Minor performance fix for NEON RAID-Z. #9725
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The NEON code replicates too closely the SSE code, including a masked 16-bits shift. But NEON, like AltiVec (openzfs#9539), has unsigned 8-bits shift, so use that instead and drop the masking. Signed-off-by: Romain Dolbeau <romain.dolbeau@european-processor-initiative.eu>
Codecov Report
@@ Coverage Diff @@
## master #9725 +/- ##
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- Coverage 79% 79% -<1%
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Files 420 420
Lines 123654 123654
========================================
- Hits 98069 98041 -28
- Misses 25585 25613 +28
Continue to review full report at Codecov.
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behlendorf
approved these changes
Dec 16, 2019
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This looks right to me after consulting the ARM reference manual. |
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... and sorry about that, this inefficiency should not have made it in the original submission for NEON :-( |
behlendorf
added
Status: Accepted
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The NEON code replicates too closely the SSE code, including
a masked 16-bits shift. But NEON, like AltiVec (#9539), has
unsigned 8-bits shift, so use that instead and drop the masking.
Signed-off-by: Romain Dolbeau romain.dolbeau@european-processor-initiative.eu
Motivation and Context
Performance.
Description
See commit message - removes two 'and' by using the proper shift.
How Has This Been Tested?
raidz_test
Types of changes
Checklist:
Signed-off-by.