PR target/18916

	* builtins.c (std_gimplify_va_arg_expr): Adjust alignment of *ap.
	* expr.h (struct locate_and_pad_arg_data): Add "boundary".
	* function.c (locate_and_pad_parm): Set new field.
	(assign_parm_find_stack_rtl): Use it instead of FUNCTION_ARG_BOUNDARY.
	Tweak where_pad test to include "none".  Always set mem align for
	stack_parm.
	(assign_parm_adjust_stack_rtl): Discard stack_parm if alignment
	not sufficient for type.
	(assign_parm_setup_block): If stack_parm is zero on entry, always
	make a new stack local.  Block move old stack parm if necessary
	to new aligned stack local.
	(assign_parm_setup_stack): Use a block move to handle
	potentially misaligned entry_parm.
	(assign_parms_unsplit_complex): Specify required alignment when
	creating stack local.
	* calls.c (compute_argument_addresses): Override alignment of stack
	arg calculated from its type with the alignment given by
	FUNCTION_ARG_BOUNDARY.
	(store_one_arg): Likewise.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@93179 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 13 insertions, 1 deletions

diff --git a/gcc/builtins.c b/gcc/builtins.c
index b41212ae2e0..e231d8361cc 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -1,6 +1,6 @@
 /* Expand builtin functions.
    Copyright (C) 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
-   2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
+   2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -3894,6 +3894,18 @@ std_gimplify_va_arg_expr (tree valist, tree type, tree *pre_p, tree *post_p)
 		  build2 (BIT_AND_EXPR, TREE_TYPE (valist), valist_tmp, t));
       gimplify_and_add (t, pre_p);
     }
+  else
+    boundary = align;
+
+  /* If the actual alignment is less than the alignment of the type,
+     adjust the type accordingly so that we don't assume strict alignment
+     when deferencing the pointer.  */
+  boundary *= BITS_PER_UNIT;
+  if (boundary < TYPE_ALIGN (type))
+    {
+      type = build_variant_type_copy (type);
+      TYPE_ALIGN (type) = boundary;
+    }
 
   /* Compute the rounded size of the type.  */
   type_size = size_in_bytes (type);