RFR (L): 7173584: Implement arraycopy as a macro node
Vladimir Kozlov
vladimir.kozlov at oracle.com
Tue Oct 2 07:07:08 PDT 2012
Roland,
Leave your ConvI2L code as it is. It is ugly but touching ConI2LNode::Ideal() and Value() methods is a little dangerous. We better do it as separate change.
Thanks,
Vladimir
On Oct 1, 2012, at 11:41 AM, Vladimir Kozlov wrote:
> I don't think you need suffix "_any_phase" in the name gen_subtype_check_any_phase(). Just add comment that it is also used in phase Macro. Generally speaking GraphKit class is wrong place for it. May be it should be in base class Phase but keep the code in graphKit.cpp file.
>
> You don't need special gvn_transform(). It is already done since Macro phase sets gvn._delay_transform flag to true and:
>
> Node *PhaseIterGVN::transform( Node *n ) {
> if (_delay_transform) {
> // Register the node but don't optimize for now
> register_new_node_with_optimizer(n);
> return n;
> }
>
> gvn_transform_ctrl() should remain to be record_for_igvn() but virtual as you suggested.
>
> It would be also nice to factor out IfNode creation into separate method (it used 5 times):
>
> + Node* cmp = gvn_transform(new(C, 3) CmpPNode(subklass, superklass), gvn);
> + Node* bol = gvn_transform(new(C, 2) BoolNode(cmp, BoolTest::eq), gvn);
> + IfNode* iff = new (C, 2) IfNode(*ctrl, bol, PROB_STATIC_FREQUENT, COUNT_UNKNOWN);
> + gvn_transform(iff, gvn);
> + if (!bol->is_Con()) gvn_transform_ctrl(iff, gvn);
>
>
> Next optimization belongs to ConvI2LNode::Value(). May be we should not widen type in ConvI2LNode::Ideal() and Value() if input is singleton (constant).
>
> + Node *chk_off_X = LP64_ONLY(NULL) NOT_LP64(chk_off);
> +#ifdef _LP64
> + jint chk_off_con = gvn->find_int_con(chk_off, Type::OffsetBot);
> + if (chk_off_con != Type::OffsetBot) {
> + chk_off_X = gvn->longcon((jlong) chk_off_con);
> + } else {
> + chk_off_X = gvn_transform(new (C, 2) ConvI2LNode(chk_off), gvn);
> + }
> +#endif
>
> Thanks,
> Vladimir
>
>
> Roland Westrelin wrote:
>>> Also instead of duplicating gen_subtype_check() in macroArrayCopy.cpp can you modify the original one to work for you (by passing additional flag)?
>> This (on top of previous webrev - I've done only minimal testing)?
>> http://cr.openjdk.java.net/~roland/7173584/webrev.02/
>> Or do we want gvn_transform/gvn_transform_ctrl to be virtual methods of PhaseGVN/PhaseIterGVN?
>> Roland.
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