Backports
Issue | Fix Version | Assignee | Priority | Status | Resolution | Resolved In Build |
---|---|---|---|---|---|---|
JDK-8260756 | openjdk8u292 | Andrew Hughes | P4 | Resolved | Fixed | b01 |
Description
For several times I noticed the following pattern in JIT code (the java heap size is set to 200MB):
2042 0x0000007f6c9419c4: ldr w14, [x11,#32] ;*getfield buffer
2043 ; - org.apache.hadoop.io.DataInputBuffer::reset@1 (line 83)
2044 ; - org.apache.hadoop.mapreduce.task.ReduceContextImpl::nextKeyValue@88 (line 141)
2045 ; - org.apache.hadoop.mapreduce.task.ReduceContextImpl$ValueIterator::next@209 (li ne 239)
2046 ; - org.apache.hadoop.examples.WordCount$IntSumReducer::reduce@23 (line 60)
2047
2048 0x0000007f6c9419c8: cmp w14, wzr
2049 0x0000007f6c9419cc: b.eq 0x0000007f6c9425e4 ;*invokevirtual reset
2050 ; - org.apache.hadoop.io.DataInputBuffer::reset@7 (line 83)
2051 ; - org.apache.hadoop.mapreduce.task.ReduceContextImpl::nextKeyValue@88 (line 141)
2052 ; - org.apache.hadoop.mapreduce.task.ReduceContextImpl$ValueIterator::next@209 (li ne 239)
The two cmp and b.eq instructions can be combined into one "cbz" instruction.
Currently, the aarch64 port only makes use of CBZ and CBNZ when comparing operands with Integer/Long/Pointer type with zero. The issue can be fixed by add one similar combine template in the ad file for Narrow pointer types, just like the sparc port does.
2042 0x0000007f6c9419c4: ldr w14, [x11,#32] ;*getfield buffer
2043 ; - org.apache.hadoop.io.DataInputBuffer::reset@1 (line 83)
2044 ; - org.apache.hadoop.mapreduce.task.ReduceContextImpl::nextKeyValue@88 (line 141)
2045 ; - org.apache.hadoop.mapreduce.task.ReduceContextImpl$ValueIterator::next@209 (li ne 239)
2046 ; - org.apache.hadoop.examples.WordCount$IntSumReducer::reduce@23 (line 60)
2047
2048 0x0000007f6c9419c8: cmp w14, wzr
2049 0x0000007f6c9419cc: b.eq 0x0000007f6c9425e4 ;*invokevirtual reset
2050 ; - org.apache.hadoop.io.DataInputBuffer::reset@7 (line 83)
2051 ; - org.apache.hadoop.mapreduce.task.ReduceContextImpl::nextKeyValue@88 (line 141)
2052 ; - org.apache.hadoop.mapreduce.task.ReduceContextImpl$ValueIterator::next@209 (li ne 239)
The two cmp and b.eq instructions can be combined into one "cbz" instruction.
Currently, the aarch64 port only makes use of CBZ and CBNZ when comparing operands with Integer/Long/Pointer type with zero. The issue can be fixed by add one similar combine template in the ad file for Narrow pointer types, just like the sparc port does.
Attachments
Issue Links
- backported by
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JDK-8260756 aarch64: Make use of CBZ and CBNZ when comparing narrow pointer with zero
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- Resolved
-
- relates to
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JDK-8257192 Integrate AArch64 JIT port into 8u
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- Resolved
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