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>

diff --git a/editors/ed.c b/editors/ed.c
index a2a389c2bfad7985a1e0252d62b0c906914f5844..b13c3ed594900faa35ccbbf6597e9e1a4038659a 100644 (file)
--- 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;