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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 tree-optimization/18755] New: invariant/constant not recomputed when ADDR_EXPR changed Date: Wed, 01 Dec 2004 14:42:00 -0000 [thread overview] Message-ID: <20041201144152.18755.pinskia@gcc.gnu.org> (raw) Take the following code: struct X { float array[4]; }; X a,b; float foobar () { float s = 0; X c; for (unsigned int d=0; d<4; ++d) c.array[d] = a.array[d] * b.array[d]; for (unsigned int d=0; d<4; ++d) s+=c.array[d]; return s; } With -O3 -funroll-loops, we get in .vars: c.array[0] = a.array[0] * b.array[0]; c.array[1] = a.array[1] * b.array[1]; c.array[2] = a.array[2] * b.array[2]; ivtmp.34 = &a.array[3]; ivtmp.38 = &b.array[3]; ivtmp.40 = &c.array[3]; D.1572 = *ivtmp.34 * *ivtmp.38; *ivtmp.40 = D.1572; return D.1572 + c.array[0] + c.array[1] + c.array[2]; Note how we have ivtmp's still there which is wrong. I am using Daniel Berlin's patch to find these. -- Summary: invariant/constant not recomputed when ADDR_EXPR changed Product: gcc Version: 4.0.0 Status: UNCONFIRMED Keywords: missed-optimization, TREE Severity: normal 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=18755
next reply other threads:[~2004-12-01 14:42 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2004-12-01 14:42 pinskia at gcc dot gnu dot org [this message] 2004-12-06 5:01 ` [Bug tree-optimization/18755] " pinskia at gcc dot gnu dot org 2005-01-12 1:14 ` pinskia at gcc dot gnu dot org 2005-05-07 21:00 ` pinskia at gcc dot gnu dot org
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