[aarch64-port-dev ] RFR: 8195859: AArch64: vtableStubs gtest fails after 8174962

[Andrew Dinn]

This new gtest exercises the i/vtable lookup code using very large table
indexes. This causes a test failure on AArch64 when the vtable offset is
too large to use as an immmediate literal in an ldr instruction (the
assembler barfs). This patch fixes the problem by using a load constant
and indirect register load in cases where the offset is to large for a
load immediate.

jira:   https://bugs.openjdk.java.net/browse/JDK-8195859
webrev: http://cr.openjdk.java.net/~adinn/8195859/

Reviews welcome.

Testing:

The fix ensures that the test now passes.

The JIRA is marked with fix-version 11. I'm not really sure if it also
needs to be in 10 but I think it probably does -- because a class with a
suitably large number of methods could cause an itable or vtable lookup
to fail. Opinions from reviewers would be welcome.

regards,


Andrew Dinn
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Senior Principal Software Engineer
Red Hat UK Ltd
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