JDK-8217998: Remove method_type field associated with the appendix field of an indy or method handle call

[coleen.phillimore at oracle.com]

Hi Lois,  I like that there are no longer two resolved references for 
indy instructions, especially if it wasn't used.

http://cr.openjdk.java.net/~lfoltan/bug_jdk8217998.2/webrev/src/hotspot/share/interpreter/linkResolver.cpp.udiff.html

I can't find a call where set_handle() passes false for the 
_has_local_sig field.

Can you rename CallInfo::_has_local_signature, since it's not that much 
longer and reads better?

+ const bool has_local_sig = call_info.has_local_signature();
+ assert(has_local_sig, "MHs and indy are always sig-poly");

So why do you need this field if it's always true?  Was hoping for a 
cpCache bit back :)

Perhaps there's a future use?

http://cr.openjdk.java.net/~lfoltan/bug_jdk8217998.2/webrev/src/hotspot/share/oops/cpCache.hpp.udiff.html

+ has_local_signature_shift = 25, // (M) does the call site have a 
per-site signature (sig-poly methods)?


Can you make this an "S" vs. "M" and change the coment in the top of 
cpCache.hpp:

// _flags     [tos|0|F=0|M|A|I|f|0|vf|indy_rf|000|00000|psize] (for 
method entries)
// bit length [ 4 |1| 1 |1|1|1|1|1|1 |-4--|--8--|--8--]

And a line under this:

// A      = call site has an appendix argument (loaded from resolved 
references)

Although I don't like this comment because it gets out of date.

Thanks,
Coleen

On 2/4/19 7:32 AM, Lois Foltan wrote:
> Please review this change that removes the unused method_type field 
> associated with the appendix field of an indy or method handle call.  
> This is the first of a series of changes working towards JDK-8210685: 
> Bootstrap method consolidation.
>
> open webrev at: 
> http://cr.openjdk.java.net/~lfoltan/bug_jdk8217998.1/webrev/
> bug link: https://bugs.openjdk.java.net/browse/JDK-8217998
> co-contributors: Lois Foltan & John Rose
>
> Testing: hs-tier1-4 & jdk-tier1-3 (all platforms), hs-tier5-8 (linux 
> only), JCK vm & lang (linux only)
>
> Thanks,
> Lois