On Mon, 20 May 2024 10:52:27 GMT, Claes Redestad <[email protected]> wrote:
> We can fold the call to `Objects.checkIndex` into the code generated in
> generateTypeSwitchSkeleton instead of doing so by filtering the MH argument.
> This loads 9 less classes (of which 8 generated LFs and Species classes) on a
> minimal test, while being neutral on a throughput sanity test:
>
>
> Name Cnt Base Error Test Error Unit Change
> SwitchSanity.switchSum 15 8,162 ± 0,117 8,152 ± 0,131 ns/op 1,00x (p =
> 0,800 )
> * = significant
> ```
>
> A few additional optimizations includes generating the switch method using
> the precise type (to avoid the need for an explicitCast adaptation), and
> moving some seldom used `findStatic` calls to a holder. All in all this means
> a reduction by 33-34M cycles to bootstrap a trivial switch expression on my
> M1.
Changes requested by liach (Author).
src/java.base/share/classes/java/lang/runtime/SwitchBootstraps.java line 630:
> 628: .withMethodBody("typeSwitch",
> 629:
> MethodTypeDescImpl.ofValidated(ConstantDescs.CD_int,
> 630:
> ClassDesc.ofDescriptor(selectorType.descriptorString()),
`selectorType` can be primitive, therefore verification errors arise at `aload`
in the generated code. This is why tests fail on GitHub actions.
-------------
PR Review: https://git.openjdk.org/jdk/pull/19307#pullrequestreview-2067245226
PR Review Comment: https://git.openjdk.org/jdk/pull/19307#discussion_r1607425026
