(min_precision): Move to c-common.c

From-SVN: r8021

gcc/c-decl.c

@@ -5647,37 +5647,6 @@ start_enum (name)
   return enumtype;
 }
 
-/* Return the minimum number of bits needed to represent VALUE in a
-   signed or unsigned type, UNSIGNEDP says which.  */
-
-static int
-min_precision (value, unsignedp)
-     tree value;
-     int unsignedp;
-{
-  int log;
-
-  /* If the value is negative, compute its negative minus 1.  The latter
-     adjustment is because the absolute value of the largest negative value
-     is one larger than the largest positive value.  This is equivalent to
-     a bit-wise negation, so use that operation instead.  */
-
-  if (tree_int_cst_sgn (value) < 0)
-    value = fold (build1 (BIT_NOT_EXPR, TREE_TYPE (value), value));
-
-  /* Return the number of bits needed, taking into account the fact
-     that we need one more bit for a signed than unsigned type.  */
-
-  if (integer_zerop (value))
-    log = 0;
-  else if (TREE_INT_CST_HIGH (value) != 0)
-    log = HOST_BITS_PER_WIDE_INT + floor_log2 (TREE_INT_CST_HIGH (value));
-  else
-    log = floor_log2 (TREE_INT_CST_LOW (value));
-
-  return log + 1 + ! unsignedp;
-}
-
 /* After processing and defining all the values of an enumeration type,
    install their decls in the enumeration type and finish it off.
    ENUMTYPE is the type object and VALUES a list of decl-value pairs.