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[Bug tree-optimization/83232] fma3d spec2000 regression on zen with -Ofast (generic tuning) after r255268 by missed SLP oppurtunity
- From: "rguenth at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Fri, 01 Dec 2017 09:10:20 +0000
- Subject: [Bug tree-optimization/83232] fma3d spec2000 regression on zen with -Ofast (generic tuning) after r255268 by missed SLP oppurtunity
- Auto-submitted: auto-generated
- References: <bug-83232-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83232
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |ASSIGNED
Last reconfirmed| |2017-12-01
Version|unknown |8.0
Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot gnu.org
Ever confirmed|0 |1
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
I belive group detection is confused by those
einc[4] = 0.0;
einc[5] = 0.0;
after the vector code. Like we don't SLP vectorize
double a[2];
double b[2];
void foo (double *p, double *q)
{
a[0] = b[0];
a[1] = b[1];
*p = *q;
a[0] = b[1];
a[1] = b[0];
}
I have an idea how to fix that. Have to first confirm this is the fma3d issue.