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Subject[PATCH] vsprintf: reduce code size, clean up
From 5b5bc2f4f0499bc32d523d8121b781a89c8f1dd8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9=20Goddard=20Rosa?= <andre.goddard@gmail.com>
Date: Sat, 31 Oct 2009 14:48:49 -0200
Subject: [PATCH] vsprintf: reduce code size, clean up
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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This patch reduces code size by 382 bytes on my Core 2:
text data bss dec hex filename
15765 0 8 15773 3d9d lib/vsprintf.o-before
15383 7 8 15398 3c26 lib/vsprintf.o-after

It changes string "<NULL>" to "(null)".

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
---
lib/vsprintf.c | 170 ++++++++++++++++++++++++++++----------------------------
1 files changed, 86 insertions(+), 84 deletions(-)

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 33bed5e..fc77518 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -34,6 +34,8 @@
/* Works only for digits and letters, but small and fast */
#define TOLOWER(x) ((x) | 0x20)

+static char null[] = "(null)";
+
static unsigned int simple_guess_base(const char *cp)
{
if (cp[0] == '0') {
@@ -551,7 +553,7 @@ static char *string(char *buf, char *end, char *s,
struct printf_spec spec)
int len, i;

if ((unsigned long)s < PAGE_SIZE)
- s = "<NULL>";
+ s = null;

len = strnlen(s, spec.precision);

@@ -666,8 +668,8 @@ static char *ip4_string(char *p, const u8 *addr,
bool leading_zeros)
if (i < 3)
*p++ = '.';
}
-
*p = '\0';
+
return p;
}

@@ -735,8 +737,9 @@ static char *ip6_compressed_string(char *p, const
char *addr)
p = pack_hex_byte(p, hi);
else
*p++ = hex_asc_lo(hi);
+ p = pack_hex_byte(p, lo);
}
- if (hi || lo > 0x0f)
+ else if (lo > 0x0f)
p = pack_hex_byte(p, lo);
else
*p++ = hex_asc_lo(lo);
@@ -748,8 +751,8 @@ static char *ip6_compressed_string(char *p, const
char *addr)
*p++ = ':';
p = ip4_string(p, &in6.s6_addr[12], false);
}
-
*p = '\0';
+
return p;
}

@@ -762,8 +765,8 @@ static char *ip6_string(char *p, const char *addr,
const char *fmt)
if (fmt[0] == 'I' && i != 7)
*p++ = ':';
}
-
*p = '\0';
+
return p;
}

@@ -822,30 +825,34 @@ static char *pointer(const char *fmt, char *buf,
char *end, void *ptr,
struct printf_spec spec)
{
if (!ptr)
- return string(buf, end, "(null)", spec);
+ return string(buf, end, null, spec);

- switch (*fmt) {
- case 'F':
+ switch (TOLOWER(*fmt)) {
case 'f':
+ /* or case 'F' */
ptr = dereference_function_descriptor(ptr);
- case 's':
/* Fallthrough */
- case 'S':
+ case 's':
+ /* or case 'S' */
return symbol_string(buf, end, ptr, spec, *fmt);
case 'R':
return resource_string(buf, end, ptr, spec);
- case 'M': /* Colon separated: 00:01:02:03:04:05 */
- case 'm': /* Contiguous: 000102030405 */
+ case 'm':
+ /* or case 'M' */
+ /* case 'M': Colon separated: 00:01:02:03:04:05 */
+ /* case 'm': Contiguous: 000102030405 */
return mac_address_string(buf, end, ptr, spec, fmt);
- case 'I': /* Formatted IP supported
- * 4: 1.2.3.4
- * 6: 0001:0203:...:0708
- * 6c: 1::708 or 1::1.2.3.4
- */
- case 'i': /* Contiguous:
- * 4: 001.002.003.004
- * 6: 000102...0f
- */
+ case 'i':
+ /* or case 'I' */
+ /* case 'I': Formatted IP supported
+ * 4: 1.2.3.4
+ * 6: 0001:0203:...:0708
+ * 6c: 1::708 or 1::1.2.3.4
+ */
+ /* case 'i': Contiguous:
+ * 4: 001.002.003.004
+ * 6: 000102...0f
+ */
switch (fmt[1]) {
case '6':
return ip6_addr_string(buf, end, ptr, spec, fmt);
@@ -970,8 +977,8 @@ precision:
qualifier:
/* get the conversion qualifier */
spec->qualifier = -1;
- if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
- *fmt == 'Z' || *fmt == 'z' || *fmt == 't') {
+ if (*fmt == 'h' || TOLOWER(*fmt) == 'l' ||
+ TOLOWER(*fmt) == 'z' || *fmt == 't') {
spec->qualifier = *fmt++;
if (unlikely(spec->qualifier == *fmt)) {
if (spec->qualifier == 'l') {
@@ -1038,7 +1045,7 @@ qualifier:
spec->type = FORMAT_TYPE_LONG;
else
spec->type = FORMAT_TYPE_ULONG;
- } else if (spec->qualifier == 'Z' || spec->qualifier == 'z') {
+ } else if (TOLOWER(spec->qualifier) == 'z') {
spec->type = FORMAT_TYPE_SIZE_T;
} else if (spec->qualifier == 't') {
spec->type = FORMAT_TYPE_PTRDIFF;
@@ -1091,8 +1098,7 @@ qualifier:
int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
{
unsigned long long num;
- char *str, *end, c;
- int read;
+ char *str, *end;
struct printf_spec spec = {0};

/* Reject out-of-range values early. Large positive sizes are
@@ -1111,8 +1117,7 @@ int vsnprintf(char *buf, size_t size, const char
*fmt, va_list args)

while (*fmt) {
const char *old_fmt = fmt;
-
- read = format_decode(fmt, &spec);
+ int read = format_decode(fmt, &spec);

fmt += read;

@@ -1136,13 +1141,14 @@ int vsnprintf(char *buf, size_t size, const
char *fmt, va_list args)
spec.precision = va_arg(args, int);
break;

- case FORMAT_TYPE_CHAR:
+ case FORMAT_TYPE_CHAR: {
+ char c;
+
if (!(spec.flags & LEFT)) {
while (--spec.field_width > 0) {
if (str < end)
*str = ' ';
++str;
-
}
}
c = (unsigned char) va_arg(args, int);
@@ -1155,6 +1161,7 @@ int vsnprintf(char *buf, size_t size, const char
*fmt, va_list args)
++str;
}
break;
+ }

case FORMAT_TYPE_STR:
str = string(str, end, va_arg(args, char *), spec);
@@ -1185,8 +1192,7 @@ int vsnprintf(char *buf, size_t size, const char
*fmt, va_list args)
if (qualifier == 'l') {
long *ip = va_arg(args, long *);
*ip = (str - buf);
- } else if (qualifier == 'Z' ||
- qualifier == 'z') {
+ } else if (TOLOWER(qualifier) == 'z') {
size_t *ip = va_arg(args, size_t *);
*ip = (str - buf);
} else {
@@ -1396,7 +1402,6 @@ int vbin_printf(u32 *bin_buf, size_t size, const
char *fmt, va_list args)
{
struct printf_spec spec = {0};
char *str, *end;
- int read;

str = (char *)bin_buf;
end = (char *)(bin_buf + size);
@@ -1421,14 +1426,15 @@ do { \
str += sizeof(type); \
} while (0)

-
while (*fmt) {
- read = format_decode(fmt, &spec);
+ int read = format_decode(fmt, &spec);

fmt += read;

switch (spec.type) {
case FORMAT_TYPE_NONE:
+ case FORMAT_TYPE_INVALID:
+ case FORMAT_TYPE_PERCENT_CHAR:
break;

case FORMAT_TYPE_WIDTH:
@@ -1445,11 +1451,11 @@ do { \
size_t len;
if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
|| (unsigned long)save_str < PAGE_SIZE)
- save_str = "<NULL>";
- len = strlen(save_str);
- if (str + len + 1 < end)
- memcpy(str, save_str, len + 1);
- str += len + 1;
+ save_str = null;
+ len = strlen(save_str) + 1;
+ if (str + len < end)
+ memcpy(str, save_str, len);
+ str += len;
break;
}

@@ -1460,19 +1466,13 @@ do { \
fmt++;
break;

- case FORMAT_TYPE_PERCENT_CHAR:
- break;
-
- case FORMAT_TYPE_INVALID:
- break;
-
case FORMAT_TYPE_NRCHARS: {
/* skip %n 's argument */
int qualifier = spec.qualifier;
void *skip_arg;
if (qualifier == 'l')
skip_arg = va_arg(args, long *);
- else if (qualifier == 'Z' || qualifier == 'z')
+ else if (TOLOWER(qualifier) == 'z')
skip_arg = va_arg(args, size_t *);
else
skip_arg = va_arg(args, int *);
@@ -1538,11 +1538,9 @@ EXPORT_SYMBOL_GPL(vbin_printf);
*/
int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
{
- unsigned long long num;
- char *str, *end, c;
- const char *args = (const char *)bin_buf;
-
struct printf_spec spec = {0};
+ char *str, *end;
+ const char *args = (const char *)bin_buf;

if (WARN_ON_ONCE((int) size < 0))
return 0;
@@ -1572,10 +1570,8 @@ int bstr_printf(char *buf, size_t size, const
char *fmt, const u32 *bin_buf)
}

while (*fmt) {
- int read;
const char *old_fmt = fmt;
-
- read = format_decode(fmt, &spec);
+ int read = format_decode(fmt, &spec);

fmt += read;

@@ -1599,7 +1595,9 @@ int bstr_printf(char *buf, size_t size, const
char *fmt, const u32 *bin_buf)
spec.precision = get_arg(int);
break;

- case FORMAT_TYPE_CHAR:
+ case FORMAT_TYPE_CHAR: {
+ char c;
+
if (!(spec.flags & LEFT)) {
while (--spec.field_width > 0) {
if (str < end)
@@ -1617,11 +1615,11 @@ int bstr_printf(char *buf, size_t size, const
char *fmt, const u32 *bin_buf)
++str;
}
break;
+ }

case FORMAT_TYPE_STR: {
const char *str_arg = args;
- size_t len = strlen(str_arg);
- args += len + 1;
+ args += strlen(str_arg) + 1;
str = string(str, end, (char *)str_arg, spec);
break;
}
@@ -1648,15 +1646,15 @@ int bstr_printf(char *buf, size_t size, const
char *fmt, const u32 *bin_buf)
/* skip */
break;

- default:
+ default: {
+ unsigned long long num;
+
switch (spec.type) {

case FORMAT_TYPE_LONG_LONG:
num = get_arg(long long);
break;
case FORMAT_TYPE_ULONG:
- num = get_arg(unsigned long);
- break;
case FORMAT_TYPE_LONG:
num = get_arg(unsigned long);
break;
@@ -1686,8 +1684,9 @@ int bstr_printf(char *buf, size_t size, const
char *fmt, const u32 *bin_buf)
}

str = number(str, end, num, spec);
- }
- }
+ } /* default: */
+ } /* switch(spec.type) */
+ } /* while(*fmt) */

if (size > 0) {
if (str < end)
@@ -1727,6 +1726,13 @@ EXPORT_SYMBOL_GPL(bprintf);

#endif /* CONFIG_BINARY_PRINTF */

+static noinline const char *skip_space(const char *str)
+{
+ while (isspace(*str))
+ ++str;
+ return str;
+}
+
/**
* vsscanf - Unformat a buffer into a list of arguments
* @buf: input buffer
@@ -1742,18 +1748,16 @@ int vsscanf(const char * buf, const char *
fmt, va_list args)
int qualifier;
int base;
int field_width;
- int is_sign = 0;
+ bool is_sign;

- while(*fmt && *str) {
+ while (*fmt && *str) {
/* skip any white space in format */
/* white space in format matchs any amount of
* white space, including none, in the input.
*/
if (isspace(*fmt)) {
- while (isspace(*fmt))
- ++fmt;
- while (isspace(*str))
- ++str;
+ fmt = skip_space(fmt);
+ str = skip_space(str);
}

/* anything that is not a conversion must match exactly */
@@ -1785,8 +1789,8 @@ int vsscanf(const char * buf, const char * fmt,
va_list args)

/* get conversion qualifier */
qualifier = -1;
- if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
- *fmt == 'Z' || *fmt == 'z') {
+ if (*fmt == 'h' || TOLOWER(*fmt) == 'l' ||
+ TOLOWER(*fmt) == 'z') {
qualifier = *fmt++;
if (unlikely(qualifier == *fmt)) {
if (qualifier == 'h') {
@@ -1798,13 +1802,14 @@ int vsscanf(const char * buf, const char *
fmt, va_list args)
}
}
}
- base = 10;
- is_sign = 0;

if (!*fmt || !*str)
break;

- switch(*fmt++) {
+ base = 10;
+ is_sign = 0;
+
+ switch (TOLOWER(*fmt++)) {
case 'c':
{
char *s = (char *) va_arg(args,char*);
@@ -1822,8 +1827,7 @@ int vsscanf(const char * buf, const char * fmt,
va_list args)
if(field_width == -1)
field_width = INT_MAX;
/* first, skip leading white space in buffer */
- while (isspace(*str))
- str++;
+ str = skip_space(str);

/* now copy until next white space */
while (*str && !isspace(*str) && field_width--) {
@@ -1844,7 +1848,7 @@ int vsscanf(const char * buf, const char * fmt,
va_list args)
base = 8;
break;
case 'x':
- case 'X':
+ /* or case 'X' */
base = 16;
break;
case 'i':
@@ -1866,19 +1870,17 @@ int vsscanf(const char * buf, const char *
fmt, va_list args)
/* have some sort of integer conversion.
* first, skip white space in buffer.
*/
- while (isspace(*str))
- str++;
+ str = skip_space(str);

digit = *str;
if (is_sign && digit == '-')
digit = *(str + 1);

- if (!digit
- || (base == 16 && !isxdigit(digit))
- || (base == 10 && !isdigit(digit))
- || (base == 8 && (!isdigit(digit) || digit > '7'))
- || (base == 0 && !isdigit(digit)))
- break;
+ if (!digit || (base == 16 && !isxdigit(digit))
+ || (base == 10 && !isdigit(digit))
+ || (base == 8 && (!isdigit(digit) || digit > '7'))
+ || (base == 0 && !isdigit(digit)))
+ break;

switch(qualifier) {
case 'H': /* that's 'hh' in format */
--
1.6.5.2.140.g5f809
--
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