#include "tree.h"
#include "real.h"
#include "rtl.h"
+#include "flags.h"
#include "expr.h"
#include "java-tree.h"
#include "javaop.h"
}
return PC;
}
+
+/* Force the (direct) sub-operands of NODE to be evaluated in left-to-right
+ order, as specified by Java Language Specification.
+
+ The problem is that while expand_expr will evaluate its sub-operands in
+ left-to-right order, for variables it will just return an rtx (i.e.
+ an lvalue) for the variable (rather than an rvalue). So it is possible
+ that a later sub-operand will change the register, and when the
+ actual operation is done, it will use the new value, when it should
+ have used the original value.
+
+ We fix this by using save_expr. This forces the sub-operand to be
+ copied into a fresh virtual register,
+*/
+
+tree
+force_evaluation_order (node)
+ tree node;
+{
+ if (flag_syntax_only)
+ return node;
+ if (TREE_CODE_CLASS (TREE_CODE (node)) == '2'
+ && TREE_CODE (node) == ARRAY_REF)
+ {
+ if (TREE_SIDE_EFFECTS (TREE_OPERAND (node, 1)))
+ TREE_OPERAND (node, 0) = save_expr (TREE_OPERAND (node, 0));
+ }
+ else if (TREE_CODE (node) == CALL_EXPR || TREE_CODE (node) == NEW_CLASS_EXPR)
+ {
+ tree last_side_effecting_arg = NULL_TREE;
+ tree arg = TREE_OPERAND (node, 1);
+ for (; arg != NULL_TREE; arg = TREE_CHAIN (arg))
+ {
+ if (TREE_SIDE_EFFECTS (TREE_VALUE (arg)))
+ last_side_effecting_arg = arg;
+ }
+ arg = TREE_OPERAND (node, 1);
+ for (; arg != NULL_TREE; arg = TREE_CHAIN (arg))
+ {
+ if (arg == last_side_effecting_arg)
+ break;
+ TREE_VALUE (arg) = save_expr (TREE_VALUE (arg));
+ }
+ }
+ return node;
+}