https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110557
--- Comment #4 from Xi Ruoyao <xry111 at gcc dot gnu.org> ---
Untested patch:
diff --git a/gcc/tree-vect-patterns.cc b/gcc/tree-vect-patterns.cc
index de20e9d59cb..01df568ee61 100644
--- a/gcc/tree-vect-patterns.cc
+++ b/gcc/tree-vect-patterns.cc
@@ -2566,7 +2566,7 @@ vect_recog_widen_sum_pattern (vec_info *vinfo,
Widening with mask first, shift later:
container = (type_out) container;
masked = container & (((1 << bitsize) - 1) << bitpos);
- result = patt2 >> masked;
+ result = masked >> bitpos;
Widening with shift first, mask last:
container = (type_out) container;
@@ -2578,6 +2578,15 @@ vect_recog_widen_sum_pattern (vec_info *vinfo,
result = masked >> bitpos;
result = (type_out) result;
+ If the bitfield is signed and the its width is greater than the width
+ of type_out, we need to perform a sign-extension:
+ container = (type) container;
+ masked = container << (prec - bitsize - bitpos);
+ result = (type_out) (masked >> (prec - bitsize));
+
+ Here type is the signed variant of the wider of type_out and the type
+ of container.
+
The shifting is always optional depending on whether bitpos != 0.
*/
@@ -2636,14 +2645,22 @@ vect_recog_bitfield_ref_pattern (vec_info *vinfo,
stmt_vec_info stmt_info,
if (BYTES_BIG_ENDIAN)
shift_n = prec - shift_n - mask_width;
+ bool sign_ext = !TYPE_UNSIGNED (TREE_TYPE (bf_ref)) &&
+ TYPE_PRECISION (ret_type) > mask_width;
+ bool widening = ((TYPE_PRECISION (TREE_TYPE (container)) <
+ TYPE_PRECISION (ret_type))
+ && !useless_type_conversion_p (TREE_TYPE (container),
+ ret_type));
+
/* We move the conversion earlier if the loaded type is smaller than the
return type to enable the use of widening loads. */
- if (TYPE_PRECISION (TREE_TYPE (container)) < TYPE_PRECISION (ret_type)
- && !useless_type_conversion_p (TREE_TYPE (container), ret_type))
+ if (sign_ext || widening)
{
- pattern_stmt
- = gimple_build_assign (vect_recog_temp_ssa_var (ret_type),
- NOP_EXPR, container);
+ tree type = widening ? ret_type : container_type;
+ if (sign_ext)
+ type = gimple_signed_type (type);
+ pattern_stmt = gimple_build_assign (vect_recog_temp_ssa_var (type),
+ NOP_EXPR, container);
container = gimple_get_lhs (pattern_stmt);
container_type = TREE_TYPE (container);
prec = tree_to_uhwi (TYPE_SIZE (container_type));
@@ -2671,7 +2688,7 @@ vect_recog_bitfield_ref_pattern (vec_info *vinfo,
stmt_vec_info stmt_info,
shift_first = true;
tree result;
- if (shift_first)
+ if (shift_first && !sign_ext)
{
tree shifted = container;
if (shift_n)
@@ -2694,14 +2711,27 @@ vect_recog_bitfield_ref_pattern (vec_info *vinfo,
stmt_vec_info stmt_info,
}
else
{
- tree mask = wide_int_to_tree (container_type,
- wi::shifted_mask (shift_n, mask_width,
- false, prec));
- pattern_stmt
- = gimple_build_assign (vect_recog_temp_ssa_var (container_type),
- BIT_AND_EXPR, container, mask);
- tree masked = gimple_assign_lhs (pattern_stmt);
+ tree temp = vect_recog_temp_ssa_var (container_type);
+ if (!sign_ext)
+ {
+ tree mask = wide_int_to_tree (container_type,
+ wi::shifted_mask (shift_n,
+ mask_width,
+ false, prec));
+ pattern_stmt = gimple_build_assign (temp, BIT_AND_EXPR,
+ container, mask);
+ }
+ else
+ {
+ HOST_WIDE_INT shl = prec - shift_n - mask_width;
+ shift_n += shl;
+ pattern_stmt = gimple_build_assign (temp, LSHIFT_EXPR,
+ container,
+ build_int_cst (sizetype,
+ shl));
+ }
+ tree masked = gimple_assign_lhs (pattern_stmt);
append_pattern_def_seq (vinfo, stmt_info, pattern_stmt, vectype);
pattern_stmt
= gimple_build_assign (vect_recog_temp_ssa_var (container_type),
