This patch avoids adding CREATE mapping clauses for loop index variables. It
also sets TREE_ADDRESSABLE on newly mapped declarations, which fixes an ICE that
sometimes appears due to an assert firing in omp-low.c.
2019-07-16 Julian Brown <jul...@codesourcery.com>
gcc/
* omp-oacc-kernels.c (find_omp_for_index_vars_1,
find_omp_for_index_vars): New functions.
(maybe_build_inner_data_region): Add IDX_VARS argument. Don't add
CREATE mapping clauses for loop index variables. Set TREE_ADDRESSABLE
flag on newly-mapped declarations as a side effect.
(decompose_kernels_region_body): Call find_omp_for_index_vars. Don't
create PRESENT clause for loop index variables. Pass index variable
set to maybe_build_inner_data_region.
---
gcc/omp-oacc-kernels.c | 58 ++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 51 insertions(+), 7 deletions(-)
diff --git a/gcc/omp-oacc-kernels.c b/gcc/omp-oacc-kernels.c
index d65e6c6..2091385 100644
--- a/gcc/omp-oacc-kernels.c
+++ b/gcc/omp-oacc-kernels.c
@@ -766,6 +766,43 @@ flatten_binds (gbind *bind, bool include_toplevel_vars =
false)
return vars;
}
+/* Recursively search BODY_SEQUENCE for 'for' loops, and record their loop
+ indices in IDX_VARS. */
+
+static void
+find_omp_for_index_vars_1 (gimple_seq body_sequence, hash_set<tree> *idx_vars)
+{
+ gimple_stmt_iterator gsi;
+
+ for (gsi = gsi_start (body_sequence); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple *stmt = gsi_stmt (gsi);
+ gimple *for_stmt = top_level_omp_for_in_stmt (stmt);
+
+ if (for_stmt)
+ {
+ tree idx = gimple_omp_for_index (for_stmt, 0);
+ idx_vars->add (idx);
+ find_omp_for_index_vars_1 (gimple_omp_body (for_stmt), idx_vars);
+ }
+ else if (gimple_code (stmt) == GIMPLE_BIND)
+ find_omp_for_index_vars_1 (gimple_bind_body (as_a <gbind *> (stmt)),
+ idx_vars);
+ }
+}
+
+/* Find all loop index variables in a bind. */
+
+static hash_set<tree>
+find_omp_for_index_vars (gbind *bind)
+{
+ hash_set<tree> idx_vars;
+
+ find_omp_for_index_vars_1 (gimple_bind_body (bind), &idx_vars);
+
+ return idx_vars;
+}
+
/* Helper function for places where we construct data regions. Wraps the BODY
inside a try-finally construct at LOC that calls __builtin_GOACC_data_end
in its cleanup block. Returns this try statement. */
@@ -784,13 +821,15 @@ make_data_region_try_statement (location_t loc, gimple
*body)
/* If INNER_BIND_VARS holds variables, build an OpenACC data region with
location LOC containing BODY and having "create(var)" clauses for each
- variable. If INNER_CLEANUP is present, add a try-finally statement with
- this cleanup code in the finally block. Return the new data region, or
- the original BODY if no data region was needed. */
+ variable (such variables are also made addressable as a side effect). If
+ INNER_CLEANUP is present, add a try-finally statement with this cleanup
+ code in the finally block. Return the new data region, or the original
+ BODY if no data region was needed. */
static gimple *
maybe_build_inner_data_region (location_t loc, gimple *body,
- tree inner_bind_vars, gimple *inner_cleanup)
+ tree inner_bind_vars, gimple *inner_cleanup,
+ hash_set<tree> *idx_vars)
{
/* Build data "create(var)" clauses for these local variables.
Below we will add these to a data region enclosing the entire body
@@ -817,7 +856,7 @@ maybe_build_inner_data_region (location_t loc, gimple *body,
else
inner_bind_vars = next;
}
- else
+ else if (!idx_vars->contains (v))
{
/* Otherwise, build the map clause. */
tree new_clause = build_omp_clause (loc, OMP_CLAUSE_MAP);
@@ -825,6 +864,7 @@ maybe_build_inner_data_region (location_t loc, gimple *body,
OMP_CLAUSE_DECL (new_clause) = v;
OMP_CLAUSE_SIZE (new_clause) = DECL_SIZE_UNIT (v);
OMP_CLAUSE_CHAIN (new_clause) = inner_data_clauses;
+ TREE_ADDRESSABLE (v) = 1;
inner_data_clauses = new_clause;
prev_mapped_var = v;
@@ -1156,6 +1196,8 @@ decompose_kernels_region_body (gimple *kernels_region,
tree kernels_clauses)
tree inner_bind_vars = flatten_binds (kernels_bind);
gimple_seq body_sequence = gimple_bind_body (kernels_bind);
+ hash_set<tree> idx_vars = find_omp_for_index_vars (kernels_bind);
+
/* All these inner variables will get allocated on the device (below, by
calling maybe_build_inner_data_region). Here we create "present"
clauses for them and add these clauses to the list of clauses to be
@@ -1163,7 +1205,9 @@ decompose_kernels_region_body (gimple *kernels_region,
tree kernels_clauses)
tree present_clauses = kernels_clauses;
for (tree var = inner_bind_vars; var; var = TREE_CHAIN (var))
{
- if (!DECL_ARTIFICIAL (var) && TREE_CODE (var) != CONST_DECL)
+ if (!DECL_ARTIFICIAL (var)
+ && TREE_CODE (var) != CONST_DECL
+ && !idx_vars.contains (var))
{
tree present_clause = build_omp_clause (loc, OMP_CLAUSE_MAP);
OMP_CLAUSE_SET_MAP_KIND (present_clause, GOMP_MAP_FORCE_PRESENT);
@@ -1342,7 +1386,7 @@ decompose_kernels_region_body (gimple *kernels_region,
tree kernels_clauses)
/* If we found variables declared in nested scopes, build a data region to
map them to the device. */
body = maybe_build_inner_data_region (loc, body, inner_bind_vars,
- inner_cleanup);
+ inner_cleanup, &idx_vars);
return body;
}
--
2.8.1
