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* [Bug java/17187] New: Call to java.lang.Object constructor is redundant
@ 2004-08-25 15:45 mckinlay at redhat dot com
2004-08-25 15:58 ` [Bug java/17187] " pinskia at gcc dot gnu dot org
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: mckinlay at redhat dot com @ 2004-08-25 15:45 UTC (permalink / raw)
To: java-prs
The constructor for java.lang.Object does nothing. Its probably a reasonable
assumption that it will always do nothing, so, we should change the compiler to
not generate calls to it when generating native code. This would save 1 call for
every "new" operation, and also improve the number of inlining opportunities
available to the compiler, as many constructor calls could now be fully inlined.
One way to do this might be to extend the java "builtins" mechanism to allow us
to turn other well known calls, not just Math.* calls, into inlined trees. If
we see a java.lang.Object() call, check_for_builtin() would just return an empty
statement tree.
--
Summary: Call to java.lang.Object constructor is redundant
Product: gcc
Version: 3.5.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: enhancement
Priority: P2
Component: java
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: mckinlay at redhat dot com
CC: gcc-bugs at gcc dot gnu dot org,java-prs at gcc dot gnu
dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17187
^ permalink raw reply [flat|nested] 4+ messages in thread* [Bug java/17187] Call to java.lang.Object constructor is redundant 2004-08-25 15:45 [Bug java/17187] New: Call to java.lang.Object constructor is redundant mckinlay at redhat dot com @ 2004-08-25 15:58 ` pinskia at gcc dot gnu dot org 2004-08-25 16:16 ` mckinlay at redhat dot com 2004-11-08 2:49 ` pinskia at gcc dot gnu dot org 2 siblings, 0 replies; 4+ messages in thread From: pinskia at gcc dot gnu dot org @ 2004-08-25 15:58 UTC (permalink / raw) To: java-prs ------- Additional Comments From pinskia at gcc dot gnu dot org 2004-08-25 15:58 ------- Confirmed. But I should note that even the Sun's javac does not do this optimization so ... -- What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Ever Confirmed| |1 Last reconfirmed|0000-00-00 00:00:00 |2004-08-25 15:58:47 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17187 ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug java/17187] Call to java.lang.Object constructor is redundant 2004-08-25 15:45 [Bug java/17187] New: Call to java.lang.Object constructor is redundant mckinlay at redhat dot com 2004-08-25 15:58 ` [Bug java/17187] " pinskia at gcc dot gnu dot org @ 2004-08-25 16:16 ` mckinlay at redhat dot com 2004-11-08 2:49 ` pinskia at gcc dot gnu dot org 2 siblings, 0 replies; 4+ messages in thread From: mckinlay at redhat dot com @ 2004-08-25 16:16 UTC (permalink / raw) To: java-prs ------- Additional Comments From mckinlay at redhat dot com 2004-08-25 16:16 ------- pinskia: bytecode compilation is a different story. Obviously we should only do this when compiling to _native_ code. We know our java.lang.Object constructor doesn't do anything, but we can't make that assumption about other implementations. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17187 ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug java/17187] Call to java.lang.Object constructor is redundant 2004-08-25 15:45 [Bug java/17187] New: Call to java.lang.Object constructor is redundant mckinlay at redhat dot com 2004-08-25 15:58 ` [Bug java/17187] " pinskia at gcc dot gnu dot org 2004-08-25 16:16 ` mckinlay at redhat dot com @ 2004-11-08 2:49 ` pinskia at gcc dot gnu dot org 2 siblings, 0 replies; 4+ messages in thread From: pinskia at gcc dot gnu dot org @ 2004-11-08 2:49 UTC (permalink / raw) To: java-prs ------- Additional Comments From pinskia at gcc dot gnu dot org 2004-11-08 02:49 ------- Man this is a semi hard problem, I could figure out where the call expression is built but we patch it up which makes it harder (maybe we should pass a pointer to the tree which we patch up and then change it to a nop). -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17187 ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2004-11-08 2:49 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2004-08-25 15:45 [Bug java/17187] New: Call to java.lang.Object constructor is redundant mckinlay at redhat dot com 2004-08-25 15:58 ` [Bug java/17187] " pinskia at gcc dot gnu dot org 2004-08-25 16:16 ` mckinlay at redhat dot com 2004-11-08 2:49 ` pinskia at gcc dot gnu dot org
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