On 12/07/2019 12:38 pm, Kwok Cheung Yeung wrote:
This patch fixes a similar situation that occurs with the use_device
clause, where the lowering would result in a null dereference if applied
to a non-present optional argument. This patch builds a conditional
check that skips the dereference if the argument is non-present, and
ensures that optional arguments are treated like references.
With the updated patch in part 2 of this series, this patch can be
simplified slightly by reducing the number of calls to
omp_is_optional_argument.
Kwok
gcc/
* omp-low.c (lower_omp_target): For use_device clauses that take
optional arguments, generate conditional statements to avoid
dereferences of non-present arguments.
---
gcc/omp-low.c | 75
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 73 insertions(+), 2 deletions(-)
diff --git a/gcc/omp-low.c b/gcc/omp-low.c
index 1c7b43b..9c40100 100644
--- a/gcc/omp-low.c
+++ b/gcc/omp-low.c
@@ -11636,9 +11636,40 @@ lower_omp_target (gimple_stmt_iterator *gsi_p,
omp_context *ctx)
tkind = GOMP_MAP_FIRSTPRIVATE_INT;
type = TREE_TYPE (ovar);
if (TREE_CODE (type) == ARRAY_TYPE)
- var = build_fold_addr_expr (var);
+ {
+ var = build_fold_addr_expr (var);
+ gimplify_assign (x, var, &ilist);
+ }
else
{
+ tree opt_arg_label;
+ bool optional_arg_p
+ = TREE_CODE (TREE_TYPE (ovar)) == POINTER_TYPE
+ && omp_is_optional_argument (ovar);
+
+ if (optional_arg_p)
+ {
+ tree null_label
+ = create_artificial_label (UNKNOWN_LOCATION);
+ tree notnull_label
+ = create_artificial_label (UNKNOWN_LOCATION);
+ opt_arg_label
+ = create_artificial_label (UNKNOWN_LOCATION);
+ tree new_x = copy_node (x);
+ gcond *cond = gimple_build_cond (EQ_EXPR, ovar,
+ null_pointer_node,
+ null_label,
+ notnull_label);
+ gimple_seq_add_stmt (&ilist, cond);
+ gimple_seq_add_stmt (&ilist,
+ gimple_build_label (null_label));
+ gimplify_assign (new_x, null_pointer_node, &ilist);
+ gimple_seq_add_stmt (&ilist,
+ gimple_build_goto (opt_arg_label));
+ gimple_seq_add_stmt (&ilist,
+ gimple_build_label (notnull_label));
+ }
+
if (omp_is_reference (ovar))
{
type = TREE_TYPE (type);
@@ -11646,8 +11677,12 @@ lower_omp_target (gimple_stmt_iterator *gsi_p,
omp_context *ctx)
var = build_simple_mem_ref (var);
var = fold_convert (TREE_TYPE (x), var);
}
+
+ gimplify_assign (x, var, &ilist);
+ if (optional_arg_p)
+ gimple_seq_add_stmt (&ilist,
+ gimple_build_label (opt_arg_label));
}
- gimplify_assign (x, var, &ilist);
s = size_int (0);
purpose = size_int (map_idx++);
CONSTRUCTOR_APPEND_ELT (vsize, purpose, s);
@@ -11829,11 +11864,43 @@ lower_omp_target (gimple_stmt_iterator *gsi_p,
omp_context *ctx)
{
tree type = TREE_TYPE (var);
tree new_var = lookup_decl (var, ctx);
+ tree opt_arg_label = NULL_TREE;
+
if (omp_is_reference (var))
{
type = TREE_TYPE (type);
if (TREE_CODE (type) != ARRAY_TYPE)
{
+ if (omp_is_optional_argument (var))
+ {
+ tree null_label
+ = create_artificial_label (UNKNOWN_LOCATION);
+ tree notnull_label
+ = create_artificial_label (UNKNOWN_LOCATION);
+ opt_arg_label
+ = create_artificial_label (UNKNOWN_LOCATION);
+ glabel *null_glabel
+ = gimple_build_label (null_label);
+ glabel *notnull_glabel
+ = gimple_build_label (notnull_label);
+ ggoto *opt_arg_ggoto
+ = gimple_build_goto (opt_arg_label);
+ gcond *cond;
+
+ gimplify_expr (&x, &new_body, NULL, is_gimple_val,
+ fb_rvalue);
+ cond = gimple_build_cond (EQ_EXPR, x,
+ null_pointer_node,
+ null_label,
+ notnull_label);
+ gimple_seq_add_stmt (&new_body, cond);
+ gimple_seq_add_stmt (&new_body, null_glabel);
+ gimplify_assign (new_var, null_pointer_node,
+ &new_body);
+ gimple_seq_add_stmt (&new_body, opt_arg_ggoto);
+ gimple_seq_add_stmt (&new_body, notnull_glabel);
+ }
+
tree v = create_tmp_var_raw (type, get_name (var));
gimple_add_tmp_var (v);
TREE_ADDRESSABLE (v) = 1;
@@ -11850,6 +11917,10 @@ lower_omp_target (gimple_stmt_iterator *gsi_p,
omp_context *ctx)
gimplify_expr (&x, &new_body, NULL, is_gimple_val, fb_rvalue);
gimple_seq_add_stmt (&new_body,
gimple_build_assign (new_var, x));
+
+ if (opt_arg_label != NULL_TREE)
+ gimple_seq_add_stmt (&new_body,
+ gimple_build_label (opt_arg_label));
}
break;
}
--
2.8.1
