https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80705
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Ok, SLP seems fine here, on x86_64 needs -fno-vect-cost-model to vectorize it.
LIM also looks fine on x86 (does nothing) so it must be IVOPTs messing up the
refs on ppc64le. Ah, on ppc64le:
vect_cst__43 = {__gcov0.foo_I_lsm.13_187, __gcov0.foo_I_lsm.10_168};
vect_cst__152 = {__gcov0.foo_I_lsm.11_105, __gcov0.foo_I_lsm.12_164};
vect_cst__178 = {__gcov0.foo_I_lsm.14_204, PROF_edge_counter_193};
MEM[(long int *)&__gcov0.foo + 32B] = vect_cst__178;
_198 = &__gcov0.foo[4] + 16;
MEM[(long int *)_198] = vect_cst__152;
_39 = _198 + 16;
MEM[(long int *)_39] = vect_cst__43;
actually similar on x86_64 without AVX:
vect_cst__174 = {__gcov0.foo_I_lsm.10_109, __gcov0.foo_I_lsm.11_164};
vect_cst__36 = {__gcov0.foo_I_lsm.12_147, PROF_edge_counter_167};
MEM[(long int *)&__gcov0.foo + 24B] = vect_cst__36;
_181 = &__gcov0.foo[3] + 16;
MEM[(long int *)_181] = vect_cst__174;
the last ref is problematic as it aliases __gcov0.foo and that is not allowed.
I presume that vectorizing the counter update stores isn't really useful
anyway,
so the easiest thing may be to simply not allow vectorizing DECL_NONALIASED
refs.
Index: gcc/tree-vect-data-refs.c
===================================================================
--- gcc/tree-vect-data-refs.c (revision 247879)
+++ gcc/tree-vect-data-refs.c (working copy)
@@ -3957,6 +4023,27 @@ again:
datarefs[i] = dr;
}
+ if (TREE_CODE (DR_BASE_ADDRESS (dr)) == ADDR_EXPR
+ && DECL_P (TREE_OPERAND (DR_BASE_ADDRESS (dr), 0))
+ && DECL_NONALIASED (TREE_OPERAND (DR_BASE_ADDRESS (dr), 0)))
+ {
+ if (dump_enabled_p ())
+ {
+ dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
+ "not vectorized: base object not addressable "
+ "for stmt: ");
+ dump_gimple_stmt (MSG_MISSED_OPTIMIZATION, TDF_SLIM, stmt, 0);
+ }
+ if (is_a <bb_vec_info> (vinfo))
+ {
+ /* In BB vectorization the ref can still participate
+ in dependence analysis, we just can't vectorize it. */
+ STMT_VINFO_VECTORIZABLE (stmt_info) = false;
+ continue;
+ }
+ return false;
+ }
+
/* Set vectype for STMT. */
scalar_type = TREE_TYPE (DR_REF (dr));
STMT_VINFO_VECTYPE (stmt_info)
