RFR(M): optional flattening - interpreter/runtime part

[Frederic Parain]

Here’s the layouts with the fix:

java.lang.__Value: field layout
  @ 16 --- instance fields start ---
  @ 16 --- instance fields end ---
  @ 16 --- instance ends ---
  @112 --- static fields start ---
  @112 --- static fields end ---

 OopMapBlocks:   0  /  0

compiler.valhalla.valuetypes.MyValue2: field layout
  @ 16 --- instance fields start ---
  @ 24 "x" I
  @ 28 "y" B
  @ 29 "b" Z
  @ 16 "c" J
  @ 32 --- instance fields end ---
  @ 32 --- instance ends ---
  @112 --- static fields start ---
  @112 --- static fields end ---

 OopMapBlocks:   0  /  0

compiler.valhalla.valuetypes.MyValue1: field layout
  @ 16 --- instance fields start ---
  @ 24 "x" I
  @ 16 "y" J
  @ 32 "z" S
  @ 36 "o" Ljava.lang.Integer;
  @ 40 "oa" [I
  @ 44 "v1" Qcompiler.valhalla.valuetypes.MyValue2;
  @ 48 "v2" Qcompiler.valhalla.valuetypes.MyValue2;
  @ 28 "c" I
  @ 56 --- instance fields end ---
  @ 56 --- instance ends ---
  @112 --- static fields start ---
  @128 "s" I
  @120 "sf" J
  @112 "v3" Qcompiler.valhalla.valuetypes.MyValue2;
  @136 --- static fields end ---

 OopMapBlocks:   1  /  4
    Offset:  36  - 48 Count:   4

compiler.valhalla.valuetypes.MyValue3: field layout
  @ 16 --- instance fields start ---
  @ 76 "c" C
  @ 80 "bb" B
  @ 78 "s" S
  @ 56 "i" I
  @ 16 "l" J
  @ 84 "o" Ljava.lang.Object;
  @ 60 "f1" F
  @ 24 "f2" D
  @ 64 "f3" F
  @ 32 "f4" D
  @ 68 "f5" F
  @ 40 "f6" D
  @ 72 "f7" F
  @ 48 "f8" D
  @ 88 --- instance fields end ---
  @ 88 --- instance ends ---
  @112 --- static fields start ---
  @112 --- static fields end ---

 OopMapBlocks:   1  /  1
    Offset:  84  - 84 Count:   1

compiler.valhalla.valuetypes.MyValue4: field layout
  @ 16 --- instance fields start ---
  @ 16 "v1" Qcompiler.valhalla.valuetypes.MyValue3;
  @ 20 "v2" Qcompiler.valhalla.valuetypes.MyValue3;
  @ 24 --- instance fields end ---
  @ 24 --- instance ends ---
  @112 --- static fields start ---
  @112 --- static fields end ---

 OopMapBlocks:   1  /  2
    Offset:  16  - 20 Count:   2

compiler.valhalla.valuetypes.ValueCapableClass1$Value: field layout
  @ 16 --- instance fields start ---
  @ 16 "t" J
  @ 24 "x" I
  @ 28 "y" S
  @ 30 "z" S
  @ 32 --- instance fields end ---
  @ 32 --- instance ends ---
  @112 --- static fields start ---
  @112 --- static fields end ---

 OopMapBlocks:   0  /  0

For random generator using seed: 1551026262373040118
To re-run test with same seed value please add "-Djdk.test.lib.random.seed=1551026262373040118" to command line.
compiler.valhalla.valuetypes.ValueCapableClass2$Value: field layout
  @ 16 --- instance fields start ---
  @ 16 "u" J
  @ 24 --- instance fields end ---
  @ 24 --- instance ends ---
  @112 --- static fields start ---
  @112 --- static fields end ---

 OopMapBlocks:   0  /  0


Fred

> On Sep 14, 2017, at 10:50, Frederic Parain <frederic.parain at oracle.com> wrote:
> 
> Tobias,
> 
> Thank you for catching that.
> 
> There’s a bug in the layout computation, optional flattening code moves non-flattened
> values from the value types section of the layout to the nonstatic_oop section, but the size
> of the later was not updated accordingly.
> 
> Here’s an updated webrev fixing this issue:
> 
> http://cr.openjdk.java.net/~fparain/optional-flattening-interp/webrev.01/index.html
> 
> Regards,
> 
> Fred
> 
>> On Sep 14, 2017, at 03:46, Tobias Hartmann <tobias.hartmann at oracle.com> wrote:
>> 
>> Hi Fred,
>> 
>> there seems to be a problem with the field layout:
>> 
>> compiler.valhalla.valuetypes.MyValue1: field layout
>> @ 16 --- instance fields start ---
>> @ 24 "x" I
>> @ 16 "y" J
>> @ 32 "z" S
>> @ 40 "o" Ljava.lang.Integer;
>> @ 48 "oa" [I
>> @ 56 "v1" Qcompiler.valhalla.valuetypes.MyValue2;
>> @ 64 "v2" Qcompiler.valhalla.valuetypes.MyValue2;
>> @ 28 "c" I
>> @ 56 --- instance fields end ---
>> @ 56 --- instance ends ---
>> @176 --- static fields start ---
>> @192 "s" I
>> @184 "sf" J
>> @176 "v3" Qcompiler.valhalla.valuetypes.MyValue2;
>> @200 --- static fields end ---
>> 
>> OopMapBlocks:   1  /  4
>>   Offset:  40  - 64 Count:   4
>> 
>> "instance fields end" points to offset 56 which is not correct because the non-flattened field v2 is at offset 64.
>> 
>> Thanks,
>> Tobias
>> 
>> On 13.09.2017 21:41, Frederic Parain wrote:
>>> Greetings,
>>> Please review this changeset implementing optional field flattening
>>> in the interpreter and the runtime. The support for C2 is provided by
>>> Tobias in a separate changeset.
>>> http://cr.openjdk.java.net/~fparain/optional-flattening-interp/webrev.00/index.html
>>> Note that trying to run some programs/tests with this changeset and
>>> not Tobias’ changeset is likely to cause crashes unless interpreted mode
>>> is forced and passing/returning values in registers is disabled.
>>> Thank you,
>>> Fred
>