re PR target/25960 (__gcc_qadd doesn't handle -0.0L properly)

	PR target/25960
gcc/
	* config/rs6000/darwin-ldouble.c (__gcc_qadd): Preserve -0.0 result.
gcc/testsuite/
	* gcc.target/powerpc/pr25960.c: New test.

From-SVN: r110540

gcc/ChangeLog

+2006-02-03  Alan Modra  <amodra@bigpond.net.au>
+
+	PR target/25960
+	* config/rs6000/darwin-ldouble.c (__gcc_qadd): Preserve -0.0 result.
+
 2006-02-03  Andreas Krebbel  <krebbel1@de.ibm.com>
             Ulrich Weigand  <uweigand@de.ibm.com>
 
@@ -1544,6 +1549,7 @@
 
 2006-01-20  Alan Modra  <amodra@bigpond.net.au>
 
+	PR target/25668
 	* libgcc2.c (__floatdisf, __floatdidf): Don't use IBM Extended
 	Double TFmode.
 	(__floatundisf, __floatundidf): Likewise.

gcc/config/rs6000/darwin-ldouble.c

@@ -117,8 +117,12 @@ __gcc_qadd (double a, double aa, double c, double cc)
     {
       q = a - z;
       zz = q + c + (a - (q + z)) + aa + cc;
-      xh = z + zz;
 
+      /* Keep -0 result.  */
+      if (zz == 0.0)
+	return z;
+
+      xh = z + zz;
       if (nonfinite (xh))
 	return xh;
 

gcc/testsuite/ChangeLog

+2006-02-03  Alan Modra  <amodra@bigpond.net.au>
+
+	* gcc.target/powerpc/pr25960.c: New test.
+
 2006-02-02  Steven G. Kargl  <kargls@comcast>
 
 	PR fortran/24958

gcc/testsuite/gcc.target/powerpc/pr25960.c

+/* { dg-do run { target { powerpc*-*-darwin* powerpc*-*-aix* rs6000-*-* powerpc*-*-linux* } } } */
+/* { dg-options "-O2 -mlong-double-128" } */
+
+extern void abort (void);
+
+volatile long double l, m, n;
+
+int
+main (void)
+{
+  l = __builtin_copysignl (0.0L, -1.0L);
+  m = __builtin_copysignl (0.0L, -1.0L);
+  n = l + m;
+  if (__builtin_copysignl (1.0L, n) >= 0.0L)
+    abort ();
+  return 0;
+}