The following fixes the fact that the vectorizer doesn't bother to
preserve restrict information on its generated loads/stores which
in turn causes missed predictive commonings. The regression happened
because there's now a IPA-CP clone which wrecks points-to info,
but restrict is properly preserved. But with the vectorizer
throwing it away we lost all of the info.
Bootstrap and regtest running on x86_64-unknown-linux-gnu.
Dependend on how close we are to a RC I consider to fix this
only for GCC 8.2.
Richard.
2018-04-19 Richard Biener <rguent...@suse.de>
PR tree-optimization/84737
* tree-vect-data-refs.c (vect_copy_ref_info): New function
copying restrict info.
(vect_setup_realignment): Use it.
* tree-vectorizer.h (vect_copy_ref_info): Declare.
* tree-vect-stmts.c (vectorizable_store): Copy ref info from
the first DR to all generated stores.
(vectorizable_load): Likewise for loads.
Index: gcc/tree-vect-data-refs.c
===================================================================
--- gcc/tree-vect-data-refs.c (revision 259489)
+++ gcc/tree-vect-data-refs.c (working copy)
@@ -5010,6 +5010,24 @@ bump_vector_ptr (tree dataref_ptr, gimpl
}
+/* Copy memory reference info such as base/clique from the SRC reference
+ to the DEST MEM_REF. */
+
+void
+vect_copy_ref_info (tree dest, tree src)
+{
+ tree src_base = src;
+ while (handled_component_p (src_base))
+ src_base = TREE_OPERAND (src_base, 0);
+ if (TREE_CODE (src_base) != MEM_REF
+ && TREE_CODE (src_base) != TARGET_MEM_REF)
+ return;
+
+ MR_DEPENDENCE_CLIQUE (dest) = MR_DEPENDENCE_CLIQUE (src_base);
+ MR_DEPENDENCE_BASE (dest) = MR_DEPENDENCE_BASE (src_base);
+}
+
+
/* Function vect_create_destination_var.
Create a new temporary of type VECTYPE. */
@@ -5561,6 +5579,7 @@ vect_setup_realignment (gimple *stmt, gi
data_ref
= build2 (MEM_REF, TREE_TYPE (vec_dest), new_temp,
build_int_cst (reference_alias_ptr_type (DR_REF (dr)), 0));
+ vect_copy_ref_info (data_ref, DR_REF (dr));
new_stmt = gimple_build_assign (vec_dest, data_ref);
new_temp = make_ssa_name (vec_dest, new_stmt);
gimple_assign_set_lhs (new_stmt, new_temp);
Index: gcc/tree-vect-stmts.c
===================================================================
--- gcc/tree-vect-stmts.c (revision 259489)
+++ gcc/tree-vect-stmts.c (working copy)
@@ -6660,6 +6660,7 @@ vectorizable_store (gimple *stmt, gimple
group_el * elsz);
newref = build2 (MEM_REF, ltype,
running_off, this_off);
+ vect_copy_ref_info (newref, DR_REF (first_dr));
/* And store it to *running_off. */
assign = gimple_build_assign (newref, elem);
@@ -7052,6 +7053,7 @@ vectorizable_store (gimple *stmt, gimple
TREE_TYPE (data_ref)
= build_aligned_type (TREE_TYPE (data_ref),
TYPE_ALIGN (elem_type));
+ vect_copy_ref_info (data_ref, DR_REF (first_dr));
new_stmt = gimple_build_assign (data_ref, vec_oprnd);
}
vect_finish_stmt_generation (stmt, new_stmt, gsi);
@@ -7659,9 +7661,9 @@ vectorizable_load (gimple *stmt, gimple_
{
tree this_off = build_int_cst (TREE_TYPE (alias_off),
group_el * elsz + cst_offset);
- new_stmt = gimple_build_assign (make_ssa_name (ltype),
- build2 (MEM_REF, ltype,
- running_off, this_off));
+ tree data_ref = build2 (MEM_REF, ltype, running_off, this_off);
+ vect_copy_ref_info (data_ref, DR_REF (first_dr));
+ new_stmt = gimple_build_assign (make_ssa_name (ltype), data_ref);
vect_finish_stmt_generation (stmt, new_stmt, gsi);
if (nloads > 1)
CONSTRUCTOR_APPEND_ELT (v, NULL_TREE,
@@ -8205,6 +8207,7 @@ vectorizable_load (gimple *stmt, gimple_
data_ref
= build2 (MEM_REF, vectype, ptr,
build_int_cst (ref_type, 0));
+ vect_copy_ref_info (data_ref, DR_REF (first_dr));
vec_dest = vect_create_destination_var (scalar_dest,
vectype);
new_stmt = gimple_build_assign (vec_dest, data_ref);
@@ -8251,6 +8254,7 @@ vectorizable_load (gimple *stmt, gimple_
default:
gcc_unreachable ();
}
+ vect_copy_ref_info (data_ref, DR_REF (first_dr));
vec_dest = vect_create_destination_var (scalar_dest, vectype);
/* DATA_REF is null if we've already built the statement. */
if (data_ref)
Index: gcc/tree-vectorizer.h
===================================================================
--- gcc/tree-vectorizer.h (revision 259489)
+++ gcc/tree-vectorizer.h (working copy)
@@ -1494,6 +1494,7 @@ extern tree vect_create_data_ref_ptr (gi
tree = NULL_TREE, tree = NULL_TREE);
extern tree bump_vector_ptr (tree, gimple *, gimple_stmt_iterator *, gimple *,
tree);
+extern void vect_copy_ref_info (tree, tree);
extern tree vect_create_destination_var (tree, tree);
extern bool vect_grouped_store_supported (tree, unsigned HOST_WIDE_INT);
extern bool vect_store_lanes_supported (tree, unsigned HOST_WIDE_INT, bool);
