float128: Add strfromf128

Add strfromf128 to stdlib when _Float128 support is enabled.

	* stdio-common/printf-parsemb.c (__parse_one_specmb): Initialize
	spec->info.is_binary128 to zero.
	* stdio-common/printf.h (printf_info): Add new member is_binary128
	to indicate that the number being converted to string is compatible
	with the IEC 60559 binary128 format.
	* stdio-common/printf_fp.c (__printf_fp_l): Add code to deal with
	_Float128 numbers.
	* stdio-common/printf_fphex.c: Include ieee754_float128.h and
	ldbl-128/printf_fphex_macros.h
	(__printf_fphex): Add code to deal with _Float128 numbers.
	* stdio-common/printf_size.c (__printf_size): Likewise.
	* stdio-common/vfprintf.c (process_arg): Initialize member
	info.is_binary128 to zero.
	* stdlib/fpioconst.h (FLT128_MAX_10_EXP_LOG): New macro.
	* stdlib/stdlib.h: Include bits/floatn.h for _Float128 support.
	(strfromf128): New declaration.
	* stdlib/strfrom-skeleton.c (STRFROM): Set member info.is_binary128
	to one.
	* sysdeps/ieee754/float128/Makefile: Add strfromf128.
	* sysdeps/ieee754/float128/Versions: Likewise.
	* sysdeps/ieee754/float128/strfromf128.c: New file.

6 files changed, 99 insertions, 7 deletions

diff --git a/stdio-common/printf-parsemb.c b/stdio-common/printf-parsemb.c
index edb066e..a42336c 100644
--- a/stdio-common/printf-parsemb.c
+++ b/stdio-common/printf-parsemb.c
@@ -79,6 +79,7 @@ __parse_one_specmb (const UCHAR_T *format, size_t posn,
   spec->info.extra = 0;
   spec->info.pad = ' ';
   spec->info.wide = sizeof (UCHAR_T) > 1;
+  spec->info.is_binary128 = 0;
 
   /* Test for positional argument.  */
   if (ISDIGIT (*format))
diff --git a/stdio-common/printf.h b/stdio-common/printf.h
index 5d82e8d..6b207d2 100644
--- a/stdio-common/printf.h
+++ b/stdio-common/printf.h
@@ -47,7 +47,9 @@ struct printf_info
   unsigned int is_char:1;	/* hh flag.  */
   unsigned int wide:1;		/* Nonzero for wide character streams.  */
   unsigned int i18n:1;		/* I flag.  */
-  unsigned int __pad:4;		/* Unused so far.  */
+  unsigned int is_binary128:1;	/* Floating-point argument is ABI-compatible
+				   with IEC 60559 binary128.  */
+  unsigned int __pad:3;		/* Unused so far.  */
   unsigned short int user;	/* Bits for user-installed modifiers.  */
   wchar_t pad;			/* Padding character.  */
 };
diff --git a/stdio-common/printf_fp.c b/stdio-common/printf_fp.c
index 65ee9a7..514b698 100644
--- a/stdio-common/printf_fp.c
+++ b/stdio-common/printf_fp.c
@@ -218,6 +218,9 @@ __printf_fp_l (FILE *fp, locale_t loc,
     {
       double dbl;
       __long_double_t ldbl;
+#if __HAVE_DISTINCT_FLOAT128
+      _Float128 f128;
+#endif
     }
   fpnum;
 
@@ -234,9 +237,17 @@ __printf_fp_l (FILE *fp, locale_t loc,
   const char *special = NULL;
   const wchar_t *wspecial = NULL;
 
+  /* When _Float128 is enabled in the library and ABI-distinct from long
+     double, we need mp_limbs enough for any of them.  */
+#if __HAVE_DISTINCT_FLOAT128
+# define GREATER_MANT_DIG FLT128_MANT_DIG
+#else
+# define GREATER_MANT_DIG LDBL_MANT_DIG
+#endif
   /* We need just a few limbs for the input before shifting to the right
      position.	*/
-  mp_limb_t fp_input[(LDBL_MANT_DIG + BITS_PER_MP_LIMB - 1) / BITS_PER_MP_LIMB];
+  mp_limb_t fp_input[(GREATER_MANT_DIG + BITS_PER_MP_LIMB - 1)
+		     / BITS_PER_MP_LIMB];
   /* We need to shift the contents of fp_input by this amount of bits.	*/
   int to_shift = 0;
 
@@ -371,6 +382,11 @@ __printf_fp_l (FILE *fp, locale_t loc,
   }
 
   /* Fetch the argument value.	*/
+#if __HAVE_DISTINCT_FLOAT128
+  if (info->is_binary128)
+    PRINTF_FP_FETCH (_Float128, fpnum.f128, float128, FLT128_MANT_DIG)
+  else
+#endif
 #ifndef __NO_LONG_DOUBLE_MATH
   if (info->is_long_double && sizeof (long double) > sizeof (double))
     PRINTF_FP_FETCH (long double, fpnum.ldbl, long_double, LDBL_MANT_DIG)
@@ -414,7 +430,8 @@ __printf_fp_l (FILE *fp, locale_t loc,
   {
     mp_size_t bignum_size = ((abs (p.exponent) + BITS_PER_MP_LIMB - 1)
 			     / BITS_PER_MP_LIMB
-			     + (LDBL_MANT_DIG / BITS_PER_MP_LIMB > 2 ? 8 : 4))
+			     + (GREATER_MANT_DIG / BITS_PER_MP_LIMB > 2
+				? 8 : 4))
 			    * sizeof (mp_limb_t);
     p.frac = (mp_limb_t *) alloca (bignum_size);
     p.tmp = (mp_limb_t *) alloca (bignum_size);
@@ -429,7 +446,15 @@ __printf_fp_l (FILE *fp, locale_t loc,
     {
       /* |FP| >= 8.0.  */
       int scaleexpo = 0;
-      int explog = LDBL_MAX_10_EXP_LOG;
+      int explog;
+#if __HAVE_DISTINCT_FLOAT128
+      if (info->is_binary128)
+	explog = FLT128_MAX_10_EXP_LOG;
+      else
+	explog = LDBL_MAX_10_EXP_LOG;
+#else
+      explog = LDBL_MAX_10_EXP_LOG;
+#endif
       int exp10 = 0;
       const struct mp_power *powers = &_fpioconst_pow10[explog + 1];
       int cnt_h, cnt_l, i;
@@ -463,6 +488,27 @@ __printf_fp_l (FILE *fp, locale_t loc,
 	    {
 	      if (p.scalesize == 0)
 		{
+#if __HAVE_DISTINCT_FLOAT128
+		  if ((FLT128_MANT_DIG
+			    > _FPIO_CONST_OFFSET * BITS_PER_MP_LIMB)
+			   && info->is_binary128)
+		    {
+#define _FLT128_FPIO_CONST_SHIFT \
+  (((FLT128_MANT_DIG + BITS_PER_MP_LIMB - 1) / BITS_PER_MP_LIMB) \
+   - _FPIO_CONST_OFFSET)
+		      /* 64bit const offset is not enough for
+			 IEEE 854 quad long double (_Float128).  */
+		      p.tmpsize = powers->arraysize + _FLT128_FPIO_CONST_SHIFT;
+		      memcpy (p.tmp + _FLT128_FPIO_CONST_SHIFT,
+			      &__tens[powers->arrayoff],
+			      p.tmpsize * sizeof (mp_limb_t));
+		      MPN_ZERO (p.tmp, _FLT128_FPIO_CONST_SHIFT);
+		      /* Adjust p.exponent, as scaleexpo will be this much
+			 bigger too.  */
+		      p.exponent += _FLT128_FPIO_CONST_SHIFT * BITS_PER_MP_LIMB;
+		    }
+		  else
+#endif /* __HAVE_DISTINCT_FLOAT128 */
 #ifndef __NO_LONG_DOUBLE_MATH
 		  if (LDBL_MANT_DIG > _FPIO_CONST_OFFSET * BITS_PER_MP_LIMB
 		      && info->is_long_double)
@@ -603,7 +649,15 @@ __printf_fp_l (FILE *fp, locale_t loc,
     {
       /* |FP| < 1.0.  */
       int exp10 = 0;
-      int explog = LDBL_MAX_10_EXP_LOG;
+      int explog;
+#if __HAVE_DISTINCT_FLOAT128
+      if (info->is_binary128)
+	explog = FLT128_MAX_10_EXP_LOG;
+      else
+	explog = LDBL_MAX_10_EXP_LOG;
+#else
+      explog = LDBL_MAX_10_EXP_LOG;
+#endif
       const struct mp_power *powers = &_fpioconst_pow10[explog + 1];
 
       /* Now shift the input value to its right place.	*/
diff --git a/stdio-common/printf_fphex.c b/stdio-common/printf_fphex.c
index 7b469c0..004d2aa 100644
--- a/stdio-common/printf_fphex.c
+++ b/stdio-common/printf_fphex.c
@@ -31,6 +31,14 @@
 #include <stdbool.h>
 #include <rounding-mode.h>
 
+#if __HAVE_DISTINCT_FLOAT128
+# include "ieee754_float128.h"
+# include <ldbl-128/printf_fphex_macros.h>
+# define PRINT_FPHEX_FLOAT128 \
+   PRINT_FPHEX (_Float128, fpnum.flt128, ieee854_float128, \
+		IEEE854_FLOAT128_BIAS)
+#endif
+
 /* #define NDEBUG 1*/		/* Undefine this for debugging assertions.  */
 #include <assert.h>
 
@@ -94,6 +102,9 @@ __printf_fphex (FILE *fp,
     {
       union ieee754_double dbl;
       long double ldbl;
+#if __HAVE_DISTINCT_FLOAT128
+      _Float128 flt128;
+#endif
     }
   fpnum;
 
@@ -195,6 +206,11 @@ __printf_fphex (FILE *fp,
   }
 
   /* Fetch the argument value.	*/
+#if __HAVE_DISTINCT_FLOAT128
+  if (info->is_binary128)
+    PRINTF_FPHEX_FETCH (_Float128, fpnum.flt128)
+  else
+#endif
 #ifndef __NO_LONG_DOUBLE_MATH
   if (info->is_long_double && sizeof (long double) > sizeof (double))
     PRINTF_FPHEX_FETCH (long double, fpnum.ldbl)
@@ -230,6 +246,11 @@ __printf_fphex (FILE *fp,
       return done;
     }
 
+#if __HAVE_DISTINCT_FLOAT128
+  if (info->is_binary128)
+    PRINT_FPHEX_FLOAT128;
+  else
+#endif
   if (info->is_long_double == 0 || sizeof (double) == sizeof (long double))
     {
       /* We have 52 bits of mantissa plus one implicit digit.  Since
diff --git a/stdio-common/printf_size.c b/stdio-common/printf_size.c
index bc953dc..e20b76c 100644
--- a/stdio-common/printf_size.c
+++ b/stdio-common/printf_size.c
@@ -104,6 +104,9 @@ __printf_size (FILE *fp, const struct printf_info *info,
     {
       union ieee754_double dbl;
       long double ldbl;
+#if __HAVE_DISTINCT_FLOAT128
+      _Float128 f128;
+#endif
     }
   fpnum;
   const void *ptr = &fpnum;
@@ -144,6 +147,11 @@ __printf_size (FILE *fp, const struct printf_info *info,
   }
 
   /* Fetch the argument value.	*/
+#if __HAVE_DISTINCT_FLOAT128
+  if (info->is_binary128)
+    PRINTF_SIZE_FETCH (_Float128, fpnum.f128)
+  else
+#endif
 #ifndef __NO_LONG_DOUBLE_MATH
   if (info->is_long_double && sizeof (long double) > sizeof (double))
     PRINTF_SIZE_FETCH (long double, fpnum.ldbl)
diff --git a/stdio-common/vfprintf.c b/stdio-common/vfprintf.c
index 2cf7c8a..b8c87a5 100644
--- a/stdio-common/vfprintf.c
+++ b/stdio-common/vfprintf.c
@@ -770,7 +770,8 @@ static const uint8_t jump_table[] =
 					.pad = pad,			      \
 					.extra = 0,			      \
 					.i18n = use_outdigits,		      \
-					.wide = sizeof (CHAR_T) != 1 };	      \
+					.wide = sizeof (CHAR_T) != 1,	      \
+					.is_binary128 = 0};		      \
 									      \
 	    if (is_long_double)						      \
 	      the_arg.pa_long_double = va_arg (ap, long double);	      \
@@ -788,6 +789,8 @@ static const uint8_t jump_table[] =
 		fspec->data_arg_type = PA_DOUBLE;			      \
 		fspec->info.is_long_double = 0;				      \
 	      }								      \
+	    /* Not supported by *printf functions.  */			      \
+	    fspec->info.is_binary128 = 0;				      \
 									      \
 	    function_done = __printf_fp (s, &fspec->info, &ptr);	      \
 	  }								      \
@@ -827,7 +830,8 @@ static const uint8_t jump_table[] =
 					.group = group,			      \
 					.pad = pad,			      \
 					.extra = 0,			      \
-					.wide = sizeof (CHAR_T) != 1 };	      \
+					.wide = sizeof (CHAR_T) != 1,	      \
+					.is_binary128 = 0};		      \
 									      \
 	    if (is_long_double)						      \
 	      the_arg.pa_long_double = va_arg (ap, long double);	      \
@@ -842,6 +846,8 @@ static const uint8_t jump_table[] =
 	    ptr = (const void *) &args_value[fspec->data_arg];		      \
 	    if (__ldbl_is_dbl)						      \
 	      fspec->info.is_long_double = 0;				      \
+	    /* Not supported by *printf functions.  */			      \
+	    fspec->info.is_binary128 = 0;				      \
 									      \
 	    function_done = __printf_fphex (s, &fspec->info, &ptr);	      \
 	  }								      \