--- gcc/expr.c.jj	2010-06-11 11:06:01.320346755 +0200
+++ gcc/expr.c	2010-09-21 15:54:55.512656325 +0200
@@ -8314,10 +8314,32 @@ expand_expr_real_1 (tree exp, rtx target
 	 results.  */
       if (MEM_P (op0))
 	{
+	  enum insn_code icode;
 	  op0 = copy_rtx (op0);
 
 	  if (TYPE_ALIGN_OK (type))
 	    set_mem_align (op0, MAX (MEM_ALIGN (op0), TYPE_ALIGN (type)));
+	  else if (mode != BLKmode
+		   && MEM_ALIGN (op0) < GET_MODE_ALIGNMENT (mode)
+		   /* If the target does have special handling for unaligned
+		      loads of mode then use them.  */
+		   && ((icode = optab_handler (movmisalign_optab,
+					       mode)->insn_code)
+		       != CODE_FOR_nothing))
+	      {
+		rtx reg, insn;
+
+		op0 = adjust_address (op0, mode, 0);
+		/* We've already validated the memory, and we're creating a
+		   new pseudo destination.  The predicates really can't
+		   fail.  */
+		reg = gen_reg_rtx (mode);
+
+		/* Nor can the insn generator.  */
+		insn = GEN_FCN (icode) (reg, op0);
+		emit_insn (insn);
+		return reg;
+	      }
 	  else if (STRICT_ALIGNMENT
 		   && mode != BLKmode
 		   && MEM_ALIGN (op0) < GET_MODE_ALIGNMENT (mode))
--- gcc/cfgexpand.c.jj	2010-06-11 11:06:01.000000000 +0200
+++ gcc/cfgexpand.c	2010-09-21 15:56:38.953377699 +0200
@@ -826,7 +826,7 @@ dump_stack_var_partition (void)
 static void
 expand_one_stack_var_at (tree decl, HOST_WIDE_INT offset)
 {
-  HOST_WIDE_INT align;
+  HOST_WIDE_INT align, max_align;
   rtx x;
 
   /* If this fails, we've overflowed the stack frame.  Error nicely?  */
@@ -839,8 +839,9 @@ expand_one_stack_var_at (tree decl, HOST
   offset -= frame_phase;
   align = offset & -offset;
   align *= BITS_PER_UNIT;
-  if (align > STACK_BOUNDARY || align == 0)
-    align = STACK_BOUNDARY;
+  max_align = crtl->max_used_stack_slot_alignment;
+  if (align == 0 || align > max_align)
+    align = max_align;
   DECL_ALIGN (decl) = align;
   DECL_USER_ALIGN (decl) = 0;
 
--- gcc/testsuite/gcc.dg/torture/pr45678-1.c.jj	2010-09-21 15:54:55.516770526 +0200
+++ gcc/testsuite/gcc.dg/torture/pr45678-1.c	2010-09-21 15:54:55.517780104 +0200
@@ -0,0 +1,16 @@
+/* { dg-do run } */
+
+typedef float V __attribute__ ((vector_size (16)));
+V g;
+float d[4] = { 4, 3, 2, 1 };
+
+int
+main ()
+{
+  V e;
+  __builtin_memcpy (&e, &d, sizeof (d));
+  V f = { 5, 15, 25, 35 };
+  e = e * f;
+  g = e;
+  return 0;
+}
--- gcc/testsuite/gcc.dg/torture/pr45678-2.c.jj	2010-09-21 15:54:55.518403039 +0200
+++ gcc/testsuite/gcc.dg/torture/pr45678-2.c	2010-09-21 15:54:55.518403039 +0200
@@ -0,0 +1,16 @@
+/* { dg-do run } */
+
+typedef float V __attribute__ ((vector_size (16)));
+V g;
+
+int
+main ()
+{
+  float d[4] = { 4, 3, 2, 1 };
+  V e;
+  __builtin_memcpy (&e, &d, sizeof (d));
+  V f = { 5, 15, 25, 35 };
+  e = e * f;
+  g = e;
+  return 0;
+}