Amogh Margoor has posted comments on this change. ( http://gerrit.cloudera.org:8080/17389 )
Change subject: IMPALA-10680: Replace StringToFloatInternal using fast_double_parser library ...................................................................... Patch Set 6: > Agree that the performance numbers are OK WRT strings of 20 or 30 > bytes long. > > Would it be possible to make another performance by calling > strtod() instead? > > According to the performance numbers documented here > (https://github.com/lemire/fast_double_parser), fast_double is > about 9.4x faster than strtod, tested with Apple Clang. > > I just curious how fast fast_double is in Impala, compared to > strtod(). So for both 20 and 30 length string fast_double_parser also uses strtod so not any noticeable difference observed. On checking code, they specify that more than 19 digits will generally cause overflow and are highly unlikely to occur so they just send it to strtod(). Just that even for strtod we need a null terminated string. So I think short string optimisation should work well here as longer strings are not likely. -- To view, visit http://gerrit.cloudera.org:8080/17389 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: Ic105ad38a2fcbf2fb4e8ae8af6d9a8e251a9c141 Gerrit-Change-Number: 17389 Gerrit-PatchSet: 6 Gerrit-Owner: Amogh Margoor <amarg...@gmail.com> Gerrit-Reviewer: Amogh Margoor <amarg...@gmail.com> Gerrit-Reviewer: Csaba Ringhofer <csringho...@cloudera.com> Gerrit-Reviewer: Impala Public Jenkins <impala-public-jenk...@cloudera.com> Gerrit-Reviewer: Qifan Chen <qc...@cloudera.com> Gerrit-Reviewer: Zoltan Borok-Nagy <borokna...@cloudera.com> Gerrit-Comment-Date: Wed, 26 May 2021 17:58:08 +0000 Gerrit-HasComments: No
