Bug #18517: 0 << (2**40) is NoMemoryError but 0 << (2**80) is 0

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 3.0.2p107 (2021-07-07 revision 0db68f0233) [x86_64-linux]
• Backport: 2.6: UNKNOWN, 2.7: DONE, 3.0: DONE, 3.1: DONE

[Eregon (Benoit Daloze)]

I've been looking at Integer#{<<,>>} with RHS bignum and long and there are several issues.

This seems a clear bug though:

$ruby -e 'p 0 << (2**40)'
-e: failed to allocate memory (NoMemoryError)
$ ruby -e 'p 0 << (2**80)'
0

[Eregon (Benoit Daloze)]

• Related to Bug #18518: NoMemoryError + [FATAL] failed to allocate memory for twice 1 << large added

[nobu (Nobuyoshi Nakada)]

https://github.com/ruby/ruby/pull/5494

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed

Applied in changeset git|6a6227e0168b059c3ed34c9f0ace2e5dc2364221.

---

Shifting zero always results in zero [Bug #18517]

[byroot (Jean Boussier)]

• Backport changed from 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN to 2.6: UNKNOWN, 2.7: REQUIRED, 3.0: REQUIRED, 3.1: REQUIRED

[naruse (Yui NARUSE)]

• Backport changed from 2.6: UNKNOWN, 2.7: REQUIRED, 3.0: REQUIRED, 3.1: REQUIRED to 2.6: UNKNOWN, 2.7: REQUIRED, 3.0: REQUIRED, 3.1: DONE

ruby_3_1 1f17463dec2ab1535096cb56005a840eae4fea5b merged revision(s) 6a6227e0168b059c3ed34c9f0ace2e5dc2364221.

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 2.6: UNKNOWN, 2.7: REQUIRED, 3.0: REQUIRED, 3.1: DONE to 2.6: UNKNOWN, 2.7: REQUIRED, 3.0: DONE, 3.1: DONE

ruby_3_0 9c2213f6695a16917dbe7b5a3a334116d6d8bbf6 merged revision(s) 6a6227e0168b059c3ed34c9f0ace2e5dc2364221.

[usa (Usaku NAKAMURA)]

• Backport changed from 2.6: UNKNOWN, 2.7: REQUIRED, 3.0: DONE, 3.1: DONE to 2.6: UNKNOWN, 2.7: DONE, 3.0: DONE, 3.1: DONE