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diff src/number-mp.c @ 5602:c9e5612f5424

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Support the MP library on recent FreeBSD, have it pass relevant tests. src/ChangeLog addition: 2011-11-26 Aidan Kehoe <kehoea@parhasard.net> * number-mp.c (bignum_to_string): Don't overwrite the accumulator we've just set up for this function. * number-mp.c (BIGNUM_TO_TYPE): mp_itom() doesn't necessarily do what this code used to think with negative numbers, it can treat them as unsigned ints. Subtract numbers from bignum_zero instead of multiplying them by -1 to convert them to their negative equivalents. * number-mp.c (bignum_to_int): * number-mp.c (bignum_to_uint): * number-mp.c (bignum_to_long): * number-mp.c (bignum_to_ulong): * number-mp.c (bignum_to_double): Use the changed BIGNUM_TO_TYPE() in these functions. * number-mp.c (bignum_ceil): * number-mp.c (bignum_floor): In these functions, be more careful about rounding to positive and negative infinity, respectively. Don't use the sign of QUOTIENT when working out out whether to add or subtract one, rather use the sign QUOTIENT would have if arbitrary-precision division were done. * number-mp.h: * number-mp.h (MP_GCD): Wrap #include <mp.h> in BEGIN_C_DECLS/END_C_DECLS. * number.c (Fbigfloat_get_precision): * number.c (Fbigfloat_set_precision): Don't attempt to call XBIGFLOAT_GET_PREC if this build doesn't support big floats.
author Aidan Kehoe <kehoea@parhasard.net>
date Sat, 26 Nov 2011 17:59:14 +0000
parents 2aa9cd456ae7
children 7aa144d1404b
line wrap: on
line diff
--- a/src/number-mp.c	Mon Nov 21 19:46:04 2011 +0100
+++ b/src/number-mp.c	Sat Nov 26 17:59:14 2011 +0000
@@ -42,7 +42,7 @@
   /* FIXME: signal something if base is < 2 or doesn't fit into a short. */
 
   /* Save the sign for later */
-  sign = MP_MCMP (b, bignum_zero);
+  sign = bignum_sign (b);
 
   if (sign == 0)
     {
@@ -57,8 +57,6 @@
   else
     MP_MOVE (b, quo);
 
-  quo = MP_ITOM (0);
-
   /* Loop over the digits of b (in BASE) and place each one into buffer */
   for (i = 0U; MP_MCMP(quo, bignum_zero) > 0; i++)
     {
@@ -90,13 +88,28 @@
 }
 
 #define BIGNUM_TO_TYPE(type,accumtype) do {	\
-  MP_MULT (b, quo, quo);			\
+    if (0 == sign)				\
+      {						\
+	return (type)0;				\
+      }						\
+						\
+    bignum_init (quo);				\
+						\
+    if (sign < 0)				\
+      {						\
+	MP_MSUB (bignum_zero, b, quo);		\
+      }						\
+    else					\
+      {						\
+	MP_MOVE (b, quo);			\
+      }						\
+						\
   for (i = 0U; i < sizeof(type); i++)		\
     {						\
       MP_SDIV (quo, 256, quo, &rem);		\
       retval |= ((accumtype) rem) << (8 * i);	\
     }						\
-  MP_MFREE (quo);				\
+  bignum_fini (quo);				\
 } while (0)
 
 int
@@ -107,8 +120,7 @@
   REGISTER unsigned int i;
   MINT *quo;
 
-  sign = MP_MCMP (b, bignum_zero) < 0 ? -1 : 1;
-  quo = MP_ITOM (sign);
+  sign = bignum_sign (b);
   BIGNUM_TO_TYPE (int, unsigned int);
   return ((int) retval) * sign;
 }
@@ -116,12 +128,12 @@
 unsigned int
 bignum_to_uint (bignum b)
 {
-  short rem;
+  short rem, sign;
   unsigned int retval = 0U;
   REGISTER unsigned int i;
   MINT *quo;
 
-  quo = MP_ITOM (MP_MCMP (b, bignum_zero) < 0 ? -1 : 1);
+  sign = bignum_sign (b);
   BIGNUM_TO_TYPE (unsigned int, unsigned int);
   return retval;
 }
@@ -134,8 +146,7 @@
   REGISTER unsigned int i;
   MINT *quo;
 
-  sign = MP_MCMP (b, bignum_zero) < 0 ? -1 : 1;
-  quo = MP_ITOM (sign);
+  sign = bignum_sign (b);
   BIGNUM_TO_TYPE (long, unsigned long);
   return ((long) retval) * sign;
 }
@@ -143,12 +154,12 @@
 unsigned long
 bignum_to_ulong (bignum b)
 {
-  short rem;
+  short rem, sign;
   unsigned long retval = 0UL;
   REGISTER unsigned int i;
   MINT *quo;
 
-  quo = MP_ITOM (MP_MCMP (b, bignum_zero) < 0 ? -1 : 1);
+  sign = bignum_sign (b);
   BIGNUM_TO_TYPE (unsigned long, unsigned long);
   return retval;
 }
@@ -161,9 +172,17 @@
   REGISTER unsigned int i;
   MINT *quo;
 
-  sign = MP_MCMP (b, bignum_zero) < 0 ? -1 : 1;
-  quo = MP_ITOM (sign);
-  MP_MULT (b, quo, quo);
+  sign = bignum_sign (b);
+  bignum_init (quo);
+  if (sign < 0)
+    {
+      MP_MSUB (bignum_zero, b, quo);
+    }
+  else
+    {
+      MP_MOVE (b, quo);
+    }
+
   for (i = 0U; MP_MCMP (quo, bignum_zero) > 0; i++)
     {
       MP_SDIV (quo, 256, quo, &rem);
@@ -303,17 +322,51 @@
 void bignum_ceil (bignum quotient, bignum N, bignum D)
 {
   MP_MDIV (N, D, quotient, intern_bignum);
-  if (MP_MCMP (intern_bignum, bignum_zero) > 0 &&
-      MP_MCMP (quotient, bignum_zero) > 0)
-    MP_MADD (quotient, bignum_one, quotient);
+  MP_MDIV (N, D, quotient, intern_bignum);
+  if (MP_MCMP (intern_bignum, bignum_zero) != 0)
+    {
+      short signN = MP_MCMP (N, bignum_zero);
+      short signD = MP_MCMP (D, bignum_zero);
+
+      /* If the quotient is positive, add one, since we're rounding to
+	 positive infinity. */
+      if (signD < 0)
+	{
+	  if (signN <= 0)
+	    {
+	      MP_MADD (quotient, bignum_one, quotient);
+	    }
+	}
+      else if (signN >= 0)
+	{
+	  MP_MADD (quotient, bignum_one, quotient);
+	}
+    }
 }
 
 void bignum_floor (bignum quotient, bignum N, bignum D)
 {
   MP_MDIV (N, D, quotient, intern_bignum);
-  if (MP_MCMP (intern_bignum, bignum_zero) > 0 &&
-      MP_MCMP (quotient, bignum_zero) < 0)
-    MP_MSUB (quotient, bignum_one, quotient);
+
+  if (MP_MCMP (intern_bignum, bignum_zero) != 0)
+    {
+      short signN = MP_MCMP (N, bignum_zero);
+      short signD = MP_MCMP (D, bignum_zero);
+
+      /* If the quotient is negative, subtract one, we're rounding to minus
+	 infinity.  */
+      if (signD < 0)
+	{
+	  if (signN >= 0)
+	    {
+	      MP_MSUB (quotient, bignum_one, quotient);
+	    }
+	}
+      else if (signN < 0)
+	{
+	  MP_MSUB (quotient, bignum_one, quotient);
+	}
+    }
 }
 
 /* RESULT = N to the POWth power */