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-rw-r--r--stdlib/drand48-iter.c57
-rw-r--r--stdlib/drand48_r.c9
-rw-r--r--stdlib/erand48_r.c42
3 files changed, 46 insertions, 62 deletions
diff --git a/stdlib/drand48-iter.c b/stdlib/drand48-iter.c
index 967c404706..65e78eb3ce 100644
--- a/stdlib/drand48-iter.c
+++ b/stdlib/drand48-iter.c
@@ -20,7 +20,7 @@ Boston, MA 02111-1307, USA.  */
 #include <errno.h>
 #include <stdlib.h>
 #include <limits.h>
-
+#include <sys/types.h>
 
 /* Global state for non-reentrent functions.  */
 struct drand48_data __libc_drand48_data;
@@ -31,12 +31,7 @@ __drand48_iterate (xsubi, buffer)
      unsigned short int xsubi[3];
      struct drand48_data *buffer;
 {
-  /* Be generous for the arguments, detect some errors.  */
-  if (xsubi == NULL || buffer == NULL)
-    {
-      errno = EFAULT;
-      return -1;
-    }
+  u_int64_t X, a, result;
 
   /* Initialize buffer, if not yet done.  */
   if (!buffer->init)
@@ -58,42 +53,28 @@ __drand48_iterate (xsubi, buffer)
      48 bits.  Because we compute the modulus it does not care how
      many bits really are computed.  */
 
-  if (sizeof (long int) >= 6)
+  if (sizeof (unsigned short int) == 2)
     {
-      /* The `long' data type is sufficent.  */
-      unsigned long int X, a, result;
+      X = (xsubi[2] << 16 | xsubi[1]) << 16 | xsubi[0];
+      a = (buffer->a[2] << 16 | buffer->a[1]) << 16 | buffer->a[0];
 
-#define ONE_STEP							    \
-      if (sizeof (unsigned short int) == 2)				    \
-	{								    \
-	  X = (xsubi[2] << 16 | xsubi[1]) << 16 | xsubi[0];		    \
-	  a = (buffer->a[2] << 16 | buffer->a[1]) << 16 | buffer->a[0];	    \
-									    \
-	  result = X * a + buffer->c;					    \
-									    \
-	  xsubi[0] = result & 0xffff;					    \
-	  result >>= 16;						    \
-	  xsubi[1] = result & 0xffff;					    \
-	  result >>= 16;						    \
-	  xsubi[2] = result & 0xffff;					    \
-	}								    \
-      else								    \
-	{								    \
-	  X = xsubi[2] << 16 | xsubi[1] >> 16;				    \
-	  a = buffer->a[2] << 16 | buffer->a[1] >> 16;			    \
-									    \
-	  result = X * a + buffer->c;					    \
-									    \
-	  xsubi[0] = result >> 16 & 0xffffffffl;			    \
-	  xsubi[1] = result << 16 & 0xffff0000l;			    \
-	}
-      ONE_STEP;
+      result = X * a + buffer->c;
+
+      xsubi[0] = result & 0xffff;
+      result >>= 16;
+      xsubi[1] = result & 0xffff;
+      result >>= 16;
+      xsubi[2] = result & 0xffff;
     }
   else
     {
-      /* We have to use the `long long' data type.  */
-      unsigned long long int X, a, result;
-      ONE_STEP;
+      X = xsubi[2] << 16 | xsubi[1] >> 16;
+      a = buffer->a[2] << 16 | buffer->a[1] >> 16;
+
+      result = X * a + buffer->c;
+
+      xsubi[0] = result >> 16 & 0xffffffffl;
+      xsubi[1] = result << 16 & 0xffff0000l;
     }
 
   return 0;
diff --git a/stdlib/drand48_r.c b/stdlib/drand48_r.c
index eaba057fa1..3b774863e9 100644
--- a/stdlib/drand48_r.c
+++ b/stdlib/drand48_r.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1995 Free Software Foundation, Inc.
+/* Copyright (C) 1995, 1996 Free Software Foundation, Inc.
 This file is part of the GNU C Library.
 Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, August 1995.
 
@@ -26,12 +26,5 @@ drand48_r (buffer, result)
      struct drand48_data *buffer;
      double *result;
 {
-  /* be generous for the arguments, detect some errors.  */
-  if (buffer == NULL)
-    {
-      errno = EFAULT;
-      return -1;
-    }
-
   return erand48_r (buffer->X, buffer, result);
 }
diff --git a/stdlib/erand48_r.c b/stdlib/erand48_r.c
index 86d2f734d9..ab41474aca 100644
--- a/stdlib/erand48_r.c
+++ b/stdlib/erand48_r.c
@@ -17,9 +17,15 @@ License along with the GNU C Library; see the file COPYING.LIB.  If
 not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 Boston, MA 02111-1307, USA.  */
 
-#include <errno.h>
-#include <math.h>
 #include <stdlib.h>
+#include "gmp.h"
+#include "gmp-mparam.h"
+#include <float.h>
+
+
+/* Function to construct a floating point number from an MP integer
+   containing the fraction bits, a base 2 exponent, and a sign flag.  */
+extern double __mpn_construct_double (mp_srcptr mpn, int exponent, int neg);
 
 int
 erand48_r (xsubi, buffer, result)
@@ -27,26 +33,30 @@ erand48_r (xsubi, buffer, result)
      struct drand48_data *buffer;
      double *result;
 {
-  int i;
-
-  /* Be generous for the arguments, detect some errors.  */
-  if (result == NULL)
-    {
-      errno = EFAULT;
-      return -1;
-    }
+  mp_limb mpn[(3 * sizeof (unsigned short int) + sizeof (mp_limb) - 1)
+	      / sizeof (mp_limb)];
 
   /* Compute next state.  */
   if (__drand48_iterate (xsubi, buffer) < 0)
     return -1;
 
-  *result = 0.0;
-  for (i = 4 / sizeof (unsigned short int); i >= 0; --i)
-    {
-      double factor = ldexp (1.0, (i - 6) * sizeof (unsigned short int));
+  /* Build a 48-bit mpn containing the 48 random bits.  */
+
+#if BITS_PER_MP_LIMB == 64
+  mpn[0] = (xsubi[0] << 32) | (xsubi[1] << 16) | xsubi[2];
+#elif BITS_PER_MP_LIMB == 32
+  mpn[0] = (xsubi[1] << 16) | xsubi[2];
+  mpn[1] = xsubi[0];
+#else
+ #error "BITS_PER_MP_LIMB value not handled"
+#endif
+
+  /* Shift them up so they are most significant bits of the fraction.  */
+  __mpn_lshift (mpn, mpn, sizeof mpn / sizeof mpn[0], DBL_MANT_DIG - 48);
 
-      *result += factor * (double) xsubi[i];
-    }
+  /* Construct a positive double using those bits for the fractional part,
+     and a zero exponent so the resulting FP number is [0.0,1.0).  */
+  *result = __mpn_construct_double (mpn, 0, 0);
 
   return 0;
 }