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Enhancement
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Resolution: Fixed
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P4
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17
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b14
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x86
X86 I2L conversion can be skipped for certain masked positive values
For the following expression:
(long)(value & mask)
Where value is of int type and mask is constant (power of two – 1), we can directly generate bzhi instruction to zero the upper bits
Instead of doing an andl, followed by movslq
Before:
Benchmark Mode Cnt Score Error Units
SkipIntToLongCast.skipMaskedSmallPositiveCast avgt 15 10.679 ± 1.496 ns/op
After:
Benchmark Mode Cnt Score Error Units
SkipIntToLongCast.skipMaskedSmallPositiveCast avgt 15 7.870 ± 0.067 ns/op
For the following expression:
(long)(value & mask)
Where value is of int type and mask is constant (power of two – 1), we can directly generate bzhi instruction to zero the upper bits
Instead of doing an andl, followed by movslq
Before:
Benchmark Mode Cnt Score Error Units
SkipIntToLongCast.skipMaskedSmallPositiveCast avgt 15 10.679 ± 1.496 ns/op
After:
Benchmark Mode Cnt Score Error Units
SkipIntToLongCast.skipMaskedSmallPositiveCast avgt 15 7.870 ± 0.067 ns/op
- relates to
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JDK-8263753 two new tests from JDK-8261671 fail with "Error. can not find ClassFileInstaller in test directory or libraries"
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- Resolved
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- Resolved
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- Resolved
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- Resolved
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