* [ruby-core:103453] [Ruby master Bug#17804] Math.cbrt(0.0) returns NaN
@ 2021-04-15 1:17 ray.chason
2021-04-15 1:34 ` [ruby-core:103456] " xtkoba+ruby
2021-04-28 21:36 ` [ruby-core:103647] " merch-redmine
0 siblings, 2 replies; 3+ messages in thread
From: ray.chason @ 2021-04-15 1:17 UTC (permalink / raw)
To: ruby-core
Issue #17804 has been reported by chasonr (Ray chason).
----------------------------------------
Bug #17804: Math.cbrt(0.0) returns NaN
https://bugs.ruby-lang.org/issues/17804
* Author: chasonr (Ray chason)
* Status: Open
* Priority: Normal
* ruby -v: ruby 3.0.1p64 (2021-04-05 revision 0fb782ee38) [x86_64-linux]
* Backport: 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: UNKNOWN
----------------------------------------
Math.cbrt(0.0) returns NaN. It should return 0.0.
From reading the implementation, I expect this bug to happen only if glibc is in use. The failing section reads:
#if defined __GLIBC__
if (isfinite(r)) {
r = (2.0 * r + (f / r / r)) / 3.0;
}
#endif
and this produces a NaN when f and r are both 0.
--
https://bugs.ruby-lang.org/
^ permalink raw reply [flat|nested] 3+ messages in thread* [ruby-core:103456] [Ruby master Bug#17804] Math.cbrt(0.0) returns NaN 2021-04-15 1:17 [ruby-core:103453] [Ruby master Bug#17804] Math.cbrt(0.0) returns NaN ray.chason @ 2021-04-15 1:34 ` xtkoba+ruby 2021-04-28 21:36 ` [ruby-core:103647] " merch-redmine 1 sibling, 0 replies; 3+ messages in thread From: xtkoba+ruby @ 2021-04-15 1:34 UTC (permalink / raw) To: ruby-core Issue #17804 has been updated by xtkoba (Tee KOBAYASHI). FWIW, that code was introduced by commit commit:c995315153f7403636ec0d6119b7885668b32039. ---------------------------------------- Bug #17804: Math.cbrt(0.0) returns NaN https://bugs.ruby-lang.org/issues/17804#change-91551 * Author: chasonr (Ray Chason) * Status: Open * Priority: Normal * ruby -v: ruby 3.0.1p64 (2021-04-05 revision 0fb782ee38) [x86_64-linux] * Backport: 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: UNKNOWN ---------------------------------------- Math.cbrt(0.0) returns NaN. It should return 0.0. From reading the implementation, I expect this bug to happen only if glibc is in use. The failing section reads: #if defined __GLIBC__ if (isfinite(r)) { r = (2.0 * r + (f / r / r)) / 3.0; } #endif and this produces a NaN when f and r are both 0. -- https://bugs.ruby-lang.org/ ^ permalink raw reply [flat|nested] 3+ messages in thread
* [ruby-core:103647] [Ruby master Bug#17804] Math.cbrt(0.0) returns NaN 2021-04-15 1:17 [ruby-core:103453] [Ruby master Bug#17804] Math.cbrt(0.0) returns NaN ray.chason 2021-04-15 1:34 ` [ruby-core:103456] " xtkoba+ruby @ 2021-04-28 21:36 ` merch-redmine 1 sibling, 0 replies; 3+ messages in thread From: merch-redmine @ 2021-04-28 21:36 UTC (permalink / raw) To: ruby-core Issue #17804 has been updated by jeremyevans0 (Jeremy Evans). I've submitted a pull request to fix this: https://github.com/ruby/ruby/pull/4425 ---------------------------------------- Bug #17804: Math.cbrt(0.0) returns NaN https://bugs.ruby-lang.org/issues/17804#change-91743 * Author: chasonr (Ray Chason) * Status: Open * Priority: Normal * ruby -v: ruby 3.0.1p64 (2021-04-05 revision 0fb782ee38) [x86_64-linux] * Backport: 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: UNKNOWN ---------------------------------------- Math.cbrt(0.0) returns NaN. It should return 0.0. From reading the implementation, I expect this bug to happen only if glibc is in use. The failing section reads: #if defined __GLIBC__ if (isfinite(r)) { r = (2.0 * r + (f / r / r)) / 3.0; } #endif and this produces a NaN when f and r are both 0. -- https://bugs.ruby-lang.org/ ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-04-28 21:36 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-04-15 1:17 [ruby-core:103453] [Ruby master Bug#17804] Math.cbrt(0.0) returns NaN ray.chason 2021-04-15 1:34 ` [ruby-core:103456] " xtkoba+ruby 2021-04-28 21:36 ` [ruby-core:103647] " merch-redmine
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