490 lines
12 KiB
C
490 lines
12 KiB
C
/* Print floating point number in hexadecimal notation according to ISO C99.
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Copyright (C) 1997-2022 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <array_length.h>
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#include <ctype.h>
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#include <ieee754.h>
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#include <math.h>
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#include <printf.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
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#include <wchar.h>
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#include <_itoa.h>
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#include <_itowa.h>
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#include <locale/localeinfo.h>
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#include <stdbool.h>
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#include <rounding-mode.h>
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#if __HAVE_DISTINCT_FLOAT128
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# include "ieee754_float128.h"
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# include <ldbl-128/printf_fphex_macros.h>
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# define PRINT_FPHEX_FLOAT128 \
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PRINT_FPHEX (_Float128, fpnum.flt128, ieee854_float128, \
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IEEE854_FLOAT128_BIAS)
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#endif
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/* #define NDEBUG 1*/ /* Undefine this for debugging assertions. */
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#include <assert.h>
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#include <libioP.h>
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#define PUT(f, s, n) _IO_sputn (f, s, n)
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#define PAD(f, c, n) (wide ? _IO_wpadn (f, c, n) : _IO_padn (f, c, n))
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#undef putc
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#define putc(c, f) (wide \
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? (int)_IO_putwc_unlocked (c, f) : _IO_putc_unlocked (c, f))
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/* Macros for doing the actual output. */
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#define outchar(ch) \
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do \
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{ \
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const int outc = (ch); \
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if (putc (outc, fp) == EOF) \
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return -1; \
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++done; \
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} while (0)
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#define PRINT(ptr, wptr, len) \
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do \
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{ \
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size_t outlen = (len); \
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if (wide) \
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while (outlen-- > 0) \
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outchar (*wptr++); \
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else \
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while (outlen-- > 0) \
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outchar (*ptr++); \
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} while (0)
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#define PADN(ch, len) \
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do \
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{ \
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if (PAD (fp, ch, len) != len) \
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return -1; \
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done += len; \
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} \
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while (0)
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#ifndef MIN
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# define MIN(a,b) ((a)<(b)?(a):(b))
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#endif
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int
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__printf_fphex (FILE *fp,
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const struct printf_info *info,
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const void *const *args)
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{
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/* The floating-point value to output. */
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union
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{
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union ieee754_double dbl;
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long double ldbl;
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#if __HAVE_DISTINCT_FLOAT128
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_Float128 flt128;
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#endif
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}
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fpnum;
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/* Locale-dependent representation of decimal point. */
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const char *decimal;
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wchar_t decimalwc;
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/* "NaN" or "Inf" for the special cases. */
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const char *special = NULL;
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const wchar_t *wspecial = NULL;
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/* Buffer for the generated number string for the mantissa. The
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maximal size for the mantissa is 128 bits. */
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char numbuf[32];
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char *numstr;
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char *numend;
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wchar_t wnumbuf[32];
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wchar_t *wnumstr;
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wchar_t *wnumend;
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int negative;
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/* The maximal exponent of two in decimal notation has 5 digits. */
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char expbuf[5];
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char *expstr;
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wchar_t wexpbuf[5];
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wchar_t *wexpstr;
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int expnegative;
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int exponent;
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/* Non-zero is mantissa is zero. */
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int zero_mantissa;
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/* The leading digit before the decimal point. */
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char leading;
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/* Precision. */
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int precision = info->prec;
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/* Width. */
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int width = info->width;
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/* Number of characters written. */
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int done = 0;
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/* Nonzero if this is output on a wide character stream. */
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int wide = info->wide;
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/* Figure out the decimal point character. */
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if (info->extra == 0)
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{
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decimal = _NL_CURRENT (LC_NUMERIC, DECIMAL_POINT);
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decimalwc = _NL_CURRENT_WORD (LC_NUMERIC, _NL_NUMERIC_DECIMAL_POINT_WC);
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}
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else
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{
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decimal = _NL_CURRENT (LC_MONETARY, MON_DECIMAL_POINT);
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decimalwc = _NL_CURRENT_WORD (LC_MONETARY,
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_NL_MONETARY_DECIMAL_POINT_WC);
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}
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/* The decimal point character must never be zero. */
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assert (*decimal != '\0' && decimalwc != L'\0');
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#define PRINTF_FPHEX_FETCH(FLOAT, VAR) \
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{ \
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(VAR) = *(const FLOAT *) args[0]; \
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\
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/* Check for special values: not a number or infinity. */ \
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if (isnan (VAR)) \
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{ \
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if (isupper (info->spec)) \
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{ \
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special = "NAN"; \
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wspecial = L"NAN"; \
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} \
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else \
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{ \
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special = "nan"; \
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wspecial = L"nan"; \
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} \
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} \
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else \
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{ \
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if (isinf (VAR)) \
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{ \
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if (isupper (info->spec)) \
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{ \
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special = "INF"; \
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wspecial = L"INF"; \
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} \
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else \
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{ \
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special = "inf"; \
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wspecial = L"inf"; \
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} \
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} \
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} \
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negative = signbit (VAR); \
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}
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/* Fetch the argument value. */
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#if __HAVE_DISTINCT_FLOAT128
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if (info->is_binary128)
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PRINTF_FPHEX_FETCH (_Float128, fpnum.flt128)
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else
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#endif
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#ifndef __NO_LONG_DOUBLE_MATH
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if (info->is_long_double && sizeof (long double) > sizeof (double))
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PRINTF_FPHEX_FETCH (long double, fpnum.ldbl)
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else
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#endif
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PRINTF_FPHEX_FETCH (double, fpnum.dbl.d)
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#undef PRINTF_FPHEX_FETCH
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if (special)
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{
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int width = info->width;
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if (negative || info->showsign || info->space)
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--width;
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width -= 3;
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if (!info->left && width > 0)
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PADN (' ', width);
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if (negative)
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outchar ('-');
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else if (info->showsign)
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outchar ('+');
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else if (info->space)
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outchar (' ');
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PRINT (special, wspecial, 3);
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if (info->left && width > 0)
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PADN (' ', width);
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return done;
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}
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#if __HAVE_DISTINCT_FLOAT128
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if (info->is_binary128)
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PRINT_FPHEX_FLOAT128;
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else
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#endif
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if (info->is_long_double == 0 || sizeof (double) == sizeof (long double))
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{
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/* We have 52 bits of mantissa plus one implicit digit. Since
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52 bits are representable without rest using hexadecimal
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digits we use only the implicit digits for the number before
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the decimal point. */
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unsigned long long int num;
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num = (((unsigned long long int) fpnum.dbl.ieee.mantissa0) << 32
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| fpnum.dbl.ieee.mantissa1);
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zero_mantissa = num == 0;
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if (sizeof (unsigned long int) > 6)
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{
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wnumstr = _itowa_word (num, wnumbuf + (sizeof wnumbuf) / sizeof (wchar_t), 16,
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info->spec == 'A');
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numstr = _itoa_word (num, numbuf + sizeof numbuf, 16,
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info->spec == 'A');
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}
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else
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#if (!defined __LCC__) || (__WORDSIZE == 32)
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{
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wnumstr = _itowa (num, wnumbuf + sizeof wnumbuf / sizeof (wchar_t), 16,
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info->spec == 'A');
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numstr = _itoa (num, numbuf + sizeof numbuf, 16,
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info->spec == 'A');
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}
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#else /* (! defined __LCC__) || (__WORDSIZE == 32) */
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{
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int *p = 0;
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*p = 0;
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}
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#endif /* (! defined __LCC__) || (__WORDSIZE == 32) */
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/* Fill with zeroes. */
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while (wnumstr > wnumbuf + (sizeof wnumbuf - 52) / sizeof (wchar_t))
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{
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*--wnumstr = L'0';
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*--numstr = '0';
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}
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leading = fpnum.dbl.ieee.exponent == 0 ? '0' : '1';
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exponent = fpnum.dbl.ieee.exponent;
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if (exponent == 0)
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{
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if (zero_mantissa)
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expnegative = 0;
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else
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{
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/* This is a denormalized number. */
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expnegative = 1;
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exponent = IEEE754_DOUBLE_BIAS - 1;
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}
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}
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else if (exponent >= IEEE754_DOUBLE_BIAS)
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{
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expnegative = 0;
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exponent -= IEEE754_DOUBLE_BIAS;
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}
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else
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{
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expnegative = 1;
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exponent = -(exponent - IEEE754_DOUBLE_BIAS);
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}
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}
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#ifdef PRINT_FPHEX_LONG_DOUBLE
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else
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PRINT_FPHEX_LONG_DOUBLE;
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#endif
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/* Look for trailing zeroes. */
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if (! zero_mantissa)
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{
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wnumend = array_end (wnumbuf);
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numend = array_end (numbuf);
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while (wnumend[-1] == L'0')
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{
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--wnumend;
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--numend;
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}
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bool do_round_away = false;
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if (precision != -1 && precision < numend - numstr)
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{
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char last_digit = precision > 0 ? numstr[precision - 1] : leading;
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char next_digit = numstr[precision];
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int last_digit_value = (last_digit >= 'A' && last_digit <= 'F'
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? last_digit - 'A' + 10
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: (last_digit >= 'a' && last_digit <= 'f'
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? last_digit - 'a' + 10
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: last_digit - '0'));
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int next_digit_value = (next_digit >= 'A' && next_digit <= 'F'
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? next_digit - 'A' + 10
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: (next_digit >= 'a' && next_digit <= 'f'
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? next_digit - 'a' + 10
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: next_digit - '0'));
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bool more_bits = ((next_digit_value & 7) != 0
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|| precision + 1 < numend - numstr);
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int rounding_mode = get_rounding_mode ();
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do_round_away = round_away (negative, last_digit_value & 1,
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next_digit_value >= 8, more_bits,
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rounding_mode);
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}
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if (precision == -1)
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precision = numend - numstr;
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else if (do_round_away)
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{
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/* Round up. */
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int cnt = precision;
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while (--cnt >= 0)
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{
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char ch = numstr[cnt];
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/* We assume that the digits and the letters are ordered
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like in ASCII. This is true for the rest of GNU, too. */
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if (ch == '9')
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{
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wnumstr[cnt] = (wchar_t) info->spec;
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numstr[cnt] = info->spec; /* This is tricky,
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think about it! */
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break;
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}
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else if (tolower (ch) < 'f')
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{
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++numstr[cnt];
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++wnumstr[cnt];
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break;
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}
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else
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{
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numstr[cnt] = '0';
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wnumstr[cnt] = L'0';
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}
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}
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if (cnt < 0)
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{
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/* The mantissa so far was fff...f Now increment the
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leading digit. Here it is again possible that we
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get an overflow. */
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if (leading == '9')
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leading = info->spec;
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else if (tolower (leading) < 'f')
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++leading;
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else
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{
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leading = '1';
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if (expnegative)
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{
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exponent -= 4;
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if (exponent <= 0)
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{
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exponent = -exponent;
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expnegative = 0;
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}
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}
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else
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exponent += 4;
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}
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}
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}
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}
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else
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{
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if (precision == -1)
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precision = 0;
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numend = numstr;
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wnumend = wnumstr;
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}
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/* Now we can compute the exponent string. */
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expstr = _itoa_word (exponent, expbuf + sizeof expbuf, 10, 0);
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wexpstr = _itowa_word (exponent,
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wexpbuf + sizeof wexpbuf / sizeof (wchar_t), 10, 0);
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/* Now we have all information to compute the size. */
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width -= ((negative || info->showsign || info->space)
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/* Sign. */
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+ 2 + 1 + 0 + precision + 1 + 1
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/* 0x h . hhh P ExpoSign. */
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+ ((expbuf + sizeof expbuf) - expstr));
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/* Exponent. */
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/* Count the decimal point.
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A special case when the mantissa or the precision is zero and the `#'
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is not given. In this case we must not print the decimal point. */
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if (precision > 0 || info->alt)
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width -= wide ? 1 : strlen (decimal);
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if (!info->left && info->pad != '0' && width > 0)
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PADN (' ', width);
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if (negative)
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outchar ('-');
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else if (info->showsign)
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outchar ('+');
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else if (info->space)
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outchar (' ');
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outchar ('0');
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if ('X' - 'A' == 'x' - 'a')
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outchar (info->spec + ('x' - 'a'));
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else
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outchar (info->spec == 'A' ? 'X' : 'x');
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if (!info->left && info->pad == '0' && width > 0)
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PADN ('0', width);
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outchar (leading);
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if (precision > 0 || info->alt)
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{
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const wchar_t *wtmp = &decimalwc;
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PRINT (decimal, wtmp, wide ? 1 : strlen (decimal));
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}
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if (precision > 0)
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{
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ssize_t tofill = precision - (numend - numstr);
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PRINT (numstr, wnumstr, MIN (numend - numstr, precision));
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if (tofill > 0)
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PADN ('0', tofill);
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}
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if ('P' - 'A' == 'p' - 'a')
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outchar (info->spec + ('p' - 'a'));
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else
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outchar (info->spec == 'A' ? 'P' : 'p');
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outchar (expnegative ? '-' : '+');
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PRINT (expstr, wexpstr, (expbuf + sizeof expbuf) - expstr);
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if (info->left && info->pad != '0' && width > 0)
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PADN (info->pad, width);
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return done;
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}
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