gcc/

2011-10-30  Mikael Pettersson  <mikpe@it.uu.se>

	PR middle-end/50708
	* double-int.c (rshift_double): COUNT must be positive.

--- gcc-4.6.2/gcc/double-int.c.~1~	2010-11-30 17:36:19.000000000 +0100
+++ gcc-4.6.2/gcc/double-int.c	2011-10-30 17:28:29.000000000 +0100
@@ -250,7 +250,7 @@ lshift_double (unsigned HOST_WIDE_INT l1
 }
 
 /* Shift the doubleword integer in L1, H1 right by COUNT places
-   keeping only PREC bits of result.  Shift left if COUNT is negative.
+   keeping only PREC bits of result.  COUNT must be positive.
    ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
    Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV.  */
 
@@ -262,12 +262,6 @@ rshift_double (unsigned HOST_WIDE_INT l1
 {
   unsigned HOST_WIDE_INT signmask;
 
-  if (count < 0)
-    {
-      lshift_double (l1, h1, -count, prec, lv, hv, arith);
-      return;
-    }
-
   signmask = (arith
 	      ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
 	      : 0);