2011/10/11 Michael Matz <m...@suse.de>:
> Hi,
>
> On Mon, 10 Oct 2011, Kai Tietz wrote:
>
>> To ensure that we use simple_operand_p in all cases, beside for
>> branching AND/OR chains, in same way as before, I added to this function
>> an additional argument, by which the looking into comparisons can be
>> activated.
>
> Better make it a separate function the first tests your new conditions,
> and then calls simple_operand_p.
Well, either I make it a new function and call it instead of
simple_operand_p, or I need to modify old simple_operand_p. The logic
of new and old version is incompatible and has not to be called on
same tree, as otherwise new check is vain.
>> +fold_truth_andor_1 (location_t loc, enum tree_code code, tree truth_type,
>> + tree lhs, tree rhs)
>> {
>> /* If this is the "or" of two comparisons, we can do something if
>> the comparisons are NE_EXPR. If this is the "and", we can do something
>> @@ -5149,13 +5176,6 @@ fold_truthop (location_t loc, enum tree_
>> build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
>> ll_arg, rl_arg),
>> build_int_cst (TREE_TYPE (ll_arg), 0));
>> -
>> - if (LOGICAL_OP_NON_SHORT_CIRCUIT)
>> - {
>> - if (code != orig_code || lhs != orig_lhs || rhs != orig_rhs)
>> - return build2_loc (loc, code, truth_type, lhs, rhs);
>> - return NULL_TREE;
>> - }
>
> Why do you remove this hunk? Shouldn't you instead move the hunk you
> added to fold_truth_andor() here. I realize this needs some TLC to
> fold_truth_andor_1, because right now it early-outs for non-comparisons,
> but it seems the better place. I.e. somehow move the below code into the
> above branch, with the associated diddling on fold_truth_andor_1 that it
> gets called.
This hunk is removed, as it is vain to do here. Btw richi asked for
it, and I agree that new TRUTH-AND/OR packing is better done at a
single place in fold_truth_andor only.
>> + if ((code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
>> + && (BRANCH_COST (optimize_function_for_speed_p (cfun),
>> + false) >= 2)
>> + && !TREE_SIDE_EFFECTS (arg1)
>> + && LOGICAL_OP_NON_SHORT_CIRCUIT
>> + && simple_operand_p (arg1, true))
>> + {
>> + enum tree_code ncode = (code == TRUTH_ANDIF_EXPR ? TRUTH_AND_EXPR
>> + : TRUTH_OR_EXPR);
>> +
>> + /* We don't want to pack more then two leafs to an non-IF
>
> Missing continuation of the sentence?
Well, here is a colon missing.
>> + If tree-code of left-hand operand isn't an AND/OR-IF code and not
>> + equal to CODE, then we don't want to add right-hand operand.
>> + If the inner right-hand side of left-hand operand has side-effects,
>> + or isn't simple, then we can't add to it, as otherwise we might
>> + destroy if-sequence. */
>
>
>> + if (TREE_CODE (arg0) == code
>> + /* Needed for sequence points to handle trappings, and
>> + side-effects. */
>> + && !TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1))
>> + && simple_operand_p (TREE_OPERAND (arg0, 1), true))
>> + {
>> + tem = fold_build2_loc (loc, ncode, type, TREE_OPERAND (arg0, 1),
>> + arg1);
>> + return fold_build2_loc (loc, code, type, TREE_OPERAND (arg0, 0),
>> + tem);
>> + }
>> + /* Needed for sequence points to handle trappings, and side-effects.
>> */
>> + else if (!TREE_SIDE_EFFECTS (arg0)
>> + && simple_operand_p (arg0, true))
>> + return fold_build2_loc (loc, ncode, type, arg0, arg1);
>> + }
>> +
>
>
> Ciao,
> Michael.
>
Kai
