Jim Apple has posted comments on this change. Change subject: IMPALA-2809: Improve ByteSwap with builtin function or SSE or AVX2. ......................................................................
Patch Set 11: (6 comments) http://gerrit.cloudera.org:8080/#/c/3081/11/be/src/benchmarks/bswap-benchmark.cc File be/src/benchmarks/bswap-benchmark.cc: Line 49: // SIMD 57.73 2.18X Why is SIMD so much slower? Line 222: MACRO_TEST_FBS_CASE(8, 5) This code can be further reduced by making 8,5 to 8,8 a loop. Line 260: FIXED_LEN_SIZE Which values are of interest? Is 3? Line 263: NUM_BYTES Please explain this in the comment above. Line 273: bit range The bit range of what? What are we doing with that bit range? where does "1" come from in "1x8=8"? Line 537: MACRO_TEST_AVX2_CASE(16, 9) Again, this can be reduced in size with a loop over the second param. -- 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: 11 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
