Commit 0f4f81dc authored Dec 14, 2009 by André Goddard Rosa Committed by Linus Torvalds Dec 15, 2009

vsprintf: factorize "(null)" string



This patchset reduces lib/lib.a code size by 482 bytes on my Core 2 with
gcc 4.4.1 even considering that it exports a newly defined function
skip_spaces() to drivers:

   text    data     bss     dec     hex filename
  64867     840     592   66299   102fb (TOTALS-lib.a-BEFORE)
  64641     584     592   65817   10119 (TOTALS-lib.a-AFTER)
and implements some code tidy up.

Besides reducing lib.a size, it converts many in-tree drivers to use the
newly defined function, which makes another small reduction on kernel size
overall when those drivers are used.

This patch:

Change "<NULL>" to "(null)", unifying 3 equal strings.
glibc also uses "(null)" for the same purpose.

It decreases code size by 7 bytes:
 text    data     bss     dec     hex filename
15765       0       8   15773    3d9d vsprintf.o (ex lib/lib.a-BEFORE)
15758       0       8   15766    3d96 vsprintf.o (ex lib/lib.a-AFTER)

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 3768f0b1

lib/vsprintf.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -546,12 +546,12 @@ static char number(char buf, char *end, unsigned long long num,
		return buf;
		}

		static char string(char buf, char end, char s, struct printf_spec spec)
		static char string(char buf, char end, const char s, struct printf_spec spec)
		{
		int len, i;

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

		len = strnlen(s, spec.precision);

		@@ -1498,7 +1498,7 @@ do { \
		size_t len;
		if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
		\|\| (unsigned long)save_str < PAGE_SIZE)
		save_str = "<NULL>";
		save_str = "(null)";
		len = strlen(save_str);
		if (str + len + 1 < end)
		memcpy(str, save_str, len + 1);

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