RFR: 8289552: Make intrinsic conversions between bit representations of half precision values and floats [v8]

[Vladimir Kozlov]

On Fri, 2 Sep 2022 00:52:49 GMT, Smita Kamath <svkamath at openjdk.org> wrote:

>> 8289552: Make intrinsic conversions between bit representations of half precision values and floats
>
> Smita Kamath has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Addressed review comments

I still got failures in tier1. All JVMCI tests filed with runs on AMD you with:

jdk.vm.ci.common.JVMCIError: Missing CPU feature constants: [F16C]
	at jdk.internal.vm.ci/jdk.vm.ci.hotspot.HotSpotJVMCIBackendFactory.convertFeatures(HotSpotJVMCIBackendFactory.java:79)
	at jdk.internal.vm.ci/jdk.vm.ci.hotspot.amd64.AMD64HotSpotJVMCIBackendFactory.computeFeatures(AMD64HotSpotJVMCIBackendFactory.java:53)
	at jdk.internal.vm.ci/jdk.vm.ci.hotspot.amd64.AMD64HotSpotJVMCIBackendFactory.createTarget(AMD64HotSpotJVMCIBackendFactory.java:74)
	at jdk.internal.vm.ci/jdk.vm.ci.hotspot.amd64.AMD64HotSpotJVMCIBackendFactory.createJVMCIBackend(AMD64HotSpotJVMCIBackendFactory.java:109)
	at jdk.internal.vm.ci/jdk.vm.ci.hotspot.HotSpotJVMCIRuntime.<init>(HotSpotJVMCIRuntime.java:587)
	at jdk.internal.vm.ci/jdk.vm.ci.hotspot.HotSpotJVMCIRuntime.runtime(HotSpotJVMCIRuntime.java:179)
	at jdk.internal.vm.ci/jdk.vm.ci.runtime.JVMCI.initializeRuntime(Native Method)
	at jdk.internal.vm.ci/jdk.vm.ci.runtime.JVMCI.getRuntime(JVMCI.java:65)

And `jdk/test/whitebox/CPUInfoTest.java` test failed with:

----------System.err:(13/810)----------
java.lang.RuntimeException: not all features are known: expected true, was false
	at jdk.test.lib.Asserts.fail(Asserts.java:594)
	at jdk.test.lib.Asserts.assertTrue(Asserts.java:486)
	at CPUInfoTest.main(CPUInfoTest.java:92)

-------------

PR: https://git.openjdk.org/jdk/pull/9781