cal: small code shrink

1 files changed, 50 insertions, 55 deletions

diff --git a/coreutils/cal.c b/coreutils/cal.c
index ce910bc63..f8fc0b0d3 100644
--- a/coreutils/cal.c
+++ b/coreutils/cal.c
@@ -19,6 +19,8 @@
 
 #include "libbb.h"
 
+/* We often use "unsigned" intead of "int", it's easier to div on most CPUs */
+
 #define THURSDAY                4               /* for reformation */
 #define SATURDAY                6               /* 1 Jan 1 was a Saturday */
 
@@ -28,29 +30,25 @@
 #define MAXDAYS                 42              /* max slots in a month array */
 #define SPACE                   -1              /* used in day array */
 
-static const char days_in_month[] = {
+static const unsigned char days_in_month[] = {
         0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
 };
 
-static const char sep1752[] = {
+static const unsigned char sep1752[] = {
                  1,     2,      14,     15,     16,
         17,     18,     19,     20,     21,     22,     23,
         24,     25,     26,     27,     28,     29,     30
 };
 
-static int julian;
+static unsigned julian;
 
 /* leap year -- account for Gregorian reformation in 1752 */
-#define leap_year(yr) \
-        ((yr) <= 1752 ? !((yr) % 4) : \
-        (!((yr) % 4) && ((yr) % 100)) || !((yr) % 400))
-
-static int is_leap_year(int year)
+static int leap_year(unsigned yr)
 {
-        return leap_year(year);
+        if (yr <= 1752) 
+                return !(yr % 4);
+        return (!(yr % 4) && (yr % 100)) || !(yr % 400);
 }
-#undef leap_year
-#define leap_year(yr) is_leap_year(yr)
 
 /* number of centuries since 1700, not inclusive */
 #define centuries_since_1700(yr) \
@@ -64,12 +62,12 @@ static int is_leap_year(int year)
 #define leap_years_since_year_1(yr) \
         ((yr) / 4 - centuries_since_1700(yr) + quad_centuries_since_1700(yr))
 
-static void center (char *, int, int);
-static void day_array (int, int, int *);
-static void trim_trailing_spaces_and_print (char *);
+static void center(char *, unsigned, unsigned);
+static void day_array(unsigned, unsigned, unsigned *);
+static void trim_trailing_spaces_and_print(char *);
 
 static void blank_string(char *buf, size_t buflen);
-static char *build_row(char *p, int *dp);
+static char *build_row(char *p, unsigned *dp);
 
 #define DAY_LEN         3               /* 3 spaces per day */
 #define J_DAY_LEN       (DAY_LEN + 1)
@@ -83,20 +81,18 @@ int cal_main(int argc, char **argv)
         struct tm *local_time;
         struct tm zero_tm;
         time_t now;
-        int month, year, flags, i;
+        unsigned month, year, flags, i;
         char *month_names[12];
         char day_headings[28];  /* 28 for julian, 21 for nonjulian */
         char buf[40];
 
         flags = getopt32(argc, argv, "jy");
-
         julian = flags & 1;
-
-        argv += optind;
-
         month = 0;
+        argv += optind;
+        argc -= optind;
 
-        if ((argc -= optind) > 2) {
+        if (argc > 2) {
                 bb_show_usage();
         }
 
@@ -109,12 +105,12 @@ int cal_main(int argc, char **argv)
                 }
         } else {
                 if (argc == 2) {
-                        month = xatoul_range(*argv++, 1, 12);
+                        month = xatou_range(*argv++, 1, 12);
                 }
-                year = xatoul_range(*argv, 1, 9999);
+                year = xatou_range(*argv, 1, 9999);
         }
 
-        blank_string(day_headings, sizeof(day_headings) - 7 +  7*julian);
+        blank_string(day_headings, sizeof(day_headings) - 7 + 7*julian);
 
         i = 0;
         do {
@@ -130,8 +126,8 @@ int cal_main(int argc, char **argv)
         } while (++i < 12);
 
         if (month) {
-                int row, len, days[MAXDAYS];
-                int *dp = days;
+                unsigned row, len, days[MAXDAYS];
+                unsigned *dp = days;
                 char lineout[30];
 
                 day_array(month, year, dp);
@@ -145,8 +141,8 @@ int cal_main(int argc, char **argv)
                         trim_trailing_spaces_and_print(lineout);
                 }
         } else {
-                int row, which_cal, week_len, days[12][MAXDAYS];
-                int *dp;
+                unsigned row, which_cal, week_len, days[12][MAXDAYS];
+                unsigned *dp;
                 char lineout[80];
 
                 sprintf(lineout, "%d", year);
@@ -193,19 +189,21 @@ int cal_main(int argc, char **argv)
  *      out end to end.  You would have 42 numbers or spaces.  This routine
  *      builds that array for any month from Jan. 1 through Dec. 9999.
  */
-static void day_array(int month, int year, int *days)
+static void day_array(unsigned month, unsigned year, unsigned *days)
 {
-        long temp;
-        int i;
-        int j_offset;
-        int day, dw, dm;
+        unsigned long temp;
+        unsigned i;
+        unsigned day, dw, dm;
 
         memset(days, SPACE, MAXDAYS * sizeof(int));
 
         if ((month == 9) && (year == 1752)) {
+                /* Assumes the Gregorian reformation eliminates
+                 * 3 Sep. 1752 through 13 Sep. 1752.
+                 */
+                unsigned j_offset = julian * 244;
                 size_t oday = 0;
 
-                j_offset = julian * 244;
                 do {
                         days[oday+2] = sep1752[oday] + j_offset;
                 } while (++oday < sizeof(sep1752));
@@ -214,7 +212,7 @@ static void day_array(int month, int year, int *days)
         }
 
         /* day_in_year
-         *      return the 1 based day number within the year
+         * return the 1 based day number within the year
          */
         day = 1;
         if ((month > 2) && leap_year(year)) {
@@ -227,17 +225,15 @@ static void day_array(int month, int year, int *days)
         }
 
         /* day_in_week
-         *      return the 0 based day number for any date from 1 Jan. 1 to
-         *      31 Dec. 9999.  Assumes the Gregorian reformation eliminates
-         *      3 Sep. 1752 through 13 Sep. 1752.  Returns Thursday for all
-         *      missing days.
+         * return the 0 based day number for any date from 1 Jan. 1 to
+         * 31 Dec. 9999.  Assumes the Gregorian reformation eliminates
+         * 3 Sep. 1752 through 13 Sep. 1752.  Returns Thursday for all
+         * missing days.
          */
-        dw = THURSDAY;
-        temp = (long)(year - 1) * 365 + leap_years_since_year_1(year - 1)
-                + day;
+        temp = (long)(year - 1) * 365 + leap_years_since_year_1(year - 1) + day;
         if (temp < FIRST_MISSING_DAY) {
                 dw = ((temp - 1 + SATURDAY) % 7);
-        } else if (temp >= (FIRST_MISSING_DAY + NUMBER_MISSING_DAYS)) {
+        } else {
                 dw = (((temp - 1 + SATURDAY) - NUMBER_MISSING_DAYS) % 7);
         }
 
@@ -250,10 +246,9 @@ static void day_array(int month, int year, int *days)
                 ++dm;
         }
 
-        while (dm) {
+        do {
                 days[dw++] = day++;
-                --dm;
-        }
+        } while (--dm);
 }
 
 static void trim_trailing_spaces_and_print(char *s)
@@ -263,7 +258,7 @@ static void trim_trailing_spaces_and_print(char *s)
         while (*p) {
                 ++p;
         }
-        while (p > s) {
+        while (p != s) {
                 --p;
                 if (!(isspace)(*p)) {   /* We want the function... not the inline. */
                         p[1] = '\0';
@@ -274,9 +269,9 @@ static void trim_trailing_spaces_and_print(char *s)
         puts(s);
 }
 
-static void center(char *str, int len, int separate)
+static void center(char *str, unsigned len, unsigned separate)
 {
-        int n = strlen(str);
+        unsigned n = strlen(str);
         len -= n;
         printf("%*s%*s", (len/2) + n, str, (len/2) + (len % 2) + separate, "");
 }
@@ -287,15 +282,16 @@ static void blank_string(char *buf, size_t buflen)
         buf[buflen-1] = '\0';
 }
 
-static char *build_row(char *p, int *dp)
+static char *build_row(char *p, unsigned *dp)
 {
-        int col, val, day;
+        unsigned col, val, day;
 
         memset(p, ' ', (julian + DAY_LEN) * 7);
 
         col = 0;
         do {
-                if ((day = *dp++) != SPACE) {
+                day = *dp++;
+                if (day != SPACE) {
                         if (julian) {
                                 ++p;
                                 if (day >= 100) {
@@ -304,7 +300,8 @@ static char *build_row(char *p, int *dp)
                                         day %= 100;
                                 }
                         }
-                        if ((val = day / 10) > 0) {
+                        val = day / 10;
+                        if (val > 0) {
                                 *p = val + '0';
                         }
                         *++p = day % 10 + '0';
@@ -348,5 +345,3 @@ static char *build_row(char *p, int *dp)
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
-
-