Request for reviews (XS): 7123926: Some CTW test crash: !_control.contains(ctrl)

[Vladimir Kozlov]

Thank you, Christian

Vladimir

Christian Thalinger wrote:
> Looks good.  -- Chris
> 
> On Jul 13, 2012, at 12:46 PM, Vladimir Kozlov wrote:
> 
>> I updated webrev. I removed uncast() changes from this fix, we do it later. Tested with compiler and java/jang regression tests.
>>
>> http://cr.openjdk.java.net/~kvn/7123926/webrev.01
>>
>> Thanks,
>> Vladimir
>>
>> Vladimir Kozlov wrote:
>>> I looked again on my changes and, I think, the lines with push_int();continue; should be also under (arg->outcnt() == 1) condition. If we don't remove call to Integer.toString() - use its result. Otherwise we have to generate conversion from int to String by hand for each use (see int_getChars()). As result Integer.toString() code will not be folded by later optimizations for the case I showed in previous mail. I need to do more testing for this and will resend webrev later.
>>>> I'm a little bit worried about this part after seeing your fix for 7181658. Do you think it's safe to use uncast()
>>> It was another Vladimir (Ivanov) who fixed 7181658 :-)
>>>> this way, or should we use eqv_uncast() for comparison at the use sites of StringConcat::argument_uncast()?
>>> I think using uncast() in argument_uncast() is safe, it is used only in related code. The first time argument_uncast() is called to find a Proj node from SB.toString() call. Then that Proj node passed to merge() method as 'arg'. And in the merge() method argument_uncast() is called second time to compare with that passed 'arg'.
>>> Thanks,
>>> Vladimir
>>> On 7/5/12 8:23 PM, Krystal Mok wrote:
>>>> Comments inline:
>>>>
>>>> On Fri, Jul 6, 2012 at 10:38 AM, Vladimir Kozlov <vladimir.kozlov at oracle.com <mailto:vladimir.kozlov at oracle.com>> wrote:
>>>>
>>>>    Thank you, Kris
>>>>
>>>>
>>>>    Krystal Mok wrote:
>>>>
>>>>        Hi Vladimir,
>>>>
>>>>        foo(Integer intobj) {
>>>>           String intstr = intobj.toString();
>>>>           String str = intstr + ", " + intstr;
>>>>
>>>>        What should be the desired behavior for the case above?
>>>>        Is it all right to skip all Integer.toString() calls, and let later optimizations handle it?
>>>>
>>>>
>>>>    You have only one toString() call. And it will be kept because it is referenced by debug info which is copied from
>>>>    SB constructor to new char[] constructor (AllocateArray node). It is needed for deoptimization since the bytecode
>>>>    will be executed after that call.
>>>>
>>>> I see. So that's what you meant in the original "Keep case". That makes sense.
>>>>
>>>>    The next code is the case when Integer.toString() will be eliminated by later optimizations:
>>>>
>>>>       StringBuilder sb = new StringBuilder();
>>>>       String intstr = intobj.toString();
>>>>       String str = sb.append(intstr).append(__intstr).toString();
>>>>
>>>>    I also applied your uncast() suggestion in argument_uncast() method.
>>>>
>>>> I'm a little bit worried about this part after seeing your fix for 7181658. Do you think it's safe to use uncast() this
>>>> way, or should we use eqv_uncast() for comparison at the use sites of StringConcat::argument_uncast()?
>>>>
>>>> Thanks,
>>>> Kris
>>>>
>>>>    And I fixed typos.
>>>>
>>>>    Thanks,
>>>>    Vladimir
>>>>
>>>>
>>>>        And, two typos:
>>>>
>>>>        541               // chain. It's node could be eliminated only if it's result
>>>>
>>>>        It's -> Its. Other occurrences of "it's" should also be replaced with "its".
>>>>
>>>>        543               // An other limitation: it should be used only once because
>>>>
>>>>        An other -> Another.
>>>>
>>>>        - Kris
>>>>
>>>>        On Fri, Jul 6, 2012 at 4:37 AM, Vladimir Kozlov <vladimir.kozlov at oracle.com <mailto:vladimir.kozlov at oracle.com>
>>>>        <mailto:vladimir.kozlov at __oracle.com <mailto:vladimir.kozlov at oracle.com>>> wrote:
>>>>
>>>>             Vladimir Kozlov wrote:
>>>>
>>>>        http://cr.openjdk.java.net/~____kvn/7123926/webrev <http://cr.openjdk.java.net/~__kvn/7123926/webrev>
>>>>
>>>>        <http://cr.openjdk.java.net/~__kvn/7123926/webrev <http://cr.openjdk.java.net/~kvn/7123926/webrev>>
>>>>
>>>>                 7123926: Some CTW test crash: !_control.contains(ctrl)
>>>>
>>>>                 Don't try to eliminate Integer::toString() call node during
>>>>                 String concatenation optimization if it's result has several uses.
>>>>
>>>>                 Eliminate case:
>>>>                   foo (Integer intob) {
>>>>                     String str = "int: " + intobj;
>>>>
>>>>                 Keep case:
>>>>                   foo (Integer intob) {
>>>>                     String intstr = intobj.toString();
>>>>                     String str = "int: " + intobj; // second use is in SB
>>>>                 allocation
>>>>
>>>>
>>>>             Sorry, it should be: "int: " + intstr;
>>>>
>>>>             Vladimir
>>>>
>>>>
>>>>                 debug info
>>>>
>>>>                 Tested with failed test.
>>>>
>>>>                 Thanks,
>>>>                 Vladimir
>>>>
>>>>
>>>>
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