Implement WideToString locally, printf is slow

Even though it shouldn't need to, sprintf uses the libc-internal mutex,
locale support, and other parts making it slow.

[while] busy loop     -       306 ms       311 ms	-
[for] busy loop       -       180 ms       182 ms	-
mini loops            -       146 ms       146 ms	-
fibonacci(25)         -       191 ms       176 ms	92.1466
heapsort              -       138 ms       131 ms	94.9275
sieve                 -       182 ms       143 ms	78.5714
sieve [dict]          -       162 ms       138 ms	85.1852
ary                   -       188 ms       166 ms	88.2979
ary [dict]            -       173 ms       156 ms	90.1734
repeat                -       132 ms       130 ms	-
upvar                 -       142 ms       147 ms	-
nested loops          -       173 ms       173 ms	-
rotate                -        22 ms        22 ms	-
dynamic code          -       108 ms        97 ms	89.8148
dynamic code (list)   -        45 ms        46 ms	-
PI digits             -       333 ms       319 ms	95.7958
expand                -        46 ms        45 ms	-
wiki.tcl.tk/8566      -       251 ms       235 ms	93.6255
mandel                -       212 ms       199 ms	93.8679

Signed-off-by: Lauri Kasanen <cand@gmx.com>

1 files changed, 37 insertions, 2 deletions

diff --git a/jim.c b/jim.c
index 86bf242..bb9dd25 100644
--- a/jim.c
+++ b/jim.c
@@ -412,9 +412,44 @@ static int JimStringLastUtf8(const char *s1, int l1, const char *s2, int l2)
 
 int Jim_WideToString(char *buf, jim_wide wideValue)
 {
-    const char *fmt = "%" JIM_WIDE_MODIFIER;
+    char tmp[32];
+    int num = 0;
+    int negative = 0;
+    int i, pos = 0;
 
-    return sprintf(buf, fmt, wideValue);
+    if (wideValue < 0) {
+        negative = 1;
+        wideValue = -wideValue;
+    }
+
+    if (!wideValue) {
+        tmp[0] = '0';
+        num = 1;
+    }
+
+    while (wideValue) {
+        tmp[num] = '0' + abs(wideValue % 10);
+        wideValue /= 10;
+        num++;
+    }
+
+    for (i = 0, pos = num - 1; i < pos; i++, pos--) {
+        char a = tmp[i];
+        tmp[i] = tmp[pos];
+        tmp[pos] = a;
+    }
+
+    pos = 0;
+    if (negative) {
+        buf[0] = '-';
+        pos = 1;
+        num++;
+    }
+
+    memcpy(buf + pos, tmp, num);
+    buf[num] = 0;
+
+    return num;
 }
 
 /**