ed: code shrink

function                                             old     new   delta
findString                                           117     115      -2
skip_blank                                            16       -     -16
getNum                                               369     345     -24
doCommands                                          2448    2183    -265
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 0/3 up/down: 0/-307)           Total: -307 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 43 insertions, 51 deletions

diff --git a/editors/ed.c b/editors/ed.c
index a2a389c2b..b13c3ed59 100644
--- a/editors/ed.c
+++ b/editors/ed.c
@@ -78,13 +78,6 @@ static int bad_nums(int num1, int num2, const char *for_what)
         return 0;
 }
 
-static char *skip_blank(const char *cp)
-{
-        while (isblank(*cp))
-                cp++;
-        return (char *)cp;
-}
-
 /*
  * Return a pointer to the specified line number.
  */
@@ -138,15 +131,13 @@ static int findString(const LINE *lp, const char *str, int len, int offset)
         const char *cp, *ncp;
 
         cp = &lp->data[offset];
-        left = lp->len - offset;
+        left = lp->len - offset - len;
 
-        while (left >= len) {
-                ncp = memchr(cp, *str, left);
+        while (left >= 0) {
+                ncp = memchr(cp, str[0], left + 1);
                 if (ncp == NULL)
                         return -1;
                 left -= (ncp - cp);
-                if (left < len)
-                        return -1;
                 cp = ncp;
                 if (memcmp(cp, str, len) == 0)
                         return (cp - lp->data);
@@ -203,25 +194,23 @@ static NOINLINE int searchLines(const char *str, int num1, int num2)
 /*
  * Parse a line number argument if it is present.  This is a sum
  * or difference of numbers, '.', '$', 'x, or a search string.
- * Returns TRUE if successful (whether or not there was a number).
- * Returns FALSE if there was a parsing error, with a message output.
+ * Returns pointer which stopped the scan if successful (whether or not
+ * there was a number).
+ * Returns NULL if there was a parsing error, with a message output.
  * Whether there was a number is returned indirectly, as is the number.
- * The character pointer which stopped the scan is also returned.
  */
-static int getNum(const char **retcp, smallint *retHaveNum, int *retNum)
+static const char* getNum(const char *cp, smallint *retHaveNum, int *retNum)
 {
-        const char *cp;
         char *endStr, str[USERSIZE];
         int value, num;
         smallint haveNum, minus;
 
-        cp = *retcp;
         value = 0;
         haveNum = FALSE;
         minus = 0;
 
         while (TRUE) {
-                cp = skip_blank(cp);
+                cp = skip_whitespace(cp);
 
                 switch (*cp) {
                         case '.':
@@ -240,7 +229,7 @@ static int getNum(const char **retcp, smallint *retHaveNum, int *retNum)
                                 cp++;
                                 if ((*cp < 'a') || (*cp > 'z')) {
                                         bb_error_msg("bad mark name");
-                                        return FALSE;
+                                        return NULL;
                                 }
                                 haveNum = TRUE;
                                 num = marks[*cp++ - 'a'];
@@ -256,16 +245,15 @@ static int getNum(const char **retcp, smallint *retHaveNum, int *retNum)
                                         cp = "";
                                 num = searchLines(str, curNum, lastNum);
                                 if (num == 0)
-                                        return FALSE;
+                                        return NULL;
                                 haveNum = TRUE;
                                 break;
 
                         default:
                                 if (!isdigit(*cp)) {
-                                        *retcp = cp;
                                         *retHaveNum = haveNum;
                                         *retNum = value;
-                                        return TRUE;
+                                        return cp;
                                 }
                                 num = 0;
                                 while (isdigit(*cp))
@@ -276,7 +264,7 @@ static int getNum(const char **retcp, smallint *retHaveNum, int *retNum)
 
                 value += (minus ? -num : num);
 
-                cp = skip_blank(cp);
+                cp = skip_whitespace(cp);
 
                 switch (*cp) {
                         case '-':
@@ -290,10 +278,9 @@ static int getNum(const char **retcp, smallint *retHaveNum, int *retNum)
                                 break;
 
                         default:
-                                *retcp = cp;
                                 *retHaveNum = haveNum;
                                 *retNum = value;
-                                return TRUE;
+                                return cp;
                 }
         }
 }
@@ -789,12 +776,13 @@ static void subCommand(const char *cmd, int num1, int num2)
  */
 static void doCommands(void)
 {
-        const char *cp;
-        char *endbuf, buf[USERSIZE];
-        int len, num1, num2;
-        smallint have1, have2;
-
         while (TRUE) {
+                char buf[USERSIZE];
+                const char *cp;
+                int len;
+                int n, num1, num2;
+                smallint h, have1, have2;
+
                 /* Returns:
                  * -1 on read errors or EOF, or on bare Ctrl-D.
                  * 0  on ctrl-C,
@@ -803,32 +791,36 @@ static void doCommands(void)
                 len = read_line_input(NULL, ": ", buf, sizeof(buf), /*timeout*/ -1);
                 if (len <= 0)
                         return;
-                endbuf = &buf[len - 1];
-                while ((endbuf > buf) && isblank(endbuf[-1]))
-                        endbuf--;
-                *endbuf = '\0';
-
-                cp = skip_blank(buf);
-                have1 = FALSE;
-                have2 = FALSE;
+                while (len && isblank(buf[--len]))
+                        buf[len] = '\0';
 
                 if ((curNum == 0) && (lastNum > 0)) {
                         curNum = 1;
                         curLine = lines.next;
                 }
 
-                if (!getNum(&cp, &have1, &num1))
+                have1 = FALSE;
+                have2 = FALSE;
+                /* Don't pass &have1, &num1 to getNum() since this forces
+                 * compiler to keep them on stack, not in registers,
+                 * which is usually quite suboptimal.
+                 * Using intermediate variables shrinks code by ~150 bytes.
+                 */
+                cp = getNum(skip_whitespace(buf), &h, &n);
+                if (!cp)
                         continue;
+                have1 = h;
+                num1 = n;
 
-                cp = skip_blank(cp);
-
+                cp = skip_whitespace(cp);
                 if (*cp == ',') {
-                        cp++;
-                        if (!getNum(&cp, &have2, &num2))
+                        cp = getNum(cp + 1, &h, &n);
+                        if (!cp)
                                 continue;
+                        num2 = n;
                         if (!have1)
                                 num1 = 1;
-                        if (!have2)
+                        if (!h)
                                 num2 = lastNum;
                         have1 = TRUE;
                         have2 = TRUE;
@@ -857,7 +849,7 @@ static void doCommands(void)
                                 bb_error_msg("bad file command");
                                 break;
                         }
-                        cp = skip_blank(cp);
+                        cp = skip_whitespace(cp);
                         if (*cp == '\0') {
                                 if (fileName)
                                         printf("\"%s\"\n", fileName);
@@ -874,7 +866,7 @@ static void doCommands(void)
                         break;
 
                 case 'k':
-                        cp = skip_blank(cp);
+                        cp = skip_whitespace(cp);
                         if ((*cp < 'a') || (*cp > 'z') || cp[1]) {
                                 bb_error_msg("bad mark name");
                                 break;
@@ -891,7 +883,7 @@ static void doCommands(void)
                         break;
 
                 case 'q':
-                        cp = skip_blank(cp);
+                        cp = skip_whitespace(cp);
                         if (have1 || *cp) {
                                 bb_error_msg("bad quit command");
                                 break;
@@ -902,7 +894,7 @@ static void doCommands(void)
                         /* read error/EOF - no way to continue */
                         if (len < 0)
                                 return;
-                        cp = skip_blank(buf);
+                        cp = skip_whitespace(buf);
                         if ((*cp | 0x20) == 'y') /* Y or y */
                                 return;
                         break;
@@ -912,7 +904,7 @@ static void doCommands(void)
                                 bb_error_msg("bad read command");
                                 break;
                         }
-                        cp = skip_blank(cp);
+                        cp = skip_whitespace(cp);
                         if (*cp == '\0') {
                                 bb_error_msg("no file name");
                                 break;
@@ -934,7 +926,7 @@ static void doCommands(void)
                                 bb_error_msg("bad write command");
                                 break;
                         }
-                        cp = skip_blank(cp);
+                        cp = skip_whitespace(cp);
                         if (!have1) {
                                 num1 = 1;
                                 num2 = lastNum;