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From: "pinskia at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/35691] New: Missed (a == 0) && (b == 0) into (a|(typeof(a)(b)) == 0 when the types don't match Date: Tue, 25 Mar 2008 04:32:00 -0000 [thread overview] Message-ID: <bug-35691-6528@http.gcc.gnu.org/bugzilla/> (raw) While looking into PR 35429, I noticed this small missed optimization. If we have: typedef unsigned int1; int foo(int z0, int1 z1) { return z0 != 0 || z1 != 0; } int foo1(int z0, int1 z1) { return z0 == 0 && z1 == 0; } --- CUT --- Both of those should optimize as int is the same size as unsigned and we are comparing against 0. The same thing should happen with int and long on a ILP32 target. -- Summary: Missed (a == 0) && (b == 0) into (a|(typeof(a)(b)) == 0 when the types don't match Product: gcc Version: 4.4.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: enhancement Priority: P3 Component: middle-end 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=35691
next reply other threads:[~2008-03-25 4:32 UTC|newest] Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2008-03-25 4:32 pinskia at gcc dot gnu dot org [this message] 2008-03-25 9:43 ` [Bug middle-end/35691] " rguenth at gcc dot gnu dot org
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