Aldy Hernandez wrote:
I'm in the process of converting the C++ FE to tuples. In doing so I have noticed that the C++ FE will frequently gimplify bits of a tree, and then expect gimplify_expr() to gimplify the rest. This seems redundant, as gimplify_expr() more often than not will gimplify the entire tree structure, without regard to what parts the C++ FE already gimplified.
Yes, the gimplifier often makes several passes over the same trees to get them completely lowered. cp_gimplify_expr is a subroutine of the gimplifier.
This behavior is common throughout C++. The C++ FE calls gimplify_stmt on bits of trees, but then gimplify_expr() has to gimplify again.
It seems to me that a better approach would be to pass the tree structure as generic as we can (without calls to gimplify_stmt in the C++ FE), and then let gimplify_expr do its job.
Sure. Another alternative would be to leave the calls to gimplify_stmt (or probably change them to gimplify_to_stmt_list) and return GS_ALL_DONE from cp_gimplify_expr.
Jason
