Impala Public Jenkins has submitted this change and it was merged. Change subject: IMPALA-4164: Avoid overly aggressive inlining in LLVM IR ......................................................................
IMPALA-4164: Avoid overly aggressive inlining in LLVM IR When generating IR functions during codegen, we used to always tag the functions with the "AlwaysInline" attribute. That potentially leads to excessive inlining, causing very long optimization / compilation time with marginal performance benefit at runtime. One of the reasons for doing it was that the "target-cpu" and "target-features" attributes were missing in the generated IR functions so the LLVM inliner considers them incompatible with the cross-compiled functions. As a result, the inliner will not inline the generated IR functions into cross-compiled functions and vice versa unless the "AlwaysInline" attributes exist. This change fixes the problem above by setting the "target-cpu" and "target-features" attributes of all IR functions to match that of of the host's CPUs so both generated IR functions and cross-compiled functions will have the same values for those attributes. With these attributes set, we now rely on the inliner of LLVM to determine whether a function is worth being inlined. With this change, the codegen time of a query with very long predicate went from 15s to 4s and the overall runtime went from 19s to 8s. Change-Id: I2d87ae8d222b415587e7320cb9072e4a8d6615ce Reviewed-on: http://gerrit.cloudera.org:8080/6941 Reviewed-by: Michael Ho <[email protected]> Tested-by: Impala Public Jenkins --- M be/src/codegen/llvm-codegen.cc M be/src/codegen/llvm-codegen.h A testdata/workloads/targeted-perf/queries/primitive_long_predicate.test 3 files changed, 214 insertions(+), 12 deletions(-) Approvals: Impala Public Jenkins: Verified Michael Ho: Looks good to me, approved -- To view, visit http://gerrit.cloudera.org:8080/6941 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: merged Gerrit-Change-Id: I2d87ae8d222b415587e7320cb9072e4a8d6615ce Gerrit-PatchSet: 11 Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-Owner: Michael Ho <[email protected]> Gerrit-Reviewer: Dan Hecht <[email protected]> Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Michael Ho <[email protected]> Gerrit-Reviewer: Tim Armstrong <[email protected]>
