MVT change in new opcode numbers?
karen.kinnear at oracle.com
Thu Jul 27 21:02:52 UTC 2017
Many thanks for being flexible here.
> On Jul 27, 2017, at 4:01 PM, Bjorn B Vardal <bjornvar at ca.ibm.com> wrote:
> Yes, we should be able to work with the lower range.
> ----- Original message -----
> From: Karen Kinnear <karen.kinnear at oracle.com>
> To: Bjorn B Vardal <bjornvar at ca.ibm.com>
> Cc: valhalla-spec-experts at openjdk.java.net
> Subject: Re: MVT change in new opcode numbers?
> Date: Thu, Jul 27, 2017 3:10 PM
> Sigh - it does matter to us where it starts - we do quickening internally using the higher ranges and our code knows about
> ranges for “real” java byte codes vs internal byte codes.
> If it is possible we would appreciate the lower numbers since the higher numbers would slow down our range checking.
>> On Jul 27, 2017, at 2:09 PM, Bjorn B Vardal <bjornvar at ca.ibm.com <mailto:bjornvar at ca.ibm.com>> wrote:
>> If you want to make it contiguous, does it matter to you (HotSpot) where it starts? If not, the most practical for us would be 217-225. If that doesn't work, I believe we'll be able to work with 203-211.
>> ----- Original message -----
>> From: Karen Kinnear <karen.kinnear at oracle.com <mailto:karen.kinnear at oracle.com>>
>> Sent by: "valhalla-spec-experts" <valhalla-spec-experts-bounces at openjdk.java.net <mailto:valhalla-spec-experts-bounces at openjdk.java.net>>
>> To: valhalla-spec-experts at openjdk.java.net <mailto:valhalla-spec-experts at openjdk.java.net>
>> Subject: MVT change in new opcode numbers?
>> Date: Thu, Jul 27, 2017 1:38 PM
>> Dan Smith, Bjorn, Dan H, Remi -
>> Does it work for you if we change the JVMS to use the following value-type byte codes - i.e.
>> make them contiguous?
>> In the hotspot implementation, we ran out of internally-usable byte codes when we left holes here.
>> _vload = 203, // 0xcb
>> 248 _vstore = 204, // 0xcc
>> 249 _vaload = 205, // 0xcd
>> 250 _vastore = 206, // 0xce
>> 251 _vreturn = 207, // 0xcf
>> 252 _vdefault = 208, // 0xd0
>> 253 _vwithfield = 209, // 0xd1
>> 254 _vbox = 210, // 0xd2
>> 255 _vunbox = 211, // 0xd3
>> (note: we removed vgetfield)
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