8267791: [lworld][lw3] Support compiler blackholes for inline types

[shipilev]

JDK-8259316 added the support for compiler blackholes. We need to check and implement the support for inline type arguments for them. I am sure we would find more wrinkles with nano-benchmarks, but insofar sample benchmark work as they should:

public class PrimitiveClasses {
    static primitive class Value {
        long x;
        long y;
        public Value(long x, long y) {
            this.x = x;
            this.y = y;
        }
    }

    [volatile] Value v = Value.default;

    @Benchmark
    public Value test() {
        return v;
    }
}

Before: crash on assert, assert(vt->fast_out(i)->is_InlineTypeBase(), "Unexpected inline type user");

After, generated code in non-volatile case shows blackhole of individual components:

$ java -Djmh.blackhole.mode=COMPILER -jar target/benchmarks.jar PrimitiveClasses -prof perfasm
...
....[Hottest Region 1]..............................................................................
c2, level 4, org.openjdk.jmh_generated.PrimitiveClasses_test_jmhTest::test_avgt_jmhStub, version 641 (39 bytes) 
...
         ↗  0x00007f67bcc8eee0:   mov    0x18(%r8),%r10        ; read and blackhole MyValue.x
  0.02%  │  0x00007f67bcc8eee4:   mov    0x10(%r8),%r11        ; read and blackhole MyValue.y
  0.10%  │  0x00007f67bcc8eee8:   movzbl 0x94(%r14),%r11d      ; read isDone
  0.10%  │  0x00007f67bcc8eef0:   mov    0x3b0(%r15),%r10      ; TL handshake
  2.79%  │  0x00007f67bcc8eef7:   add    $0x1,%rbp             ; ops++
         │  0x00007f67bcc8eefb:   test   %eax,(%r10)           ; TL handshake
 86.74%  │  0x00007f67bcc8eefe:   test   %r11d,%r11d           ; isDone?
  2.31%  ╰  0x00007f67bcc8ef01:   je     0x00007f67bcc8eee0    

And generated code in volatile case shows blackhole of the box (with the null-check):

          ↗   0x00007f3948c8db70:   shl    $0x3,%r10            ; unpack and blackhole MyValue
  0.02%   │↗  0x00007f3948c8db74:   movzbl 0x94(%r14),%r8d      ; read isDone
  0.68%   ││  0x00007f3948c8db7c:   mov    0x3b0(%r15),%r9      ; TL handshake
  0.72%   ││  0x00007f3948c8db83:   add    $0x1,%rbp            ; ops++
          ││  0x00007f3948c8db87:   test   %eax,(%r9)           ; TL handshake
 92.30%   ││  0x00007f3948c8db8a:   test   %r8d,%r8d            ; isDone?
         ╭││  0x00007f3948c8db8d:   jne    0x00007f3948c8dba4   
         │││  0x00007f3948c8db8f:   mov    0xc(%r11),%r10d      ; load "v" (MyValue box)
  0.35%  │││  0x00007f3948c8db93:   test   %r10d,%r10d          ; null check it
         │╰│  0x00007f3948c8db96:   jne    0x00007f3948c8db70   

---

Progress

• Change must not contain extraneous whitespace

Issue

• JDK-8267791: [lworld][lw3] Support compiler blackholes for inline types

Reviewers

• Tobias Hartmann (@TobiHartmann - Committer)

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@shipilev This change now passes all automated pre-integration checks.

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8267791: [lworld][lw3] Support compiler blackholes for inline types

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At the time when this comment was updated there had been 4 new commits pushed to the lworld branch:

• f1b3269: 8267923: [lworld] Javac's implementation differs from JEP401 in a few matters.
• 44cb67e: 8267818: [lworld] [AArch64] Shenandoah barrier set build warnings and register conflict
• 0871590: 8266890: [lworld] [AArch64] add support for InlineTypePassFieldsAsArgs
• 0f1c33c: 8267710: [lworld][lw3] Hook AlwaysAtomicAccesses to primitive classes atomicity rules

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Webrevs

• 01: Full - Incremental (20ecae3f)
• 00: Full (909d929a)

[shipilev]

/integrate

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@shipilev
Your change (at version 20ecae3) is now ready to be sponsored by a Committer.

[TobiHartmann]

/sponsor

[openjdk]

@TobiHartmann @shipilev Since your change was applied there have been 4 commits pushed to the lworld branch:

• f1b3269: 8267923: [lworld] Javac's implementation differs from JEP401 in a few matters.
• 44cb67e: 8267818: [lworld] [AArch64] Shenandoah barrier set build warnings and register conflict
• 0871590: 8266890: [lworld] [AArch64] add support for InlineTypePassFieldsAsArgs
• 0f1c33c: 8267710: [lworld][lw3] Hook AlwaysAtomicAccesses to primitive classes atomicity rules

Your commit was automatically rebased without conflicts.

Pushed as commit f931661.

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