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Type: Enhancement
Resolution: Fixed
Priority: P3
Fix Version/s: hs16
Affects Version/s: hs17, hs22.5, 6, 7
Component/s: hotspot
Labels:

Subcomponent:
compiler
Resolved In Build:
b12
CPU:

generic, x86, sparc
OS:

generic, solaris_9, windows_xp
Verification:
Not verified

Issue	Fix Version	Assignee	Priority	Status	Resolution	Resolved In Build
JDK-2187064	7	Tom Rodriguez	P3	Closed	Fixed	b79
JDK-2197825	6u23	Tom Rodriguez	P3	Resolved	Fixed	b01
JDK-2199725	6u22m	Tom Rodriguez	P3	Resolved	Fixed	b01
JDK-2197534	6u21p	Tom Rodriguez	P3	Resolved	Fixed	b03
JDK-2189905	6u21	Tom Rodriguez	P3	Resolved	Fixed	b01
JDK-2184995	6u18	Tom Rodriguez	P3	Resolved	Fixed	b05
JDK-2186905	hs17	Tom Rodriguez	P3	Resolved	Fixed	b06

There are many common patterns of string concatenation using StringBuilder that could be transformed into much more efficient patterns. StringBuilder has some assumptions that it might be used in a persistent way that result in many extra copies and intermediate values being produced. Transforming these patterns into an optimal set of string operations can greatly speed up these operations.

Doing this within in the context of hotspot has some extra complexity because of deoptimization. It always has to be possible to recover a valid execution state where you can resume in the interpeter. This we can handled by introducing a transactional style of code generation where an early JVMState capture the starting point and any uncommon traps lead back to that execution point. Any code like allocations also reuses that point to describe the current state.

backported by

JDK-2184995 C2 should optimize some stringbuilder patterns

Resolved

JDK-2186905 C2 should optimize some stringbuilder patterns

Resolved

JDK-2189905 C2 should optimize some stringbuilder patterns

Resolved

JDK-2197534 C2 should optimize some stringbuilder patterns

Resolved

JDK-2197825 C2 should optimize some stringbuilder patterns

Resolved

JDK-2199725 C2 should optimize some stringbuilder patterns

Resolved

JDK-2187064 C2 should optimize some stringbuilder patterns

Closed

duplicates

JDK-6951567 Pass StringBuilder's buffer directly to String

Closed

JDK-7088426 Pass StringBuilder Buffer Directly to String without copy

Closed

JDK-6650179 StringBuilder.toString() and StringBuffer.toString() optimization

Closed

JDK-6650182 new String(string1 + string2) optimization

Closed

relates to

JDK-6953539 after 6892658 c1 reports that it doesn't inline StringBuffer.append

Resolved

JDK-6904191 OptimizeStringConcat should be product instead of experimental

Closed

JDK-6908167 jbb2005, OptimizeStringConcat causes assert in EA

Closed

JDK-6658422 Special TLABs for char[] and 16-,32-bytes aligned objects

Closed

JDK-8214862 assert(proj != __null) at compile.cpp:3251

Resolved

(2 backported by, 4 duplicates, 5 relates to)

Assignee:: Tom Rodriguez

Reporter:: Tom Rodriguez

Votes:: 0 Vote for this issue

Watchers:: 6 Start watching this issue

Created:: 2009-10-16 15:58

Updated:: 2018-12-05 04:11

Resolved:: 2010-01-15 00:02

Imported:: 17/Sep/12 12:53 AM

Indexed:: 19/Jul/12 6:08 PM

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