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* [Bug optimization/14721] New: jump optimization involving a sibling call within a jump table @ 2004-03-24 17:42 kazu at cs dot umass dot edu 2004-03-24 17:45 ` [Bug optimization/14721] " kazu at cs dot umass dot edu ` (3 more replies) 0 siblings, 4 replies; 5+ messages in thread From: kazu at cs dot umass dot edu @ 2004-03-24 17:42 UTC (permalink / raw) To: gcc-bugs We could put a function address in a jump table. void bar0 (void); void bar1 (void); void bar2 (void); void bar3 (void); void bar4 (void); void foo (int i) { switch (i) { case 0: bar0 (); break; case 1: bar1 (); break; case 2: bar2 (); break; case 3: bar3 (); break; case 4: bar4 (); break; } } Here is what I get on i686-pc-linux-gnu. foo: movl 4(%esp), %eax cmpl $4, %eax ja .L1 jmp *.L8(,%eax,4) .section .rodata .align 4 .align 4 .L8: .long .L3 .long .L4 .long .L5 .long .L6 .long .L7 .text .p2align 2,,3 .L1: ret .L7: jmp bar4 .L3: jmp bar0 .L4: jmp bar1 .L5: jmp bar2 .L6: jmp bar3 It would be nice if I can get something like: foo: movl 4(%esp), %eax cmpl $4, %eax ja .L1 jmp *.L8(,%eax,4) .section .rodata .align 4 .align 4 .L8: .long bar0 .long bar1 .long bar2 .long bar3 .long bar4 .text .p2align 2,,3 .L1: ret -- Summary: jump optimization involving a sibling call within a jump table Product: gcc Version: 3.5.0 Status: UNCONFIRMED Severity: normal Priority: P2 Component: optimization AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: kazu at cs dot umass dot edu CC: gcc-bugs at gcc dot gnu dot org GCC build triplet: pessimizes-code http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14721 ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug optimization/14721] jump optimization involving a sibling call within a jump table 2004-03-24 17:42 [Bug optimization/14721] New: jump optimization involving a sibling call within a jump table kazu at cs dot umass dot edu @ 2004-03-24 17:45 ` kazu at cs dot umass dot edu 2004-03-24 17:47 ` kazu at cs dot umass dot edu ` (2 subsequent siblings) 3 siblings, 0 replies; 5+ messages in thread From: kazu at cs dot umass dot edu @ 2004-03-24 17:45 UTC (permalink / raw) To: gcc-bugs -- What |Removed |Added ---------------------------------------------------------------------------- Keywords| |pessimizes-code http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14721 ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug optimization/14721] jump optimization involving a sibling call within a jump table 2004-03-24 17:42 [Bug optimization/14721] New: jump optimization involving a sibling call within a jump table kazu at cs dot umass dot edu 2004-03-24 17:45 ` [Bug optimization/14721] " kazu at cs dot umass dot edu @ 2004-03-24 17:47 ` kazu at cs dot umass dot edu 2004-03-24 17:48 ` pinskia at gcc dot gnu dot org 2004-12-22 4:34 ` [Bug rtl-optimization/14721] " pinskia at gcc dot gnu dot org 3 siblings, 0 replies; 5+ messages in thread From: kazu at cs dot umass dot edu @ 2004-03-24 17:47 UTC (permalink / raw) To: gcc-bugs -- What |Removed |Added ---------------------------------------------------------------------------- Severity|normal |enhancement http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14721 ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug optimization/14721] jump optimization involving a sibling call within a jump table 2004-03-24 17:42 [Bug optimization/14721] New: jump optimization involving a sibling call within a jump table kazu at cs dot umass dot edu 2004-03-24 17:45 ` [Bug optimization/14721] " kazu at cs dot umass dot edu 2004-03-24 17:47 ` kazu at cs dot umass dot edu @ 2004-03-24 17:48 ` pinskia at gcc dot gnu dot org 2004-12-22 4:34 ` [Bug rtl-optimization/14721] " pinskia at gcc dot gnu dot org 3 siblings, 0 replies; 5+ messages in thread From: pinskia at gcc dot gnu dot org @ 2004-03-24 17:48 UTC (permalink / raw) To: gcc-bugs ------- Additional Comments From pinskia at gcc dot gnu dot org 2004-03-24 17:48 ------- Confirmed, yes that would be nice. -- What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Ever Confirmed| |1 Last reconfirmed|0000-00-00 00:00:00 |2004-03-24 17:48:16 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14721 ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug rtl-optimization/14721] jump optimization involving a sibling call within a jump table 2004-03-24 17:42 [Bug optimization/14721] New: jump optimization involving a sibling call within a jump table kazu at cs dot umass dot edu ` (2 preceding siblings ...) 2004-03-24 17:48 ` pinskia at gcc dot gnu dot org @ 2004-12-22 4:34 ` pinskia at gcc dot gnu dot org 3 siblings, 0 replies; 5+ messages in thread From: pinskia at gcc dot gnu dot org @ 2004-12-22 4:34 UTC (permalink / raw) To: gcc-bugs -- What |Removed |Added ---------------------------------------------------------------------------- CC| |pinskia at gcc dot gnu dot | |org Last reconfirmed|2004-09-22 13:17:13 |2004-12-22 04:34:49 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14721 ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2004-12-22 4:34 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2004-03-24 17:42 [Bug optimization/14721] New: jump optimization involving a sibling call within a jump table kazu at cs dot umass dot edu 2004-03-24 17:45 ` [Bug optimization/14721] " kazu at cs dot umass dot edu 2004-03-24 17:47 ` kazu at cs dot umass dot edu 2004-03-24 17:48 ` pinskia at gcc dot gnu dot org 2004-12-22 4:34 ` [Bug rtl-optimization/14721] " pinskia at gcc dot gnu dot org
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