Issue #4040 has been updated by jeremyevans0 (Jeremy Evans). I've updated my pull request to include additional optimizations for: * cfunc: 10-15* for f(*a) and 35-40% for f(*a, **kw) if kw is empty * send: 5-115% depending on type of call * symproc: 5-100% depending of type of call * method_missing: 10-115% depending on type of call The cfunc optimization works by copying the array contents to the stack instead of using CALLER_SETUP_ARG. The send, symproc, and method_missing optimizations are achieved by avoiding unnecessary use of CALLER_SETUP_ARG. Hopefully these additional optimizations help offset any performance decrease from the additional checks needed to fix this issue. ---------------------------------------- Bug #4040: SystemStackError with Hash[*a] for Large _a_ https://bugs.ruby-lang.org/issues/4040#change-102613 * Author: runpaint (Run Paint Run Run) * Status: Open * Priority: Normal * Assignee: ko1 (Koichi Sasada) * ruby -v: ruby 1.9.3dev (2010-11-09 trunk 29737) [x86_64-linux] * Backport: 2.2: UNKNOWN, 2.3: UNKNOWN, 2.4: UNKNOWN ---------------------------------------- =begin I've been hesitating over whether to file a ticket about this, so please feel free to close if I've made the wrong choice. I often use Hash[*array.flatten] in IRB to convert arrays of arrays into hashes. Today I noticed that if the array is big enough, this would raise a SystemStackError. Puzzled, I looked deeper. I assumed I was hitting the maximum number of arguments a method's argc can hold, but realised that the minimum size of the array needed to trigger this exception differed depending on whether I used IRB or not. So, presumably this is indeed exhausting the stack... In IRB, the following is the minimal reproduction of this problem: Hash[*130648.times.map{ 1 }]; true I haven't looked for the minimum value needed with `ruby -e`, but the following reproduces: ruby -e 'Hash[*1380888.times.map{ 1 }]' I suppose this isn't technically a bug, but maybe it offers another argument for either #666 or an extension of #3131. =end -- https://bugs.ruby-lang.org/