8271627: Use local field access in favor of Class.getClassLoader0

[cl4es]

Trivial startup hack/cleanup to use the classLoader field directly rather than the getClassLoader0 accessor.

Before aa12c8f there was no classLoader field and getClassLoader0 was a native method that retrieved the ClassLoader by calling into the runtime. However, now that classLoader is injected on mirror creation it makes less sense to use the accessor when not necessary.

---

Progress

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Issue

• JDK-8271627: Use local field access in favor of Class.getClassLoader0

Reviewers

• Mandy Chung (@mlchung - Reviewer)

Reviewing

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[mlbridge]

Webrevs

• 00: Full (2f65483d)

[mlchung]

This looks okay. I assume you concern about the early startup when this method is running in interpreted mode. Do you see any startup improvement by this change?

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8271627: Use local field access in favor of Class.getClassLoader0

Reviewed-by: mchung

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[cl4es]

Do you see any startup improvement by this change?

Very tiny, ~90 calls on bootstrap.

This looks okay.

Thanks!

I assume you concern about the early startup when this method is running in interpreted mode. Do you see any startup improvement by this change?

Yes. Many of these things that will be executed only when loading and bootstrapping, so might be interpreted for most of a JVM lifecycle. Right off the bat see a thousand or so less bytecode get executed on a hello world with this patch.

[cl4es]

/integrate

[openjdk]

Going to push as commit e621cff.

[openjdk]

@cl4es Pushed as commit e621cff.

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