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* [Bug tree-optimization/27109] New: Simplify "a - 10 > 150" into "a > 160" when range of a is known (in VRP or somewhere else) @ 2006-04-11 2:04 pinskia at gcc dot gnu dot org 2006-04-11 2:04 ` [Bug tree-optimization/27109] " pinskia at gcc dot gnu dot org 2006-12-28 12:03 ` rguenth at gcc dot gnu dot org 0 siblings, 2 replies; 3+ messages in thread From: pinskia at gcc dot gnu dot org @ 2006-04-11 2:04 UTC (permalink / raw) To: gcc-bugs Kinda like PR 14490 but for the -fwrapv and unsigned cases: void bar (void); void foo (unsigned a) { if (a < 100) return; if (200 < a) return; if (a - 10 > 150) bar (); } -- Summary: Simplify "a - 10 > 150" into "a > 160" when range of a is known (in VRP or somewhere else) Product: gcc Version: 4.2.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: normal Priority: P3 Component: tree-optimization AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: pinskia at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27109 ^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug tree-optimization/27109] Simplify "a - 10 > 150" into "a > 160" when range of a is known (in VRP or somewhere else) 2006-04-11 2:04 [Bug tree-optimization/27109] New: Simplify "a - 10 > 150" into "a > 160" when range of a is known (in VRP or somewhere else) pinskia at gcc dot gnu dot org @ 2006-04-11 2:04 ` pinskia at gcc dot gnu dot org 2006-12-28 12:03 ` rguenth at gcc dot gnu dot org 1 sibling, 0 replies; 3+ messages in thread From: pinskia at gcc dot gnu dot org @ 2006-04-11 2:04 UTC (permalink / raw) To: gcc-bugs -- pinskia at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Severity|normal |enhancement http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27109 ^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug tree-optimization/27109] Simplify "a - 10 > 150" into "a > 160" when range of a is known (in VRP or somewhere else) 2006-04-11 2:04 [Bug tree-optimization/27109] New: Simplify "a - 10 > 150" into "a > 160" when range of a is known (in VRP or somewhere else) pinskia at gcc dot gnu dot org 2006-04-11 2:04 ` [Bug tree-optimization/27109] " pinskia at gcc dot gnu dot org @ 2006-12-28 12:03 ` rguenth at gcc dot gnu dot org 1 sibling, 0 replies; 3+ messages in thread From: rguenth at gcc dot gnu dot org @ 2006-12-28 12:03 UTC (permalink / raw) To: gcc-bugs ------- Comment #1 from rguenth at gcc dot gnu dot org 2006-12-28 12:03 ------- Confirmed. compare_values needs to be teached to look at value ranges for operands and decide on overflow there - but only for substitute and fold as earlier we can have invalid intermediate value ranges. -- rguenth at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |rguenth at gcc dot gnu dot | |org Status|UNCONFIRMED |NEW Ever Confirmed|0 |1 Last reconfirmed|0000-00-00 00:00:00 |2006-12-28 12:03:15 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27109 ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2006-12-28 12:03 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2006-04-11 2:04 [Bug tree-optimization/27109] New: Simplify "a - 10 > 150" into "a > 160" when range of a is known (in VRP or somewhere else) pinskia at gcc dot gnu dot org 2006-04-11 2:04 ` [Bug tree-optimization/27109] " pinskia at gcc dot gnu dot org 2006-12-28 12:03 ` rguenth at gcc dot gnu dot org
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