X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=tests%2Ftest-trunc2.c;h=e8e33793e4df290cc3ad5fff67318d7e6c205e4c;hb=70a72e0f50411ccc776379a761725d8c8bec58a3;hp=c9f0d8fdd675a5d45df0f4ccad11755df705899a;hpb=ba564f2164f381af846d9695e6465cffe7ec918c;p=gnulib.git

diff --git a/tests/test-trunc2.c b/tests/test-trunc2.c
index c9f0d8fdd..e8e33793e 100644
--- a/tests/test-trunc2.c
+++ b/tests/test-trunc2.c
@@ -1,5 +1,5 @@
 /* Test of rounding towards zero.
-   Copyright (C) 2007-2010 Free Software Foundation, Inc.
+   Copyright (C) 2007-2011 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -29,6 +29,7 @@
 #include <stdio.h>
 
 #include "isnand-nolibm.h"
+#include "minus-zero.h"
 #include "macros.h"
 
 
@@ -38,6 +39,9 @@
 #define MANT_DIG DBL_MANT_DIG
 #define L_(literal) literal
 
+/* -0.0.  See minus-zero.h.  */
+#define MINUS_ZERO minus_zerod
+
 /* 2^(MANT_DIG-1).  */
 static const DOUBLE TWO_MANT_DIG =
   /* Assume MANT_DIG <= 5 * 31.
@@ -63,8 +67,12 @@ trunc_reference (DOUBLE x)
 
   if (z > L_(0.0))
     {
+      /* For 0 < x < 1, return +0.0 even if the current rounding mode is
+         FE_DOWNWARD.  */
+      if (z < L_(1.0))
+        z = L_(0.0);
       /* Avoid rounding errors for values near 2^k, where k >= MANT_DIG-1.  */
-      if (z < TWO_MANT_DIG)
+      else if (z < TWO_MANT_DIG)
         {
           /* Round to the next integer (nearest or up or down, doesn't matter).  */
           z += TWO_MANT_DIG;
@@ -76,8 +84,12 @@ trunc_reference (DOUBLE x)
     }
   else if (z < L_(0.0))
     {
+      /* For -1 < x < 0, return -0.0 regardless of the current rounding
+         mode.  */
+      if (z > L_(-1.0))
+        z = MINUS_ZERO;
       /* Avoid rounding errors for values near -2^k, where k >= MANT_DIG-1.  */
-      if (z > - TWO_MANT_DIG)
+      else if (z > - TWO_MANT_DIG)
         {
           /* Round to the next integer (nearest or up or down, doesn't matter).  */
           z -= TWO_MANT_DIG;