calls.c (store_one_arg): Rename default_align to parm_align; always adjust parm_align for downward padding.

	* calls.c (store_one_arg): Rename default_align to parm_align;
	always adjust parm_align for downward padding.

From-SVN: r57292

1 files changed, 20 insertions, 12 deletions

diff --git a/gcc/calls.c b/gcc/calls.c
index 578bd98..97e7e04 100644
--- a/gcc/calls.c
+++ b/gcc/calls.c
@@ -4491,7 +4491,7 @@ store_one_arg (arg, argblock, flags, variable_size, reg_parm_stack_space)
     {
       /* BLKmode, at least partly to be pushed.  */
 
-      unsigned int default_align = PARM_BOUNDARY;
+      unsigned int parm_align;
       int excess;
       rtx size_rtx;
 
@@ -4499,13 +4499,6 @@ store_one_arg (arg, argblock, flags, variable_size, reg_parm_stack_space)
 	 If part is passed in registers, PARTIAL says how much
 	 and emit_push_insn will take care of putting it there.  */
 
-#ifdef ARGS_GROW_DOWNWARD
-      /* When an argument is padded down, the block is not aligned to
-	 PARM_BOUNDARY.  */
-      if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
-	default_align = BITS_PER_UNIT;
-#endif
-
       /* Round its size up to a multiple
 	 of the allocation unit for arguments.  */
 
@@ -4524,6 +4517,23 @@ store_one_arg (arg, argblock, flags, variable_size, reg_parm_stack_space)
 				  NULL_RTX, TYPE_MODE (sizetype), 0);
 	}
 
+      /* Some types will require stricter alignment, which will be
+	 provided for elsewhere in argument layout.  */
+      parm_align = MAX (PARM_BOUNDARY, TYPE_ALIGN (TREE_TYPE (pval)));
+
+      /* When an argument is padded down, the block is aligned to
+	 PARM_BOUNDARY, but the actual argument isn't.  */
+      if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
+	{
+	  if (arg->size.var)
+	    parm_align = BITS_PER_UNIT;
+	  else if (excess)
+	    {
+	      int excess_align = (excess & -excess) * BITS_PER_UNIT;
+	      parm_align = MIN (parm_align, excess_align);
+	    }
+	}
+
       if ((flags & ECF_SIBCALL) && GET_CODE (arg->value) == MEM)
 	{
 	  /* emit_push_insn might not work properly if arg->value and
@@ -4581,8 +4591,7 @@ store_one_arg (arg, argblock, flags, variable_size, reg_parm_stack_space)
           {
 	    rtx size_rtx1 = GEN_INT (reg_parm_stack_space - arg->offset.constant);
 	    emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx1,
-		            MAX (default_align, TYPE_ALIGN (TREE_TYPE (pval))),
-			    partial, reg, excess, argblock,
+		            parm_align, partial, reg, excess, argblock,
 			    ARGS_SIZE_RTX (arg->offset), reg_parm_stack_space,
 		            ARGS_SIZE_RTX (arg->alignment_pad));
 	  }
@@ -4590,8 +4599,7 @@ store_one_arg (arg, argblock, flags, variable_size, reg_parm_stack_space)
 	
 
       emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
-		      MAX (default_align, TYPE_ALIGN (TREE_TYPE (pval))),
-		      partial, reg, excess, argblock,
+		      parm_align, partial, reg, excess, argblock,
 		      ARGS_SIZE_RTX (arg->offset), reg_parm_stack_space,
 		      ARGS_SIZE_RTX (arg->alignment_pad));