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From: "eres at il dot ibm dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/34223] New: missed optimization - complete unrolling pass before the vectorizer Date: Sun, 25 Nov 2007 10:26:00 -0000 [thread overview] Message-ID: <bug-34223-13229@http.gcc.gnu.org/bugzilla/> (raw) Consider the following test compiled with r130351 on ppc64-linux: #define M 10 #define N 3 void foo (int n, int *ub, int *uc) { int i, j, tmp1; for (i = 0; i < n; i++) { tmp1 = 0; for (j = 0; j < M; j++) { tmp1 += uc[i] * ((int)(j << N) / M); } ub[i] = tmp1; } } Here is a snippet from the vectorizer dump: c.c:12: note: not vectorized: relevant stmt not supported: D.1652_13 = j_29 << 3 c.c:12: note: bad operation or unsupported loop bound. [Adding a complete unrolling + ccp passes before the vectorizer can help to vectorize the outer loop] -- Summary: missed optimization - complete unrolling pass before the vectorizer Product: gcc Version: 4.3.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: eres at il dot ibm dot com http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34223
next reply other threads:[~2007-11-25 10:26 UTC|newest] Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top 2007-11-25 10:26 eres at il dot ibm dot com [this message] 2007-11-25 12:50 ` [Bug tree-optimization/34223] " rguenth at gcc dot gnu dot org 2007-11-25 13:36 ` steven at gcc dot gnu dot org 2007-11-25 14:13 ` eres at il dot ibm dot com 2008-04-22 9:51 ` rguenth at gcc dot gnu dot org 2008-04-27 16:28 ` rguenth at gcc dot gnu dot org 2008-04-27 17:16 ` rguenth at gcc dot gnu dot org 2008-04-28 9:23 ` rguenth at gcc dot gnu dot org
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