Andrew Pinski wrote: > > I have been experimenting with a simple patch adding side effects > > checks to the conditions, like "! TREE_SIDE_EFFECTS (value)" > > in init_ctor_eval > > Yes the one in needs to gimplify only the expression as a statement > and not add a modify statement. More on the testcase later.
> You should not need the check in modify_expr as the side effects are > never mishandled as we always will add the lhs and rhs to the > instruction stream: Oh, I see - misread what it did. Thanks. I was confused by the fact that the check in init_ctor_eval did not help for C while it did for Ada. It actually doesn't change the behavior for C (at least on my testcases) because we don't get into init_ctor_eval at all, but in gimplify_expr <case CONSTRUCTOR_EXPR> instead, which precisely processes values with TREE_SIDE_EFFECTS set. I'm not yet clear why the call is not issued there. This is my first dive in the gimplifier, so it might well be simple. > Here is a testcase which should pass: ... It doesn't pass with the init_ctor_eval check either. > If you want me to file a bug, I can, I can also look into the issue > some too and figure out where the f++ is going to. Either is fine with me (thanks for the offer :). On my side, I will test again with only the init_ctor_eval change and submit on gcc-patches with an Ada testcase. The only regressions I had with the two changes were the ICEs on zero-strct-4.c. I don't see them with the modify_expr change removed, so hopefully the second round will go well. > Note if we change struct g to be a non zero sized struct, it works. Indeed. Thanks for your feedback. Olivier
