
-      if (!strncmp(setup_strings[x], "next", strlen("next")))
+      if (!strncmp(setup_strings[x], "next", (sizeof("next")-1)))
          return 0;
       }
    if (x == MAX_SETUP_STRINGS)
diff -ru 2.4.19/drivers/scsi/megaraid.c 2.4.19-strlen/drivers/scsi/megaraid.c
--- 2.4.19/drivers/scsi/megaraid.c	2002-08-02 10:48:53.000000000 -0700
+++ 2.4.19-strlen/drivers/scsi/megaraid.c	2002-08-28 01:17:14.000000000 -0700
@@ -3194,7 +3194,7 @@
 	}
 #endif
 	skip_id = -1;
-	if (megaraid && !strncmp (megaraid, "skip", strlen ("skip"))) {
+	if (megaraid && !strncmp (megaraid, "skip", (sizeof("skip")-1))) {
 		if (megaraid[4] != '\0') {
 			skip_id = megaraid[4] - '0';
 			if (megaraid[5] != '\0') {
diff -ru 2.4.19/drivers/scsi/wd33c93.c 2.4.19-strlen/drivers/scsi/wd33c93.c
--- 2.4.19/drivers/scsi/wd33c93.c	2002-08-02 10:48:53.000000000 -0700
+++ 2.4.19-strlen/drivers/scsi/wd33c93.c	2002-08-28 01:17:14.000000000 -0700
@@ -1727,7 +1727,7 @@
          continue;
       if (!strncmp(setup_args[x], key, strlen(key)))
          break;
-      if (!strncmp(setup_args[x], "next", strlen("next")))
+      if (!strncmp(setup_args[x], "next", (sizeof("next")-1)))
          return 0;
       }
    if (x == MAX_SETUP_ARGS)
diff -ru 2.4.19/fs/intermezzo/journal.c 2.4.19-strlen/fs/intermezzo/journal.c
--- 2.4.19/fs/intermezzo/journal.c	2002-01-26 13:09:53.000000000 -0800
+++ 2.4.19-strlen/fs/intermezzo/journal.c	2002-08-28 01:17:07.000000000 -0700
@@ -697,7 +697,7 @@
         ENTRY;
 
         mtpt_len = strlen(cache->cache_mtpt);
-        path_len = mtpt_len + strlen("/.intermezzo/") +
+        path_len = mtpt_len + (sizeof("/.intermezzo/")-1) +
                 strlen(fset->fset_name) + strlen(name);
 
         error = -ENOMEM;
diff -ru 2.4.19/fs/intermezzo/methods.c 2.4.19-strlen/fs/intermezzo/methods.c
--- 2.4.19/fs/intermezzo/methods.c	2001-11-13 09:20:56.000000000 -0800
+++ 2.4.19-strlen/fs/intermezzo/methods.c	2002-08-28 01:17:07.000000000 -0700
@@ -130,8 +130,8 @@
 
 void filter_setup_journal_ops(struct filter_fs *ops, char *cache_type)
 {
-        if ( strlen(cache_type) == strlen("ext2") &&
-             memcmp(cache_type, "ext2", strlen("ext2")) == 0 ) {
+        if ( strlen(cache_type) == (sizeof("ext2")-1) &&
+             memcmp(cache_type, "ext2", (sizeof("ext2")-1)) == 0 ) {
 #if CONFIG_EXT2_FS
                 ops->o_trops = &presto_ext2_journal_ops;
 #else
@@ -140,8 +140,8 @@
                 FDEBUG(D_SUPER, "ops at %p\n", ops);
         }
 
-        if ( strlen(cache_type) == strlen("ext3") &&
-             memcmp(cache_type, "ext3", strlen("ext3")) == 0 ) {
+        if ( strlen(cache_type) == (sizeof("ext3")-1) &&
+             memcmp(cache_type, "ext3", (sizeof("ext3")-1)) == 0 ) {
 #if defined(CONFIG_EXT3_FS) || defined (CONFIG_EXT3_FS_MODULE)
                 ops->o_trops = &presto_ext3_journal_ops;
 #else
@@ -150,8 +150,8 @@
                 FDEBUG(D_SUPER, "ops at %p\n", ops);
         }
 
-        if ( strlen(cache_type) == strlen("reiserfs") &&
-             memcmp(cache_type, "reiserfs", strlen("reiserfs")) == 0 ) {
+        if ( strlen(cache_type) == (sizeof("reiserfs")-1) &&
+             memcmp(cache_type, "reiserfs", (sizeof("reiserfs")-1)) == 0 ) {
 #if 0
 		/* #if defined(CONFIG_REISERFS_FS) || defined(CONFIG_REISERFS_FS_MODULE) */
                 ops->o_trops = &presto_reiserfs_journal_ops;
@@ -161,8 +161,8 @@
                 FDEBUG(D_SUPER, "ops at %p\n", ops);
         }
 
-        if ( strlen(cache_type) == strlen("xfs") &&
-             memcmp(cache_type, "xfs", strlen("xfs")) == 0 ) {
+        if ( strlen(cache_type) == (sizeof("xfs")-1) &&
+             memcmp(cache_type, "xfs", (sizeof("xfs")-1)) == 0 ) {
 #if 0
                 //#if defined(CONFIG_XFS_FS) || defined (CONFIG_XFS_FS_MODULE)
                 ops->o_trops = &presto_xfs_journal_ops;
@@ -172,8 +172,8 @@
                 FDEBUG(D_SUPER, "ops at %p\n", ops);
         }
 
-        if ( strlen(cache_type) == strlen("obdfs") &&
-             memcmp(cache_type, "obdfs", strlen("obdfs")) == 0 ) {
+        if ( strlen(cache_type) == (sizeof("obdfs")-1) &&
+             memcmp(cache_type, "obdfs", (sizeof("obdfs")-1)) == 0 ) {
 #if defined(CONFIG_OBDFS_FS) || defined (CONFIG_OBDFS_FS_MODULE)
                 ops->o_trops = presto_obdfs_journal_ops;
 #else
@@ -190,30 +190,30 @@
         struct filter_fs *ops = NULL;
         FENTRY;
 
-        if ( strlen(cache_type) == strlen("ext2") &&
-             memcmp(cache_type, "ext2", strlen("ext2")) == 0 ) {
+        if ( strlen(cache_type) == (sizeof("ext2")-1) &&
+             memcmp(cache_type, "ext2", (sizeof("ext2")-1)) == 0 ) {
                 ops = &filter_oppar[FILTER_FS_EXT2];
                 FDEBUG(D_SUPER, "ops at %p\n", ops);
         }
 
-        if ( strlen(cache_type) == strlen("xfs") &&
-             memcmp(cache_type, "xfs", strlen("xfs")) == 0 ) {
+        if ( strlen(cache_type) == (sizeof("xfs")-1) &&
+             memcmp(cache_type, "xfs", (sizeof("xfs")-1)) == 0 ) {
                 ops = &filter_oppar[FILTER_FS_XFS];
                 FDEBUG(D_SUPER, "ops at %p\n", ops);
         }
 
-        if ( strlen(cache_type) == strlen("ext3") &&
-             memcmp(cache_type, "ext3", strlen("ext3")) == 0 ) {
+        if ( strlen(cache_type) == (sizeof("ext3")-1) &&
+             memcmp(cache_type, "ext3", (sizeof("ext3")-1)) == 0 ) {
                 ops = &filter_oppar[FILTER_FS_EXT3];
                 FDEBUG(D_SUPER, "ops at %p\n", ops);
         }
-        if ( strlen(cache_type) == strlen("reiserfs") &&
-             memcmp(cache_type, "reiserfs", strlen("reiserfs")) == 0 ) {
+        if ( strlen(cache_type) == (sizeof("reiserfs")-1) &&
+             memcmp(cache_type, "reiserfs", (sizeof("reiserfs")-1)) == 0 ) {
                 ops = &filter_oppar[FILTER_FS_REISERFS];
                 FDEBUG(D_SUPER, "ops at %p\n", ops);
         }
-        if ( strlen(cache_type) == strlen("obdfs") &&
-             memcmp(cache_type, "obdfs", strlen("obdfs")) == 0 ) {
+        if ( strlen(cache_type) == (sizeof("obdfs")-1) &&
+             memcmp(cache_type, "obdfs", (sizeof("obdfs")-1)) == 0 ) {
                 ops = &filter_oppar[FILTER_FS_OBDFS];
                 FDEBUG(D_SUPER, "ops at %p\n", ops);
         }
diff -ru 2.4.19/fs/nfs/dir.c 2.4.19-strlen/fs/nfs/dir.c
--- 2.4.19/fs/nfs/dir.c	2002-08-02 10:48:56.000000000 -0700
+++ 2.4.19-strlen/fs/nfs/dir.c	2002-08-28 01:17:06.000000000 -0700
@@ -741,7 +741,7 @@
 	static unsigned int sillycounter;
 	const int      i_inosize  = sizeof(dir->i_ino)*2;
 	const int      countersize = sizeof(sillycounter)*2;
-	const int      slen       = strlen(".nfs") + i_inosize + countersize;
+	const int      slen       = (sizeof(".nfs")-1) + i_inosize + countersize;
 	char           silly[slen+1];
 	struct qstr    qsilly;
 	struct dentry *sdentry;
diff -ru 2.4.19/fs/reiserfs/dir.c 2.4.19-strlen/fs/reiserfs/dir.c
--- 2.4.19/fs/reiserfs/dir.c	2002-08-02 10:48:56.000000000 -0700
+++ 2.4.19-strlen/fs/reiserfs/dir.c	2002-08-28 01:17:07.000000000 -0700
@@ -202,7 +202,7 @@
     deh[0].deh_dir_id = dirid;
     deh[0].deh_objectid = objid;
     deh[0].deh_state = 0; /* Endian safe if 0 */
-    put_deh_location( &(deh[0]), EMPTY_DIR_SIZE_V1 - strlen( "." ));
+    put_deh_location( &(deh[0]), EMPTY_DIR_SIZE_V1 - (sizeof(".")-1));
     mark_de_visible(&(deh[0]));
   
     /* direntry header of ".." */
@@ -212,7 +212,7 @@
     deh[1].deh_dir_id = par_dirid;
     deh[1].deh_objectid = par_objid;
     deh[1].deh_state = 0; /* Endian safe if 0 */
-    put_deh_location( &(deh[1]), deh_location( &(deh[0]) ) - strlen( ".." ) );
+    put_deh_location( &(deh[1]), deh_location( &(deh[0]) ) - (sizeof("..")-1) );
     mark_de_visible(&(deh[1]));
 
     /* copy ".." and "." */
@@ -235,7 +235,7 @@
     deh[0].deh_dir_id = dirid;
     deh[0].deh_objectid = objid;
     deh[0].deh_state = 0; /* Endian safe if 0 */
-    put_deh_location( &(deh[0]), EMPTY_DIR_SIZE - ROUND_UP( strlen( "." ) ) );
+    put_deh_location( &(deh[0]), EMPTY_DIR_SIZE - ROUND_UP( (sizeof(".")-1) ) );
     mark_de_visible(&(deh[0]));
   
     /* direntry header of ".." */
@@ -245,7 +245,7 @@
     deh[1].deh_dir_id = par_dirid;
     deh[1].deh_objectid = par_objid;
     deh[1].deh_state = 0; /* Endian safe if 0 */
-    put_deh_location( &(deh[1]), deh_location( &(deh[0])) - ROUND_UP( strlen( ".." ) ) );
+    put_deh_location( &(deh[1]), deh_location( &(deh[0])) - ROUND_UP( (sizeof("..")-1) ) );
     mark_de_visible(&(deh[1]));
 
     /* copy ".." and "." */
diff -ru 2.4.19/include/linux/reiserfs_fs.h 2.4.19-strlen/include/linux/reiserfs_fs.h
--- 2.4.19/include/linux/reiserfs_fs.h	2002-08-24 01:20:57.000000000 -0700
+++ 2.4.19-strlen/include/linux/reiserfs_fs.h	2002-08-28 01:17:07.000000000 -0700
@@ -869,7 +869,7 @@
 
 /* empty directory contains two entries "." and ".." and their headers */
 #define EMPTY_DIR_SIZE \
-(DEH_SIZE * 2 + ROUND_UP (strlen (".")) + ROUND_UP (strlen ("..")))
+(DEH_SIZE * 2 + ROUND_UP ((sizeof(".")-1)) + ROUND_UP ((sizeof("..")-1)))
 
 /* old format directories have this size when empty */
 #define EMPTY_DIR_SIZE_V1 (DEH_SIZE * 2 + 3)

Re: [TRIVIAL] strlen("literal string") -> (sizeof("literal string")-1)

[Jim Treadway]

On Wed, 28 Aug 2002 junkio@cox.net wrote:

> Here is a patch that does the same as what Keith Owens did in
> his patch recently.
> 
>     Message-ID: <fa.iks3ohv.1flge08@ifi.uio.no>
>     From: Keith Owens <kaos@ocs.com.au>
>     Subject: [patch] 2.4.19 Generate better code for nfs_sillyrename
>     Date: Wed, 28 Aug 2002 07:08:17 GMT
> 
>     Using strlen() generates an unnecessary inline function expansion plus
>     dynamic stack adjustment.  For constant strings, strlen() == sizeof()-1
>     and the object code is better.
> 
> The patch is against 2.4.19.
> 
> diff -ru 2.4.19/arch/mips/hp-lj/utils.c 2.4.19-strlen/arch/mips/hp-lj/utils.c
> --- 2.4.19/arch/mips/hp-lj/utils.c	2002-08-02 10:48:43.000000000 -0700
> +++ 2.4.19-strlen/arch/mips/hp-lj/utils.c	2002-08-28 01:17:20.000000000 -0700
> @@ -48,7 +48,7 @@
>  {
>  	char* pos = strstr(cl, "reserved_buffer=");
>   	if (pos) {
> -		buffer_size = simple_strtol(pos+strlen("reserved_buffer="), 
> +		buffer_size = simple_strtol(pos+(sizeof("reserved_buffer=")-1), 
>  					    0, 10);
>  		buffer_size <<= 20;
>  		if (buffer_size + MIN_GEN_MEM > base_mem)

Would redefining strlen() as __strlen() and then using

#define strlen(x) (__builtin_constant_p(x) ? (sizeof(x) - 1) : __strlen(x))

work in this situation?


Jim

Re: [TRIVIAL] strlen("literal string") -> (sizeof("literal string")-1)

[junio]

>>>>> "JT" == Jim Treadway <jim@stardot-tech.com> writes:

JT> Would redefining strlen() as __strlen() and then using

JT> #define strlen(x) (__builtin_constant_p(x) ? (sizeof(x) - 1) : __strlen(x))

JT> work in this situation?

I thought about that before I posted the previous patch, but
rejected it.

If it worked in all situations then it would have been great,
but it fails in at least one way [*1*], so you cannot generally
define the above in a header file which everybody includes.
Instead, you end up examining each use of strlen() and make the
above "#define" only where it does not break; it is not worth
the aggravation.  Something named "strlen" must work in all
situations, and "in this situation" is not good enough.
Otherwise it would confuse/surprise people.

[Footnotes]

*1*  It fails on the following:

#define FOOBARBAZ &("foobarbaz"[0])

void
main(void) {
  int sz;
  if (__builtin_constant_p(FOOBARBAZ)) {
    sz = sizeof(FOOBARBAZ) - 1;
    printf("sizeof(FOOBARBAZ) -1 = %d\n", sz);
  }
  printf("strlen(FOOBARBAZ) = %d\n", strlen(FOOBARBAZ));
  exit(0);
}

Re: [TRIVIAL] strlen("literal string") -> (sizeof("literal string")-1)

[Rusty Russell]

In message <200208282131.g7SLVVGx024191@siamese.dyndns.org> you write:
> Here is a patch that does the same as what Keith Owens did in
> his patch recently.
> 
>     Message-ID: <fa.iks3ohv.1flge08@ifi.uio.no>
>     From: Keith Owens <kaos@ocs.com.au>
>     Subject: [patch] 2.4.19 Generate better code for nfs_sillyrename
>     Date: Wed, 28 Aug 2002 07:08:17 GMT
> 
>     Using strlen() generates an unnecessary inline function expansion plus
>     dynamic stack adjustment.  For constant strings, strlen() == sizeof()-1
>     and the object code is better.

Disagree.  If you really care make strlen use __builtin_constant_p().
Then authors don't have to sacrifice readability.

#define strlen(x) (__builtin_constant_p(x) ? sizeof(x)-1 : __strlen(x))

Rusty.
--
  Anyone who quotes me in their sig is an idiot. -- Rusty Russell.

Re: [TRIVIAL] strlen("literal string") -> (sizeof("literal string")-1)

[Rusty Russell]

In message <7vd6s2lc9c.fsf@siamese.dyndns.org> you write:
> >>>>> "JT" == Jim Treadway <jim@stardot-tech.com> writes:
> 
> JT> Would redefining strlen() as __strlen() and then using
> 
> JT> #define strlen(x) (__builtin_constant_p(x) ? (sizeof(x) - 1) : __strlen(x
))
> 
> JT> work in this situation?
> 
> I thought about that before I posted the previous patch, but
> rejected it.
> 
> If it worked in all situations then it would have been great,
> but it fails in at least one way [*1*], so you cannot generally
> define the above in a header file which everybody includes.

If you really care about that, try:

	/* Be paranoid in case someone uses strlen(&("FOO"[0])) */
	#define strlen(x) \
		(__builtin_constant_p(x) && sizeof(x) != sizeof(char *)
		? (sizeof(x) - 1) : __strlen(x))

Rusty.
--
  Anyone who quotes me in their sig is an idiot. -- Rusty Russell.

Re: [TRIVIAL] strlen("literal string") -> (sizeof("literal string")-1)

[Daniel Jacobowitz]

On Thu, Aug 29, 2002 at 01:09:05PM +1000, Rusty Russell wrote:
> In message <200208282131.g7SLVVGx024191@siamese.dyndns.org> you write:
> > Here is a patch that does the same as what Keith Owens did in
> > his patch recently.
> > 
> >     Message-ID: <fa.iks3ohv.1flge08@ifi.uio.no>
> >     From: Keith Owens <kaos@ocs.com.au>
> >     Subject: [patch] 2.4.19 Generate better code for nfs_sillyrename
> >     Date: Wed, 28 Aug 2002 07:08:17 GMT
> > 
> >     Using strlen() generates an unnecessary inline function expansion plus
> >     dynamic stack adjustment.  For constant strings, strlen() == sizeof()-1
> >     and the object code is better.
> 
> Disagree.  If you really care make strlen use __builtin_constant_p().
> Then authors don't have to sacrifice readability.
> 
> #define strlen(x) (__builtin_constant_p(x) ? sizeof(x)-1 : __strlen(x))

Also disagree; besides, the evidence implies that Keith is wrong.  GCC
2.95.3:

drow@nevyn:~% cat strlen.c
int foo() { return strlen ("baz"); }
int bar() { return sizeof ("baz") - 1; }
drow@nevyn:~% cat strlen.s
        .file   "strlen.c"
        .version        "01.01"
gcc2_compiled.:
.text
        .align 4
.globl foo
        .type    foo,@function
foo:
        pushl %ebp
        movl %esp,%ebp
        movl $3,%eax
        leave
        ret
.Lfe1:
        .size    foo,.Lfe1-foo
        .align 4
.globl bar
        .type    bar,@function
bar:
        pushl %ebp
        movl %esp,%ebp
        movl $3,%eax
        leave
        ret
.Lfe2:
        .size    bar,.Lfe2-bar
        .ident  "GCC: (GNU) 2.95.4 20011002 (Debian prerelease)"

3.2 does the same thing.  With -fomit-frame-pointer the results are as
expected, just a move and a return.

If you include headers that define strlen, that's another problem.

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer

Re: [TRIVIAL] strlen("literal string") -> (sizeof("literal string")-1)

[Rusty Russell]

In message <20020829032642.GA9201@nevyn.them.org> you write:
> Also disagree; besides, the evidence implies that Keith is wrong.  GCC
> 2.95.3:

i386, m68k, s390 and s390x define inline strlen() versions, so they
are don't optimize strlen("literal").

This premature optimization should probably be fixed,
Rusty.
--
  Anyone who quotes me in their sig is an idiot. -- Rusty Russell.

Re: [TRIVIAL] strlen("literal string") -> (sizeof("literal string")-1)

[Jakub Jelinek]

On Thu, Aug 29, 2002 at 04:29:04PM +1000, Rusty Russell wrote:
> In message <20020829032642.GA9201@nevyn.them.org> you write:
> > Also disagree; besides, the evidence implies that Keith is wrong.  GCC
> > 2.95.3:
> 
> i386, m68k, s390 and s390x define inline strlen() versions, so they
> are don't optimize strlen("literal").
> 
> This premature optimization should probably be fixed,

Well, IMHO at least for the more recent GCC versions kernel
should leave the job to GCC (ie. either just prototype str* functions,
or define them to __builtin_str* variants).

	Jakub

Re: [TRIVIAL] strlen("literal string") -> (sizeof("literal string")-1)

[Thunder from the hill]

Hi,

On Thu, 29 Aug 2002, Rusty Russell wrote:
> If you really care about that, try:
> 
> 	/* Be paranoid in case someone uses strlen(&("FOO"[0])) */
> 	#define strlen(x) \
> 		(__builtin_constant_p(x) && sizeof(x) != sizeof(char *)
> 		? (sizeof(x) - 1) : __strlen(x))

I must say that doesn't make the code any cleaner, which leads to it being 
not as clean as Keith suggested. It was a code cleanup, not a code messup.

			Thunder
-- 
--./../...-/. -.--/---/..-/.-./..././.-../..-. .---/..-/.../- .-
--/../-./..-/-/./--..-- ../.----./.-../.-.. --./../...-/. -.--/---/..-
.- -/---/--/---/.-./.-./---/.--/.-.-.-
--./.-/-.../.-./.././.-../.-.-.-

Re: [TRIVIAL] strlen("literal string") -> (sizeof("literal string")-1)

[Dave Jones]

On Thu, Aug 29, 2002 at 09:39:14AM -0600, Thunder from the hill wrote:

 > > 	#define strlen(x) \
 > > 		(__builtin_constant_p(x) && sizeof(x) != sizeof(char *)
 > > 		? (sizeof(x) - 1) : __strlen(x))
 > 
 > I must say that doesn't make the code any cleaner, which leads to it being 
 > not as clean as Keith suggested. It was a code cleanup, not a code messup.

Sure the macro is fugly, but the code that uses it becomes
cleaner which was the whole point here.

        Dave

-- 
| Dave Jones.        http://www.codemonkey.org.uk
| SuSE Labs

Re: [TRIVIAL] strlen("literal string") -> (sizeof("literal string")-1)

[Linus Torvalds]

On Thu, 29 Aug 2002, Jakub Jelinek wrote:
> 
> Well, IMHO at least for the more recent GCC versions kernel
> should leave the job to GCC (ie. either just prototype str* functions,
> or define them to __builtin_str* variants).

I agree. That x86 strlen() inline is from 1991 with fixes ever after, and 
pre-dates gcc having any support for inline at all. We're much more likely 
to be better off just removing it these days. Is somebody willing to 
compare code quality? I wouldn't be in the least surprised if gcc did a 
better job these days..

		Linus

Re: [TRIVIAL] strlen("literal string") -> (sizeof("literal string")-1)

[Andi Kleen]

Linus Torvalds <torvalds@transmeta.com> writes:

> On Thu, 29 Aug 2002, Jakub Jelinek wrote:
> > 
> > Well, IMHO at least for the more recent GCC versions kernel
> > should leave the job to GCC (ie. either just prototype str* functions,
> > or define them to __builtin_str* variants).
> 
> I agree. That x86 strlen() inline is from 1991 with fixes ever after, and 
> pre-dates gcc having any support for inline at all. We're much more likely 
> to be better off just removing it these days. Is somebody willing to 
> compare code quality? I wouldn't be in the least surprised if gcc did a 
> better job these days..

It does a better job for near all the string.h stuff. x86-64 just uses
the builtins. Only exception  is memcpy, where it likes to call out of line 
memcpy when it is not absolutely sure about all the alignments 
(especally lots of casting causes that) 

Still having an empty (or the one from x86-64 ;) string.h should be fine.

-Andi

Re: [TRIVIAL] strlen("literal string") -> (sizeof("literal string")-1)

[Alexander Viro]

On 29 Aug 2002, Andi Kleen wrote:

> It does a better job for near all the string.h stuff. x86-64 just uses
> the builtins. Only exception  is memcpy, where it likes to call out of line 
> memcpy when it is not absolutely sure about all the alignments 
> (especally lots of casting causes that) 

memcpy() on x86 includes uses of mmx_memcpy().  Not likely to be done by gcc...

Re: [TRIVIAL] strlen("literal string") -> (sizeof("literal string")-1)

[Andi Kleen]

On Thu, Aug 29, 2002 at 01:51:00PM -0400, Alexander Viro wrote:
> 
> 
> On 29 Aug 2002, Andi Kleen wrote:
> 
> > It does a better job for near all the string.h stuff. x86-64 just uses
> > the builtins. Only exception  is memcpy, where it likes to call out of line 
> > memcpy when it is not absolutely sure about all the alignments 
> > (especally lots of casting causes that) 
> 
> memcpy() on x86 includes uses of mmx_memcpy().  Not likely to be done by gcc...
Only for big arguments. That is why it calls the out of line function.
Basically it only inlines when the limit is known and small and the alignments
are known. IMHO the alignment check is overkill for x86, but that is what
it does. That is why I wrapped it a bit (see include/asm-x86_64/string.h) 


-Andi

Re: [TRIVIAL] strlen("literal string") -> (sizeof("literal string")-1)

[Denis Zaitsev]

On Thu, Aug 29, 2002 at 09:56:44AM -0700, Linus Torvalds wrote:
> 
> On Thu, 29 Aug 2002, Jakub Jelinek wrote:
> > 
> > Well, IMHO at least for the more recent GCC versions kernel
> > should leave the job to GCC (ie. either just prototype str* functions,
> > or define them to __builtin_str* variants).
> 
> I agree. That x86 strlen() inline is from 1991 with fixes ever after, and 
> pre-dates gcc having any support for inline at all. We're much more likely 
> to be better off just removing it these days. Is somebody willing to 
> compare code quality? I wouldn't be in the least surprised if gcc did a 
> better job these days..
> 

GCC-3.2 doesn't do any inlining for __builtin_strlen at all, if -mcpu > i386.
It just does call/jump outline strlen...  Isn't very good?

Re: [TRIVIAL] strlen("literal string") -> (sizeof("literal string")-1)

[Rusty Russell]

In message <Pine.LNX.4.44.0208290938180.3234-100000@hawkeye.luckynet.adm> you w
rite:
> Hi,
> 
> On Thu, 29 Aug 2002, Rusty Russell wrote:
> > If you really care about that, try:
> > 
> > 	/* Be paranoid in case someone uses strlen(&("FOO"[0])) */
> > 	#define strlen(x) \
> > 		(__builtin_constant_p(x) && sizeof(x) != sizeof(char *)
> > 		? (sizeof(x) - 1) : __strlen(x))
> 
> I must say that doesn't make the code any cleaner, which leads to it being 
> not as clean as Keith suggested. It was a code cleanup, not a code messup.

Think harder.

This code would exist in one place: those (four) architectures which
insist on having an inline strlen function.  These guys already eat
inline asm for breakfast: it's *their* jobs to jump through hoops so
the driver writers can write simple code and have it work well.

Rusty.
--
  Anyone who quotes me in their sig is an idiot. -- Rusty Russell.

Re: [TRIVIAL] strlen("literal string") -> (sizeof("literal string")-1)

[Pavel Machek]

Hi!

> Here is a patch that does the same as what Keith Owens did in
> his patch recently.
> 
>     Message-ID: <fa.iks3ohv.1flge08@ifi.uio.no>
>     From: Keith Owens <kaos@ocs.com.au>
>     Subject: [patch] 2.4.19 Generate better code for nfs_sillyrename
>     Date: Wed, 28 Aug 2002 07:08:17 GMT
> 
>     Using strlen() generates an unnecessary inline function expansion plus
>     dynamic stack adjustment.  For constant strings, strlen() == sizeof()-1
>     and the object code is better.

Gcc should be able to do this itself.

> The patch is against 2.4.19.
> 

-- 
Philips Velo 1: 1"x4"x8", 300gram, 60, 12MB, 40bogomips, linux, mutt,
details at http://atrey.karlin.mff.cuni.cz/~pavel/velo/index.html.