Allow multianewarray for 1D arrays on Z

[JamesKingdon]

The existing multianewarray evaluator assumes at least 2 dimensions which is consistent with normal usage. However the spec permits 1D arrays and this is exploited by some languages, e.g. Groovy.

See #17360 for more background and #17358 for the corresponding change on X

[JamesKingdon]

Personal build 17174 passed sanity.functional

I used a test case with asm to exercise multianewarray for a 1D array and logged the compile. The following line in the log indicates the new code is active:

Disabling inline allocations for multianewarray of dim 1

Bytecode for the test method:

        0, JBbipush                                  10
        2, JBmultianewarray                       3                      1
        6, JBastore0
        7, JBaload0
        8, JBreturn1

The generated code was:

<instructions
        title="Mixed Mode Disassembly"
        method="AsmTestClass.doTest()Ljava/lang/Object;">


 \\ AsmTestClass.doTest()Ljava/lang/Object;
 \\    0 JBbipush 10

     0x3ff5e5073f8 fffffffc [     0x3ff5d511d50]                                                   Label L0016:
     0x3ff5e5073f8 fffffffc [     0x3ff5d4b2900] 00 00 00 05                                       .dd     0x00000005
     0x3ff5e5073fc 00000000 [     0x3ff5d4b29d0]                                                   proc
     0x3ff5e5073fc 00000000 [     0x3ff5d512070] e3 e0 5f f8 ff 24                                 STG     GPR14,#401 -8(GPR5)
     0x3ff5e507402 00000006 [     0x3ff5d512200] e3 50 5f d8 ff 71                                 LAY     GPR5,#402 -40(GPR5)
     0x3ff5e507408 0000000c [     0x3ff5d512390] e3 50 d0 50 00 21                                 CLG     GPR5,#403 80(GPR13)
     0x3ff5e50740e 00000012 [     0x3ff5d512520] a7 44 00 1e                                       BRC     BM(0x4), Snippet Label L0018, labelTargetAddr=0x000003FF5E50744A
     0x3ff5e507412 00000016 [     0x3ff5d512700]                                                   Label L0019:
     0x3ff5e507412 00000016 [     0x3ff5d512ee0]                                                   assocreg
     0x3ff5e507412 00000016 [     0x3ff5d5128a0] e5 48 50 18 00 00                                 MVGHI   #404 24(GPR5),0x0000
     0x3ff5e507418 0000001c [     0x3ff5d4b2af0]                                                   fence   Relative [ 000003FF5D44E0E0 ] BBStart <block_2> (frequency 10000)
     0x3ff5e507418 0000001c [     0x3ff5d4b2e50] e5 4c 50 14 00 0a                                 MVHI     Auto[<auto slot -1>] 20(GPR5),0x000a

 \\ AsmTestClass.doTest()Ljava/lang/Object;
 \\    2 JBmultianewarray 3 dims 1 [Ljava/lang/Class;

     0x3ff5e50741e 00000022 [     0x3ff5d4b42b0] c0 1f 00 09 b4 00                                 LLILF   GPR1,635904
     0x3ff5e507424 00000028 [     0x3ff5d4b43c0] c0 18 00 00 00 00                                 IIHF    GPR1,0
     0x3ff5e50742a 0000002e [     0x3ff5d4b4540] a7 28 00 01                                       LHI     GPR2,0x1
     0x3ff5e50742e 00000032 [     0x3ff5d4b4710] 41 30 50 14                                       LA      GPR3, Auto[<auto slot -1>] 20(GPR5)
     0x3ff5e507432 00000036 [     0x3ff5d50ef30]                                                   assocreg
     0x3ff5e507432 00000036 [     0x3ff5d50e940] c0 e5 13 a3 d8 a7                                 BRASL   GPR14,0x0000000000000000, targetAddr=0x000003FF85982580 (offset=0x000000002747B14E)

 \\ AsmTestClass.doTest()Ljava/lang/Object;
 \\    6 JBastore0

     0x3ff5e507438 0000003c [     0x3ff5d50fa20] e3 20 50 18 00 24                                 STG     GPR2, Auto[<auto slot 0>] 24(GPR5)
     0x3ff5e50743e 00000042 [     0x3ff5d510340]                                                   assocreg

 \\ AsmTestClass.doTest()Ljava/lang/Object;
 \\    8 JBreturn1

     0x3ff5e50743e 00000042 [     0x3ff5d5131f0] e3 e0 50 20 00 04                                 LG      GPR14,#405 32(GPR5)
     0x3ff5e507444 00000048 [     0x3ff5d513440] 41 50 50 28                                       LA      GPR5,#407 40(GPR5)

 \\ AsmTestClass.doTest()Ljava/lang/Object;
 \\    6 JBastore0

     0x3ff5e507448 0000004c [     0x3ff5d513510] 07 fe                                             BCR     BER(mask=0xf), GPR14
     0x3ff5e50744a 0000004e [     0x3ff5d50fd70]                                                   retn
     0x3ff5e50744a 0000004e [     0x3ff5d5104d0]                                                   fence   Relative [ 000003FF5D44E0E4 ] BBEnd </block_2>

     0x3ff5e50744a 0000004e [     0x3ff5d510aa0]                                                   assocreg
     0x3ff5e50744a 0000004e [     0x3ff5d511e90]                                                   Label L0017:
</instructions>

[r30shah]

Do we need a comment here? I think text in the Assert message is clear about disabling the inline allocation for multianewarray and also the comment on function makes it clear that for <1 dimensional array it calls helper.

[JamesKingdon]

thanks, deleted

[r30shah]

Thanks a lot @JamesKingdon for fixing this on Z. Changes looks good to me. Left a comment about small nit-pick.

@joransiu can I request you to launch test on this PR and merge this ?

[joransiu]

LGTM. I agree the comment Rahil highlighted is unnecessary.

[joransiu]

Jenkins test sanity zlinux jdk11,jdk17