diff options
Diffstat (limited to 'stdio-common/printf_fp.c')
| -rw-r--r-- | stdio-common/printf_fp.c | 97 |
1 files changed, 69 insertions, 28 deletions
diff --git a/stdio-common/printf_fp.c b/stdio-common/printf_fp.c index e4e32f9c28..c7a381a69d 100644 --- a/stdio-common/printf_fp.c +++ b/stdio-common/printf_fp.c @@ -1,6 +1,5 @@ /* Floating point output for `printf'. - Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2006 - Free Software Foundation, Inc. + Copyright (C) 1995-2003, 2006, 2007 Free Software Foundation, Inc. This file is part of the GNU C Library. Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995. @@ -793,7 +792,7 @@ ___printf_fp (FILE *fp, else { /* This is a special case. We don't need a factor because the - numbers are in the range of 0.0 <= fp < 8.0. We simply + numbers are in the range of 1.0 <= |fp| < 8.0. We simply shift it to the right place and divide it by 1.0 to get the leading digit. (Of course this division is not really made.) */ assert (0 <= exponent && exponent < 3 && @@ -811,12 +810,14 @@ ___printf_fp (FILE *fp, int chars_needed; int expscale; int intdig_max, intdig_no = 0; - int fracdig_min, fracdig_max, fracdig_no = 0; + int fracdig_min; + int fracdig_max; int dig_max; int significant; int ngroups = 0; + char spec = _tolower (info->spec); - if (_tolower (info->spec) == 'e') + if (spec == 'e') { type = info->spec; intdig_max = 1; @@ -826,7 +827,7 @@ ___printf_fp (FILE *fp, dig_max = INT_MAX; /* Unlimited. */ significant = 1; /* Does not matter here. */ } - else if (_tolower (info->spec) == 'f') + else if (spec == 'f') { type = 'f'; fracdig_min = fracdig_max = info->prec < 0 ? 6 : info->prec; @@ -923,7 +924,9 @@ ___printf_fp (FILE *fp, } /* Generate the needed number of fractional digits. */ - while (fracdig_no < fracdig_min + int fracdig_no = 0; + int added_zeros = 0; + while (fracdig_no < fracdig_min + added_zeros || (fracdig_no < fracdig_max && (fracsize > 1 || frac[0] != 0))) { ++fracdig_no; @@ -934,7 +937,7 @@ ___printf_fp (FILE *fp, { ++fracdig_max; if (fracdig_min > 0) - ++fracdig_min; + ++added_zeros; } } @@ -971,11 +974,23 @@ ___printf_fp (FILE *fp, { /* Process fractional digits. Terminate if not rounded or radix character is reached. */ + int removed = 0; while (*--wtp != decimalwc && *wtp == L'9') - *wtp = '0'; + { + *wtp = L'0'; + ++removed; + } + if (removed == fracdig_min && added_zeros > 0) + --added_zeros; if (*wtp != decimalwc) /* Round up. */ (*wtp)++; + else if (__builtin_expect (spec == 'g' && type == 'f' && info->alt, + 0)) + /* This is a special case: the rounded number is 1.0, + the format is 'g' or 'G', and the alternative format + is selected. This means the result must be "1.". */ + --added_zeros; } if (fracdig_no == 0 || *wtp == decimalwc) @@ -997,6 +1012,12 @@ ___printf_fp (FILE *fp, { *wstartp = '1'; exponent += expsign == 0 ? 1 : -1; + + /* The above exponent adjustment could lead to 1.0e-00, + e.g. for 0.999999999. Make sure exponent 0 always + uses + sign. */ + if (exponent == 0) + expsign = 0; } else if (intdig_no == dig_max) { @@ -1042,7 +1063,7 @@ ___printf_fp (FILE *fp, do_expo: /* Now remove unnecessary '0' at the end of the string. */ - while (fracdig_no > fracdig_min && *(wcp - 1) == L'0') + while (fracdig_no > fracdig_min + added_zeros && *(wcp - 1) == L'0') { --wcp; --fracdig_no; @@ -1060,26 +1081,46 @@ ___printf_fp (FILE *fp, /* Write the exponent if it is needed. */ if (type != 'f') { - *wcp++ = (wchar_t) type; - *wcp++ = expsign ? L'-' : L'+'; + if (__builtin_expect (expsign != 0 && exponent == 4 && spec == 'g', 0)) + { + /* This is another special case. The exponent of the number is + really smaller than -4, which requires the 'e'/'E' format. + But after rounding the number has an exponent of -4. */ + assert (wcp >= wstartp + 1); + assert (wstartp[0] == L'1'); + __wmemcpy (wstartp, L"0.0001", 6); + wstartp[1] = decimalwc; + if (wcp >= wstartp + 2) + { + wmemset (wstartp + 6, L'0', wcp - (wstartp + 2)); + wcp += 4; + } + else + wcp += 5; + } + else + { + *wcp++ = (wchar_t) type; + *wcp++ = expsign ? L'-' : L'+'; - /* Find the magnitude of the exponent. */ - expscale = 10; - while (expscale <= exponent) - expscale *= 10; + /* Find the magnitude of the exponent. */ + expscale = 10; + while (expscale <= exponent) + expscale *= 10; - if (exponent < 10) - /* Exponent always has at least two digits. */ - *wcp++ = L'0'; - else - do - { - expscale /= 10; - *wcp++ = L'0' + (exponent / expscale); - exponent %= expscale; - } - while (expscale > 10); - *wcp++ = L'0' + exponent; + if (exponent < 10) + /* Exponent always has at least two digits. */ + *wcp++ = L'0'; + else + do + { + expscale /= 10; + *wcp++ = L'0' + (exponent / expscale); + exponent %= expscale; + } + while (expscale > 10); + *wcp++ = L'0' + exponent; + } } /* Compute number of characters which must be filled with the padding |