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Type: Enhancement
Resolution: Fixed
Priority: P4
Fix Version/s: hs15
Affects Version/s: 6, 7
Component/s: hotspot
Labels:
- performance
- webbug

Subcomponent:
compiler
Resolved In Build:
b04
CPU:

x86, sparc
OS:

solaris, windows_xp
Verification:
Verified

Issue	Fix Version	Assignee	Priority	Status	Resolution	Resolved In Build
JDK-2175223	7	Christian Thalinger	P4	Closed	Fixed	b53
JDK-2180549	6u18	Christian Thalinger	P4	Resolved	Fixed	b01

bitCount() should use POPC on SPARC processors where POPC is implemented directly in hardware. (The existing bitCount() implementation comes from "Hacker's Delight" and is fairly fast). Beware, however, that POPC is implemented by kernel-level trap-based emulation on some processors. In those environments we want to use the existing bitCount() implemenation. isainfo (try "isainfo -x") should allow the JVM to identify those processors that support POPC in hardware.

x86 processors include a popcnt instruction in SSE4a for AMD and SSE4.2 for Intel.

backported by

JDK-2180549 bitCount() should use POPC on SPARC processors and AMD+10h

Resolved

JDK-2175223 bitCount() should use POPC on SPARC processors and AMD+10h

Closed

relates to

JDK-6832016 {DigestMD5Base,Des3DkCrypto}.setParityBit should use Integer.bitCount

Resolved

JDK-6832045 DefaultSynthStyle.{getStateInfo,getMatchCount) should use Integer.bitCount

Resolved

JDK-7063674 Wrong results from basic comparisons after calls to Long.bitCount(long)

Closed

Assignee:: Christian Thalinger (Inactive)

Reporter:: Dave Dice

Votes:: 0 Vote for this issue

Watchers:: 1 Start watching this issue

Created:: 2006-01-30 14:17

Updated:: 2013-11-01 15:14

Resolved:: 2011-03-07 21:06

Imported:: 17/Sep/12 12:15 AM

Indexed:: 19/Jul/12 5:48 PM

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