Index: gcc/fortran/intrinsic.texi
===================================================================
--- gcc/fortran/intrinsic.texi	(revision 272261)
+++ gcc/fortran/intrinsic.texi	(working copy)
@@ -9689,10 +9689,10 @@
 @table @asis
 @item @emph{Description}:
 @code{LSHIFT} returns a value corresponding to @var{I} with all of the
-bits shifted left by @var{SHIFT} places.  If the absolute value of
-@var{SHIFT} is greater than @code{BIT_SIZE(I)}, the value is undefined.
-Bits shifted out from the left end are lost; zeros are shifted in from
-the opposite end.
+bits shifted left by @var{SHIFT} places.  @var{SHIFT} shall be
+nonnegative and less than or equal to @code{BIT_SIZE(I)}, otherwise
+the result value is undefined.  Bits shifted out from the left end are
+lost; zeros are shifted in from the opposite end.

 This function has been superseded by the @code{ISHFT} intrinsic, which
 is standard in Fortran 95 and later, and the @code{SHIFTL} intrinsic,
@@ -12244,11 +12244,12 @@
 @table @asis
 @item @emph{Description}:
 @code{RSHIFT} returns a value corresponding to @var{I} with all of the
-bits shifted right by @var{SHIFT} places.  If the absolute value of
-@var{SHIFT} is greater than @code{BIT_SIZE(I)}, the value is undefined.
-Bits shifted out from the right end are lost. The fill is arithmetic: the
-bits shifted in from the left end are equal to the leftmost bit, which in
-two's complement representation is the sign bit.
+bits shifted right by @var{SHIFT} places.  @var{SHIFT} shall be
+nonnegative and less than or equal to @code{BIT_SIZE(I)}, otherwise
+the result value is undefined.  Bits shifted out from the right end
+are lost. The fill is arithmetic: the bits shifted in from the left
+end are equal to the leftmost bit, which in two's complement
+representation is the sign bit.

 This function has been superseded by the @code{SHIFTA} intrinsic, which
 is standard in Fortran 2008 and later.
@@ -12783,11 +12784,12 @@
 @table @asis
 @item @emph{Description}:
 @code{SHIFTA} returns a value corresponding to @var{I} with all of the
-bits shifted right by @var{SHIFT} places.  If the absolute value of
-@var{SHIFT} is greater than @code{BIT_SIZE(I)}, the value is undefined.
-Bits shifted out from the right end are lost. The fill is arithmetic: the
-bits shifted in from the left end are equal to the leftmost bit, which in
-two's complement representation is the sign bit.
+bits shifted right by @var{SHIFT} places.  @var{SHIFT} that be
+nonnegative and less than or equal to @code{BIT_SIZE(I)}, otherwise
+the result value is undefined.  Bits shifted out from the right end
+are lost. The fill is arithmetic: the bits shifted in from the left
+end are equal to the leftmost bit, which in two's complement
+representation is the sign bit.

 @item @emph{Standard}:
 Fortran 2008 and later
@@ -12823,10 +12825,10 @@
 @table @asis
 @item @emph{Description}:
 @code{SHIFTL} returns a value corresponding to @var{I} with all of the
-bits shifted left by @var{SHIFT} places.  If the absolute value of
-@var{SHIFT} is greater than @code{BIT_SIZE(I)}, the value is undefined.
-Bits shifted out from the left end are lost, and bits shifted in from
-the right end are set to 0.
+bits shifted left by @var{SHIFT} places.  @var{SHIFT} shall be
+nonnegative and less than or equal to @code{BIT_SIZE(I)}, otherwise
+the result value is undefined.  Bits shifted out from the left end are
+lost, and bits shifted in from the right end are set to 0.

 @item @emph{Standard}:
 Fortran 2008 and later
@@ -12862,10 +12864,10 @@
 @table @asis
 @item @emph{Description}:
 @code{SHIFTR} returns a value corresponding to @var{I} with all of the
-bits shifted right by @var{SHIFT} places.  If the absolute value of
-@var{SHIFT} is greater than @code{BIT_SIZE(I)}, the value is undefined.
-Bits shifted out from the right end are lost, and bits shifted in from
-the left end are set to 0.
+bits shifted right by @var{SHIFT} places.  @var{SHIFT} shall be
+nonnegative and less than or equal to @code{BIT_SIZE(I)}, otherwise
+the result value is undefined.  Bits shifted out from the right end
+are lost, and bits shifted in from the left end are set to 0.

 @item @emph{Standard}:
 Fortran 2008 and later
Index: gcc/fortran/trans-intrinsic.c
===================================================================
--- gcc/fortran/trans-intrinsic.c	(revision 272261)
+++ gcc/fortran/trans-intrinsic.c	(working copy)
@@ -6346,6 +6346,7 @@
 			  bool arithmetic)
 {
   tree args[2], type, num_bits, cond;
+  tree bigshift;

   gfc_conv_intrinsic_function_args (se, expr, args, 2);

@@ -6365,6 +6366,18 @@
   if (!arithmetic)
     se->expr = fold_convert (type, se->expr);

+  if (!arithmetic)
+    bigshift = build_int_cst (type, 0);
+  else
+    {
+      tree nonneg = fold_build2_loc (input_location, GE_EXPR,
+				     logical_type_node, args[0],
+				     build_int_cst (TREE_TYPE (args[0]), 0));
+      bigshift = fold_build3_loc (input_location, COND_EXPR, type, nonneg,
+				  build_int_cst (type, 0),
+				  build_int_cst (type, -1));
+    }
+
   /* The Fortran standard allows shift widths <= BIT_SIZE(I), whereas
      gcc requires a shift width < BIT_SIZE(I), so we have to catch this
      special case.  */
@@ -6373,7 +6386,7 @@
 			  args[1], num_bits);

   se->expr = fold_build3_loc (input_location, COND_EXPR, type, cond,
-			      build_int_cst (type, 0), se->expr);
+			      bigshift, se->expr);
 }

 /* ISHFT (I, SHIFT) = (abs (shift) >= BIT_SIZE (i))