Summary: | JSC Math.pow tests makes wrong assumptions on precision | ||||||||
---|---|---|---|---|---|---|---|---|---|
Product: | WebKit | Reporter: | Guillaume Emont <guijemont> | ||||||
Component: | JavaScriptCore | Assignee: | Nobody <webkit-unassigned> | ||||||
Status: | RESOLVED INVALID | ||||||||
Severity: | Normal | CC: | fpizlo | ||||||
Priority: | P2 | ||||||||
Version: | WebKit Nightly Build | ||||||||
Hardware: | Unspecified | ||||||||
OS: | Unspecified | ||||||||
Bug Depends on: | |||||||||
Bug Blocks: | 108664 | ||||||||
Attachments: |
|
Description
Guillaume Emont
2015-10-21 11:42:44 PDT
Created attachment 263708 [details]
Patch
Created attachment 263752 [details]
Patch
New version with typo corrected
Comment on attachment 263752 [details]
Patch
Sounds like a mips bug. Jsc aims to have strong precision guarantees.
After further checking, it seems like the issue that I encountered with that test only happens when using uclibc. In that case, Math.pow(2,42.5) returns 6219777023950.949. Though that number looks like it has more precision, it turns out[1] that it seems that it is not rounded properly, but rather truncated (the correct rounding to 3 digits would be 6219777023950.950), so it seems like it is a uclibc issue. Sorry for the noise. [1] http://www.wolframalpha.com/input/?i=2%5E42.5 |