quadmath-rounding-mode.h: New.

2012-11-23  Tobias Burnus  <burnus@net-b.de>
            Joseph Myers  <joseph@codesourcery.com>

        * quadmath-rounding-mode.h: New.
        * printf/fpioconst.c: Update from GLIBC. Fix strtod rounding.
        * printf/fpioconst.h: Ditto.
        * printf/printf_fp.c (__quadmath_printf_fp): Update from GLIBC.
        Make printf respect the rounding mode for decimal output.
        * printf/printf_fphex.c (__quadmath_printf_fphex): Update from
        GLIBC.  Make printf respect the rounding mode for hex output.
        * strtod/strtod_l.c: Update from GLIBC. Make strtod respect the
        rounding mode. Fix strtod handling of underflow.


Co-Authored-By: Joseph Myers <joseph@codesourcery.com>

From-SVN: r193770

libquadmath/ChangeLog

+2012-11-23  Tobias Burnus  <burnus@net-b.de>
+	    Joseph Myers  <joseph@codesourcery.com>
+
+	* quadmath-rounding-mode.h: New.
+	* printf/fpioconst.c: Update from GLIBC. Fix strtod rounding.
+	* printf/fpioconst.h: Ditto.
+	* printf/printf_fp.c (__quadmath_printf_fp): Update from GLIBC.
+	Make printf respect the rounding mode for decimal output.
+	* printf/printf_fphex.c (__quadmath_printf_fphex): Update from
+	GLIBC.  Make printf respect the rounding mode for hex output.
+	* strtod/strtod_l.c: Update from GLIBC. Make strtod respect the
+	rounding mode. Fix strtod handling of underflow.
+
 2012-11-22  David S. Miller  <davem@davemloft.net>
 	    Tobias Burnus  <burnus@net-b.de>
 	    Joseph Myers  <joseph@codesourcery.com>

libquadmath/printf/fpioconst.h

@@ -35,6 +35,14 @@
 
 #define FLT128_MAX_10_EXP_LOG	12 /* = floor(log_2(FLT128_MAX_10_EXP)) */
 
+/* For strtoq, we need powers of 10 up to floor (log_2 (FLT128_MANT_DIG
+   - FLT128_MIN_EXP + 2)).  */
+#if !defined __NO_LONG_DOUBLE_MATH && FLT128_MAX_EXP > 1024
+# define FPIOCONST_POW10_ARRAY_SIZE    15
+#else
+# define FPIOCONST_POW10_ARRAY_SIZE    11
+#endif
+
 
 /* The array with the number representation. */
 #define __tens __quadmath_tens
@@ -50,7 +58,7 @@ struct mp_power
     int m_expo;			/* Exponent of the number 10^-(2^i-1).  */
   };
 #define _fpioconst_pow10 __quadmath_fpioconst_pow10
-extern const struct mp_power _fpioconst_pow10[FLT128_MAX_10_EXP_LOG + 1]
+extern const struct mp_power _fpioconst_pow10[FPIOCONST_POW10_ARRAY_SIZE]
      attribute_hidden;
 
 /* The constants in the array `_fpioconst_pow10' have an offset.  */

libquadmath/printf/printf_fp.c

 /* Floating point output for `printf'.
-   Copyright (C) 1995-2003, 2006-2008, 2011 Free Software Foundation, Inc.
+   Copyright (C) 1995-2012 Free Software Foundation, Inc.
 
    This file is part of the GNU C Library.
    Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995.
@@ -15,16 +15,17 @@
    Lesser General Public License for more details.
 
    You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, write to the Free
-   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
-   02111-1307 USA.  */
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
 
 #include <config.h>
 #include <float.h>
+#include <limits.h>
 #include <math.h>
 #include <string.h>
 #include <unistd.h>
 #include <stdlib.h>
+#include <stdbool.h>
 #define NDEBUG
 #include <assert.h>
 #ifdef HAVE_ERRNO_H
@@ -32,6 +33,9 @@
 #endif
 #include <stdio.h>
 #include <stdarg.h>
+#ifdef HAVE_FENV_H
+#include "quadmath-rounding-mode.h"
+#endif
 #include "quadmath-printf.h"
 #include "fpioconst.h"
 
@@ -162,7 +166,8 @@ __quadmath_printf_fp (struct __quadmath_printf_file *fp,
   MPN_VAR(tmp);
 
   /* Digit which is result of last hack_digit() call.  */
-  wchar_t digit;
+  wchar_t last_digit, next_digit;
+  bool more_bits;
 
   /* The type of output format that will be used: 'e'/'E' or 'f'.  */
   int type;
@@ -935,20 +940,14 @@ __quadmath_printf_fp (struct __quadmath_printf_file *fp,
       }
 
     /* Do rounding.  */
-    digit = hack_digit ();
-    if (digit > L_('4'))
-      {
-	wchar_t *wtp = wcp;
-
-	if (digit == L_('5')
-	    && ((*(wcp - 1) != decimalwc && (*(wcp - 1) & 1) == 0)
-		|| ((*(wcp - 1) == decimalwc && (*(wcp - 2) & 1) == 0))))
-	  {
-	    /* This is the critical case.	 */
-	    if (fracsize == 1 && frac[0] == 0)
-	      /* Rest of the number is zero -> round to even.
-		 (IEEE 754-1985 4.1 says this is the default rounding.)  */
-	      goto do_expo;
+    last_digit = wcp[-1] != decimalwc ? wcp[-1] : wcp[-2];
+    next_digit =hack_digit ();
+
+    if (next_digit != L_('0') && next_digit != L_('5'))
+      more_bits = true;
+    else if (fracsize == 1 && frac[0] == 0)
+      /* Rest of the number is zero.  */
+      more_bits = false;
     else if (scalesize == 0)
       {
 	/* Here we have to see whether all limbs are zero since no
@@ -956,12 +955,17 @@ __quadmath_printf_fp (struct __quadmath_printf_file *fp,
 	size_t lcnt = fracsize;
 	while (lcnt >= 1 && frac[lcnt - 1] == 0)
 	  --lcnt;
-		if (lcnt == 0)
-		  /* Rest of the number is zero -> round to even.
-		     (IEEE 754-1985 4.1 says this is the default rounding.)  */
-		  goto do_expo;
-	      }
+	more_bits = lcnt > 0;
       }
+    else
+      more_bits = true;
+
+#ifdef HAVE_FENV_H
+    int rounding_mode = get_rounding_mode ();
+    if (round_away (is_neg, (last_digit - L_('0')) & 1, next_digit >= L_('5'),
+		    more_bits, rounding_mode))
+      {
+	wchar_t *wtp = wcp;
 
 	if (fracdig_no > 0)
 	  {
@@ -1055,8 +1059,8 @@ __quadmath_printf_fp (struct __quadmath_printf_file *fp,
 	      }
 	  }
       }
+#endif
 
-  do_expo:
     /* Now remove unnecessary '0' at the end of the string.  */
     while (fracdig_no > fracdig_min + added_zeros && *(wcp - 1) == L_('0'))
       {
@@ -1249,15 +1253,19 @@ guess_grouping (unsigned int intdig_max, const char *grouping)
       ++groups;
       intdig_max -= *grouping++;
 
-      if (*grouping == 0)
+      if (*grouping == CHAR_MAX
+#if CHAR_MIN < 0
+	  || *grouping < 0
+#endif
+	  )
+	/* No more grouping should be done.  */
+	break;
+      else if (*grouping == 0)
 	{
 	  /* Same grouping repeats.  */
 	  groups += (intdig_max - 1) / grouping[-1];
 	  break;
 	}
-      else if (*grouping == CHAR_MAX || *grouping <= 0)
-	/* No more grouping should be done.  */
-	break;
     }
 
   return groups;
@@ -1289,12 +1297,16 @@ group_number (wchar_t *buf, wchar_t *bufend, unsigned int intdig_no,
       while (--len > 0);
       *p-- = thousands_sep;
 
-      if (*grouping == 0)
-	/* Same grouping repeats.  */
-	--grouping;
-      else if (*grouping == CHAR_MAX || *grouping <= 0)
+      if (*grouping == CHAR_MAX
+#if CHAR_MIN < 0
+	  || *grouping < 0
+#endif
+	  )
 	/* No more grouping should be done.  */
 	break;
+      else if (*grouping == 0)
+	/* Same grouping repeats.  */
+	--grouping;
     } while (intdig_no > (unsigned int) *grouping);
 
   /* Copy the remaining ungrouped digits.  */

libquadmath/printf/printf_fphex.c

 /* Print floating point number in hexadecimal notation according to ISO C99.
-   Copyright (C) 1997-2002,2004,2006 Free Software Foundation, Inc.
+   Copyright (C) 1997-2012 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
 
@@ -14,17 +14,18 @@
    Lesser General Public License for more details.
 
    You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, write to the Free
-   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
-   02111-1307 USA.  */
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
 
 #include <config.h>
 #include <math.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#include <stdbool.h>
 #define NDEBUG
 #include <assert.h>
+#include "quadmath-rounding-mode.h"
 #include "quadmath-printf.h"
 #include "_itoa.h"
 #include "_itowa.h"
@@ -116,6 +117,8 @@ __quadmath_printf_fphex (struct __quadmath_printf_file *fp,
   /* Nonzero if this is output on a wide character stream.  */
   int wide = info->wide;
 
+  bool do_round_away;
+
   /* Figure out the decimal point character.  */
 #ifdef USE_NL_LANGINFO
   if (info->extra == 0)
@@ -274,8 +277,8 @@ __quadmath_printf_fphex (struct __quadmath_printf_file *fp,
       /* Fill with zeroes.  */
       while (numstr > numbuf + (sizeof numbuf - 112 / 4))
 	{
-	  *--numstr = '0';
 	  *--wnumstr = L_('0');
+	  *--numstr = '0';
 	}
 
       leading = fpnum.ieee.exponent == 0 ? '0' : '1';
@@ -316,21 +319,35 @@ __quadmath_printf_fphex (struct __quadmath_printf_file *fp,
 	  --numend;
 	}
 
+      do_round_away = false;
+
+      if (precision != -1 && precision < numend - numstr)
+	{
+	  char last_digit = precision > 0 ? numstr[precision - 1] : leading;
+	  char next_digit = numstr[precision];
+	  int last_digit_value = (last_digit >= 'A' && last_digit <= 'F'
+				  ? last_digit - 'A' + 10
+				  : (last_digit >= 'a' && last_digit <= 'f'
+				     ? last_digit - 'a' + 10
+				     : last_digit - '0'));
+	  int next_digit_value = (next_digit >= 'A' && next_digit <= 'F'
+				  ? next_digit - 'A' + 10
+				  : (next_digit >= 'a' && next_digit <= 'f'
+				     ? next_digit - 'a' + 10
+				     : next_digit - '0'));
+	  bool more_bits = ((next_digit_value & 7) != 0
+			    || precision + 1 < numend - numstr);
+#ifdef HAVE_FENV_H
+	  int rounding_mode = get_rounding_mode ();
+	  do_round_away = round_away (negative, last_digit_value & 1,
+				      next_digit_value >= 8, more_bits,
+				      rounding_mode);
+#endif
+	}
+
       if (precision == -1)
 	precision = numend - numstr;
-      else if (precision < numend - numstr
-	       && (numstr[precision] > '8'
-		   || (('A' < '0' || 'a' < '0')
-		       && numstr[precision] < '0')
-		   || (numstr[precision] == '8'
-		       && (precision + 1 < numend - numstr
-			   /* Round to even.  */
-			   || (precision > 0
-			       && ((numstr[precision - 1] & 1)
-				   ^ (isdigit (numstr[precision - 1]) == 0)))
-			   || (precision == 0
-			       && ((leading & 1)
-				   ^ (isdigit (leading) == 0)))))))
+      else if (do_round_away)
 	{
 	  /* Round up.  */
 	  int cnt = precision;