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[Bug tree-optimization/57162] Ofast does not make use of avx while O3 does
- 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: Mon, 06 May 2013 11:46:24 +0000
- Subject: [Bug tree-optimization/57162] Ofast does not make use of avx while O3 does
- Auto-submitted: auto-generated
- References: <bug-57162-4 at http dot gcc dot gnu dot org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57162
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |missed-optimization
Status|UNCONFIRMED |NEW
Last reconfirmed| |2013-05-06
Blocks| |53947
Ever Confirmed|0 |1
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> 2013-05-06 11:46:24 UTC ---
-ffast-math reassociates the expressions which then causes us to fail
the SLP build because of
-t.C:6: note: Load permutation 0 0 0 0 1 1 1 1 2 2 2 2 3 3 3 3
-t.C:6: note: vect_model_load_cost: aligned.
-t.C:6: note: vect_model_load_cost: inside_cost = 1, prologue_cost = 0 .
+t.C:6: note: Load permutation 0 1 1 1 1 0 0 0 3 2 2 2 2 3 3 3
+t.C:6: note: Build SLP failed: unsupported load permutation c[i_37][0] =
sum_44;