expr.c (expand_expr_real_1): For a bit-field destination type...

	* expr.c (expand_expr_real_1) <case VIEW_CONVERT_EXPR>: For a bit-field
	destination type, extract only the valid bits if the source type is not
	integral and has a different mode.

From-SVN: r207902

1 files changed, 9 insertions, 4 deletions

diff --git a/gcc/expr.c b/gcc/expr.c
index 29ce694..be62c53 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -10436,6 +10436,11 @@ expand_expr_real_1 (tree exp, rtx target, enum machine_mode tmode,
       else if (INTEGRAL_TYPE_P (type) && INTEGRAL_TYPE_P (TREE_TYPE (treeop0)))
 	op0 = convert_modes (mode, GET_MODE (op0), op0,
 			     TYPE_UNSIGNED (TREE_TYPE (treeop0)));
+      /* If the output type is a bit-field type, do an extraction.  */
+      else if (reduce_bit_field)
+	return extract_bit_field (op0, TYPE_PRECISION (type), 0,
+				  TYPE_UNSIGNED (type), NULL_RTX,
+				  mode, mode);
       /* As a last resort, spill op0 to memory, and reload it in a
 	 different mode.  */
       else if (!MEM_P (op0))
@@ -10458,10 +10463,10 @@ expand_expr_real_1 (tree exp, rtx target, enum machine_mode tmode,
 	  op0 = target;
 	}
 
-      /* At this point, OP0 is in the correct mode.  If the output type is
-	 such that the operand is known to be aligned, indicate that it is.
-	 Otherwise, we need only be concerned about alignment for non-BLKmode
-	 results.  */
+      /* If OP0 is (now) a MEM, we need to deal with alignment issues.  If the
+	 output type is such that the operand is known to be aligned, indicate
+	 that it is.  Otherwise, we need only be concerned about alignment for
+	 non-BLKmode results.  */
       if (MEM_P (op0))
 	{
 	  enum insn_code icode;