Withdrawn: 8285246: AArch64: remove overflow check from InterpreterMacroAssembler::increment_mdp_data_at

[duke]

On Fri, 22 Apr 2022 14:35:00 GMT, Nick Gasson <ngasson at openjdk.org> wrote:

> Several reasons to do this:
> 
> - A 64-bit counter is realistically never going to overflow in the interpreter.  The PPC64 port also doesn't check for overflow for this reason.
> 
> - It's inconsistent with C1 which does not check for overflow.  (See e.g. `LIRGenerator::profile_branch()` which does `__ leal(...)` to add and explicitly doesn't set the flags.)
> 
> - We're checking for 64-bit overflow as the MDO cells are word-sized but accessors like `BranchData::taken()` silently truncate to uint which is 32 bit.  So I don't think this check is doing anything useful.
> 
> - I'd like to experiment with using LSE far atomics to update the MDO counters here, but the overflow check prevents that.
> 
> Tested jtreg tier1-3 and also verified that the counters for a particular test method were the same before and after when run with -Xbatch.

This pull request has been closed without being integrated.

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PR: https://git.openjdk.org/jdk/pull/8363