lib/vsprintf.c: another small hack

Making ZEROPAD == '0'-' ', we can eliminate a few more instructions.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 7a299d43987a01c798a7a93b9822c73bece81afc..2753f9261115e8beb3e4bef7c1d28101905cd810 100644 (file)
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -341,10 +341,10 @@ int num_to_str(char *buf, int size, unsigned long long num)
 }
 
 #define SIGN   1               /* unsigned/signed, must be 1 */
-#define ZEROPAD        2               /* pad with zero */
+#define LEFT   2               /* left justified */
 #define PLUS   4               /* show plus */
 #define SPACE  8               /* space if plus */
-#define LEFT   16              /* left justified */
+#define ZEROPAD        16              /* pad with zero, must be 16 == '0' - ' ' */
 #define SMALL  32              /* use lowercase in hex (must be 32 == 0x20) */
 #define SPECIAL        64              /* prefix hex with "0x", octal with "0" */
 
@@ -467,7 +467,8 @@ char *number(char *buf, char *end, unsigned long long num,
        }
        /* zero or space padding */
        if (!(spec.flags & LEFT)) {
-               char c = (spec.flags & ZEROPAD) ? '0' : ' ';
+               char c = ' ' + (spec.flags & ZEROPAD);
+               BUILD_BUG_ON(' ' + ZEROPAD != '0');
                while (--spec.field_width >= 0) {
                        if (buf < end)
                                *buf = c;