On Thu, Jan 05, 2017 at 04:39:40PM +0100, Marek Polacek wrote:
> Coming back to this...
> > Right, after h0 == h1 is missing && operand_equal_p (thenb, elseb, 0)
> > or so (the exact last operand needs to be figured out).
> > OEP_ONLY_CONST is certainly wrong, we want the same VAR_DECLs to mean the
> > same thing. 0 is a tiny bit better, but still it will give up on e.g. pure
> > and other calls. OEP_PURE_SAME is tiny bit better than that, but still
> > calls with the same arguments to the same function will not be considered
> > equal, plus likely operand_equal_p doesn't handle STATEMENT_LIST etc.
> > So maybe we need another OEP_* mode for this.
>
> Yea, if I add "&& operand_equal_p (thenb, elseb, 0)" then this warning doesn't
> trigger for certain cases, such as MODIFY_EXPR, RETURN_EXPR, probably
> STATEMENT_LIST and others. So I suppose I could introduce a new OEP_ mode for
> this (names? OEP_EXTENDED?) and then in operand_equal_p in case
> tcc_expression
> do
>
> case MODIFY_EXPR:
> if (flags & OEP_EXTENDED)
> // compare LHS and RHS of both
>
> ?
Yeah. Not sure what is the best name for that. Maybe Richi has some clever
ideas.
Jakub
