expr.c (expand_expr_real_1): handle misaligned scalar reads from memory through MEM_REFs by calling...

2012-03-16  Martin Jambor  <mjambor@suse.cz>

	* expr.c (expand_expr_real_1): handle misaligned scalar reads from
	memory through MEM_REFs by calling extract_bit_field.

	* testsuite/gcc.dg/misaligned-expand-1.c: New test.
	* testsuite/gcc.dg/misaligned-expand-3.c: Likewise.

From-SVN: r185470

1 files changed, 20 insertions, 14 deletions

diff --git a/gcc/expr.c b/gcc/expr.c
index df7cb03..2b0a176 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -9347,21 +9347,27 @@ expand_expr_real_1 (tree exp, rtx target, enum machine_mode tmode,
 	  MEM_VOLATILE_P (temp) = 1;
 	if (modifier != EXPAND_WRITE
 	    && mode != BLKmode
-	    && align < GET_MODE_ALIGNMENT (mode)
-	    /* If the target does not have special handling for unaligned
-	       loads of mode then it can use regular moves for them.  */
-	    && ((icode = optab_handler (movmisalign_optab, mode))
-		!= CODE_FOR_nothing))
+	    && align < GET_MODE_ALIGNMENT (mode))
 	  {
-	    struct expand_operand ops[2];
-
-	    /* We've already validated the memory, and we're creating a
-	       new pseudo destination.  The predicates really can't fail,
-	       nor can the generator.  */
-	    create_output_operand (&ops[0], NULL_RTX, mode);
-	    create_fixed_operand (&ops[1], temp);
-	    expand_insn (icode, 2, ops);
-	    return ops[0].value;
+	    if ((icode = optab_handler (movmisalign_optab, mode))
+		!= CODE_FOR_nothing)
+	      {
+		struct expand_operand ops[2];
+
+		/* We've already validated the memory, and we're creating a
+		   new pseudo destination.  The predicates really can't fail,
+		   nor can the generator.  */
+		create_output_operand (&ops[0], NULL_RTX, mode);
+		create_fixed_operand (&ops[1], temp);
+		expand_insn (icode, 2, ops);
+		return ops[0].value;
+	      }
+	    else if (SLOW_UNALIGNED_ACCESS (mode, align))
+	      temp = extract_bit_field (temp, GET_MODE_BITSIZE (mode),
+					0, TYPE_UNSIGNED (TREE_TYPE (exp)),
+					true, (modifier == EXPAND_STACK_PARM
+					       ? NULL_RTX : target),
+					mode, mode);
 	  }
 	return temp;
       }