On 29 Sep 03:10, Jan Hubicka wrote:
> dump for me implied debug dump. LTO is usually called streaming, so prehaps
> need_lto_stremaing?
Fixed.
> > +initialize_offload (void)
> Perhaps have_offload_p? Nothing is initialized here...
The next patch will add some initialization to this function. And they'll be
committed in a series. So, I'd prefer to keep this name.
> How does LTO combine with offloading?
Both .gnu.lto_ and .gnu.target_lto_ sections are created. LTO just ignores
target sections, and offload compiler ignores .gnu.lto_ sections. Everything
works fine on my testcases.
> > @@ -4325,11 +4325,6 @@ void
> > inline_free_summary (void)
> > {
> > struct cgraph_node *node;
> > - if (!inline_edge_summary_vec.exists ())
> > - return;
> > - FOR_EACH_DEFINED_FUNCTION (node)
> > - if (!node->alias)
> > - reset_inline_summary (node);
> > if (function_insertion_hook_holder)
> > symtab->remove_cgraph_insertion_hook (function_insertion_hook_holder);
> > function_insertion_hook_holder = NULL;
> > @@ -4345,6 +4340,11 @@ inline_free_summary (void)
> > if (edge_duplication_hook_holder)
> > symtab->remove_edge_duplication_hook (edge_duplication_hook_holder);
> > edge_duplication_hook_holder = NULL;
> > + if (!inline_edge_summary_vec.exists ())
> > + return;
> > + FOR_EACH_DEFINED_FUNCTION (node)
> > + if (!node->alias)
> > + reset_inline_summary (node);
>
> Why this is needed?
Without this change gcc/testsuite/g++.dg/gomp/declare-simd-1.C will fail at -O0,
since inline_generate_summary adds add_new_function hook, but at -O0 the
inline_edge_summary_vec is empty, and we don't call remove_cgraph_insertion_hook
( https://gcc.gnu.org/ml/gcc-patches/2014-02/msg00055.html )
> > lto_set_symtab_encoder_in_partition (lto_symtab_encoder_t encoder,
> > symtab_node *node)
> > {
> > + /* Ignore not needed nodes. */
> > + if (!node->need_dump)
> > + return;
>
> I think it should be rather done at caller side (in the loop setting what to
> output)
> rather than in this simple datastructure accestor.
Done.
> > + /* Ignore references from non-target functions in offload lto mode.
> > */
> > + if (offload_lto_mode
> > + && !lookup_attribute ("omp declare target",
> > + DECL_ATTRIBUTES (ref->referring->decl)))
> > + continue;
>
> Those are quite busy loops, you may consder making offload a flag. Why you
> can't test
> need_dump here?
Definitely. I have no idea why I did not used this flag here :) Fixed.
> I think you also need to run free lang data when you decide to stream
> something.
When I compile a file with offloading, but without -flto, I see free lang data,
executed during all_small_ipa_passes:
#0 free_lang_data () at gcc/tree.c:5655
#1 in (anonymous namespace)::pass_ipa_free_lang_data::execute (this=0x20ce470)
at gcc/tree.c:5708
#2 in execute_one_pass (pass=0x20ce470) at gcc/passes.c:2151
#3 in execute_ipa_pass_list (pass=0x20ce470) at gcc/passes.c:2543
#4 in ipa_passes () at gcc/cgraphunit.c:2055
#5 in symbol_table::compile (this=0x7ffff19fd000) at gcc/cgraphunit.c:2187
#6 in symbol_table::finalize_compilation_unit (this=0x7ffff19fd000) at
gcc/cgraphunit.c:2340
#7 in c_write_global_declarations () at gcc/c/c-decl.c:10431
#8 in compile_file () at gcc/toplev.c:566
#9 in do_compile () at gcc/toplev.c:1949
#10 in toplev_main (argc=17, argv=0x7fffffffe3a8) at gcc/toplev.c:2025
#11 in main (argc=17, argv=0x7fffffffe3a8) at gcc/main.c:36
> Otherwise the cgraph bits seems resonable. I think Richi will want to comment
> on LTO
> part.
Here is updated patch. Bootstrapped and regtested.
OK for trunk (after all patches from the series will be approved)?
Thanks,
-- Ilya
gcc/
* cgraph.h (symtab_node): Add need_lto_streaming flag.
* cgraphunit.c: Include lto-section-names.h.
(initialize_offload): New function.
(ipa_passes): Initialize offload and call ipa_write_summaries if there
is something to write to OMP_SECTION_NAME_PREFIX sections.
(symbol_table::compile): Call lto_streamer_hooks_init under flag_openmp.
* ipa-inline-analysis.c (inline_generate_summary): Do not exit under
flag_openmp.
(inline_free_summary): Always remove hooks.
* lto-cgraph.c (referenced_from_other_partition_p): Ignore references
from non-target functions to target functions if we are streaming out
target-side bytecode (offload lto mode).
(reachable_from_other_partition_p): Likewise.
(select_what_to_stream): New function.
(compute_ltrans_boundary): Do not call
lto_set_symtab_encoder_in_partition if the node should not be streamed.
* lto-section-names.h (OMP_SECTION_NAME_PREFIX): Define.
(section_name_prefix): Declare.
* lto-streamer.c (section_name_prefix): New variable.
(lto_get_section_name): Use section_name_prefix instead of
LTO_SECTION_NAME_PREFIX.
* lto-streamer.h (select_what_to_stream): Declare.
* omp-low.c (is_targetreg_ctx): New function.
(create_omp_child_function, check_omp_nesting_restrictions): Use it.
(expand_omp_target): Set mark_force_output for the target functions.
(lower_omp_critical): Add target attribute for omp critical symbol.
* passes.c (ipa_write_summaries): New argument offload_lto_mode. Call
select_what_to_stream. Do not call lto_set_symtab_encoder_in_partition
if the node should not be streamed out.
* tree-pass.h (ipa_write_summaries): New bool argument.
gcc/lto/
* lto-object.c (lto_obj_add_section): Use section_name_prefix instead of
LTO_SECTION_NAME_PREFIX.
* lto-partition.c (lto_promote_cross_file_statics): Call
select_what_to_stream.
* lto.c (lto_section_with_id): Use section_name_prefix instead of
LTO_SECTION_NAME_PREFIX.
(read_cgraph_and_symbols): Read OMP_SECTION_NAME_PREFIX sections, if
being built as an offload compiler.
---
diff --git a/gcc/cgraph.h b/gcc/cgraph.h
index 4fd58a5..df0b0e2 100644
--- a/gcc/cgraph.h
+++ b/gcc/cgraph.h
@@ -444,6 +444,10 @@ public:
/* Set when init priority is set. */
unsigned in_init_priority_hash : 1;
+ /* Set when symbol needs to be streamed into LTO bytecode for LTO, or in case
+ of offloading, for separate compilation for a different target. */
+ unsigned need_lto_streaming : 1;
+
/* Ordering of all symtab entries. */
int order;
diff --git a/gcc/cgraphunit.c b/gcc/cgraphunit.c
index d463505..a6b0bac 100644
--- a/gcc/cgraphunit.c
+++ b/gcc/cgraphunit.c
@@ -211,6 +211,7 @@ along with GCC; see the file COPYING3. If not see
#include "tree-nested.h"
#include "gimplify.h"
#include "dbgcnt.h"
+#include "lto-section-names.h"
/* Queue of cgraph nodes scheduled to be added into cgraph. This is a
secondary queue used during optimization to accommodate passes that
@@ -1994,9 +1995,40 @@ output_in_order (bool no_reorder)
free (nodes);
}
+/* Check whether there is at least one function or global variable to offload.
+ */
+
+static bool
+initialize_offload (void)
+{
+ bool have_offload = false;
+ struct cgraph_node *node;
+ struct varpool_node *vnode;
+
+ FOR_EACH_DEFINED_FUNCTION (node)
+ if (lookup_attribute ("omp declare target", DECL_ATTRIBUTES (node->decl)))
+ {
+ have_offload = true;
+ break;
+ }
+
+ FOR_EACH_DEFINED_VARIABLE (vnode)
+ {
+ if (!lookup_attribute ("omp declare target",
+ DECL_ATTRIBUTES (vnode->decl))
+ || TREE_CODE (vnode->decl) != VAR_DECL
+ || DECL_SIZE (vnode->decl) == 0)
+ continue;
+ have_offload = true;
+ }
+
+ return have_offload;
+}
+
static void
ipa_passes (void)
{
+ bool have_offload = false;
gcc::pass_manager *passes = g->get_passes ();
set_cfun (NULL);
@@ -2004,6 +2036,14 @@ ipa_passes (void)
gimple_register_cfg_hooks ();
bitmap_obstack_initialize (NULL);
+ if (!in_lto_p && flag_openmp)
+ {
+ have_offload = initialize_offload ();
+ /* OpenMP offloading requires LTO infrastructure. */
+ if (have_offload)
+ flag_generate_lto = 1;
+ }
+
invoke_plugin_callbacks (PLUGIN_ALL_IPA_PASSES_START, NULL);
if (!in_lto_p)
@@ -2041,7 +2081,18 @@ ipa_passes (void)
targetm.asm_out.lto_start ();
if (!in_lto_p)
- ipa_write_summaries ();
+ {
+ if (have_offload)
+ {
+ section_name_prefix = OMP_SECTION_NAME_PREFIX;
+ ipa_write_summaries (true);
+ }
+ if (flag_lto)
+ {
+ section_name_prefix = LTO_SECTION_NAME_PREFIX;
+ ipa_write_summaries (false);
+ }
+ }
if (flag_generate_lto)
targetm.asm_out.lto_end ();
@@ -2122,7 +2173,7 @@ symbol_table::compile (void)
state = IPA;
/* If LTO is enabled, initialize the streamer hooks needed by GIMPLE. */
- if (flag_lto)
+ if (flag_lto || flag_openmp)
lto_streamer_hooks_init ();
/* Don't run the IPA passes if there was any error or sorry messages. */
diff --git a/gcc/ipa-inline-analysis.c b/gcc/ipa-inline-analysis.c
index 38f56d2..076a1e8 100644
--- a/gcc/ipa-inline-analysis.c
+++ b/gcc/ipa-inline-analysis.c
@@ -4010,7 +4010,7 @@ inline_generate_summary (void)
/* When not optimizing, do not bother to analyze. Inlining is still done
because edge redirection needs to happen there. */
- if (!optimize && !flag_lto && !flag_wpa)
+ if (!optimize && !flag_lto && !flag_wpa && !flag_openmp)
return;
function_insertion_hook_holder =
@@ -4325,11 +4325,6 @@ void
inline_free_summary (void)
{
struct cgraph_node *node;
- if (!inline_edge_summary_vec.exists ())
- return;
- FOR_EACH_DEFINED_FUNCTION (node)
- if (!node->alias)
- reset_inline_summary (node);
if (function_insertion_hook_holder)
symtab->remove_cgraph_insertion_hook (function_insertion_hook_holder);
function_insertion_hook_holder = NULL;
@@ -4345,6 +4340,11 @@ inline_free_summary (void)
if (edge_duplication_hook_holder)
symtab->remove_edge_duplication_hook (edge_duplication_hook_holder);
edge_duplication_hook_holder = NULL;
+ if (!inline_edge_summary_vec.exists ())
+ return;
+ FOR_EACH_DEFINED_FUNCTION (node)
+ if (!node->alias)
+ reset_inline_summary (node);
vec_free (inline_summary_vec);
inline_edge_summary_vec.release ();
if (edge_predicate_pool)
diff --git a/gcc/lto-cgraph.c b/gcc/lto-cgraph.c
index 0584946..ed22289 100644
--- a/gcc/lto-cgraph.c
+++ b/gcc/lto-cgraph.c
@@ -321,6 +321,11 @@ referenced_from_other_partition_p (symtab_node *node,
lto_symtab_encoder_t encod
for (i = 0; node->iterate_referring (i, ref); i++)
{
+ /* Ignore references from non-target nodes while streaming NODE into
+ offload target section. */
+ if (!ref->referring->need_lto_streaming)
+ continue;
+
if (ref->referring->in_other_partition
|| !lto_symtab_encoder_in_partition_p (encoder, ref->referring))
return true;
@@ -339,9 +344,16 @@ reachable_from_other_partition_p (struct cgraph_node
*node, lto_symtab_encoder_t
if (node->global.inlined_to)
return false;
for (e = node->callers; e; e = e->next_caller)
- if (e->caller->in_other_partition
- || !lto_symtab_encoder_in_partition_p (encoder, e->caller))
- return true;
+ {
+ /* Ignore references from non-target nodes while streaming NODE into
+ offload target section. */
+ if (!e->caller->need_lto_streaming)
+ continue;
+
+ if (e->caller->in_other_partition
+ || !lto_symtab_encoder_in_partition_p (encoder, e->caller))
+ return true;
+ }
return false;
}
@@ -802,6 +814,18 @@ create_references (lto_symtab_encoder_t encoder,
symtab_node *node)
lto_symtab_encoder_encode (encoder, ref->referred);
}
+/* Select what needs to be streamed out. In regular lto mode stream
everything.
+ In offload lto mode stream only stuff marked with an attribute. */
+void
+select_what_to_stream (bool offload_lto_mode)
+{
+ struct symtab_node *snode;
+ FOR_EACH_SYMBOL (snode)
+ snode->need_lto_streaming
+ = !offload_lto_mode || lookup_attribute ("omp declare target",
+ DECL_ATTRIBUTES (snode->decl));
+}
+
/* Find all symbols we want to stream into given partition and insert them
to encoders.
@@ -828,6 +852,8 @@ compute_ltrans_boundary (lto_symtab_encoder_t in_encoder)
!lsei_end_p (lsei); lsei_next_function_in_partition (&lsei))
{
struct cgraph_node *node = lsei_cgraph_node (lsei);
+ if (!node->need_lto_streaming)
+ continue;
add_node_to (encoder, node, true);
lto_set_symtab_encoder_in_partition (encoder, node);
create_references (encoder, node);
@@ -844,6 +870,8 @@ compute_ltrans_boundary (lto_symtab_encoder_t in_encoder)
{
varpool_node *vnode = lsei_varpool_node (lsei);
+ if (!vnode->need_lto_streaming)
+ continue;
lto_set_symtab_encoder_in_partition (encoder, vnode);
lto_set_symtab_encoder_encode_initializer (encoder, vnode);
create_references (encoder, vnode);
diff --git a/gcc/lto-section-names.h b/gcc/lto-section-names.h
index cb75230..06d2caf 100644
--- a/gcc/lto-section-names.h
+++ b/gcc/lto-section-names.h
@@ -25,6 +25,11 @@ along with GCC; see the file COPYING3. If not see
name for the functions and static_initializers. For other types of
sections a '.' and the section type are appended. */
#define LTO_SECTION_NAME_PREFIX ".gnu.lto_"
+#define OMP_SECTION_NAME_PREFIX ".gnu.target_lto_"
+
+/* Can be either OMP_SECTION_NAME_PREFIX when we stream 'pragma omp target'
+ stuff, or LTO_SECTION_NAME_PREFIX for LTO case. */
+extern const char *section_name_prefix;
/* Segment name for LTO sections. This is only used for Mach-O. */
diff --git a/gcc/lto-streamer.c b/gcc/lto-streamer.c
index 3480723..161e12d 100644
--- a/gcc/lto-streamer.c
+++ b/gcc/lto-streamer.c
@@ -48,6 +48,7 @@ struct lto_stats_d lto_stats;
static bitmap_obstack lto_obstack;
static bool lto_obstack_initialized;
+const char *section_name_prefix = LTO_SECTION_NAME_PREFIX;
/* Return a string representing LTO tag TAG. */
@@ -177,7 +178,7 @@ lto_get_section_name (int section_type, const char *name,
struct lto_file_decl_d
sprintf (post, "." HOST_WIDE_INT_PRINT_HEX_PURE, f->id);
else
sprintf (post, "." HOST_WIDE_INT_PRINT_HEX_PURE, get_random_seed (false));
- return concat (LTO_SECTION_NAME_PREFIX, sep, add, post, NULL);
+ return concat (section_name_prefix, sep, add, post, NULL);
}
diff --git a/gcc/lto-streamer.h b/gcc/lto-streamer.h
index 4bec969..ba00ab4 100644
--- a/gcc/lto-streamer.h
+++ b/gcc/lto-streamer.h
@@ -831,6 +831,7 @@ bool referenced_from_this_partition_p (symtab_node *,
bool reachable_from_this_partition_p (struct cgraph_node *,
lto_symtab_encoder_t);
lto_symtab_encoder_t compute_ltrans_boundary (lto_symtab_encoder_t encoder);
+void select_what_to_stream (bool);
/* In lto-symtab.c. */
diff --git a/gcc/lto/lto-object.c b/gcc/lto/lto-object.c
index 323f7b2..4ee752f 100644
--- a/gcc/lto/lto-object.c
+++ b/gcc/lto/lto-object.c
@@ -230,8 +230,7 @@ lto_obj_add_section (void *data, const char *name, off_t
offset,
void **slot;
struct lto_section_list *list = loasd->list;
- if (strncmp (name, LTO_SECTION_NAME_PREFIX,
- strlen (LTO_SECTION_NAME_PREFIX)) != 0)
+ if (strncmp (name, section_name_prefix, strlen (section_name_prefix)))
return 1;
new_name = xstrdup (name);
diff --git a/gcc/lto/lto-partition.c b/gcc/lto/lto-partition.c
index 0451a66..aae2be9 100644
--- a/gcc/lto/lto-partition.c
+++ b/gcc/lto/lto-partition.c
@@ -920,6 +920,8 @@ lto_promote_cross_file_statics (void)
gcc_assert (flag_wpa);
+ select_what_to_stream (false);
+
/* First compute boundaries. */
n_sets = ltrans_partitions.length ();
for (i = 0; i < n_sets; i++)
diff --git a/gcc/lto/lto.c b/gcc/lto/lto.c
index 6cbb178..f23d997 100644
--- a/gcc/lto/lto.c
+++ b/gcc/lto/lto.c
@@ -2125,7 +2125,7 @@ lto_section_with_id (const char *name, unsigned
HOST_WIDE_INT *id)
{
const char *s;
- if (strncmp (name, LTO_SECTION_NAME_PREFIX, strlen
(LTO_SECTION_NAME_PREFIX)))
+ if (strncmp (name, section_name_prefix, strlen (section_name_prefix)))
return 0;
s = strrchr (name, '.');
return s && sscanf (s, "." HOST_WIDE_INT_PRINT_HEX_PURE, id) == 1;
@@ -2899,6 +2899,10 @@ read_cgraph_and_symbols (unsigned nfiles, const char
**fnames)
timevar_push (TV_IPA_LTO_DECL_IN);
+#ifdef ACCEL_COMPILER
+ section_name_prefix = OMP_SECTION_NAME_PREFIX;
+#endif
+
real_file_decl_data
= decl_data = ggc_cleared_vec_alloc<lto_file_decl_data_ptr> (nfiles + 1);
real_file_count = nfiles;
diff --git a/gcc/omp-low.c b/gcc/omp-low.c
index eb0a7ee..c0a6393 100644
--- a/gcc/omp-low.c
+++ b/gcc/omp-low.c
@@ -257,6 +257,16 @@ is_parallel_ctx (omp_context *ctx)
}
+/* Return true if CTX is for an omp target region. */
+
+static inline bool
+is_targetreg_ctx (omp_context *ctx)
+{
+ return gimple_code (ctx->stmt) == GIMPLE_OMP_TARGET
+ && gimple_omp_target_kind (ctx->stmt) == GF_OMP_TARGET_KIND_REGION;
+}
+
+
/* Return true if CTX is for an omp task. */
static inline bool
@@ -1930,9 +1940,7 @@ create_omp_child_function (omp_context *ctx, bool
task_copy)
{
omp_context *octx;
for (octx = ctx; octx; octx = octx->outer)
- if (gimple_code (octx->stmt) == GIMPLE_OMP_TARGET
- && gimple_omp_target_kind (octx->stmt)
- == GF_OMP_TARGET_KIND_REGION)
+ if (is_targetreg_ctx (octx))
{
target_p = true;
break;
@@ -2588,8 +2596,7 @@ check_omp_nesting_restrictions (gimple stmt, omp_context
*ctx)
break;
case GIMPLE_OMP_TARGET:
for (; ctx != NULL; ctx = ctx->outer)
- if (gimple_code (ctx->stmt) == GIMPLE_OMP_TARGET
- && gimple_omp_target_kind (ctx->stmt) == GF_OMP_TARGET_KIND_REGION)
+ if (is_targetreg_ctx (ctx))
{
const char *name;
switch (gimple_omp_target_kind (stmt))
@@ -8206,6 +8213,7 @@ expand_omp_target (struct omp_region *region)
if (kind == GF_OMP_TARGET_KIND_REGION)
{
unsigned srcidx, dstidx, num;
+ struct cgraph_node *node;
/* If the target region needs data sent from the parent
function, then the very first statement (except possible
@@ -8337,6 +8345,11 @@ expand_omp_target (struct omp_region *region)
push_cfun (child_cfun);
cgraph_edge::rebuild_edges ();
+ /* Prevent IPA from removing child_fn as unreachable, since there are no
+ refs from the parent function to the target side child_fn. */
+ node = cgraph_node::get (child_fn);
+ node->mark_force_output ();
+
/* Some EH regions might become dead, see PR34608. If
pass_cleanup_cfg isn't the first pass to happen with the
new child, these dead EH edges might cause problems.
@@ -9207,6 +9220,19 @@ lower_omp_critical (gimple_stmt_iterator *gsi_p,
omp_context *ctx)
DECL_COMMON (decl) = 1;
DECL_ARTIFICIAL (decl) = 1;
DECL_IGNORED_P (decl) = 1;
+
+ /* If '#pragma omp critical' is inside target region, the symbol must
+ have an 'omp declare target' attribute. */
+ omp_context *octx;
+ for (octx = ctx->outer; octx; octx = octx->outer)
+ if (is_targetreg_ctx (octx))
+ {
+ DECL_ATTRIBUTES (decl)
+ = tree_cons (get_identifier ("omp declare target"),
+ NULL_TREE, DECL_ATTRIBUTES (decl));
+ break;
+ }
+
varpool_node::finalize_decl (decl);
splay_tree_insert (critical_name_mutexes, (splay_tree_key) name,
diff --git a/gcc/passes.c b/gcc/passes.c
index 5001c3d..0d5667d 100644
--- a/gcc/passes.c
+++ b/gcc/passes.c
@@ -2297,7 +2297,7 @@ ipa_write_summaries_1 (lto_symtab_encoder_t encoder)
/* Write out summaries for all the nodes in the callgraph. */
void
-ipa_write_summaries (void)
+ipa_write_summaries (bool offload_lto_mode)
{
lto_symtab_encoder_t encoder;
int i, order_pos;
@@ -2308,6 +2308,8 @@ ipa_write_summaries (void)
if (!flag_generate_lto || seen_error ())
return;
+ select_what_to_stream (offload_lto_mode);
+
encoder = lto_symtab_encoder_new (false);
/* Create the callgraph set in the same order used in
@@ -2334,15 +2336,16 @@ ipa_write_summaries (void)
renumber_gimple_stmt_uids ();
pop_cfun ();
}
- if (node->definition)
+ if (node->definition && node->need_lto_streaming)
lto_set_symtab_encoder_in_partition (encoder, node);
}
FOR_EACH_DEFINED_FUNCTION (node)
- if (node->alias)
+ if (node->alias && node->need_lto_streaming)
lto_set_symtab_encoder_in_partition (encoder, node);
FOR_EACH_DEFINED_VARIABLE (vnode)
- lto_set_symtab_encoder_in_partition (encoder, vnode);
+ if (vnode->need_lto_streaming)
+ lto_set_symtab_encoder_in_partition (encoder, vnode);
ipa_write_summaries_1 (compute_ltrans_boundary (encoder));
diff --git a/gcc/tree-pass.h b/gcc/tree-pass.h
index ed109c3..0bc5ca1 100644
--- a/gcc/tree-pass.h
+++ b/gcc/tree-pass.h
@@ -592,7 +592,7 @@ extern void pass_fini_dump_file (opt_pass *);
extern const char *get_current_pass_name (void);
extern void print_current_pass (FILE *);
extern void debug_pass (void);
-extern void ipa_write_summaries (void);
+extern void ipa_write_summaries (bool);
extern void ipa_write_optimization_summaries (struct lto_symtab_encoder_d *);
extern void ipa_read_summaries (void);
extern void ipa_read_optimization_summaries (void);
--
1.7.1
