Hi,
The commit r10-7415 brings scalar type consideration
to eliminate epilogue peeling for gaps, but it exposed
one problem that the current handling doesn't consider
the memory access type VMAT_CONTIGUOUS_REVERSE, for
which the overrun happens on low address side. This
patch is to make the code take care of it by updating
the offset and construction element order accordingly.
Bootstrapped/regtested on powerpc64le-linux-gnu P8
and aarch64-linux-gnu.
BR,
Kewen
-----------
gcc/ChangeLog
2020-04-02 Kewen Lin <li...@gcc.gnu.org>
PR tree-optimization/94401
* tree-vect-loop.c (vectorizable_load): Handle VMAT_CONTIGUOUS_REVERSE
access type when loading halves of vector to avoid peeling for gaps.
diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c
index 12beef6978c..3d27f59ba22 100644
--- a/gcc/tree-vect-stmts.c
+++ b/gcc/tree-vect-stmts.c
@@ -9590,11 +9590,20 @@ vectorizable_load (stmt_vec_info stmt_info,
gimple_stmt_iterator *gsi,
if (new_vtype != NULL_TREE)
ltype = half_vtype;
}
+ tree offset = dataref_offset
+ ? dataref_offset
+ : build_int_cst (ref_type, 0);
+ if (ltype != vectype
+ && memory_access_type == VMAT_CONTIGUOUS_REVERSE)
+ offset = size_binop (
+ PLUS_EXPR,
+ build_int_cst (ref_type,
+ DR_GROUP_GAP (first_stmt_info)
+ * tree_to_uhwi (
+ TYPE_SIZE_UNIT (elem_type))),
+ offset);
data_ref
- = fold_build2 (MEM_REF, ltype, dataref_ptr,
- dataref_offset
- ? dataref_offset
- : build_int_cst (ref_type, 0));
+ = fold_build2 (MEM_REF, ltype, dataref_ptr, offset);
if (alignment_support_scheme == dr_aligned)
;
else if (DR_MISALIGNMENT (first_dr_info) == -1)
@@ -9607,16 +9616,27 @@ vectorizable_load (stmt_vec_info stmt_info,
gimple_stmt_iterator *gsi,
TYPE_ALIGN (elem_type));
if (ltype != vectype)
{
- vect_copy_ref_info (data_ref, DR_REF
(first_dr_info->dr));
+ vect_copy_ref_info (data_ref,
+ DR_REF (first_dr_info->dr));
tree tem = make_ssa_name (ltype);
new_stmt = gimple_build_assign (tem, data_ref);
- vect_finish_stmt_generation (stmt_info, new_stmt,
gsi);
+ vect_finish_stmt_generation (stmt_info, new_stmt,
+ gsi);
data_ref = NULL;
vec<constructor_elt, va_gc> *v;
vec_alloc (v, 2);
- CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, tem);
- CONSTRUCTOR_APPEND_ELT (v, NULL_TREE,
- build_zero_cst (ltype));
+ if (memory_access_type == VMAT_CONTIGUOUS_REVERSE)
+ {
+ CONSTRUCTOR_APPEND_ELT (v, NULL_TREE,
+ build_zero_cst (ltype));
+ CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, tem);
+ }
+ else
+ {
+ CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, tem);
+ CONSTRUCTOR_APPEND_ELT (v, NULL_TREE,
+ build_zero_cst (ltype));
+ }
gcc_assert (new_vtype != NULL_TREE);
if (new_vtype == vectype)
new_stmt = gimple_build_assign (
