8221249: x86: make r12_heapbase register available when compressed oops do not require it

[shipilev]

JDK-8217909 untied %r12 (heap_base) register when CompressedOops are disabled. We can improve on that by also untying heap_base register when zero-based/32-bit compressed oops are enabled,.

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Progress

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Issue

• JDK-8221249: x86: make r12_heapbase register available when compressed oops do not require it

Download

$ git fetch https://git.openjdk.java.net/jdk pull/92/head:pull/92
$ git checkout pull/92

[shipilev]

/test tier1

[openjdk]

@shipilev you need to get approval to run the tests in tier1 for commits up until 19c252f

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[shipilev]

/test builds

[openjdk]

@shipilev you need to get approval to run the tests in builds for commits up until 19c252f

[openjdk]

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