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-rw-r--r--sysdeps/libm-ieee754/s_lround.c143
1 files changed, 22 insertions, 121 deletions
diff --git a/sysdeps/libm-ieee754/s_lround.c b/sysdeps/libm-ieee754/s_lround.c
index 974dbde050..a6468ba78a 100644
--- a/sysdeps/libm-ieee754/s_lround.c
+++ b/sysdeps/libm-ieee754/s_lround.c
@@ -1,4 +1,4 @@
-/* Round long double value to long int.
+/* Round double value to long int.
    Copyright (C) 1997 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
@@ -23,13 +23,8 @@
 #include "math_private.h"
 
 
-#ifdef NO_LONG_DOUBLE
-/* The `long double' is in fact the IEEE `double' type.  */
-
-/* This code does not presently work.  */
-
 long int
-__lround (long double x)
+__lround (double x)
 {
   int32_t j0;
   u_int32_t i1, i0;
@@ -40,138 +35,44 @@ __lround (long double x)
   j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;
   sign = (i0 & 0x80000000) != 0 ? -1 : 1;
   i0 &= 0xfffff;
+  i0 |= 0x100000;
+
   if (j0 < 20)
     {
       if (j0 < 0)
-	result = j0 < -1 ? 0 : sign;
+	return j0 < -1 ? 0 : sign;
       else
 	{
-	  u_int32_t i = 0xfffff >> j0;
-	  i0 |= 0x100000;
-	  if (((i0 & i) | i1) == 0)
-	    result = i0 >> j0;
-	  else
-	    /* X is not integral.  */
-	    result = (i0 + (0x80000 >> j0)) >> (20 - j0);
+	  i0 += 0x80000 >> j0;
+
+	  result = i0 >> (20 - j0);
 	}
     }
-  else if (j0 >= 8 * sizeof (long int) || j0 > 51)
-    {
-      /* The number is too large.  It is left implementation defined
-	 what happens.  */
-      return (long int) x;
-    }
-  else
+  else if (j0 < (int32_t) (8 * sizeof (long int)))
     {
-      u_int32_t i = ((u_int32_t) (0xffffffff)) >> (j0 - 20);
-      if ((i1 & i) != 0)
+      if (j0 >= 52)
+	result = ((long int) i0 << (j0 - 20)) | (i1 << (j0 - 52));
+      else
 	{
-	  /* x is not integral.  */
 	  u_int32_t j = i1 + (0x80000000 >> (j0 - 20));
 	  if (j < i1)
-	    {
-	      j = i0 + 1;
-	      if ((j & 0xfffff) == 0)
-		{
-		  if (sizeof (long int) <= 4)
-		    /* Overflow.  */
-		    result = (long int) x;
-		  else
-		    result = 1l << (j0 + 1);
-		}
-	      else
-		result = (long int) ((i0 & 0xfffff) | 0x100000) << (j0 - 31);
-	    }
-	  else
-	    {
-	      result = (long int) ((i0 & 0xfffff) | 0x100000) << (j0 - 31);
-	      if (sizeof (long int) > 4 && j0 > 31)
-		result |= j >> (63 - j0);
-	    }
-	}
-      else
-	{
-	  result = (long int) ((i0 & 0xfffff) | 0x100000) << (j0 - 31);
-	  if (sizeof (long int) > 4 && j0 > 31)
-	    result |= i1 >> (63 - j0);
-	}
-    }
-
-  return sign * result;
-}
-#else
-long int
-__lround (long double x)
-{
-  int32_t j0;
-  u_int32_t se, i1, i0;
-  long int result;
+	    ++i0;
 
-  GET_LDOUBLE_WORDS (se, i0, i1, x);
-  j0 = (se & 0x7fff) - 0x3fff;
-  if (j0 < 31)
-    {
-      if (j0 < 0)
-	result = j0 < -1 ? 0 : 1;
-      else
-	{
-	  u_int32_t i = 0x7fffffff >> j0;
-	  if (((i0 & i) | i1) == 0)
-	    result = (long int) i0 >> j0;
-	  else
-	    {
-	      /* X is not integral.  */
-	      u_int32_t j = i0 + (0x40000000 >> j0);
-              if (j < i0)
-		result = 0x80000000l >> (30 - j0);
-	      else
-		result = j >> (31 - j0);
-	    }
+	  result = ((long int) i0 << (j0 - 20)) | (j >> (52 - j0));
 	}
     }
-  else if ((unsigned int) j0 >= 8 * sizeof (long int) || j0 > 62)
+  else
     {
       /* The number is too large.  It is left implementation defined
 	 what happens.  */
-      result = (long int) x;
-    }
-  else
-    {
-      u_int32_t i = ((u_int32_t) (0xffffffff)) >> (j0 - 31);
-      if ((i1 & i) != 0)
-	{
-	  /* x is not integral.  */
-	  u_int32_t j = i1 + (0x80000000 >> (j0 - 31));
-	  if (j < i1)
-	    {
-	      j = i0 + 1;
-	      if (j == 0)
-		{
-		  if (sizeof (long int) <= 4)
-		    /* Overflow.  */
-		    result = (long int) x;
-		  else
-		    result = 1l << (j0 + 1);
-		}
-	      else
-		result = (long int) i0 << (j0 - 31);
-	    }
-	  else
-	    {
-	      result = (long int) i0 << (j0 - 31);
-	      if (sizeof (long int) > 4 && j0 > 31)
-		result |= j >> (63 - j0);
-	    }
-	}
-      else
-	{
-	  result = (long int) i0 << (j0 - 31);
-	  if (sizeof (long int) > 4 && j0 > 31)
-	    result |= i1 >> (63 - j0);
-	}
+      return (long int) x;
     }
 
-  return se & 0x8000 ? -result : result;
+  return sign * result;
 }
-#endif
+
 weak_alias (__lround, lround)
+#ifdef NO_LONG_DOUBLE
+strong_alias (__lround, __lroundl)
+weak_alias (__lround, lroundl)
+#endif