The GCN backend uses tree nodes like MEM((__lds TYPE *) <constant>)
for reduction temporaries. Unlike e.g. var decls and SSA names, these
nodes cannot be shared during gimplification, but are so in some
circumstances. This is detected when appropriate --enable-checking
options are used. This patch unshares such nodes when they are reused
more than once.
Tested with offloading to AMD GCN. I will apply shortly.
Thanks,
Julian
2020-07-30 Julian Brown <jul...@codesourcery.com>
gcc/
* config/gcn/gcn-tree.c (gcn_goacc_get_worker_red_decl): Do not
cache/share decls for reduction temporaries between invocations.
(gcn_goacc_reduction_teardown): Unshare VAR on second use.
* config/gcn/gcn.c (gcn_init_machine_status): Do not initialise
reduc_decls.
* config/gcn/gcn.h (machine_function): Remove reduc_decls cache.
---
gcc/ChangeLog.omp | 9 +++++++++
gcc/config/gcn/gcn-tree.c | 30 ++++++------------------------
gcc/config/gcn/gcn.c | 3 ---
gcc/config/gcn/gcn.h | 1 -
4 files changed, 15 insertions(+), 28 deletions(-)
diff --git a/gcc/ChangeLog.omp b/gcc/ChangeLog.omp
index 12b8c044a1b1..34622a3bfa1b 100644
--- a/gcc/ChangeLog.omp
+++ b/gcc/ChangeLog.omp
@@ -1,3 +1,12 @@
+2020-07-30 Julian Brown <jul...@codesourcery.com>
+
+ * config/gcn/gcn-tree.c (gcn_goacc_get_worker_red_decl): Do not
+ cache/share decls for reduction temporaries between invocations.
+ (gcn_goacc_reduction_teardown): Unshare VAR on second use.
+ * config/gcn/gcn.c (gcn_init_machine_status): Do not initialise
+ reduc_decls.
+ * config/gcn/gcn.h (machine_function): Remove reduc_decls cache.
+
2020-07-30 Julian Brown <jul...@codesourcery.com>
* config/gcn/gcn-tree.c (gcn_goacc_reduction_teardown): Remove useless
diff --git a/gcc/config/gcn/gcn-tree.c b/gcc/config/gcn/gcn-tree.c
index bfde71555d8a..96fdf75a8cd9 100644
--- a/gcc/config/gcn/gcn-tree.c
+++ b/gcc/config/gcn/gcn-tree.c
@@ -429,7 +429,6 @@ static tree
gcn_goacc_get_worker_red_decl (tree type, unsigned offset)
{
machine_function *machfun = cfun->machine;
- tree existing_decl;
if (TREE_CODE (type) == REFERENCE_TYPE)
type = TREE_TYPE (type);
@@ -439,29 +438,12 @@ gcn_goacc_get_worker_red_decl (tree type, unsigned offset)
(TYPE_QUALS (type)
| ENCODE_QUAL_ADDR_SPACE (ADDR_SPACE_LDS)));
- if (machfun->reduc_decls
- && offset < machfun->reduc_decls->length ()
- && (existing_decl = (*machfun->reduc_decls)[offset]))
- {
- gcc_assert (TREE_TYPE (existing_decl) == var_type);
- return existing_decl;
- }
- else
- {
- gcc_assert (offset
- < (machfun->reduction_limit - machfun->reduction_base));
- tree ptr_type = build_pointer_type (var_type);
- tree addr = build_int_cst (ptr_type, machfun->reduction_base + offset);
-
- tree decl = build_simple_mem_ref (addr);
+ gcc_assert (offset
+ < (machfun->reduction_limit - machfun->reduction_base));
+ tree ptr_type = build_pointer_type (var_type);
+ tree addr = build_int_cst (ptr_type, machfun->reduction_base + offset);
- vec_safe_grow_cleared (machfun->reduc_decls, offset + 1);
- (*machfun->reduc_decls)[offset] = decl;
-
- return decl;
- }
-
- return NULL_TREE;
+ return build_simple_mem_ref (addr);
}
/* Expand IFN_GOACC_REDUCTION_SETUP. */
@@ -616,7 +598,7 @@ gcn_goacc_reduction_teardown (gcall *call)
}
if (lhs)
- gimplify_assign (lhs, var, &seq);
+ gimplify_assign (lhs, unshare_expr (var), &seq);
pop_gimplify_context (NULL);
diff --git a/gcc/config/gcn/gcn.c b/gcc/config/gcn/gcn.c
index 4b2df3c7df06..028e5c577c07 100644
--- a/gcc/config/gcn/gcn.c
+++ b/gcc/config/gcn/gcn.c
@@ -106,9 +106,6 @@ gcn_init_machine_status (void)
f = ggc_cleared_alloc<machine_function> ();
- /* And LDS temporary decls for worker reductions. */
- vec_alloc (f->reduc_decls, 0);
-
if (TARGET_GCN3)
f->use_flat_addressing = true;
diff --git a/gcc/config/gcn/gcn.h b/gcc/config/gcn/gcn.h
index 91b3d88c062a..06475f59ad79 100644
--- a/gcc/config/gcn/gcn.h
+++ b/gcc/config/gcn/gcn.h
@@ -573,7 +573,6 @@ struct GTY(()) machine_function
unsigned HOST_WIDE_INT reduction_base;
unsigned HOST_WIDE_INT reduction_limit;
- vec<tree, va_gc> *reduc_decls;
bool use_flat_addressing;
};
--
2.23.0
