Re: notes from Valhalla meeting 5/24/17

[John Rose]

We have talked about "condy" (a constant-pool friend for indy). Enclosed is the javadoc portion of a draft spec. The JVM spec. is not ready and will be sent separately. This javadoc reflects code checked into the condy branch of Amber. On Jun 5, 2017, at 4:21 PM, Karen Kinnear <karen.kinn...@oracle.com> wrote: From: Karen Kinnear <karen.kinn...@oracle.com> Subject: notes from Valhalla meeting 5/24/17 Date: June 5, 2017 at 4:21:59 PM PDT To: valhalla-spec-experts@openjdk.java.net … Condy (ConstantDynamic) update: John & Brian   goal  1. raising BootstrapMethod static argument limit to s to the 64-1 (from 251)      variable arity - package as an array which is unlimited      if short arg list: invoke, if long, invoke with args      both behaviors aligned, so specification doesn't have to specify line between short and long      javadoc almost ready   Dan H: note: java language today limits to 251   goal  2. support lazy resolution - resolve in BSM      new BSM mode: allows catching exceptions from subsidiary constant resolution      today we push arguments, proposing pushing the number of arguments, so the BSM can pull the arguments lazily      Expose a way for the BSM to get the arguments   Dan H: is this a BSM attribute index or a CP index?   Karen: we hope this is a BSM attribute index - to reduce constraints on the runtime implementation   Dan H:   Need to work out requirements across redefinitions     John: not specify if return old or new values   Dan H: useful for _expression_ trees in constant pool - mostly constant except for 1 or 2 parameters   goal 3. Allow writing BSM more like writing ordinary methods John: Also want groups of constants to not consume CP indices http://cr.openjdk.java.net/~jrose/jvm/specdiff-condy-2017-0609.zip