On Mon, Nov 23, 2015 at 11:29 PM, Rasmus Villemoes
<li...@rasmusvillemoes.dk> wrote:
> One consequence of the reorganization of struct printf_spec to make
> field_width 24 bits was that number() gained about 180 bytes. Since
> spec is never passed to other functions, we can help gcc make number()
> lose most of that extra weight by using local variables for the field
> width and precision.
>
Reviewed-by: Andy Shevchenko <andy.shevche...@gmail.com>
One minor nitpick below
> Signed-off-by: Rasmus Villemoes <li...@rasmusvillemoes.dk>
> ---
> lib/vsprintf.c | 26 ++++++++++++++------------
> 1 file changed, 14 insertions(+), 12 deletions(-)
>
> diff --git a/lib/vsprintf.c b/lib/vsprintf.c
> index 01c3aa638582..d7e27c54fa00 100644
> --- a/lib/vsprintf.c
> +++ b/lib/vsprintf.c
> @@ -399,6 +399,8 @@ char *number(char *buf, char *end, unsigned long long num,
> int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
> int i;
> bool is_zero = num == 0LL;
> + int field_width = spec.field_width;
> + int precision = spec.precision;
I would put these before int i; But your choice.
>
> /* locase = 0 or 0x20. ORing digits or letters with 'locase'
> * produces same digits or (maybe lowercased) letters */
> @@ -410,20 +412,20 @@ char *number(char *buf, char *end, unsigned long long
> num,
> if ((signed long long)num < 0) {
> sign = '-';
> num = -(signed long long)num;
> - spec.field_width--;
> + field_width--;
> } else if (spec.flags & PLUS) {
> sign = '+';
> - spec.field_width--;
> + field_width--;
> } else if (spec.flags & SPACE) {
> sign = ' ';
> - spec.field_width--;
> + field_width--;
> }
> }
> if (need_pfx) {
> if (spec.base == 16)
> - spec.field_width -= 2;
> + field_width -= 2;
> else if (!is_zero)
> - spec.field_width--;
> + field_width--;
> }
>
> /* generate full string in tmp[], in reverse order */
> @@ -445,12 +447,12 @@ char *number(char *buf, char *end, unsigned long long
> num,
> }
>
> /* printing 100 using %2d gives "100", not "00" */
> - if (i > spec.precision)
> - spec.precision = i;
> + if (i > precision)
> + precision = i;
> /* leading space padding */
> - spec.field_width -= spec.precision;
> + field_width -= precision;
> if (!(spec.flags & (ZEROPAD | LEFT))) {
> - while (--spec.field_width >= 0) {
> + while (--field_width >= 0) {
> if (buf < end)
> *buf = ' ';
> ++buf;
> @@ -479,14 +481,14 @@ char *number(char *buf, char *end, unsigned long long
> num,
> if (!(spec.flags & LEFT)) {
> char c = ' ' + (spec.flags & ZEROPAD);
> BUILD_BUG_ON(' ' + ZEROPAD != '0');
> - while (--spec.field_width >= 0) {
> + while (--field_width >= 0) {
> if (buf < end)
> *buf = c;
> ++buf;
> }
> }
> /* hmm even more zero padding? */
> - while (i <= --spec.precision) {
> + while (i <= --precision) {
> if (buf < end)
> *buf = '0';
> ++buf;
> @@ -498,7 +500,7 @@ char *number(char *buf, char *end, unsigned long long num,
> ++buf;
> }
> /* trailing space padding */
> - while (--spec.field_width >= 0) {
> + while (--field_width >= 0) {
> if (buf < end)
> *buf = ' ';
> ++buf;
> --
> 2.6.1
>
> --
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--
With Best Regards,
Andy Shevchenko
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