RFR: 8320128: Clean up Parse constructor for OSR

[Tobias Hartmann]

On Wed, 15 Nov 2023 07:01:35 GMT, Xin Liu <xliu at openjdk.org> wrote:

> There's a special case for the constructor of Parse. If current compilation is OSR and it is handling the top-level method(depth() == 1), then
> 
> 1. _tf = C->tf();
> 2. _entry_bci = C->entry_bci();
> 3. _flow = method()->get_osr_flow_analysis(_entry_bci);
> 
> We don't need to assign those member data twice. We can also factor out _flow->failing() for the special case and normal cases. 
> 
> It's worth mentioning that we can't save ciTypeFlow computation because
> get_osr_flow_analysis(_entry_bci) actually needs get_flow_analysis(method()).

src/hotspot/share/opto/parse1.cpp line 502:

> 500:   } else {
> 501:     _tf = TypeFunc::make(method());
> 502:     _entry_bci = InvocationEntryBci;

This is already set in line 404, right? Should it be removed there?

src/hotspot/share/opto/parse1.cpp line 507:

> 505: 
> 506:   if (_flow->failing()) {
> 507:     assert(false, "type flow failed during parsing");

Suggestion:

    assert(false, "type flow analysis failed during parsing");

src/hotspot/share/opto/parse1.cpp line 511:

> 509: #ifndef PRODUCT
> 510:       if (PrintOpto && (Verbose || WizardMode)) {
> 511:         if (_entry_bci != InvocationEntryBci) {

Suggestion:

        if (C->is_osr_compilation()) {

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PR Review Comment: https://git.openjdk.org/jdk/pull/16669#discussion_r1398714843
PR Review Comment: https://git.openjdk.org/jdk/pull/16669#discussion_r1398715587
PR Review Comment: https://git.openjdk.org/jdk/pull/16669#discussion_r1398715349