Csaba Ringhofer has posted comments on this change. ( http://gerrit.cloudera.org:8080/14588 )
Change subject: IMPALA-6660: Change -0/+0 floating point to compare as equal in hash table ...................................................................... Patch Set 4: (2 comments) http://gerrit.cloudera.org:8080/#/c/14588/4/be/src/codegen/codegen-anyval.cc File be/src/codegen/codegen-anyval.cc: http://gerrit.cloudera.org:8080/#/c/14588/4/be/src/codegen/codegen-anyval.cc@787 PS4, Line 787: // Check for -0 == +0 equality : llvm::Value* cmp_zero = builder_->CreateFCmpOEQ(ConvertToPositiveZero(local_val), : ConvertToPositiveZero(val), "cmp_zero"); : llvm::Value* cmp_raw_zero = : builder_->CreateOr(cmp_raw, cmp_zero, "cmp_raw_with_zero"); Can you check whether this is really needed? http://gerrit.cloudera.org:8080/#/c/14588/4/be/src/exec/hash-table.cc File be/src/exec/hash-table.cc: http://gerrit.cloudera.org:8080/#/c/14588/4/be/src/exec/hash-table.cc@257 PS4, Line 257: if (RawValue::IsFloatingZero(val, expr_type)) { : val = const_cast<void*>(RawValue::PositiveFloatingZero(expr_type)); : } : if (RawValue::IsFloatingZero(loc, expr_type)) { : loc = const_cast<void*>(RawValue::PositiveFloatingZero(expr_type)); : } : if (RawValue::Eq(loc, val, expr_type)) continue; Does this actually make a difference? RawValue::Eq simply compares doubles and floats with == which should return true for 0.0=-0.0 I think that the only functional difference is using CanonicalValue in EvalRow, because its output is hashed bit by bit, so -0 and 0 are different there. -- To view, visit http://gerrit.cloudera.org:8080/14588 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I6bb1a817c81c452d041238c19cb6c9f602a5d565 Gerrit-Change-Number: 14588 Gerrit-PatchSet: 4 Gerrit-Owner: Norbert Luksa <norbert.lu...@cloudera.com> Gerrit-Reviewer: Csaba Ringhofer <csringho...@cloudera.com> Gerrit-Reviewer: Daniel Becker <daniel.bec...@cloudera.com> Gerrit-Reviewer: Impala Public Jenkins <impala-public-jenk...@cloudera.com> Gerrit-Reviewer: Norbert Luksa <norbert.lu...@cloudera.com> Gerrit-Reviewer: Tim Armstrong <tarmstr...@cloudera.com> Gerrit-Reviewer: Zoltan Borok-Nagy <borokna...@cloudera.com> Gerrit-Comment-Date: Thu, 14 Nov 2019 16:59:35 +0000 Gerrit-HasComments: Yes
