Jim Apple has posted comments on this change. Change subject: IMPALA-2809: Improve ByteSwap with builtin function or SSE or AVX2. ......................................................................
Patch Set 5: (2 comments) http://gerrit.cloudera.org:8080/#/c/3081/5/be/src/util/bit-util.inline.h File be/src/util/bit-util.inline.h: Line 139: __attribute__((target("sse4.2"))) > Hi Jim. This issue has been discussed with some other engineers from Cloude You have explained it clearly; thank you! I agree with what you said, but, given that we seem to compile with -march=x86-64, do these functions actually get picked up by the compiler and compiled; that is, do their __attribute__ targets become active during compilation? Line 174: static const FuncPointer SIMDFuncTable[2] = {ByteSwapSSE_Unit, ByteSwapAVX2_Unit}; > Hi Jim. Thank you so much for your clarification. As you can see here, the I don't know what "polynomial", you are referring to. I think you should check to see if a run-time computation is being made to calculate func_idx, and, if so, remove it by lifting the computation of func_idx to a compile-time constant. -- To view, visit http://gerrit.cloudera.org:8080/3081 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: comment Gerrit-Change-Id: I392ed5a8d5683f30f161282c228c1aedd7b648c1 Gerrit-PatchSet: 5 Gerrit-Project: Impala Gerrit-Branch: cdh5-trunk Gerrit-Owner: Youwei Wang <[email protected]> Gerrit-Reviewer: Alex Behm <[email protected]> Gerrit-Reviewer: Jim Apple <[email protected]> Gerrit-Reviewer: Marcel Kornacker <[email protected]> Gerrit-Reviewer: Mostafa Mokhtar <[email protected]> Gerrit-Reviewer: Tim Armstrong <[email protected]> Gerrit-Reviewer: Youwei Wang <[email protected]> Gerrit-HasComments: Yes
