- if (precision == 0)
- precision = 1;
- /* precision >= 1. */
-
- if (arg == 0.0L)
- /* The exponent is 0, >= -4, < precision.
- Use fixed-point notation. */
- {
- size_t ndigits = precision;
- /* Number of trailing zeroes that have to be
- dropped. */
- size_t nzeroes =
- (flags & FLAG_ALT ? 0 : precision - 1);
-
- --ndigits;
- *p++ = '0';
- if ((flags & FLAG_ALT) || ndigits > nzeroes)
- {
- *p++ = decimal_point_char ();
- while (ndigits > nzeroes)
- {
- --ndigits;
- *p++ = '0';
- }
- }
- }
- else
- {
- /* arg > 0.0L. */
- int exponent;
- int adjusted;
- char *digits;
- size_t ndigits;
- size_t nzeroes;
-
- exponent = floorlog10l (arg);
- adjusted = 0;
- for (;;)
- {
- digits =
- scale10_round_decimal_long_double (arg,
- (int)(precision - 1) - exponent);
- if (digits == NULL)
- {
- END_LONG_DOUBLE_ROUNDING ();
- goto out_of_memory;
- }
- ndigits = strlen (digits);
-
- if (ndigits == precision)
- break;
- if (ndigits < precision - 1
- || ndigits > precision + 1)
- /* The exponent was not guessed
- precisely enough. */
- abort ();
- if (adjusted)
- /* None of two values of exponent is
- the right one. Prevent an endless
- loop. */
- abort ();
- free (digits);
- if (ndigits < precision)
- exponent -= 1;
- else
- exponent += 1;
- adjusted = 1;
- }
- /* Here ndigits = precision. */
-
- /* Determine the number of trailing zeroes
- that have to be dropped. */
- nzeroes = 0;
- if ((flags & FLAG_ALT) == 0)
- while (nzeroes < ndigits
- && digits[nzeroes] == '0')
- nzeroes++;
-
- /* The exponent is now determined. */
- if (exponent >= -4
- && exponent < (long)precision)
- {
- /* Fixed-point notation:
- max(exponent,0)+1 digits, then the
- decimal point, then the remaining
- digits without trailing zeroes. */
- if (exponent >= 0)
- {
- size_t count = exponent + 1;
- /* Note: count <= precision = ndigits. */
- for (; count > 0; count--)
- *p++ = digits[--ndigits];
- if ((flags & FLAG_ALT) || ndigits > nzeroes)
- {
- *p++ = decimal_point_char ();
- while (ndigits > nzeroes)
- {
- --ndigits;
- *p++ = digits[ndigits];
- }
- }
- }
- else
- {
- size_t count = -exponent - 1;
- *p++ = '0';
- *p++ = decimal_point_char ();
- for (; count > 0; count--)
- *p++ = '0';
- while (ndigits > nzeroes)
- {
- --ndigits;
- *p++ = digits[ndigits];
- }
- }
- }
- else
- {
- /* Exponential notation. */
- *p++ = digits[--ndigits];
- if ((flags & FLAG_ALT) || ndigits > nzeroes)
- {
- *p++ = decimal_point_char ();
- while (ndigits > nzeroes)
- {
- --ndigits;
- *p++ = digits[ndigits];
- }
- }
- *p++ = dp->conversion - 'G' + 'E'; /* 'e' or 'E' */
-# if WIDE_CHAR_VERSION
- {
- static const wchar_t decimal_format[] =
- { '%', '+', '.', '2', 'd', '\0' };
- SNPRINTF (p, 6 + 1, decimal_format, exponent);
- }
-# else
- sprintf (p, "%+.2d", exponent);
-# endif
- while (*p != '\0')
- p++;
- }
-
- free (digits);
- }