new floating point parser/converter

[musl] / src / stdlib / strtold.c

diff --git a/src/stdlib/strtold.c b/src/stdlib/strtold.c
index 54f8046..40ecc12 100644 (file)
--- a/src/stdlib/strtold.c
+++ b/src/stdlib/strtold.c
@@ -1,93 +1,15 @@
 #include <stdlib.h>
-#include <errno.h>
-#include <ctype.h>
+#include "floatscan.h"
+#include "stdio_impl.h"
 
-long double strtold(const char *s1, char **p)
+long double strtold(const char *s, char **p)
 {
-       const unsigned char *s = s1;
-       long double x = 0;
-       long double frac;
-       int sign = 0;
-       int nonzero = 0;
-       int radix = '.';
-       long e;
-
-       if (!p) p = (char **)&s1;
-
-       /* Initial whitespace */
-       for (; isspace(*s); s++);
-
-       /* Optional sign */
-       if (*s == '-') sign = *s++;
-       else if (*s == '+') s++;
-
-       /* Handle infinities and NaNs. */
-       if ((s[0]|32)=='i' && (s[1]|32)=='n' && (s[2]|32)=='f') {
-               *p = (char *)s + 3;
-               return sign ? -1.0/0.0 : 1.0/0.0;
-       } else if ((s[0]|32)=='n' && (s[1]|32)=='a' && (s[2]|32)=='n') {
-               *p = (char *)s + 3;
-               return 0.0/0.0;
-       }
-
-       /* Possible hex float */
-       if (s[0]=='0' && (s[1]|32)=='x') {
-               /* Mantissa must be non-degenerate */
-               if (!isxdigit(s[2]) && (s[2]!=radix || !isxdigit(s[3]))) {
-                       /* Decimal float 0, 'x' extraneous */
-                       *p = (char *)++s;
-                       return 0;
-               }
-               /* We have a real hex float */
-               s += 2;
-               for (; isxdigit(*s); s++) {
-                       x = 16*x + (isdigit(*s)?*s-'0':(*s|32)-'a');
-                       if (*s!='0') nonzero=1;
-               }
-               if (*s == radix) {
-                       frac = 1.0/16.0;
-                       for (s++; isxdigit(*s); s++) {
-                               x += frac * (isdigit(*s)?*s-'0':(*s|32)-'a');
-                               frac *= 1.0/16.0;
-                               if (*s!='0') nonzero=1;
-                       }
-               }
-               if ((*s|32) == 'p') {
-                       e = strtol(s+1, (void *)&s, 10);
-                       for (; e>0; e--) x *= 2.0;
-                       for (; e<0; e++) x *= 0.5;
-               }
-               if ((nonzero && !x) || !(1.0/x))
-                       errno = ERANGE;
-               *p = (char *)s;
-               return sign ? -x : x;
-       }
-
-       /* Mantissa must be non-degenerate */
-       if (!isdigit(s[0]) && (s[0]!=radix || !isdigit(s[1]))) {
-               *p = (char *)s1;
-               return 0;
-       }
-
-       for (; isdigit(*s); s++) {
-               x = 10*x + *s-'0';
-               if (*s!='0') nonzero=1;
-       }
-       if (*s == radix) {
-               frac = 10.0;
-               for (s++; isdigit(*s); s++) {
-                       x += (*s-'0') / frac;
-                       frac *= 10.0;
-                       if (*s!='0') nonzero=1;
-               }
-       }
-       if ((*s|32)=='e') {
-               e = strtol(++s, (void *)&s, 10);
-               for (; e>0; e--) x *= 10.0;
-               for (; e<0; e++) x /= 10.0;
-       }
-       if ((nonzero && !x) || !(1.0/x))
-               errno = ERANGE;
-       *p = (char*)s;
-       return sign ? -x : x;
+       FILE f = {
+               .buf = (void *)s, .rpos = (void *)s,
+               .rend = (void *)-1, .lock = -1
+       };
+       off_t cnt;
+       long double y = __floatscan(&f, -1, 2, 1, &cnt);
+       if (p) *p = (char *)s + cnt;
+       return y;
 }