xref: /dragonfly/contrib/gcc-8.0/gcc/ipa-hsa.c (revision 92db1a35)
1 /* Callgraph based analysis of static variables.
2    Copyright (C) 2015-2018 Free Software Foundation, Inc.
3    Contributed by Martin Liska <mliska@suse.cz>
4 
5 This file is part of GCC.
6 
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
10 version.
11 
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
15 for more details.
16 
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3.  If not see
19 <http://www.gnu.org/licenses/>.  */
20 
21 /* Interprocedural HSA pass is responsible for creation of HSA clones.
22    For all these HSA clones, we emit HSAIL instructions and pass processing
23    is terminated.  */
24 
25 #include "config.h"
26 #include "system.h"
27 #include "coretypes.h"
28 #include "tm.h"
29 #include "is-a.h"
30 #include "hash-set.h"
31 #include "vec.h"
32 #include "tree.h"
33 #include "tree-pass.h"
34 #include "function.h"
35 #include "basic-block.h"
36 #include "gimple.h"
37 #include "dumpfile.h"
38 #include "gimple-pretty-print.h"
39 #include "tree-streamer.h"
40 #include "stringpool.h"
41 #include "cgraph.h"
42 #include "print-tree.h"
43 #include "symbol-summary.h"
44 #include "hsa-common.h"
45 
46 namespace {
47 
48 /* If NODE is not versionable, warn about not emiting HSAIL and return false.
49    Otherwise return true.  */
50 
51 static bool
52 check_warn_node_versionable (cgraph_node *node)
53 {
54   if (!node->local.versionable)
55     {
56       warning_at (EXPR_LOCATION (node->decl), OPT_Whsa,
57 		  "could not emit HSAIL for function %s: function cannot be "
58 		  "cloned", node->name ());
59       return false;
60     }
61   return true;
62 }
63 
64 /* The function creates HSA clones for all functions that were either
65    marked as HSA kernels or are callable HSA functions.  Apart from that,
66    we redirect all edges that come from an HSA clone and end in another
67    HSA clone to connect these two functions.  */
68 
69 static unsigned int
70 process_hsa_functions (void)
71 {
72   struct cgraph_node *node;
73 
74   if (hsa_summaries == NULL)
75     hsa_summaries = new hsa_summary_t (symtab);
76 
77   FOR_EACH_DEFINED_FUNCTION (node)
78     {
79       hsa_function_summary *s = hsa_summaries->get (node);
80 
81       /* A linked function is skipped.  */
82       if (s->m_bound_function != NULL)
83 	continue;
84 
85       if (s->m_kind != HSA_NONE)
86 	{
87 	  if (!check_warn_node_versionable (node))
88 	    continue;
89 	  cgraph_node *clone
90 	    = node->create_virtual_clone (vec <cgraph_edge *> (),
91 					  NULL, NULL, "hsa");
92 	  TREE_PUBLIC (clone->decl) = TREE_PUBLIC (node->decl);
93 	  clone->externally_visible = node->externally_visible;
94 
95 	  clone->force_output = true;
96 	  hsa_summaries->link_functions (clone, node, s->m_kind, false);
97 
98 	  if (dump_file)
99 	    fprintf (dump_file, "Created a new HSA clone: %s, type: %s\n",
100 		     clone->name (),
101 		     s->m_kind == HSA_KERNEL ? "kernel" : "function");
102 	}
103       else if (hsa_callable_function_p (node->decl)
104 	       /* At this point, this is enough to identify clones for
105 		  parallel, which for HSA would need to be kernels anyway.  */
106 	       && !DECL_ARTIFICIAL (node->decl))
107 	{
108 	  if (!check_warn_node_versionable (node))
109 	    continue;
110 	  cgraph_node *clone
111 	    = node->create_virtual_clone (vec <cgraph_edge *> (),
112 					  NULL, NULL, "hsa");
113 	  TREE_PUBLIC (clone->decl) = TREE_PUBLIC (node->decl);
114 	  clone->externally_visible = node->externally_visible;
115 
116 	  if (!cgraph_local_p (node))
117 	    clone->force_output = true;
118 	  hsa_summaries->link_functions (clone, node, HSA_FUNCTION, false);
119 
120 	  if (dump_file)
121 	    fprintf (dump_file, "Created a new HSA function clone: %s\n",
122 		     clone->name ());
123 	}
124     }
125 
126   /* Redirect all edges that are between HSA clones.  */
127   FOR_EACH_DEFINED_FUNCTION (node)
128     {
129       cgraph_edge *e = node->callees;
130 
131       while (e)
132 	{
133 	  hsa_function_summary *src = hsa_summaries->get (node);
134 	  if (src->m_kind != HSA_NONE && src->m_gpu_implementation_p)
135 	    {
136 	      hsa_function_summary *dst = hsa_summaries->get (e->callee);
137 	      if (dst->m_kind != HSA_NONE && !dst->m_gpu_implementation_p)
138 		{
139 		  e->redirect_callee (dst->m_bound_function);
140 		  if (dump_file)
141 		    fprintf (dump_file,
142 			     "Redirecting edge to HSA function: %s->%s\n",
143 			     xstrdup_for_dump (e->caller->name ()),
144 			     xstrdup_for_dump (e->callee->name ()));
145 		}
146 	    }
147 
148 	  e = e->next_callee;
149 	}
150     }
151 
152   return 0;
153 }
154 
155 /* Iterate all HSA functions and stream out HSA function summary.  */
156 
157 static void
158 ipa_hsa_write_summary (void)
159 {
160   struct bitpack_d bp;
161   struct cgraph_node *node;
162   struct output_block *ob;
163   unsigned int count = 0;
164   lto_symtab_encoder_iterator lsei;
165   lto_symtab_encoder_t encoder;
166 
167   if (!hsa_summaries)
168     return;
169 
170   ob = create_output_block (LTO_section_ipa_hsa);
171   encoder = ob->decl_state->symtab_node_encoder;
172   ob->symbol = NULL;
173   for (lsei = lsei_start_function_in_partition (encoder); !lsei_end_p (lsei);
174        lsei_next_function_in_partition (&lsei))
175     {
176       node = lsei_cgraph_node (lsei);
177       hsa_function_summary *s = hsa_summaries->get (node);
178 
179       if (s->m_kind != HSA_NONE)
180 	count++;
181     }
182 
183   streamer_write_uhwi (ob, count);
184 
185   /* Process all of the functions.  */
186   for (lsei = lsei_start_function_in_partition (encoder); !lsei_end_p (lsei);
187        lsei_next_function_in_partition (&lsei))
188     {
189       node = lsei_cgraph_node (lsei);
190       hsa_function_summary *s = hsa_summaries->get (node);
191 
192       if (s->m_kind != HSA_NONE)
193 	{
194 	  encoder = ob->decl_state->symtab_node_encoder;
195 	  int node_ref = lto_symtab_encoder_encode (encoder, node);
196 	  streamer_write_uhwi (ob, node_ref);
197 
198 	  bp = bitpack_create (ob->main_stream);
199 	  bp_pack_value (&bp, s->m_kind, 2);
200 	  bp_pack_value (&bp, s->m_gpu_implementation_p, 1);
201 	  bp_pack_value (&bp, s->m_bound_function != NULL, 1);
202 	  streamer_write_bitpack (&bp);
203 	  if (s->m_bound_function)
204 	    stream_write_tree (ob, s->m_bound_function->decl, true);
205 	}
206     }
207 
208   streamer_write_char_stream (ob->main_stream, 0);
209   produce_asm (ob, NULL);
210   destroy_output_block (ob);
211 }
212 
213 /* Read section in file FILE_DATA of length LEN with data DATA.  */
214 
215 static void
216 ipa_hsa_read_section (struct lto_file_decl_data *file_data, const char *data,
217 		       size_t len)
218 {
219   const struct lto_function_header *header
220     = (const struct lto_function_header *) data;
221   const int cfg_offset = sizeof (struct lto_function_header);
222   const int main_offset = cfg_offset + header->cfg_size;
223   const int string_offset = main_offset + header->main_size;
224   struct data_in *data_in;
225   unsigned int i;
226   unsigned int count;
227 
228   lto_input_block ib_main ((const char *) data + main_offset,
229 			   header->main_size, file_data->mode_table);
230 
231   data_in
232     = lto_data_in_create (file_data, (const char *) data + string_offset,
233 			  header->string_size, vNULL);
234   count = streamer_read_uhwi (&ib_main);
235 
236   for (i = 0; i < count; i++)
237     {
238       unsigned int index;
239       struct cgraph_node *node;
240       lto_symtab_encoder_t encoder;
241 
242       index = streamer_read_uhwi (&ib_main);
243       encoder = file_data->symtab_node_encoder;
244       node = dyn_cast<cgraph_node *> (lto_symtab_encoder_deref (encoder,
245 								index));
246       gcc_assert (node->definition);
247       hsa_function_summary *s = hsa_summaries->get (node);
248 
249       struct bitpack_d bp = streamer_read_bitpack (&ib_main);
250       s->m_kind = (hsa_function_kind) bp_unpack_value (&bp, 2);
251       s->m_gpu_implementation_p = bp_unpack_value (&bp, 1);
252       bool has_tree = bp_unpack_value (&bp, 1);
253 
254       if (has_tree)
255 	{
256 	  tree decl = stream_read_tree (&ib_main, data_in);
257 	  s->m_bound_function = cgraph_node::get_create (decl);
258 	}
259     }
260   lto_free_section_data (file_data, LTO_section_ipa_hsa, NULL, data,
261 			 len);
262   lto_data_in_delete (data_in);
263 }
264 
265 /* Load streamed HSA functions summary and assign the summary to a function.  */
266 
267 static void
268 ipa_hsa_read_summary (void)
269 {
270   struct lto_file_decl_data **file_data_vec = lto_get_file_decl_data ();
271   struct lto_file_decl_data *file_data;
272   unsigned int j = 0;
273 
274   if (hsa_summaries == NULL)
275     hsa_summaries = new hsa_summary_t (symtab);
276 
277   while ((file_data = file_data_vec[j++]))
278     {
279       size_t len;
280       const char *data = lto_get_section_data (file_data, LTO_section_ipa_hsa,
281 					       NULL, &len);
282 
283       if (data)
284 	ipa_hsa_read_section (file_data, data, len);
285     }
286 }
287 
288 const pass_data pass_data_ipa_hsa =
289 {
290   IPA_PASS, /* type */
291   "hsa", /* name */
292   OPTGROUP_OMP, /* optinfo_flags */
293   TV_IPA_HSA, /* tv_id */
294   0, /* properties_required */
295   0, /* properties_provided */
296   0, /* properties_destroyed */
297   0, /* todo_flags_start */
298   TODO_dump_symtab, /* todo_flags_finish */
299 };
300 
301 class pass_ipa_hsa : public ipa_opt_pass_d
302 {
303 public:
304   pass_ipa_hsa (gcc::context *ctxt)
305     : ipa_opt_pass_d (pass_data_ipa_hsa, ctxt,
306 		      NULL, /* generate_summary */
307 		      ipa_hsa_write_summary, /* write_summary */
308 		      ipa_hsa_read_summary, /* read_summary */
309 		      ipa_hsa_write_summary, /* write_optimization_summary */
310 		      ipa_hsa_read_summary, /* read_optimization_summary */
311 		      NULL, /* stmt_fixup */
312 		      0, /* function_transform_todo_flags_start */
313 		      NULL, /* function_transform */
314 		      NULL) /* variable_transform */
315     {}
316 
317   /* opt_pass methods: */
318   virtual bool gate (function *);
319 
320   virtual unsigned int execute (function *) { return process_hsa_functions (); }
321 
322 }; // class pass_ipa_reference
323 
324 bool
325 pass_ipa_hsa::gate (function *)
326 {
327   return hsa_gen_requested_p ();
328 }
329 
330 } // anon namespace
331 
332 ipa_opt_pass_d *
333 make_pass_ipa_hsa (gcc::context *ctxt)
334 {
335   return new pass_ipa_hsa (ctxt);
336 }
337