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* [Bug tree-optimization/20656] New: No strength reduction for a simple testcase @ 2005-03-27 19:13 pinskia at gcc dot gnu dot org 2005-04-06 18:50 ` [Bug tree-optimization/20656] " pinskia at gcc dot gnu dot org 2005-07-27 13:56 ` pinskia at gcc dot gnu dot org 0 siblings, 2 replies; 6+ messages in thread From: pinskia at gcc dot gnu dot org @ 2005-03-27 19:13 UTC (permalink / raw) To: gcc-bugs The following two function should be equivalent: int f(int offset, int len, int num_bytes) { int i; num_bytes = 0; for (i = 0; i < len; i++) num_bytes ++; return num_bytes; } int f1(int offset, int len, int num_bytes) { if (len<0) return 0; return len; } Why don't we strength reduce the loop in f? Then we just need to remove the loop and two functions would be equivalent. The orginal code which was found in real code (I think java code in classpath): int f(int offset, int len, int num_bytes) { int i; for (i = 0; i < len; i++) num_bytes +=2; return num_bytes; } int f1(int offset, int len, int num_bytes) { if (len<0) return num_bytes; return num_bytes+len*2; } -- Summary: No strength reduction for a simple testcase Product: gcc Version: 4.1.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: enhancement Priority: P2 Component: tree-optimization AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: pinskia at gcc dot gnu dot org CC: gcc-bugs at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20656 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/20656] No strength reduction for a simple testcase 2005-03-27 19:13 [Bug tree-optimization/20656] New: No strength reduction for a simple testcase pinskia at gcc dot gnu dot org @ 2005-04-06 18:50 ` pinskia at gcc dot gnu dot org 2005-07-27 13:56 ` pinskia at gcc dot gnu dot org 1 sibling, 0 replies; 6+ messages in thread From: pinskia at gcc dot gnu dot org @ 2005-04-06 18:50 UTC (permalink / raw) To: gcc-bugs ------- Additional Comments From pinskia at gcc dot gnu dot org 2005-04-06 18:50 ------- Confirmed. -- What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Ever Confirmed| |1 Last reconfirmed|0000-00-00 00:00:00 |2005-04-06 18:50:25 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20656 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/20656] No strength reduction for a simple testcase 2005-03-27 19:13 [Bug tree-optimization/20656] New: No strength reduction for a simple testcase pinskia at gcc dot gnu dot org 2005-04-06 18:50 ` [Bug tree-optimization/20656] " pinskia at gcc dot gnu dot org @ 2005-07-27 13:56 ` pinskia at gcc dot gnu dot org 1 sibling, 0 replies; 6+ messages in thread From: pinskia at gcc dot gnu dot org @ 2005-07-27 13:56 UTC (permalink / raw) To: gcc-bugs -- Bug 20656 depends on bug 22325, which changed state. Bug 22325 Summary: missed optimization in loop http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22325 What |Old Value |New Value ---------------------------------------------------------------------------- Status|ASSIGNED |RESOLVED Resolution| |FIXED http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20656 ^ permalink raw reply [flat|nested] 6+ messages in thread
[parent not found: <bug-20656-6528@http.gcc.gnu.org/bugzilla/>]
* [Bug tree-optimization/20656] No strength reduction for a simple testcase [not found] <bug-20656-6528@http.gcc.gnu.org/bugzilla/> @ 2005-11-08 0:30 ` hp at gcc dot gnu dot org 2005-11-09 3:45 ` hp at gcc dot gnu dot org 2006-02-15 19:14 ` pinskia at gcc dot gnu dot org 2 siblings, 0 replies; 6+ messages in thread From: hp at gcc dot gnu dot org @ 2005-11-08 0:30 UTC (permalink / raw) To: gcc-bugs ------- Comment #2 from hp at gcc dot gnu dot org 2005-11-08 00:30 ------- Seen at test-case reduction also for code of the form: int i; for (i = 1; i <= shift_size; i++) { } not producing the same ICE as for: int i; i = 1 <= shift_size ? shift_size : 1; (I'll put a pointer here to the complete test-case in due time.) -- hp at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |hp at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20656 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/20656] No strength reduction for a simple testcase [not found] <bug-20656-6528@http.gcc.gnu.org/bugzilla/> 2005-11-08 0:30 ` hp at gcc dot gnu dot org @ 2005-11-09 3:45 ` hp at gcc dot gnu dot org 2006-02-15 19:14 ` pinskia at gcc dot gnu dot org 2 siblings, 0 replies; 6+ messages in thread From: hp at gcc dot gnu dot org @ 2005-11-09 3:45 UTC (permalink / raw) To: gcc-bugs ------- Comment #3 from hp at gcc dot gnu dot org 2005-11-09 03:45 ------- Referring to comment #2, the test-case for PR 24750 has a few similar loops and a few other PR references that seems relevant. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20656 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/20656] No strength reduction for a simple testcase [not found] <bug-20656-6528@http.gcc.gnu.org/bugzilla/> 2005-11-08 0:30 ` hp at gcc dot gnu dot org 2005-11-09 3:45 ` hp at gcc dot gnu dot org @ 2006-02-15 19:14 ` pinskia at gcc dot gnu dot org 2 siblings, 0 replies; 6+ messages in thread From: pinskia at gcc dot gnu dot org @ 2006-02-15 19:14 UTC (permalink / raw) To: gcc-bugs ------- Comment #4 from pinskia at gcc dot gnu dot org 2006-02-15 19:14 ------- Fixed on the mainline now (I don't know what by). -- pinskia at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution| |FIXED Target Milestone|--- |4.2.0 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20656 ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2006-02-15 19:14 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2005-03-27 19:13 [Bug tree-optimization/20656] New: No strength reduction for a simple testcase pinskia at gcc dot gnu dot org 2005-04-06 18:50 ` [Bug tree-optimization/20656] " pinskia at gcc dot gnu dot org 2005-07-27 13:56 ` pinskia at gcc dot gnu dot org [not found] <bug-20656-6528@http.gcc.gnu.org/bugzilla/> 2005-11-08 0:30 ` hp at gcc dot gnu dot org 2005-11-09 3:45 ` hp at gcc dot gnu dot org 2006-02-15 19:14 ` pinskia at gcc dot gnu dot org
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