builtin-types.def (BT_FN_FLOAT_CONST_STRING): New.

gcc/
        * builtin-types.def (BT_FN_FLOAT_CONST_STRING): New.
        (BT_FN_DOUBLE_CONST_STRING, BT_FN_LONG_DOUBLE_CONST_STRING): New.
        * builtins.def (__builtin_nan, __builtin_nanf, __builtin_nanl): New.
        (__builtin_nans, __builtin_nansf, __builtin_nansl): New.
        * builtins.c (fold_builtin_nan): New.
        (fold_builtin): Call it.
        * real.c (real_nan): Parse a non-empty string.
        (round_for_format): Fix NaN significand truncation.
        * real.h (real_nan): Return bool.
        * doc/extend.texi: Document new builtins.

libstdc++/
        * include/std/std_limits.h (__glibcpp_f32_QNaN_bytes,
        __glibcpp_f32_has_QNaN, __glibcpp_f32_SNaN_bytes,
        __glibcpp_f32_has_SNaN, __glibcpp_f64_QNaN_bytes,
        __glibcpp_f64_has_QNaN, __glibcpp_f64_SNaN_bytes,
        __glibcpp_f64_has_SNaN, __glibcpp_f80_QNaN_bytes,
        __glibcpp_f80_has_QNaN, __glibcpp_f80_SNaN_bytes,
        __glibcpp_f80_has_SNaN, __glibcpp_f96_QNaN_bytes,
        __glibcpp_f96_has_QNaN, __glibcpp_f96_SNaN_bytes,
        __glibcpp_f96_has_SNaN, __glibcpp_f128_QNaN_bytes,
        __glibcpp_f128_has_QNaN, __glibcpp_f128_SNaN_bytes,
        __glibcpp_f128_has_SNaN, __glibcpp_float_QNaN_bytes,
        __glibcpp_float_has_QNaN, __glibcpp_float_SNaN_bytes,
        __glibcpp_float_has_SNaN, __glibcpp_double_QNaN_bytes,
        __glibcpp_double_has_QNaN, __glibcpp_double_SNaN_bytes,
        __glibcpp_double_has_SNaN, __glibcpp_long_double_QNaN_bytes,
        __glibcpp_long_double_has_QNaN, __glibcpp_long_double_SNaN_bytes,
        __glibcpp_long_double_has_SNaN): Remove.
        (__glibcpp_f128_is_iec559): True if IEEE.
        (__glibcpp_float_QNaN, __glibcpp_float_SNaN): Remove.
        (__glibcpp_double_QNaN, __glibcpp_double_SNaN): Remove.
        (__glibcpp_long_double_QNaN, __glibcpp_long_double_SNaN): Remove.
        (std::numeric_limits<float>::has_quiet_NaN): Use __builtin_nanf.
        (std::numeric_limits<float>::has_signaling_NaN): Mirror has_quiet_NaN.
        (std::numeric_limits<float>::quiet_NaN): Use __builtin_nanf.
        (std::numeric_limits<float>::signaling_NaN): Use __builtin_nansf.
        (std::numeric_limits<double>): Similarly.
        (std::numeric_limits<long double>): Similarly.
        * src/limits.cc (__glibcpp_float_QNaN, __glibcpp_float_SNaN): Remove.
        (__glibcpp_double_QNaN, __glibcpp_double_SNaN): Remove.
        (__glibcpp_long_double_QNaN, __glibcpp_long_double_SNaN): Remove.

        * testsuite/18_support/numeric_limits.cc (test_infinity): New.
        (test_denorm_min, test_qnan, test_is_iec559): New.

From-SVN: r57221

7 files changed, 209 insertions, 8 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 10ff912..85a32f9 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,16 @@
+2002-09-16  Richard Henderson  <rth@redhat.com>
+
+	* builtin-types.def (BT_FN_FLOAT_CONST_STRING): New.
+	(BT_FN_DOUBLE_CONST_STRING, BT_FN_LONG_DOUBLE_CONST_STRING): New.
+	* builtins.def (__builtin_nan, __builtin_nanf, __builtin_nanl): New.
+	(__builtin_nans, __builtin_nansf, __builtin_nansl): New.
+	* builtins.c (fold_builtin_nan): New.
+	(fold_builtin): Call it.
+	* real.c (real_nan): Parse a non-empty string.
+	(round_for_format): Fix NaN significand truncation.
+	* real.h (real_nan): Return bool.
+	* doc/extend.texi: Document new builtins.
+
 2002-09-16  Jason Merrill  <jason@redhat.com>
 	    Danny Smith  <dannysmith@users.sourceforge.net>
 
diff --git a/gcc/builtin-types.def b/gcc/builtin-types.def
index 89bd500..be52392 100644
--- a/gcc/builtin-types.def
+++ b/gcc/builtin-types.def
@@ -117,6 +117,10 @@ DEF_FUNCTION_TYPE_1 (BT_FN_INT_CONST_STRING, BT_INT, BT_CONST_STRING)
 DEF_FUNCTION_TYPE_1 (BT_FN_PTR_PTR, BT_PTR, BT_PTR)
 DEF_FUNCTION_TYPE_1 (BT_FN_VOID_VALIST_REF, BT_VOID, BT_VALIST_REF)
 DEF_FUNCTION_TYPE_1 (BT_FN_VOID_INT, BT_VOID, BT_INT)
+DEF_FUNCTION_TYPE_1 (BT_FN_FLOAT_CONST_STRING, BT_FLOAT, BT_CONST_STRING)
+DEF_FUNCTION_TYPE_1 (BT_FN_DOUBLE_CONST_STRING, BT_DOUBLE, BT_CONST_STRING)
+DEF_FUNCTION_TYPE_1 (BT_FN_LONG_DOUBLE_CONST_STRING,
+		     BT_LONG_DOUBLE, BT_CONST_STRING)
 
 DEF_FUNCTION_TYPE_2 (BT_FN_VOID_PTR_INT, BT_VOID, BT_PTR, BT_INT)
 DEF_FUNCTION_TYPE_2 (BT_FN_STRING_STRING_CONST_STRING, 
diff --git a/gcc/builtins.c b/gcc/builtins.c
index 2e7cd53..25fadab 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -149,6 +149,7 @@ static rtx expand_builtin_expect	PARAMS ((tree, rtx));
 static tree fold_builtin_constant_p	PARAMS ((tree));
 static tree fold_builtin_classify_type	PARAMS ((tree));
 static tree fold_builtin_inf		PARAMS ((tree, int));
+static tree fold_builtin_nan		PARAMS ((tree, tree, int));
 static tree build_function_call_expr	PARAMS ((tree, tree));
 static int validate_arglist		PARAMS ((tree, ...));
 
@@ -4149,6 +4150,28 @@ fold_builtin_inf (type, warn)
   return build_real (type, real);
 }
 
+/* Fold a call to __builtin_nan or __builtin_nans.  */
+
+static tree
+fold_builtin_nan (arglist, type, quiet)
+     tree arglist, type;
+     int quiet;
+{
+  REAL_VALUE_TYPE real;
+  const char *str;
+
+  if (!validate_arglist (arglist, POINTER_TYPE, VOID_TYPE))
+    return 0;
+  str = c_getstr (TREE_VALUE (arglist));
+  if (!str)
+    return 0;
+
+  if (!real_nan (&real, str, quiet, TYPE_MODE (type)))
+    return 0;
+
+  return build_real (type, real);
+}
+
 /* Used by constant folding to eliminate some builtin calls early.  EXP is
    the CALL_EXPR of a call to a builtin function.  */
 
@@ -4190,6 +4213,16 @@ fold_builtin (exp)
     case BUILT_IN_HUGE_VALL:
       return fold_builtin_inf (TREE_TYPE (TREE_TYPE (fndecl)), false);
 
+    case BUILT_IN_NAN:
+    case BUILT_IN_NANF:
+    case BUILT_IN_NANL:
+      return fold_builtin_nan (arglist, TREE_TYPE (TREE_TYPE (fndecl)), true);
+
+    case BUILT_IN_NANS:
+    case BUILT_IN_NANSF:
+    case BUILT_IN_NANSL:
+      return fold_builtin_nan (arglist, TREE_TYPE (TREE_TYPE (fndecl)), false);
+
     default:
       break;
     }
diff --git a/gcc/builtins.def b/gcc/builtins.def
index 60acc10..8a3dac3 100644
--- a/gcc/builtins.def
+++ b/gcc/builtins.def
@@ -427,6 +427,32 @@ DEF_GCC_BUILTIN(BUILT_IN_HUGE_VALL,
 		BT_FN_LONG_DOUBLE,
 		ATTR_CONST_NOTHROW_LIST)
 
+DEF_LIB_BUILTIN(BUILT_IN_NAN,
+		"__builtin_nan",
+		BT_FN_DOUBLE_CONST_STRING,
+		ATTR_CONST_NOTHROW_LIST)
+DEF_LIB_BUILTIN(BUILT_IN_NANF,
+		"__builtin_nanf",
+		BT_FN_FLOAT_CONST_STRING,
+		ATTR_CONST_NOTHROW_LIST)
+DEF_LIB_BUILTIN(BUILT_IN_NANL,
+		"__builtin_nanl",
+		BT_FN_LONG_DOUBLE_CONST_STRING,
+		ATTR_CONST_NOTHROW_LIST)
+
+DEF_LIB_BUILTIN(BUILT_IN_NANS,
+		"__builtin_nans",
+		BT_FN_DOUBLE_CONST_STRING,
+		ATTR_CONST_NOTHROW_LIST)
+DEF_LIB_BUILTIN(BUILT_IN_NANSF,
+		"__builtin_nansf",
+		BT_FN_FLOAT_CONST_STRING,
+		ATTR_CONST_NOTHROW_LIST)
+DEF_LIB_BUILTIN(BUILT_IN_NANSL,
+		"__builtin_nansl",
+		BT_FN_LONG_DOUBLE_CONST_STRING,
+		ATTR_CONST_NOTHROW_LIST)
+
 DEF_GCC_BUILTIN(BUILT_IN_SAVEREGS,
 		"__builtin_saveregs",
 		BT_FN_PTR_VAR,
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index e9fef25..d3e3ece 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -4863,6 +4863,44 @@ Similar to @code{__builtin_inf}, except the return
 type is @code{long double}.
 @end deftypefn
 
+@deftypefn {Built-in Function} double __builtin_nan (const char *str)
+This is an implementation of the ISO C99 function @code{nan}.
+
+Since ISO C99 defines this function in terms of @code{strtod}, which we
+do not implement, a desription of the parsing is in order.  The string
+is parsed as by @code{strtol}; that is, the base is recognized by
+leading @samp{0} or @samp{0x} prefixes.  The number parsed is placed
+in the significand such that the least significant bit of the number
+is at the least significant bit of the significand.  The number is 
+truncated to fit the significand field provided.  The significand is
+forced to be a quiet NaN.
+
+This function, if given a string literal, is evaluated early enough
+that it is considered a compile-time constant.
+@end deftypefn
+
+@deftypefn {Built-in Function} float __builtin_nanf (const char *str)
+Similar to @code{__builtin_nan}, except the return type is @code{float}.
+@end deftypefn
+
+@deftypefn {Built-in Function} long double __builtin_nanl (const char *str)
+Similar to @code{__builtin_nan}, except the return type is @code{long double}.
+@end deftypefn
+
+@deftypefn {Built-in Function} double __builtin_nans (const char *str)
+Similar to @code{__builtin_nan}, except the significand is forced 
+to be a signaling NaN.  The @code{nans} function is proposed by
+@uref{http://std.dkuug.dk/JTC1/SC22/WG14/www/docs/n965.htm,,WG14 N956}.
+@end deftypefn
+
+@deftypefn {Built-in Function} float __builtin_nansf (const char *str)
+Similar to @code{__builtin_nans}, except the return type is @code{float}.
+@end deftypefn
+
+@deftypefn {Built-in Function} long double __builtin_nansl (const char *str)
+Similar to @code{__builtin_nans}, except the return type is @code{long double}.
+@end deftypefn
+
 @node Target Builtins
 @section Built-in Functions Specific to Particular Target Machines
 
diff --git a/gcc/real.c b/gcc/real.c
index 61ab02c..5859f0f 100644
--- a/gcc/real.c
+++ b/gcc/real.c
@@ -1946,16 +1946,22 @@ real_inf (tr)
 
 /* Fills R with a NaN whose significand is described by STR.  If QUIET,
    we force a QNaN, else we force an SNaN.  The string, if not empty,
-   is parsed as a number and placed in the significand.  */
+   is parsed as a number and placed in the significand.  Return true
+   if the string was successfully parsed.  */
 
-void
+bool
 real_nan (tr, str, quiet, mode)
      REAL_VALUE_TYPE *tr;
      const char *str;
      int quiet;
-     enum machine_mode mode ATTRIBUTE_UNUSED;
+     enum machine_mode mode;
 {
   struct real_value *r = (struct real_value *) tr;
+  const struct real_format *fmt;
+
+  fmt = fmt_for_mode[mode - QFmode];
+  if (fmt == NULL)
+    abort ();
 
   if (*str == 0)
     {
@@ -1965,8 +1971,89 @@ real_nan (tr, str, quiet, mode)
 	get_canonical_snan (r, 0);
     }
   else
-    /* FIXME */
-    abort ();
+    {
+      int base = 10, d;
+      bool neg = false;
+
+      memset (r, 0, sizeof (*r));
+      r->class = rvc_nan;
+
+      /* Parse akin to strtol into the significand of R.  */
+
+      while (ISSPACE (*str))
+	str++;
+      if (*str == '-')
+	str++, neg = true;
+      else if (*str == '+')
+	str++;
+      if (*str == '0')
+	{
+	  if (*++str == 'x')
+	    str++, base = 16;
+	  else
+	    base = 8;
+	}
+
+      while ((d = hex_value (*str)) < base)
+	{
+	  struct real_value u;
+
+	  switch (base)
+	    {
+	    case 8:
+	      lshift_significand (r, r, 3);
+	      break;
+	    case 16:
+	      lshift_significand (r, r, 4);
+	      break;
+	    case 10:
+	      lshift_significand_1 (&u, r);
+	      lshift_significand (r, r, 3);
+	      add_significands (r, r, &u);
+	      break;
+	    default:
+	      abort ();
+	    }
+
+	  get_zero (&u, 0);
+	  u.sig[0] = d;
+	  add_significands (r, r, &u);
+
+	  str++;
+	}
+
+      /* Must have consumed the entire string for success.  */
+      if (*str != 0)
+	return false;
+
+      /* Shift the significand into place such that the bits
+	 are in the most significant bits for the format.  */
+      lshift_significand (r, r, SIGNIFICAND_BITS - fmt->p);
+
+      /* Our MSB is always unset for NaNs.  */
+      r->sig[SIGSZ-1] &= ~SIG_MSB;
+
+      /* Force quiet or signalling NaN.  */
+      if (quiet)
+	r->sig[SIGSZ-1] |= SIG_MSB >> 1;
+      else
+	r->sig[SIGSZ-1] &= ~(SIG_MSB >> 1);
+
+      /* Force at least one bit of the significand set.  */
+      for (d = 0; d < SIGSZ; ++d)
+	if (r->sig[d])
+	  break;
+      if (d == SIGSZ)
+	r->sig[SIGSZ-1] |= SIG_MSB >> 2;
+
+      /* Our intermediate format forces QNaNs to have MSB-1 set.
+	 If the target format has QNaNs with the top bit unset,
+	 mirror the output routines and invert the top two bits.  */
+      if (!fmt->qnan_msb_set)
+	r->sig[SIGSZ-1] ^= (SIG_MSB >> 1) | (SIG_MSB >> 2);
+    }
+
+  return true;
 }
 
 /* Fills R with 2**N.  */
@@ -2023,7 +2110,7 @@ round_for_format (fmt, r)
       return;
 
     case rvc_nan:
-      clear_significand_below (r, np2 + 1);
+      clear_significand_below (r, np2);
 
       /* If we've cleared the entire significand, we need one bit
 	 set for this to continue to be a NaN.  */
@@ -2031,7 +2118,7 @@ round_for_format (fmt, r)
 	if (r->sig[i])
 	  break;
       if (i == SIGSZ)
-	r->sig[SIGSZ-1] = SIG_MSB >> 1;
+	r->sig[SIGSZ-1] = SIG_MSB >> 2;
       return;
 
     case rvc_normal:
diff --git a/gcc/real.h b/gcc/real.h
index 31fa561..24df216 100644
--- a/gcc/real.h
+++ b/gcc/real.h
@@ -143,7 +143,7 @@ extern void real_from_target	PARAMS ((REAL_VALUE_TYPE *, const long *,
 
 extern void real_inf		PARAMS ((REAL_VALUE_TYPE *));
 
-extern void real_nan		PARAMS ((REAL_VALUE_TYPE *, const char *,
+extern bool real_nan		PARAMS ((REAL_VALUE_TYPE *, const char *,
 					 int, enum machine_mode));
 
 extern void real_2expN		PARAMS ((REAL_VALUE_TYPE *, int));