1 files changed, 59 insertions, 45 deletions
diff --git a/mdk-stage1/dietlibc/lib/strtod.c b/mdk-stage1/dietlibc/lib/strtod.c
index cbe983d84..5d50cc535 100644
--- a/mdk-stage1/dietlibc/lib/strtod.c
+++ b/mdk-stage1/dietlibc/lib/strtod.c
@@ -1,52 +1,66 @@
 #include <string.h>
+#include <stdlib.h>
+#include <ctype.h>
 
-extern char isspace(char c);
-
-#ifdef __GNUC__
-static inline char isdigit(char c) { return (c>='0' && c<='9'); }
-#endif
-
-double strtod(const char *nptr, char **endptr) {
-  double d=0;
-  register const char *c=nptr;
-  char neg=0;
-  while (*c && isspace(*c)) ++c;
-  switch (*c) {
-  case '-': neg=1;
-  case '+': c++; break;
-  default: break;
-  }
-  while (isdigit(*c)) {
-    d=d*10+(*c-'0');
-    ++c;
-  }
-  if (*c=='.') {
-    double factor=.1;
-    while (isdigit(*++c)) {
-      d=d+(factor*(*c-'0'));
-      factor/=10;
+double strtod(const char* s, char** endptr) {
+    register const char*  p     = s;
+    register long double  value = 0.L;
+    int                   sign  = +1;
+    long double           factor;
+    unsigned int          expo;
+
+    while ( isspace(*p) )
+        p++;
+
+    switch (*p) {
+    case '-': sign = -1;
+    case '+': p++;
+    default : break;
     }
-  }
-  if ((*c|32)=='e') {
-    int exp=0;
-    double factor=10;
-    if (c[1]<'0') {
-      switch (c[1]) {
-      case '-': factor=0.1;
-      case '+': c++; break;
-      default:
-	d=0;
-	c=nptr;
-	goto done;
-      }
+
+    while ( (unsigned int)(*p - '0') < 10u )
+        value = value*10 + (*p++ - '0');
+
+    if ( *p == '.' ) {
+        factor = 1.;
+
+        p++;
+        while ( (unsigned int)(*p - '0') < 10u ) {
+            factor *= 0.1;
+            value  += (*p++ - '0') * factor;
+        }
     }
-    while (isdigit(*++c))
-      exp=exp*10+(*c-'0');
-    while (exp) {	/* XXX: this introduces rounding errors */
-      d*=factor; --exp;
+
+    if ( (*p | 32) == 'e' ) {
+        expo   = 0;
+        factor = 10.L;
+
+        switch (*++p) {                 // ja hier weiß ich nicht, was mindestens nach einem 'E' folgenden MUSS.
+        case '-': factor = 0.1;
+        case '+': p++;
+                  break;
+        case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9':
+                  break;
+        default : value = 0.L;
+                  p     = s;
+                  goto done;
+        }
+
+        while ( (unsigned int)(*p - '0') < 10u )
+            expo = 10 * expo + (*p++ - '0');
+
+        while ( 1 ) {
+            if ( expo & 1 )
+                value *= factor;
+            if ( (expo >>= 1) == 0 )
+                break;
+            factor *= factor;
+        }
     }
-  }
+
 done:
-  if (endptr) *endptr=(char*)c;
-  return d;
+    if ( endptr != NULL )
+        *endptr = (char*)p;
+
+    return value * sign;
 }