re PR c/3711 (ICE in instantiate_virtual_regs_1, at function.c:3880)

	PR c/3711
	* builtins.c (std_expand_builtin_va_arg): Do all computations on
	trees.

	* gcc.c-torture/execute/20020307-2.c: New test.

From-SVN: r50438

gcc/ChangeLog

+2002-03-08  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c/3711
+	* builtins.c (std_expand_builtin_va_arg): Do all computations on
+	trees.
+
 Fri Mar  8 06:48:45 2002  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>
 
 	* rtl.c (copy_most_rtx): Move from here ...

gcc/builtins.c

@@ -2986,37 +2986,54 @@ rtx
 std_expand_builtin_va_arg (valist, type)
      tree valist, type;
 {
-  tree addr_tree, t;
-  HOST_WIDE_INT align;
-  HOST_WIDE_INT rounded_size;
+  tree addr_tree, t, type_size = NULL;
+  tree align, alignm1;
+  tree rounded_size;
   rtx addr;
 
   /* Compute the rounded size of the type.  */
-  align = PARM_BOUNDARY / BITS_PER_UNIT;
-  rounded_size = (((int_size_in_bytes (type) + align - 1) / align) * align);
+  align = size_int (PARM_BOUNDARY / BITS_PER_UNIT);
+  alignm1 = size_int (PARM_BOUNDARY / BITS_PER_UNIT - 1);
+  if (type == error_mark_node
+      || (type_size = TYPE_SIZE_UNIT (TYPE_MAIN_VARIANT (type))) == NULL
+      || TREE_OVERFLOW (type_size))
+    rounded_size = size_zero_node;
+  else
+    rounded_size = fold (build (MULT_EXPR, sizetype,
+				fold (build (TRUNC_DIV_EXPR, sizetype,
+					     fold (build (PLUS_EXPR, sizetype,
+							  type_size, alignm1)),
+					     align)),
+				align));
 
   /* Get AP.  */
   addr_tree = valist;
-  if (PAD_VARARGS_DOWN)
+  if (PAD_VARARGS_DOWN && ! integer_zerop (rounded_size))
     {
       /* Small args are padded downward.  */
-
-      HOST_WIDE_INT adj
-	= rounded_size > align ? rounded_size : int_size_in_bytes (type);
-
-      addr_tree = build (PLUS_EXPR, TREE_TYPE (addr_tree), addr_tree,
-			 build_int_2 (rounded_size - adj, 0));
+      addr_tree = fold (build (PLUS_EXPR, TREE_TYPE (addr_tree), addr_tree,
+			       fold (build (COND_EXPR, sizetype,
+					    fold (build (GT_EXPR, sizetype,
+							 rounded_size,
+							 align)),
+					    size_zero_node,
+					    fold (build (MINUS_EXPR, sizetype,
+							 rounded_size,
+							 type_size))))));
     }
 
   addr = expand_expr (addr_tree, NULL_RTX, Pmode, EXPAND_NORMAL);
   addr = copy_to_reg (addr);
 
   /* Compute new value for AP.  */
-  t = build (MODIFY_EXPR, TREE_TYPE (valist), valist,
-	     build (PLUS_EXPR, TREE_TYPE (valist), valist,
-		    build_int_2 (rounded_size, 0)));
-  TREE_SIDE_EFFECTS (t) = 1;
-  expand_expr (t, const0_rtx, VOIDmode, EXPAND_NORMAL);
+  if (! integer_zerop (rounded_size))
+    {
+      t = build (MODIFY_EXPR, TREE_TYPE (valist), valist,
+		 build (PLUS_EXPR, TREE_TYPE (valist), valist,
+			rounded_size));
+      TREE_SIDE_EFFECTS (t) = 1;
+      expand_expr (t, const0_rtx, VOIDmode, EXPAND_NORMAL);
+    }
 
   return addr;
 }

gcc/testsuite/ChangeLog

+2002-03-08  Jakub Jelinek  <jakub@redhat.com>
+
+	* gcc.c-torture/execute/20020307-2.c: New test.
+
 Thu Mar  7 10:05:31 2002  Jeffrey A Law  (law@redhat.com)
 
 	* g77.f-torture/compile/20020307-1.f: New test.

gcc/testsuite/gcc.c-torture/execute/20020307-2.c

+/* PR c/3711
+   This testcase ICEd on IA-32 at -O0 and was miscompiled otherwise,
+   because std_expand_builtin_va_arg didn't handle variable size types.  */
+
+#include <stdarg.h>
+
+extern void abort (void);
+extern void exit (int);
+
+void bar (int c)
+{
+  static int d = '0';
+
+  if (c != d++)
+    abort ();
+  if (c < '0' || c > '9')
+    abort ();
+}
+
+void foo (int size, ...)
+{
+  struct
+  {
+    char x[size];
+  } d;
+  va_list ap;
+  int i;
+
+  va_start (ap, size);
+  d = va_arg (ap, typeof (d));
+  for (i = 0; i < size; i++)
+    bar (d.x[i]);
+  d = va_arg (ap, typeof (d));
+  for (i = 0; i < size; i++)
+    bar (d.x[i]);
+  va_end (ap);
+}
+
+int main (void)
+{
+  struct { char a[5]; } x, y;
+          
+  x.a[0] = '0';
+  x.a[1] = '1';
+  x.a[2] = '2';
+  x.a[3] = '3';
+  x.a[4] = '4';
+  y.a[0] = '5';
+  y.a[1] = '6';
+  y.a[2] = '7';
+  y.a[3] = '8';
+  y.a[4] = '9';
+  foo (5, x, y);
+  exit (0);
+}