Infinities are now accepted in mpfr_cmpabs. Updated its definition

in the source (no longer sign(abs(b) - abs(c))).


git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@2469 280ebfd0-de03-0410-8827-d642c229c3f4

2 files changed, 15 insertions, 11 deletions

diff --git a/cmp_abs.c b/cmp_abs.c
index 47d1bc2e4..084e6dba2 100644
--- a/cmp_abs.c
+++ b/cmp_abs.c
@@ -24,8 +24,8 @@ MA 02111-1307, USA. */
 #include "mpfr.h"
 #include "mpfr-impl.h"
 
-/* returns sign(abs(b) - abs(c))
-   b and c must be real numbers */
+/* Return a positive value if abs(b) > abs(c), 0 if abs(b) = abs(c), and
+   a negative value if abs(b) < abs(c). Neither b nor c may be NaN. */
 
 int
 mpfr_cmpabs (mpfr_srcptr b, mpfr_srcptr c)
@@ -34,13 +34,18 @@ mpfr_cmpabs (mpfr_srcptr b, mpfr_srcptr c)
   mp_size_t bn, cn;
   mp_limb_t *bp, *cp;
 
-  MPFR_ASSERTN(MPFR_IS_FP(b));
-  MPFR_ASSERTN(MPFR_IS_FP(c));
+  MPFR_ASSERTN (! MPFR_IS_NAN (b));
+  MPFR_ASSERTN (! MPFR_IS_NAN (c));
 
-  if (MPFR_IS_ZERO(b))
-    return MPFR_IS_ZERO(c) ? 0 : -1;
-  if (MPFR_IS_ZERO(c))
-    return 1;
+  if (MPFR_IS_INF (b))
+    return ! MPFR_IS_INF (c);
+  if (MPFR_IS_INF (c))
+    return -1;
+
+  if (MPFR_IS_ZERO (c))
+    return ! MPFR_IS_ZERO (b);
+  if (MPFR_IS_ZERO (b))
+    return -1;
 
   be = MPFR_GET_EXP (b);
   ce = MPFR_GET_EXP (c);
diff --git a/mpfr.texi b/mpfr.texi
index 19b6e7318..d18aba564 100644
--- a/mpfr.texi
+++ b/mpfr.texi
@@ -1091,7 +1091,7 @@ Compare @var{op1} and @var{op2}.  Return a positive value if @math{@var{op1} >
 @math{@var{op1} < @var{op2}}.
 Both @var{op1} and @var{op2} are considered to their full own precision,
 which may differ.
-It is not allowed that one of the operands is NaN (Not-a-Number).
+If one of the operands is NaN (Not-a-Number), the behavior is undefined.
 @end deftypefun
 
 @deftypefun int mpfr_cmp_ui_2exp (mpfr_t @var{op1}, unsigned long int @var{op2}, mp_exp_t @var{e})
@@ -1104,8 +1104,7 @@ the power @var{e}}. Similar as above.
 Compare @math{|@var{op1}|} and @math{|@var{op2}|}.  Return a positive value if
 @math{|@var{op1}| > |@var{op2}|}, zero if @math{|@var{op1}| = |@var{op2}|}, and
 a negative value if @math{|@var{op1}| < |@var{op2}|}.
-It is not allowed that one of the operands is NaN (Not-a-Number) or an
-infinity.
+If one of the operands is NaN (Not-a-Number), the behavior is undefined.
 @end deftypefun
 
 @deftypefun int mpfr_eq (mpfr_t @var{op1}, mpfr_t @var{op2}, unsigned long int @var{op3})