Tim Armstrong has posted comments on this change. Change subject: IMPALA-3629: Codegen TransferScratchTuples() in hdfs-parquet-scanner ......................................................................
Patch Set 3: (2 comments) http://gerrit.cloudera.org:8080/#/c/3774/3/be/src/exec/hdfs-parquet-scanner-ir.cc File be/src/exec/hdfs-parquet-scanner-ir.cc: PS3, Line 44: if (tuple_size == 0) { > Given that if (tuple_size == 0) { ...} is handling an entire scratch patch My thought was that tuple_size is a constant most of the function should be pruned out immediately and the remainder should be cheap to compile and optimise (no branches, not much code). Handling tuple_size == 0 outside of codegen'd code might give us a gain though so could be worth doing if it's simple. PS3, Line 61: while (scratch_tuple != scratch_tuple_end) { > Can we factor the while loop (or the loop body only) out as a separate func I thought about that but I'm not sure there's much gain once we prune out the branch above with our num_tuples value - we need most of the variables computed above for this loop. -- To view, visit http://gerrit.cloudera.org:8080/3774 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: comment Gerrit-Change-Id: Ic327e437c7cd2b3f92cdb11c1e907bfee2d44ee8 Gerrit-PatchSet: 3 Gerrit-Project: Impala Gerrit-Branch: cdh5-trunk Gerrit-Owner: Thomas Tauber-Marshall <[email protected]> Gerrit-Reviewer: Michael Ho <[email protected]> Gerrit-Reviewer: Thomas Tauber-Marshall <[email protected]> Gerrit-Reviewer: Tim Armstrong <[email protected]> Gerrit-HasComments: Yes
