diff --git a/ChangeLog b/ChangeLog
index 22122b3323..edb6ec4ecd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2014-04-01  Alan Modra  <amodra@gmail.com>
+
+	[BZ #16786]
+	* sysdeps/powerpc/powerpc64/fpu/s_copysign.S: Don't trash stack.
+
 2014-03-31  Joseph Myers  <joseph@codesourcery.com>
 
 	[BZ #6803]
diff --git a/sysdeps/powerpc/powerpc64/fpu/s_copysign.S b/sysdeps/powerpc/powerpc64/fpu/s_copysign.S
index 51681aa2a8..49c793d386 100644
--- a/sysdeps/powerpc/powerpc64/fpu/s_copysign.S
+++ b/sysdeps/powerpc/powerpc64/fpu/s_copysign.S
@@ -27,11 +27,11 @@ ENTRY(__copysign)
 /* double [f1] copysign (double [f1] x, double [f2] y);
    copysign(x,y) returns a value with the magnitude of x and
    with the sign bit of y.  */
-	stfd	fp2,56(r1)
+	stfd	fp2,-8(r1)
 	nop
 	nop
 	nop
-	ld	r3,56(r1)
+	ld	r3,-8(r1)
 	cmpdi   r3,0
 	blt     L(0)
 	fabs    fp1,fp1