Mercurial > hg > graal-compiler
annotate src/share/vm/opto/gcm.cpp @ 14412:e2722a66aba7
Merge
| author | kvn |
|---|---|
| date | Thu, 05 Sep 2013 11:04:39 -0700 |
| parents | d2907f74462e adb9a7d94cb5 |
| children | 2b8e28fdf503 |
| rev | line source |
|---|---|
| 0 | 1 /* |
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2 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved. |
| 0 | 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 * | |
| 5 * This code is free software; you can redistribute it and/or modify it | |
| 6 * under the terms of the GNU General Public License version 2 only, as | |
| 7 * published by the Free Software Foundation. | |
| 8 * | |
| 9 * This code is distributed in the hope that it will be useful, but WITHOUT | |
| 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 12 * version 2 for more details (a copy is included in the LICENSE file that | |
| 13 * accompanied this code). | |
| 14 * | |
| 15 * You should have received a copy of the GNU General Public License version | |
| 16 * 2 along with this work; if not, write to the Free Software Foundation, | |
| 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
| 18 * | |
|
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
| 0 | 22 * |
| 23 */ | |
| 24 | |
| 1972 | 25 #include "precompiled.hpp" |
| 26 #include "libadt/vectset.hpp" | |
| 27 #include "memory/allocation.inline.hpp" | |
| 28 #include "opto/block.hpp" | |
| 29 #include "opto/c2compiler.hpp" | |
| 30 #include "opto/callnode.hpp" | |
| 31 #include "opto/cfgnode.hpp" | |
| 32 #include "opto/machnode.hpp" | |
| 33 #include "opto/opcodes.hpp" | |
| 34 #include "opto/phaseX.hpp" | |
| 35 #include "opto/rootnode.hpp" | |
| 36 #include "opto/runtime.hpp" | |
| 37 #include "runtime/deoptimization.hpp" | |
| 38 #ifdef TARGET_ARCH_MODEL_x86_32 | |
| 39 # include "adfiles/ad_x86_32.hpp" | |
| 40 #endif | |
| 41 #ifdef TARGET_ARCH_MODEL_x86_64 | |
| 42 # include "adfiles/ad_x86_64.hpp" | |
| 43 #endif | |
| 44 #ifdef TARGET_ARCH_MODEL_sparc | |
| 45 # include "adfiles/ad_sparc.hpp" | |
| 46 #endif | |
| 47 #ifdef TARGET_ARCH_MODEL_zero | |
| 48 # include "adfiles/ad_zero.hpp" | |
| 49 #endif | |
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50 #ifdef TARGET_ARCH_MODEL_arm |
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51 # include "adfiles/ad_arm.hpp" |
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52 #endif |
| 14391 | 53 #ifdef TARGET_ARCH_MODEL_ppc_32 |
| 54 # include "adfiles/ad_ppc_32.hpp" | |
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55 #endif |
| 14391 | 56 #ifdef TARGET_ARCH_MODEL_ppc_64 |
| 57 # include "adfiles/ad_ppc_64.hpp" | |
| 58 #endif | |
| 59 | |
| 1972 | 60 |
| 0 | 61 // Portions of code courtesy of Clifford Click |
| 62 | |
| 63 // Optimization - Graph Style | |
| 64 | |
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65 // To avoid float value underflow |
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66 #define MIN_BLOCK_FREQUENCY 1.e-35f |
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67 |
| 0 | 68 //----------------------------schedule_node_into_block------------------------- |
| 69 // Insert node n into block b. Look for projections of n and make sure they | |
| 70 // are in b also. | |
| 71 void PhaseCFG::schedule_node_into_block( Node *n, Block *b ) { | |
| 72 // Set basic block of n, Add n to b, | |
| 12023 | 73 map_node_to_block(n, b); |
| 0 | 74 b->add_inst(n); |
| 75 | |
| 76 // After Matching, nearly any old Node may have projections trailing it. | |
| 77 // These are usually machine-dependent flags. In any case, they might | |
| 78 // float to another block below this one. Move them up. | |
| 79 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { | |
| 80 Node* use = n->fast_out(i); | |
| 81 if (use->is_Proj()) { | |
| 12023 | 82 Block* buse = get_block_for_node(use); |
| 0 | 83 if (buse != b) { // In wrong block? |
| 12023 | 84 if (buse != NULL) { |
| 0 | 85 buse->find_remove(use); // Remove from wrong block |
| 12023 | 86 } |
| 87 map_node_to_block(use, b); | |
| 0 | 88 b->add_inst(use); |
| 89 } | |
| 90 } | |
| 91 } | |
| 92 } | |
| 93 | |
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94 //----------------------------replace_block_proj_ctrl------------------------- |
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95 // Nodes that have is_block_proj() nodes as their control need to use |
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96 // the appropriate Region for their actual block as their control since |
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97 // the projection will be in a predecessor block. |
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98 void PhaseCFG::replace_block_proj_ctrl( Node *n ) { |
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99 const Node *in0 = n->in(0); |
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100 assert(in0 != NULL, "Only control-dependent"); |
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101 const Node *p = in0->is_block_proj(); |
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102 if (p != NULL && p != n) { // Control from a block projection? |
| 4115 | 103 assert(!n->pinned() || n->is_MachConstantBase(), "only pinned MachConstantBase node is expected here"); |
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104 // Find trailing Region |
| 12023 | 105 Block *pb = get_block_for_node(in0); // Block-projection already has basic block |
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106 uint j = 0; |
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107 if (pb->_num_succs != 1) { // More then 1 successor? |
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108 // Search for successor |
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109 uint max = pb->_nodes.size(); |
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110 assert( max > 1, "" ); |
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111 uint start = max - pb->_num_succs; |
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112 // Find which output path belongs to projection |
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113 for (j = start; j < max; j++) { |
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114 if( pb->_nodes[j] == in0 ) |
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115 break; |
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116 } |
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117 assert( j < max, "must find" ); |
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118 // Change control to match head of successor basic block |
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119 j -= start; |
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120 } |
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121 n->set_req(0, pb->_succs[j]->head()); |
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122 } |
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123 } |
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124 |
| 0 | 125 |
| 126 //------------------------------schedule_pinned_nodes-------------------------- | |
| 127 // Set the basic block for Nodes pinned into blocks | |
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128 void PhaseCFG::schedule_pinned_nodes(VectorSet &visited) { |
| 0 | 129 // Allocate node stack of size C->unique()+8 to avoid frequent realloc |
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130 GrowableArray <Node *> spstack(C->unique() + 8); |
| 0 | 131 spstack.push(_root); |
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132 while (spstack.is_nonempty()) { |
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133 Node* node = spstack.pop(); |
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134 if (!visited.test_set(node->_idx)) { // Test node and flag it as visited |
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135 if (node->pinned() && !has_block(node)) { // Pinned? Nail it down! |
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136 assert(node->in(0), "pinned Node must have Control"); |
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137 // Before setting block replace block_proj control edge |
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138 replace_block_proj_ctrl(node); |
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139 Node* input = node->in(0); |
| 12023 | 140 while (!input->is_block_start()) { |
| 0 | 141 input = input->in(0); |
| 12023 | 142 } |
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143 Block* block = get_block_for_node(input); // Basic block of controlling input |
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144 schedule_node_into_block(node, block); |
| 0 | 145 } |
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146 |
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147 // process all inputs that are non NULL |
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148 for (int i = node->req() - 1; i >= 0; --i) { |
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149 if (node->in(i) != NULL) { |
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150 spstack.push(node->in(i)); |
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151 } |
| 0 | 152 } |
| 153 } | |
| 154 } | |
| 155 } | |
| 156 | |
| 157 #ifdef ASSERT | |
| 158 // Assert that new input b2 is dominated by all previous inputs. | |
| 159 // Check this by by seeing that it is dominated by b1, the deepest | |
| 160 // input observed until b2. | |
| 12023 | 161 static void assert_dom(Block* b1, Block* b2, Node* n, const PhaseCFG* cfg) { |
| 0 | 162 if (b1 == NULL) return; |
| 163 assert(b1->_dom_depth < b2->_dom_depth, "sanity"); | |
| 164 Block* tmp = b2; | |
| 165 while (tmp != b1 && tmp != NULL) { | |
| 166 tmp = tmp->_idom; | |
| 167 } | |
| 168 if (tmp != b1) { | |
| 169 // Detected an unschedulable graph. Print some nice stuff and die. | |
| 170 tty->print_cr("!!! Unschedulable graph !!!"); | |
| 171 for (uint j=0; j<n->len(); j++) { // For all inputs | |
| 172 Node* inn = n->in(j); // Get input | |
| 173 if (inn == NULL) continue; // Ignore NULL, missing inputs | |
| 12023 | 174 Block* inb = cfg->get_block_for_node(inn); |
| 0 | 175 tty->print("B%d idom=B%d depth=%2d ",inb->_pre_order, |
| 176 inb->_idom ? inb->_idom->_pre_order : 0, inb->_dom_depth); | |
| 177 inn->dump(); | |
| 178 } | |
| 179 tty->print("Failing node: "); | |
| 180 n->dump(); | |
| 181 assert(false, "unscheduable graph"); | |
| 182 } | |
| 183 } | |
| 184 #endif | |
| 185 | |
| 12023 | 186 static Block* find_deepest_input(Node* n, const PhaseCFG* cfg) { |
| 0 | 187 // Find the last input dominated by all other inputs. |
| 188 Block* deepb = NULL; // Deepest block so far | |
| 189 int deepb_dom_depth = 0; | |
| 190 for (uint k = 0; k < n->len(); k++) { // For all inputs | |
| 191 Node* inn = n->in(k); // Get input | |
| 192 if (inn == NULL) continue; // Ignore NULL, missing inputs | |
| 12023 | 193 Block* inb = cfg->get_block_for_node(inn); |
| 0 | 194 assert(inb != NULL, "must already have scheduled this input"); |
| 195 if (deepb_dom_depth < (int) inb->_dom_depth) { | |
| 196 // The new inb must be dominated by the previous deepb. | |
| 197 // The various inputs must be linearly ordered in the dom | |
| 198 // tree, or else there will not be a unique deepest block. | |
| 12023 | 199 DEBUG_ONLY(assert_dom(deepb, inb, n, cfg)); |
| 0 | 200 deepb = inb; // Save deepest block |
| 201 deepb_dom_depth = deepb->_dom_depth; | |
| 202 } | |
| 203 } | |
| 204 assert(deepb != NULL, "must be at least one input to n"); | |
| 205 return deepb; | |
| 206 } | |
| 207 | |
| 208 | |
| 209 //------------------------------schedule_early--------------------------------- | |
| 210 // Find the earliest Block any instruction can be placed in. Some instructions | |
| 211 // are pinned into Blocks. Unpinned instructions can appear in last block in | |
| 212 // which all their inputs occur. | |
| 213 bool PhaseCFG::schedule_early(VectorSet &visited, Node_List &roots) { | |
| 214 // Allocate stack with enough space to avoid frequent realloc | |
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215 Node_Stack nstack(roots.Size() + 8); |
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216 // _root will be processed among C->top() inputs |
| 0 | 217 roots.push(C->top()); |
| 218 visited.set(C->top()->_idx); | |
| 219 | |
| 220 while (roots.size() != 0) { | |
| 221 // Use local variables nstack_top_n & nstack_top_i to cache values | |
| 222 // on stack's top. | |
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223 Node* parent_node = roots.pop(); |
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224 uint input_index = 0; |
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225 |
| 0 | 226 while (true) { |
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227 if (input_index == 0) { |
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228 // Fixup some control. Constants without control get attached |
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229 // to root and nodes that use is_block_proj() nodes should be attached |
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230 // to the region that starts their block. |
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231 const Node* control_input = parent_node->in(0); |
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232 if (control_input != NULL) { |
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233 replace_block_proj_ctrl(parent_node); |
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234 } else { |
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235 // Is a constant with NO inputs? |
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236 if (parent_node->req() == 1) { |
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237 parent_node->set_req(0, _root); |
| 0 | 238 } |
| 239 } | |
| 240 } | |
| 241 | |
| 242 // First, visit all inputs and force them to get a block. If an | |
| 243 // input is already in a block we quit following inputs (to avoid | |
| 244 // cycles). Instead we put that Node on a worklist to be handled | |
| 245 // later (since IT'S inputs may not have a block yet). | |
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246 |
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247 // Assume all n's inputs will be processed |
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248 bool done = true; |
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249 |
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250 while (input_index < parent_node->len()) { |
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251 Node* in = parent_node->in(input_index++); |
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252 if (in == NULL) { |
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253 continue; |
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254 } |
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255 |
| 0 | 256 int is_visited = visited.test_set(in->_idx); |
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257 if (!has_block(in)) { |
| 0 | 258 if (is_visited) { |
| 259 return false; | |
| 260 } | |
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261 // Save parent node and next input's index. |
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262 nstack.push(parent_node, input_index); |
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263 // Process current input now. |
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264 parent_node = in; |
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265 input_index = 0; |
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266 // Not all n's inputs processed. |
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267 done = false; |
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268 break; |
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269 } else if (!is_visited) { |
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270 // Visit this guy later, using worklist |
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271 roots.push(in); |
| 0 | 272 } |
| 273 } | |
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274 |
| 0 | 275 if (done) { |
| 276 // All of n's inputs have been processed, complete post-processing. | |
| 277 | |
| 278 // Some instructions are pinned into a block. These include Region, | |
| 279 // Phi, Start, Return, and other control-dependent instructions and | |
| 280 // any projections which depend on them. | |
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281 if (!parent_node->pinned()) { |
| 0 | 282 // Set earliest legal block. |
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283 Block* earliest_block = find_deepest_input(parent_node, this); |
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284 map_node_to_block(parent_node, earliest_block); |
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285 } else { |
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286 assert(get_block_for_node(parent_node) == get_block_for_node(parent_node->in(0)), "Pinned Node should be at the same block as its control edge"); |
| 0 | 287 } |
| 288 | |
| 289 if (nstack.is_empty()) { | |
| 290 // Finished all nodes on stack. | |
| 291 // Process next node on the worklist 'roots'. | |
| 292 break; | |
| 293 } | |
| 294 // Get saved parent node and next input's index. | |
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295 parent_node = nstack.node(); |
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296 input_index = nstack.index(); |
| 0 | 297 nstack.pop(); |
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298 } |
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299 } |
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300 } |
| 0 | 301 return true; |
| 302 } | |
| 303 | |
| 304 //------------------------------dom_lca---------------------------------------- | |
| 305 // Find least common ancestor in dominator tree | |
| 306 // LCA is a current notion of LCA, to be raised above 'this'. | |
| 307 // As a convenient boundary condition, return 'this' if LCA is NULL. | |
| 308 // Find the LCA of those two nodes. | |
| 309 Block* Block::dom_lca(Block* LCA) { | |
| 310 if (LCA == NULL || LCA == this) return this; | |
| 311 | |
| 312 Block* anc = this; | |
| 313 while (anc->_dom_depth > LCA->_dom_depth) | |
| 314 anc = anc->_idom; // Walk up till anc is as high as LCA | |
| 315 | |
| 316 while (LCA->_dom_depth > anc->_dom_depth) | |
| 317 LCA = LCA->_idom; // Walk up till LCA is as high as anc | |
| 318 | |
| 319 while (LCA != anc) { // Walk both up till they are the same | |
| 320 LCA = LCA->_idom; | |
| 321 anc = anc->_idom; | |
| 322 } | |
| 323 | |
| 324 return LCA; | |
| 325 } | |
| 326 | |
| 327 //--------------------------raise_LCA_above_use-------------------------------- | |
| 328 // We are placing a definition, and have been given a def->use edge. | |
| 329 // The definition must dominate the use, so move the LCA upward in the | |
| 330 // dominator tree to dominate the use. If the use is a phi, adjust | |
| 331 // the LCA only with the phi input paths which actually use this def. | |
| 12023 | 332 static Block* raise_LCA_above_use(Block* LCA, Node* use, Node* def, const PhaseCFG* cfg) { |
| 333 Block* buse = cfg->get_block_for_node(use); | |
| 0 | 334 if (buse == NULL) return LCA; // Unused killing Projs have no use block |
| 335 if (!use->is_Phi()) return buse->dom_lca(LCA); | |
| 336 uint pmax = use->req(); // Number of Phi inputs | |
| 337 // Why does not this loop just break after finding the matching input to | |
| 338 // the Phi? Well...it's like this. I do not have true def-use/use-def | |
| 339 // chains. Means I cannot distinguish, from the def-use direction, which | |
| 340 // of many use-defs lead from the same use to the same def. That is, this | |
| 341 // Phi might have several uses of the same def. Each use appears in a | |
| 342 // different predecessor block. But when I enter here, I cannot distinguish | |
| 343 // which use-def edge I should find the predecessor block for. So I find | |
| 344 // them all. Means I do a little extra work if a Phi uses the same value | |
| 345 // more than once. | |
| 346 for (uint j=1; j<pmax; j++) { // For all inputs | |
| 347 if (use->in(j) == def) { // Found matching input? | |
| 12023 | 348 Block* pred = cfg->get_block_for_node(buse->pred(j)); |
| 0 | 349 LCA = pred->dom_lca(LCA); |
| 350 } | |
| 351 } | |
| 352 return LCA; | |
| 353 } | |
| 354 | |
| 355 //----------------------------raise_LCA_above_marks---------------------------- | |
| 356 // Return a new LCA that dominates LCA and any of its marked predecessors. | |
| 357 // Search all my parents up to 'early' (exclusive), looking for predecessors | |
| 358 // which are marked with the given index. Return the LCA (in the dom tree) | |
| 359 // of all marked blocks. If there are none marked, return the original | |
| 360 // LCA. | |
| 12023 | 361 static Block* raise_LCA_above_marks(Block* LCA, node_idx_t mark, Block* early, const PhaseCFG* cfg) { |
| 0 | 362 Block_List worklist; |
| 363 worklist.push(LCA); | |
| 364 while (worklist.size() > 0) { | |
| 365 Block* mid = worklist.pop(); | |
| 366 if (mid == early) continue; // stop searching here | |
| 367 | |
| 368 // Test and set the visited bit. | |
| 369 if (mid->raise_LCA_visited() == mark) continue; // already visited | |
| 370 | |
| 371 // Don't process the current LCA, otherwise the search may terminate early | |
| 372 if (mid != LCA && mid->raise_LCA_mark() == mark) { | |
| 373 // Raise the LCA. | |
| 374 LCA = mid->dom_lca(LCA); | |
| 375 if (LCA == early) break; // stop searching everywhere | |
| 376 assert(early->dominates(LCA), "early is high enough"); | |
| 377 // Resume searching at that point, skipping intermediate levels. | |
| 378 worklist.push(LCA); | |
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379 if (LCA == mid) |
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380 continue; // Don't mark as visited to avoid early termination. |
| 0 | 381 } else { |
| 382 // Keep searching through this block's predecessors. | |
| 383 for (uint j = 1, jmax = mid->num_preds(); j < jmax; j++) { | |
| 12023 | 384 Block* mid_parent = cfg->get_block_for_node(mid->pred(j)); |
| 0 | 385 worklist.push(mid_parent); |
| 386 } | |
| 387 } | |
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388 mid->set_raise_LCA_visited(mark); |
| 0 | 389 } |
| 390 return LCA; | |
| 391 } | |
| 392 | |
| 393 //--------------------------memory_early_block-------------------------------- | |
| 394 // This is a variation of find_deepest_input, the heart of schedule_early. | |
| 395 // Find the "early" block for a load, if we considered only memory and | |
| 396 // address inputs, that is, if other data inputs were ignored. | |
| 397 // | |
| 398 // Because a subset of edges are considered, the resulting block will | |
| 399 // be earlier (at a shallower dom_depth) than the true schedule_early | |
| 400 // point of the node. We compute this earlier block as a more permissive | |
| 401 // site for anti-dependency insertion, but only if subsume_loads is enabled. | |
| 12023 | 402 static Block* memory_early_block(Node* load, Block* early, const PhaseCFG* cfg) { |
| 0 | 403 Node* base; |
| 404 Node* index; | |
| 405 Node* store = load->in(MemNode::Memory); | |
| 406 load->as_Mach()->memory_inputs(base, index); | |
| 407 | |
| 408 assert(base != NodeSentinel && index != NodeSentinel, | |
| 409 "unexpected base/index inputs"); | |
| 410 | |
| 411 Node* mem_inputs[4]; | |
| 412 int mem_inputs_length = 0; | |
| 413 if (base != NULL) mem_inputs[mem_inputs_length++] = base; | |
| 414 if (index != NULL) mem_inputs[mem_inputs_length++] = index; | |
| 415 if (store != NULL) mem_inputs[mem_inputs_length++] = store; | |
| 416 | |
| 417 // In the comparision below, add one to account for the control input, | |
| 418 // which may be null, but always takes up a spot in the in array. | |
| 419 if (mem_inputs_length + 1 < (int) load->req()) { | |
| 420 // This "load" has more inputs than just the memory, base and index inputs. | |
| 421 // For purposes of checking anti-dependences, we need to start | |
| 422 // from the early block of only the address portion of the instruction, | |
| 423 // and ignore other blocks that may have factored into the wider | |
| 424 // schedule_early calculation. | |
| 425 if (load->in(0) != NULL) mem_inputs[mem_inputs_length++] = load->in(0); | |
| 426 | |
| 427 Block* deepb = NULL; // Deepest block so far | |
| 428 int deepb_dom_depth = 0; | |
| 429 for (int i = 0; i < mem_inputs_length; i++) { | |
| 12023 | 430 Block* inb = cfg->get_block_for_node(mem_inputs[i]); |
| 0 | 431 if (deepb_dom_depth < (int) inb->_dom_depth) { |
| 432 // The new inb must be dominated by the previous deepb. | |
| 433 // The various inputs must be linearly ordered in the dom | |
| 434 // tree, or else there will not be a unique deepest block. | |
| 12023 | 435 DEBUG_ONLY(assert_dom(deepb, inb, load, cfg)); |
| 0 | 436 deepb = inb; // Save deepest block |
| 437 deepb_dom_depth = deepb->_dom_depth; | |
| 438 } | |
| 439 } | |
| 440 early = deepb; | |
| 441 } | |
| 442 | |
| 443 return early; | |
| 444 } | |
| 445 | |
| 446 //--------------------------insert_anti_dependences--------------------------- | |
| 447 // A load may need to witness memory that nearby stores can overwrite. | |
| 448 // For each nearby store, either insert an "anti-dependence" edge | |
| 449 // from the load to the store, or else move LCA upward to force the | |
| 450 // load to (eventually) be scheduled in a block above the store. | |
| 451 // | |
| 452 // Do not add edges to stores on distinct control-flow paths; | |
| 453 // only add edges to stores which might interfere. | |
| 454 // | |
| 455 // Return the (updated) LCA. There will not be any possibly interfering | |
| 456 // store between the load's "early block" and the updated LCA. | |
| 457 // Any stores in the updated LCA will have new precedence edges | |
| 458 // back to the load. The caller is expected to schedule the load | |
| 459 // in the LCA, in which case the precedence edges will make LCM | |
| 460 // preserve anti-dependences. The caller may also hoist the load | |
| 461 // above the LCA, if it is not the early block. | |
| 462 Block* PhaseCFG::insert_anti_dependences(Block* LCA, Node* load, bool verify) { | |
| 463 assert(load->needs_anti_dependence_check(), "must be a load of some sort"); | |
| 464 assert(LCA != NULL, ""); | |
| 465 DEBUG_ONLY(Block* LCA_orig = LCA); | |
| 466 | |
| 467 // Compute the alias index. Loads and stores with different alias indices | |
| 468 // do not need anti-dependence edges. | |
| 469 uint load_alias_idx = C->get_alias_index(load->adr_type()); | |
| 470 #ifdef ASSERT | |
| 471 if (load_alias_idx == Compile::AliasIdxBot && C->AliasLevel() > 0 && | |
| 472 (PrintOpto || VerifyAliases || | |
| 473 PrintMiscellaneous && (WizardMode || Verbose))) { | |
| 474 // Load nodes should not consume all of memory. | |
| 475 // Reporting a bottom type indicates a bug in adlc. | |
| 476 // If some particular type of node validly consumes all of memory, | |
| 477 // sharpen the preceding "if" to exclude it, so we can catch bugs here. | |
| 478 tty->print_cr("*** Possible Anti-Dependence Bug: Load consumes all of memory."); | |
| 479 load->dump(2); | |
| 480 if (VerifyAliases) assert(load_alias_idx != Compile::AliasIdxBot, ""); | |
| 481 } | |
| 482 #endif | |
| 483 assert(load_alias_idx || (load->is_Mach() && load->as_Mach()->ideal_Opcode() == Op_StrComp), | |
| 484 "String compare is only known 'load' that does not conflict with any stores"); | |
| 681 | 485 assert(load_alias_idx || (load->is_Mach() && load->as_Mach()->ideal_Opcode() == Op_StrEquals), |
| 486 "String equals is a 'load' that does not conflict with any stores"); | |
| 487 assert(load_alias_idx || (load->is_Mach() && load->as_Mach()->ideal_Opcode() == Op_StrIndexOf), | |
| 488 "String indexOf is a 'load' that does not conflict with any stores"); | |
| 489 assert(load_alias_idx || (load->is_Mach() && load->as_Mach()->ideal_Opcode() == Op_AryEq), | |
| 490 "Arrays equals is a 'load' that do not conflict with any stores"); | |
| 0 | 491 |
| 492 if (!C->alias_type(load_alias_idx)->is_rewritable()) { | |
| 493 // It is impossible to spoil this load by putting stores before it, | |
| 494 // because we know that the stores will never update the value | |
| 495 // which 'load' must witness. | |
| 496 return LCA; | |
| 497 } | |
| 498 | |
| 499 node_idx_t load_index = load->_idx; | |
| 500 | |
| 501 // Note the earliest legal placement of 'load', as determined by | |
| 502 // by the unique point in the dom tree where all memory effects | |
| 503 // and other inputs are first available. (Computed by schedule_early.) | |
| 504 // For normal loads, 'early' is the shallowest place (dom graph wise) | |
| 505 // to look for anti-deps between this load and any store. | |
| 12023 | 506 Block* early = get_block_for_node(load); |
| 0 | 507 |
| 508 // If we are subsuming loads, compute an "early" block that only considers | |
| 509 // memory or address inputs. This block may be different than the | |
| 510 // schedule_early block in that it could be at an even shallower depth in the | |
| 511 // dominator tree, and allow for a broader discovery of anti-dependences. | |
| 512 if (C->subsume_loads()) { | |
| 12023 | 513 early = memory_early_block(load, early, this); |
| 0 | 514 } |
| 515 | |
| 516 ResourceArea *area = Thread::current()->resource_area(); | |
| 517 Node_List worklist_mem(area); // prior memory state to store | |
| 518 Node_List worklist_store(area); // possible-def to explore | |
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519 Node_List worklist_visited(area); // visited mergemem nodes |
| 0 | 520 Node_List non_early_stores(area); // all relevant stores outside of early |
| 521 bool must_raise_LCA = false; | |
| 522 | |
| 523 #ifdef TRACK_PHI_INPUTS | |
| 524 // %%% This extra checking fails because MergeMem nodes are not GVNed. | |
| 525 // Provide "phi_inputs" to check if every input to a PhiNode is from the | |
| 526 // original memory state. This indicates a PhiNode for which should not | |
| 527 // prevent the load from sinking. For such a block, set_raise_LCA_mark | |
| 528 // may be overly conservative. | |
| 529 // Mechanism: count inputs seen for each Phi encountered in worklist_store. | |
| 530 DEBUG_ONLY(GrowableArray<uint> phi_inputs(area, C->unique(),0,0)); | |
| 531 #endif | |
| 532 | |
| 533 // 'load' uses some memory state; look for users of the same state. | |
| 534 // Recurse through MergeMem nodes to the stores that use them. | |
| 535 | |
| 536 // Each of these stores is a possible definition of memory | |
| 537 // that 'load' needs to use. We need to force 'load' | |
| 538 // to occur before each such store. When the store is in | |
| 539 // the same block as 'load', we insert an anti-dependence | |
| 540 // edge load->store. | |
| 541 | |
| 542 // The relevant stores "nearby" the load consist of a tree rooted | |
| 543 // at initial_mem, with internal nodes of type MergeMem. | |
| 544 // Therefore, the branches visited by the worklist are of this form: | |
| 545 // initial_mem -> (MergeMem ->)* store | |
| 546 // The anti-dependence constraints apply only to the fringe of this tree. | |
| 547 | |
| 548 Node* initial_mem = load->in(MemNode::Memory); | |
| 549 worklist_store.push(initial_mem); | |
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550 worklist_visited.push(initial_mem); |
| 0 | 551 worklist_mem.push(NULL); |
| 552 while (worklist_store.size() > 0) { | |
| 553 // Examine a nearby store to see if it might interfere with our load. | |
| 554 Node* mem = worklist_mem.pop(); | |
| 555 Node* store = worklist_store.pop(); | |
| 556 uint op = store->Opcode(); | |
| 557 | |
| 558 // MergeMems do not directly have anti-deps. | |
| 559 // Treat them as internal nodes in a forward tree of memory states, | |
| 560 // the leaves of which are each a 'possible-def'. | |
| 561 if (store == initial_mem // root (exclusive) of tree we are searching | |
| 562 || op == Op_MergeMem // internal node of tree we are searching | |
| 563 ) { | |
| 564 mem = store; // It's not a possibly interfering store. | |
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565 if (store == initial_mem) |
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566 initial_mem = NULL; // only process initial memory once |
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567 |
| 0 | 568 for (DUIterator_Fast imax, i = mem->fast_outs(imax); i < imax; i++) { |
| 569 store = mem->fast_out(i); | |
| 570 if (store->is_MergeMem()) { | |
| 571 // Be sure we don't get into combinatorial problems. | |
| 572 // (Allow phis to be repeated; they can merge two relevant states.) | |
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573 uint j = worklist_visited.size(); |
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574 for (; j > 0; j--) { |
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575 if (worklist_visited.at(j-1) == store) break; |
| 0 | 576 } |
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577 if (j > 0) continue; // already on work list; do not repeat |
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578 worklist_visited.push(store); |
| 0 | 579 } |
| 580 worklist_mem.push(mem); | |
| 581 worklist_store.push(store); | |
| 582 } | |
| 583 continue; | |
| 584 } | |
| 585 | |
| 586 if (op == Op_MachProj || op == Op_Catch) continue; | |
| 587 if (store->needs_anti_dependence_check()) continue; // not really a store | |
| 588 | |
| 589 // Compute the alias index. Loads and stores with different alias | |
| 590 // indices do not need anti-dependence edges. Wide MemBar's are | |
| 591 // anti-dependent on everything (except immutable memories). | |
| 592 const TypePtr* adr_type = store->adr_type(); | |
| 593 if (!C->can_alias(adr_type, load_alias_idx)) continue; | |
| 594 | |
| 595 // Most slow-path runtime calls do NOT modify Java memory, but | |
| 596 // they can block and so write Raw memory. | |
| 597 if (store->is_Mach()) { | |
| 598 MachNode* mstore = store->as_Mach(); | |
| 599 if (load_alias_idx != Compile::AliasIdxRaw) { | |
| 600 // Check for call into the runtime using the Java calling | |
| 601 // convention (and from there into a wrapper); it has no | |
| 602 // _method. Can't do this optimization for Native calls because | |
| 603 // they CAN write to Java memory. | |
| 604 if (mstore->ideal_Opcode() == Op_CallStaticJava) { | |
| 605 assert(mstore->is_MachSafePoint(), ""); | |
| 606 MachSafePointNode* ms = (MachSafePointNode*) mstore; | |
| 607 assert(ms->is_MachCallJava(), ""); | |
| 608 MachCallJavaNode* mcj = (MachCallJavaNode*) ms; | |
| 609 if (mcj->_method == NULL) { | |
| 610 // These runtime calls do not write to Java visible memory | |
| 611 // (other than Raw) and so do not require anti-dependence edges. | |
| 612 continue; | |
| 613 } | |
| 614 } | |
| 615 // Same for SafePoints: they read/write Raw but only read otherwise. | |
| 616 // This is basically a workaround for SafePoints only defining control | |
| 617 // instead of control + memory. | |
| 618 if (mstore->ideal_Opcode() == Op_SafePoint) | |
| 619 continue; | |
| 620 } else { | |
| 621 // Some raw memory, such as the load of "top" at an allocation, | |
| 622 // can be control dependent on the previous safepoint. See | |
| 623 // comments in GraphKit::allocate_heap() about control input. | |
| 624 // Inserting an anti-dep between such a safepoint and a use | |
| 625 // creates a cycle, and will cause a subsequent failure in | |
| 626 // local scheduling. (BugId 4919904) | |
| 627 // (%%% How can a control input be a safepoint and not a projection??) | |
| 628 if (mstore->ideal_Opcode() == Op_SafePoint && load->in(0) == mstore) | |
| 629 continue; | |
| 630 } | |
| 631 } | |
| 632 | |
| 633 // Identify a block that the current load must be above, | |
| 634 // or else observe that 'store' is all the way up in the | |
| 635 // earliest legal block for 'load'. In the latter case, | |
| 636 // immediately insert an anti-dependence edge. | |
| 12023 | 637 Block* store_block = get_block_for_node(store); |
| 0 | 638 assert(store_block != NULL, "unused killing projections skipped above"); |
| 639 | |
| 640 if (store->is_Phi()) { | |
| 641 // 'load' uses memory which is one (or more) of the Phi's inputs. | |
| 642 // It must be scheduled not before the Phi, but rather before | |
| 643 // each of the relevant Phi inputs. | |
| 644 // | |
| 645 // Instead of finding the LCA of all inputs to a Phi that match 'mem', | |
| 646 // we mark each corresponding predecessor block and do a combined | |
| 647 // hoisting operation later (raise_LCA_above_marks). | |
| 648 // | |
| 649 // Do not assert(store_block != early, "Phi merging memory after access") | |
| 650 // PhiNode may be at start of block 'early' with backedge to 'early' | |
| 651 DEBUG_ONLY(bool found_match = false); | |
| 652 for (uint j = PhiNode::Input, jmax = store->req(); j < jmax; j++) { | |
| 653 if (store->in(j) == mem) { // Found matching input? | |
| 654 DEBUG_ONLY(found_match = true); | |
| 12023 | 655 Block* pred_block = get_block_for_node(store_block->pred(j)); |
| 0 | 656 if (pred_block != early) { |
| 657 // If any predecessor of the Phi matches the load's "early block", | |
| 658 // we do not need a precedence edge between the Phi and 'load' | |
| 605 | 659 // since the load will be forced into a block preceding the Phi. |
| 0 | 660 pred_block->set_raise_LCA_mark(load_index); |
| 661 assert(!LCA_orig->dominates(pred_block) || | |
| 662 early->dominates(pred_block), "early is high enough"); | |
| 663 must_raise_LCA = true; | |
| 788 | 664 } else { |
| 665 // anti-dependent upon PHI pinned below 'early', no edge needed | |
| 666 LCA = early; // but can not schedule below 'early' | |
| 0 | 667 } |
| 668 } | |
| 669 } | |
| 670 assert(found_match, "no worklist bug"); | |
| 671 #ifdef TRACK_PHI_INPUTS | |
| 672 #ifdef ASSERT | |
| 673 // This assert asks about correct handling of PhiNodes, which may not | |
| 674 // have all input edges directly from 'mem'. See BugId 4621264 | |
| 675 int num_mem_inputs = phi_inputs.at_grow(store->_idx,0) + 1; | |
| 676 // Increment by exactly one even if there are multiple copies of 'mem' | |
| 677 // coming into the phi, because we will run this block several times | |
| 678 // if there are several copies of 'mem'. (That's how DU iterators work.) | |
| 679 phi_inputs.at_put(store->_idx, num_mem_inputs); | |
| 680 assert(PhiNode::Input + num_mem_inputs < store->req(), | |
| 681 "Expect at least one phi input will not be from original memory state"); | |
| 682 #endif //ASSERT | |
| 683 #endif //TRACK_PHI_INPUTS | |
| 684 } else if (store_block != early) { | |
| 685 // 'store' is between the current LCA and earliest possible block. | |
| 686 // Label its block, and decide later on how to raise the LCA | |
| 687 // to include the effect on LCA of this store. | |
| 688 // If this store's block gets chosen as the raised LCA, we | |
| 689 // will find him on the non_early_stores list and stick him | |
| 690 // with a precedence edge. | |
| 691 // (But, don't bother if LCA is already raised all the way.) | |
| 692 if (LCA != early) { | |
| 693 store_block->set_raise_LCA_mark(load_index); | |
| 694 must_raise_LCA = true; | |
| 695 non_early_stores.push(store); | |
| 696 } | |
| 697 } else { | |
| 698 // Found a possibly-interfering store in the load's 'early' block. | |
| 699 // This means 'load' cannot sink at all in the dominator tree. | |
| 700 // Add an anti-dep edge, and squeeze 'load' into the highest block. | |
| 701 assert(store != load->in(0), "dependence cycle found"); | |
| 702 if (verify) { | |
| 703 assert(store->find_edge(load) != -1, "missing precedence edge"); | |
| 704 } else { | |
| 705 store->add_prec(load); | |
| 706 } | |
| 707 LCA = early; | |
| 708 // This turns off the process of gathering non_early_stores. | |
| 709 } | |
| 710 } | |
| 711 // (Worklist is now empty; all nearby stores have been visited.) | |
| 712 | |
| 713 // Finished if 'load' must be scheduled in its 'early' block. | |
| 714 // If we found any stores there, they have already been given | |
| 715 // precedence edges. | |
| 716 if (LCA == early) return LCA; | |
| 717 | |
| 718 // We get here only if there are no possibly-interfering stores | |
| 719 // in the load's 'early' block. Move LCA up above all predecessors | |
| 720 // which contain stores we have noted. | |
| 721 // | |
| 722 // The raised LCA block can be a home to such interfering stores, | |
| 723 // but its predecessors must not contain any such stores. | |
| 724 // | |
| 725 // The raised LCA will be a lower bound for placing the load, | |
| 726 // preventing the load from sinking past any block containing | |
| 727 // a store that may invalidate the memory state required by 'load'. | |
| 728 if (must_raise_LCA) | |
| 12023 | 729 LCA = raise_LCA_above_marks(LCA, load->_idx, early, this); |
| 0 | 730 if (LCA == early) return LCA; |
| 731 | |
| 732 // Insert anti-dependence edges from 'load' to each store | |
| 733 // in the non-early LCA block. | |
| 734 // Mine the non_early_stores list for such stores. | |
| 735 if (LCA->raise_LCA_mark() == load_index) { | |
| 736 while (non_early_stores.size() > 0) { | |
| 737 Node* store = non_early_stores.pop(); | |
| 12023 | 738 Block* store_block = get_block_for_node(store); |
| 0 | 739 if (store_block == LCA) { |
| 740 // add anti_dependence from store to load in its own block | |
| 741 assert(store != load->in(0), "dependence cycle found"); | |
| 742 if (verify) { | |
| 743 assert(store->find_edge(load) != -1, "missing precedence edge"); | |
| 744 } else { | |
| 745 store->add_prec(load); | |
| 746 } | |
| 747 } else { | |
| 748 assert(store_block->raise_LCA_mark() == load_index, "block was marked"); | |
| 749 // Any other stores we found must be either inside the new LCA | |
| 750 // or else outside the original LCA. In the latter case, they | |
| 751 // did not interfere with any use of 'load'. | |
| 752 assert(LCA->dominates(store_block) | |
| 753 || !LCA_orig->dominates(store_block), "no stray stores"); | |
| 754 } | |
| 755 } | |
| 756 } | |
| 757 | |
| 758 // Return the highest block containing stores; any stores | |
| 759 // within that block have been given anti-dependence edges. | |
| 760 return LCA; | |
| 761 } | |
| 762 | |
| 763 // This class is used to iterate backwards over the nodes in the graph. | |
| 764 | |
| 765 class Node_Backward_Iterator { | |
| 766 | |
| 767 private: | |
| 768 Node_Backward_Iterator(); | |
| 769 | |
| 770 public: | |
| 771 // Constructor for the iterator | |
| 12023 | 772 Node_Backward_Iterator(Node *root, VectorSet &visited, Node_List &stack, PhaseCFG &cfg); |
| 0 | 773 |
| 774 // Postincrement operator to iterate over the nodes | |
| 775 Node *next(); | |
| 776 | |
| 777 private: | |
| 778 VectorSet &_visited; | |
| 779 Node_List &_stack; | |
| 12023 | 780 PhaseCFG &_cfg; |
| 0 | 781 }; |
| 782 | |
| 783 // Constructor for the Node_Backward_Iterator | |
| 12023 | 784 Node_Backward_Iterator::Node_Backward_Iterator( Node *root, VectorSet &visited, Node_List &stack, PhaseCFG &cfg) |
| 785 : _visited(visited), _stack(stack), _cfg(cfg) { | |
| 0 | 786 // The stack should contain exactly the root |
| 787 stack.clear(); | |
| 788 stack.push(root); | |
| 789 | |
| 790 // Clear the visited bits | |
| 791 visited.Clear(); | |
| 792 } | |
| 793 | |
| 794 // Iterator for the Node_Backward_Iterator | |
| 795 Node *Node_Backward_Iterator::next() { | |
| 796 | |
| 797 // If the _stack is empty, then just return NULL: finished. | |
| 798 if ( !_stack.size() ) | |
| 799 return NULL; | |
| 800 | |
| 801 // '_stack' is emulating a real _stack. The 'visit-all-users' loop has been | |
| 802 // made stateless, so I do not need to record the index 'i' on my _stack. | |
| 803 // Instead I visit all users each time, scanning for unvisited users. | |
| 804 // I visit unvisited not-anti-dependence users first, then anti-dependent | |
| 805 // children next. | |
| 806 Node *self = _stack.pop(); | |
| 807 | |
| 808 // I cycle here when I am entering a deeper level of recursion. | |
| 809 // The key variable 'self' was set prior to jumping here. | |
| 810 while( 1 ) { | |
| 811 | |
| 812 _visited.set(self->_idx); | |
| 813 | |
| 814 // Now schedule all uses as late as possible. | |
| 12023 | 815 const Node* src = self->is_Proj() ? self->in(0) : self; |
| 816 uint src_rpo = _cfg.get_block_for_node(src)->_rpo; | |
| 0 | 817 |
| 818 // Schedule all nodes in a post-order visit | |
| 819 Node *unvisited = NULL; // Unvisited anti-dependent Node, if any | |
| 820 | |
| 821 // Scan for unvisited nodes | |
| 822 for (DUIterator_Fast imax, i = self->fast_outs(imax); i < imax; i++) { | |
| 823 // For all uses, schedule late | |
| 824 Node* n = self->fast_out(i); // Use | |
| 825 | |
| 826 // Skip already visited children | |
| 827 if ( _visited.test(n->_idx) ) | |
| 828 continue; | |
| 829 | |
| 830 // do not traverse backward control edges | |
| 831 Node *use = n->is_Proj() ? n->in(0) : n; | |
| 12023 | 832 uint use_rpo = _cfg.get_block_for_node(use)->_rpo; |
| 0 | 833 |
| 834 if ( use_rpo < src_rpo ) | |
| 835 continue; | |
| 836 | |
| 837 // Phi nodes always precede uses in a basic block | |
| 838 if ( use_rpo == src_rpo && use->is_Phi() ) | |
| 839 continue; | |
| 840 | |
| 841 unvisited = n; // Found unvisited | |
| 842 | |
| 843 // Check for possible-anti-dependent | |
| 844 if( !n->needs_anti_dependence_check() ) | |
| 845 break; // Not visited, not anti-dep; schedule it NOW | |
| 846 } | |
| 847 | |
| 848 // Did I find an unvisited not-anti-dependent Node? | |
| 849 if ( !unvisited ) | |
| 850 break; // All done with children; post-visit 'self' | |
| 851 | |
| 852 // Visit the unvisited Node. Contains the obvious push to | |
| 853 // indicate I'm entering a deeper level of recursion. I push the | |
| 854 // old state onto the _stack and set a new state and loop (recurse). | |
| 855 _stack.push(self); | |
| 856 self = unvisited; | |
| 857 } // End recursion loop | |
| 858 | |
| 859 return self; | |
| 860 } | |
| 861 | |
| 862 //------------------------------ComputeLatenciesBackwards---------------------- | |
| 863 // Compute the latency of all the instructions. | |
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864 void PhaseCFG::compute_latencies_backwards(VectorSet &visited, Node_List &stack) { |
| 0 | 865 #ifndef PRODUCT |
| 866 if (trace_opto_pipelining()) | |
| 867 tty->print("\n#---- ComputeLatenciesBackwards ----\n"); | |
| 868 #endif | |
| 869 | |
| 12023 | 870 Node_Backward_Iterator iter((Node *)_root, visited, stack, *this); |
| 0 | 871 Node *n; |
| 872 | |
| 873 // Walk over all the nodes from last to first | |
| 874 while (n = iter.next()) { | |
| 875 // Set the latency for the definitions of this instruction | |
| 876 partial_latency_of_defs(n); | |
| 877 } | |
| 878 } // end ComputeLatenciesBackwards | |
| 879 | |
| 880 //------------------------------partial_latency_of_defs------------------------ | |
| 881 // Compute the latency impact of this node on all defs. This computes | |
| 882 // a number that increases as we approach the beginning of the routine. | |
| 883 void PhaseCFG::partial_latency_of_defs(Node *n) { | |
| 884 // Set the latency for this instruction | |
| 885 #ifndef PRODUCT | |
| 886 if (trace_opto_pipelining()) { | |
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887 tty->print("# latency_to_inputs: node_latency[%d] = %d for node", n->_idx, get_latency_for_node(n)); |
| 0 | 888 dump(); |
| 889 } | |
| 890 #endif | |
| 891 | |
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892 if (n->is_Proj()) { |
| 0 | 893 n = n->in(0); |
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894 } |
| 0 | 895 |
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896 if (n->is_Root()) { |
| 0 | 897 return; |
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898 } |
| 0 | 899 |
| 900 uint nlen = n->len(); | |
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901 uint use_latency = get_latency_for_node(n); |
| 12023 | 902 uint use_pre_order = get_block_for_node(n)->_pre_order; |
| 0 | 903 |
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904 for (uint j = 0; j < nlen; j++) { |
| 0 | 905 Node *def = n->in(j); |
| 906 | |
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907 if (!def || def == n) { |
| 0 | 908 continue; |
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909 } |
| 0 | 910 |
| 911 // Walk backwards thru projections | |
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912 if (def->is_Proj()) { |
| 0 | 913 def = def->in(0); |
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914 } |
| 0 | 915 |
| 916 #ifndef PRODUCT | |
| 917 if (trace_opto_pipelining()) { | |
| 918 tty->print("# in(%2d): ", j); | |
| 919 def->dump(); | |
| 920 } | |
| 921 #endif | |
| 922 | |
| 923 // If the defining block is not known, assume it is ok | |
| 12023 | 924 Block *def_block = get_block_for_node(def); |
| 0 | 925 uint def_pre_order = def_block ? def_block->_pre_order : 0; |
| 926 | |
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927 if ((use_pre_order < def_pre_order) || (use_pre_order == def_pre_order && n->is_Phi())) { |
| 0 | 928 continue; |
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929 } |
| 0 | 930 |
| 931 uint delta_latency = n->latency(j); | |
| 932 uint current_latency = delta_latency + use_latency; | |
| 933 | |
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934 if (get_latency_for_node(def) < current_latency) { |
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935 set_latency_for_node(def, current_latency); |
| 0 | 936 } |
| 937 | |
| 938 #ifndef PRODUCT | |
| 939 if (trace_opto_pipelining()) { | |
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940 tty->print_cr("# %d + edge_latency(%d) == %d -> %d, node_latency[%d] = %d", use_latency, j, delta_latency, current_latency, def->_idx, get_latency_for_node(def)); |
| 0 | 941 } |
| 942 #endif | |
| 943 } | |
| 944 } | |
| 945 | |
| 946 //------------------------------latency_from_use------------------------------- | |
| 947 // Compute the latency of a specific use | |
| 948 int PhaseCFG::latency_from_use(Node *n, const Node *def, Node *use) { | |
| 949 // If self-reference, return no latency | |
| 12023 | 950 if (use == n || use->is_Root()) { |
| 0 | 951 return 0; |
| 12023 | 952 } |
| 0 | 953 |
| 12023 | 954 uint def_pre_order = get_block_for_node(def)->_pre_order; |
| 0 | 955 uint latency = 0; |
| 956 | |
| 957 // If the use is not a projection, then it is simple... | |
| 958 if (!use->is_Proj()) { | |
| 959 #ifndef PRODUCT | |
| 960 if (trace_opto_pipelining()) { | |
| 961 tty->print("# out(): "); | |
| 962 use->dump(); | |
| 963 } | |
| 964 #endif | |
| 965 | |
| 12023 | 966 uint use_pre_order = get_block_for_node(use)->_pre_order; |
| 0 | 967 |
| 968 if (use_pre_order < def_pre_order) | |
| 969 return 0; | |
| 970 | |
| 971 if (use_pre_order == def_pre_order && use->is_Phi()) | |
| 972 return 0; | |
| 973 | |
| 974 uint nlen = use->len(); | |
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975 uint nl = get_latency_for_node(use); |
| 0 | 976 |
| 977 for ( uint j=0; j<nlen; j++ ) { | |
| 978 if (use->in(j) == n) { | |
| 979 // Change this if we want local latencies | |
| 980 uint ul = use->latency(j); | |
| 981 uint l = ul + nl; | |
| 982 if (latency < l) latency = l; | |
| 983 #ifndef PRODUCT | |
| 984 if (trace_opto_pipelining()) { | |
| 985 tty->print_cr("# %d + edge_latency(%d) == %d -> %d, latency = %d", | |
| 986 nl, j, ul, l, latency); | |
| 987 } | |
| 988 #endif | |
| 989 } | |
| 990 } | |
| 991 } else { | |
| 992 // This is a projection, just grab the latency of the use(s) | |
| 993 for (DUIterator_Fast jmax, j = use->fast_outs(jmax); j < jmax; j++) { | |
| 994 uint l = latency_from_use(use, def, use->fast_out(j)); | |
| 995 if (latency < l) latency = l; | |
| 996 } | |
| 997 } | |
| 998 | |
| 999 return latency; | |
| 1000 } | |
| 1001 | |
| 1002 //------------------------------latency_from_uses------------------------------ | |
| 1003 // Compute the latency of this instruction relative to all of it's uses. | |
| 1004 // This computes a number that increases as we approach the beginning of the | |
| 1005 // routine. | |
| 1006 void PhaseCFG::latency_from_uses(Node *n) { | |
| 1007 // Set the latency for this instruction | |
| 1008 #ifndef PRODUCT | |
| 1009 if (trace_opto_pipelining()) { | |
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1010 tty->print("# latency_from_outputs: node_latency[%d] = %d for node", n->_idx, get_latency_for_node(n)); |
| 0 | 1011 dump(); |
| 1012 } | |
| 1013 #endif | |
| 1014 uint latency=0; | |
| 1015 const Node *def = n->is_Proj() ? n->in(0): n; | |
| 1016 | |
| 1017 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { | |
| 1018 uint l = latency_from_use(n, def, n->fast_out(i)); | |
| 1019 | |
| 1020 if (latency < l) latency = l; | |
| 1021 } | |
| 1022 | |
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1023 set_latency_for_node(n, latency); |
| 0 | 1024 } |
| 1025 | |
| 1026 //------------------------------hoist_to_cheaper_block------------------------- | |
| 1027 // Pick a block for node self, between early and LCA, that is a cheaper | |
| 1028 // alternative to LCA. | |
| 1029 Block* PhaseCFG::hoist_to_cheaper_block(Block* LCA, Block* early, Node* self) { | |
| 1030 const double delta = 1+PROB_UNLIKELY_MAG(4); | |
| 1031 Block* least = LCA; | |
| 1032 double least_freq = least->_freq; | |
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1033 uint target = get_latency_for_node(self); |
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1034 uint start_latency = get_latency_for_node(LCA->_nodes[0]); |
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1035 uint end_latency = get_latency_for_node(LCA->_nodes[LCA->end_idx()]); |
| 0 | 1036 bool in_latency = (target <= start_latency); |
| 12023 | 1037 const Block* root_block = get_block_for_node(_root); |
| 0 | 1038 |
| 1039 // Turn off latency scheduling if scheduling is just plain off | |
| 1040 if (!C->do_scheduling()) | |
| 1041 in_latency = true; | |
| 1042 | |
| 1043 // Do not hoist (to cover latency) instructions which target a | |
| 1044 // single register. Hoisting stretches the live range of the | |
| 1045 // single register and may force spilling. | |
| 1046 MachNode* mach = self->is_Mach() ? self->as_Mach() : NULL; | |
| 1047 if (mach && mach->out_RegMask().is_bound1() && mach->out_RegMask().is_NotEmpty()) | |
| 1048 in_latency = true; | |
| 1049 | |
| 1050 #ifndef PRODUCT | |
| 1051 if (trace_opto_pipelining()) { | |
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1052 tty->print("# Find cheaper block for latency %d: ", get_latency_for_node(self)); |
| 0 | 1053 self->dump(); |
| 1054 tty->print_cr("# B%d: start latency for [%4d]=%d, end latency for [%4d]=%d, freq=%g", | |
| 1055 LCA->_pre_order, | |
| 1056 LCA->_nodes[0]->_idx, | |
| 1057 start_latency, | |
| 1058 LCA->_nodes[LCA->end_idx()]->_idx, | |
| 1059 end_latency, | |
| 1060 least_freq); | |
| 1061 } | |
| 1062 #endif | |
| 1063 | |
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1064 int cand_cnt = 0; // number of candidates tried |
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1065 |
| 0 | 1066 // Walk up the dominator tree from LCA (Lowest common ancestor) to |
| 1067 // the earliest legal location. Capture the least execution frequency. | |
| 1068 while (LCA != early) { | |
| 1069 LCA = LCA->_idom; // Follow up the dominator tree | |
| 1070 | |
| 1071 if (LCA == NULL) { | |
| 1072 // Bailout without retry | |
| 1073 C->record_method_not_compilable("late schedule failed: LCA == NULL"); | |
| 1074 return least; | |
| 1075 } | |
| 1076 | |
| 1077 // Don't hoist machine instructions to the root basic block | |
| 1078 if (mach && LCA == root_block) | |
| 1079 break; | |
| 1080 | |
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1081 uint start_lat = get_latency_for_node(LCA->_nodes[0]); |
| 0 | 1082 uint end_idx = LCA->end_idx(); |
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1083 uint end_lat = get_latency_for_node(LCA->_nodes[end_idx]); |
| 0 | 1084 double LCA_freq = LCA->_freq; |
| 1085 #ifndef PRODUCT | |
| 1086 if (trace_opto_pipelining()) { | |
| 1087 tty->print_cr("# B%d: start latency for [%4d]=%d, end latency for [%4d]=%d, freq=%g", | |
| 1088 LCA->_pre_order, LCA->_nodes[0]->_idx, start_lat, end_idx, end_lat, LCA_freq); | |
| 1089 } | |
| 1090 #endif | |
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1091 cand_cnt++; |
| 0 | 1092 if (LCA_freq < least_freq || // Better Frequency |
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1093 (StressGCM && Compile::randomized_select(cand_cnt)) || // Should be randomly accepted in stress mode |
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1094 (!StressGCM && // Otherwise, choose with latency |
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1095 !in_latency && // No block containing latency |
| 0 | 1096 LCA_freq < least_freq * delta && // No worse frequency |
| 1097 target >= end_lat && // within latency range | |
| 1098 !self->is_iteratively_computed() ) // But don't hoist IV increments | |
| 1099 // because they may end up above other uses of their phi forcing | |
| 1100 // their result register to be different from their input. | |
| 1101 ) { | |
| 1102 least = LCA; // Found cheaper block | |
| 1103 least_freq = LCA_freq; | |
| 1104 start_latency = start_lat; | |
| 1105 end_latency = end_lat; | |
| 1106 if (target <= start_lat) | |
| 1107 in_latency = true; | |
| 1108 } | |
| 1109 } | |
| 1110 | |
| 1111 #ifndef PRODUCT | |
| 1112 if (trace_opto_pipelining()) { | |
| 1113 tty->print_cr("# Choose block B%d with start latency=%d and freq=%g", | |
| 1114 least->_pre_order, start_latency, least_freq); | |
| 1115 } | |
| 1116 #endif | |
| 1117 | |
| 1118 // See if the latency needs to be updated | |
| 1119 if (target < end_latency) { | |
| 1120 #ifndef PRODUCT | |
| 1121 if (trace_opto_pipelining()) { | |
| 1122 tty->print_cr("# Change latency for [%4d] from %d to %d", self->_idx, target, end_latency); | |
| 1123 } | |
| 1124 #endif | |
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1125 set_latency_for_node(self, end_latency); |
| 0 | 1126 partial_latency_of_defs(self); |
| 1127 } | |
| 1128 | |
| 1129 return least; | |
| 1130 } | |
| 1131 | |
| 1132 | |
| 1133 //------------------------------schedule_late----------------------------------- | |
| 1134 // Now schedule all codes as LATE as possible. This is the LCA in the | |
| 1135 // dominator tree of all USES of a value. Pick the block with the least | |
| 1136 // loop nesting depth that is lowest in the dominator tree. | |
| 1137 extern const char must_clone[]; | |
| 1138 void PhaseCFG::schedule_late(VectorSet &visited, Node_List &stack) { | |
| 1139 #ifndef PRODUCT | |
| 1140 if (trace_opto_pipelining()) | |
| 1141 tty->print("\n#---- schedule_late ----\n"); | |
| 1142 #endif | |
| 1143 | |
| 12023 | 1144 Node_Backward_Iterator iter((Node *)_root, visited, stack, *this); |
| 0 | 1145 Node *self; |
| 1146 | |
| 1147 // Walk over all the nodes from last to first | |
| 1148 while (self = iter.next()) { | |
| 12023 | 1149 Block* early = get_block_for_node(self); // Earliest legal placement |
| 0 | 1150 |
| 1151 if (self->is_top()) { | |
| 1152 // Top node goes in bb #2 with other constants. | |
| 1153 // It must be special-cased, because it has no out edges. | |
| 1154 early->add_inst(self); | |
| 1155 continue; | |
| 1156 } | |
| 1157 | |
| 1158 // No uses, just terminate | |
| 1159 if (self->outcnt() == 0) { | |
| 3842 | 1160 assert(self->is_MachProj(), "sanity"); |
| 0 | 1161 continue; // Must be a dead machine projection |
| 1162 } | |
| 1163 | |
| 1164 // If node is pinned in the block, then no scheduling can be done. | |
| 1165 if( self->pinned() ) // Pinned in block? | |
| 1166 continue; | |
| 1167 | |
| 1168 MachNode* mach = self->is_Mach() ? self->as_Mach() : NULL; | |
| 1169 if (mach) { | |
| 1170 switch (mach->ideal_Opcode()) { | |
| 1171 case Op_CreateEx: | |
| 1172 // Don't move exception creation | |
| 1173 early->add_inst(self); | |
| 1174 continue; | |
| 1175 break; | |
| 1176 case Op_CheckCastPP: | |
| 1177 // Don't move CheckCastPP nodes away from their input, if the input | |
| 1178 // is a rawptr (5071820). | |
| 1179 Node *def = self->in(1); | |
| 1180 if (def != NULL && def->bottom_type()->base() == Type::RawPtr) { | |
| 1181 early->add_inst(self); | |
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1182 #ifdef ASSERT |
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1183 _raw_oops.push(def); |
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1184 #endif |
| 0 | 1185 continue; |
| 1186 } | |
| 1187 break; | |
| 1188 } | |
| 1189 } | |
| 1190 | |
| 1191 // Gather LCA of all uses | |
| 1192 Block *LCA = NULL; | |
| 1193 { | |
| 1194 for (DUIterator_Fast imax, i = self->fast_outs(imax); i < imax; i++) { | |
| 1195 // For all uses, find LCA | |
| 1196 Node* use = self->fast_out(i); | |
| 12023 | 1197 LCA = raise_LCA_above_use(LCA, use, self, this); |
| 0 | 1198 } |
| 1199 } // (Hide defs of imax, i from rest of block.) | |
| 1200 | |
| 1201 // Place temps in the block of their use. This isn't a | |
| 1202 // requirement for correctness but it reduces useless | |
| 1203 // interference between temps and other nodes. | |
| 1204 if (mach != NULL && mach->is_MachTemp()) { | |
| 12023 | 1205 map_node_to_block(self, LCA); |
| 0 | 1206 LCA->add_inst(self); |
| 1207 continue; | |
| 1208 } | |
| 1209 | |
| 1210 // Check if 'self' could be anti-dependent on memory | |
| 1211 if (self->needs_anti_dependence_check()) { | |
| 1212 // Hoist LCA above possible-defs and insert anti-dependences to | |
| 1213 // defs in new LCA block. | |
| 1214 LCA = insert_anti_dependences(LCA, self); | |
| 1215 } | |
| 1216 | |
| 1217 if (early->_dom_depth > LCA->_dom_depth) { | |
| 1218 // Somehow the LCA has moved above the earliest legal point. | |
| 1219 // (One way this can happen is via memory_early_block.) | |
| 1220 if (C->subsume_loads() == true && !C->failing()) { | |
| 1221 // Retry with subsume_loads == false | |
| 1222 // If this is the first failure, the sentinel string will "stick" | |
| 1223 // to the Compile object, and the C2Compiler will see it and retry. | |
| 1224 C->record_failure(C2Compiler::retry_no_subsuming_loads()); | |
| 1225 } else { | |
| 1226 // Bailout without retry when (early->_dom_depth > LCA->_dom_depth) | |
| 1227 C->record_method_not_compilable("late schedule failed: incorrect graph"); | |
| 1228 } | |
| 1229 return; | |
| 1230 } | |
| 1231 | |
| 1232 // If there is no opportunity to hoist, then we're done. | |
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1233 // In stress mode, try to hoist even the single operations. |
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1234 bool try_to_hoist = StressGCM || (LCA != early); |
| 0 | 1235 |
| 1236 // Must clone guys stay next to use; no hoisting allowed. | |
| 1237 // Also cannot hoist guys that alter memory or are otherwise not | |
| 1238 // allocatable (hoisting can make a value live longer, leading to | |
| 1239 // anti and output dependency problems which are normally resolved | |
| 1240 // by the register allocator giving everyone a different register). | |
| 1241 if (mach != NULL && must_clone[mach->ideal_Opcode()]) | |
| 1242 try_to_hoist = false; | |
| 1243 | |
| 1244 Block* late = NULL; | |
| 1245 if (try_to_hoist) { | |
| 1246 // Now find the block with the least execution frequency. | |
| 1247 // Start at the latest schedule and work up to the earliest schedule | |
| 1248 // in the dominator tree. Thus the Node will dominate all its uses. | |
| 1249 late = hoist_to_cheaper_block(LCA, early, self); | |
| 1250 } else { | |
| 1251 // Just use the LCA of the uses. | |
| 1252 late = LCA; | |
| 1253 } | |
| 1254 | |
| 1255 // Put the node into target block | |
| 1256 schedule_node_into_block(self, late); | |
| 1257 | |
| 1258 #ifdef ASSERT | |
| 1259 if (self->needs_anti_dependence_check()) { | |
| 1260 // since precedence edges are only inserted when we're sure they | |
| 1261 // are needed make sure that after placement in a block we don't | |
| 1262 // need any new precedence edges. | |
| 1263 verify_anti_dependences(late, self); | |
| 1264 } | |
| 1265 #endif | |
| 1266 } // Loop until all nodes have been visited | |
| 1267 | |
| 1268 } // end ScheduleLate | |
| 1269 | |
| 1270 //------------------------------GlobalCodeMotion------------------------------- | |
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1271 void PhaseCFG::global_code_motion() { |
| 0 | 1272 ResourceMark rm; |
| 1273 | |
| 1274 #ifndef PRODUCT | |
| 1275 if (trace_opto_pipelining()) { | |
| 1276 tty->print("\n---- Start GlobalCodeMotion ----\n"); | |
| 1277 } | |
| 1278 #endif | |
| 1279 | |
| 12023 | 1280 // Initialize the node to block mapping for things on the proj_list |
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1281 for (uint i = 0; i < _matcher.number_of_projections(); i++) { |
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1282 unmap_node_from_block(_matcher.get_projection(i)); |
| 12023 | 1283 } |
| 0 | 1284 |
| 1285 // Set the basic block for Nodes pinned into blocks | |
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1286 Arena* arena = Thread::current()->resource_area(); |
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1287 VectorSet visited(arena); |
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1288 schedule_pinned_nodes(visited); |
| 0 | 1289 |
| 1290 // Find the earliest Block any instruction can be placed in. Some | |
| 1291 // instructions are pinned into Blocks. Unpinned instructions can | |
| 1292 // appear in last block in which all their inputs occur. | |
| 1293 visited.Clear(); | |
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1294 Node_List stack(arena); |
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1295 // Pre-grow the list |
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1296 stack.map((C->unique() >> 1) + 16, NULL); |
| 0 | 1297 if (!schedule_early(visited, stack)) { |
| 1298 // Bailout without retry | |
| 1299 C->record_method_not_compilable("early schedule failed"); | |
| 1300 return; | |
| 1301 } | |
| 1302 | |
| 1303 // Build Def-Use edges. | |
| 1304 // Compute the latency information (via backwards walk) for all the | |
| 1305 // instructions in the graph | |
| 1685 | 1306 _node_latency = new GrowableArray<uint>(); // resource_area allocation |
| 0 | 1307 |
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1308 if (C->do_scheduling()) { |
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1309 compute_latencies_backwards(visited, stack); |
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1310 } |
| 0 | 1311 |
| 1312 // Now schedule all codes as LATE as possible. This is the LCA in the | |
| 1313 // dominator tree of all USES of a value. Pick the block with the least | |
| 1314 // loop nesting depth that is lowest in the dominator tree. | |
| 1315 // ( visited.Clear() called in schedule_late()->Node_Backward_Iterator() ) | |
| 1316 schedule_late(visited, stack); | |
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1317 if (C->failing()) { |
| 0 | 1318 // schedule_late fails only when graph is incorrect. |
| 1319 assert(!VerifyGraphEdges, "verification should have failed"); | |
| 1320 return; | |
| 1321 } | |
| 1322 | |
| 1323 #ifndef PRODUCT | |
| 1324 if (trace_opto_pipelining()) { | |
| 1325 tty->print("\n---- Detect implicit null checks ----\n"); | |
| 1326 } | |
| 1327 #endif | |
| 1328 | |
| 1329 // Detect implicit-null-check opportunities. Basically, find NULL checks | |
| 1330 // with suitable memory ops nearby. Use the memory op to do the NULL check. | |
| 1331 // I can generate a memory op if there is not one nearby. | |
| 1332 if (C->is_method_compilation()) { | |
| 1333 // Don't do it for natives, adapters, or runtime stubs | |
| 1334 int allowed_reasons = 0; | |
| 1335 // ...and don't do it when there have been too many traps, globally. | |
| 1336 for (int reason = (int)Deoptimization::Reason_none+1; | |
| 1337 reason < Compile::trapHistLength; reason++) { | |
| 1338 assert(reason < BitsPerInt, "recode bit map"); | |
| 1339 if (!C->too_many_traps((Deoptimization::DeoptReason) reason)) | |
| 1340 allowed_reasons |= nth_bit(reason); | |
| 1341 } | |
| 1342 // By reversing the loop direction we get a very minor gain on mpegaudio. | |
| 1343 // Feel free to revert to a forward loop for clarity. | |
| 1344 // for( int i=0; i < (int)matcher._null_check_tests.size(); i+=2 ) { | |
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1345 for (int i = _matcher._null_check_tests.size() - 2; i >= 0; i -= 2) { |
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1346 Node* proj = _matcher._null_check_tests[i]; |
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1347 Node* val = _matcher._null_check_tests[i + 1]; |
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1348 Block* block = get_block_for_node(proj); |
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1349 block->implicit_null_check(this, proj, val, allowed_reasons); |
| 0 | 1350 // The implicit_null_check will only perform the transformation |
| 1351 // if the null branch is truly uncommon, *and* it leads to an | |
| 1352 // uncommon trap. Combined with the too_many_traps guards | |
| 1353 // above, this prevents SEGV storms reported in 6366351, | |
| 1354 // by recompiling offending methods without this optimization. | |
| 1355 } | |
| 1356 } | |
| 1357 | |
| 1358 #ifndef PRODUCT | |
| 1359 if (trace_opto_pipelining()) { | |
| 1360 tty->print("\n---- Start Local Scheduling ----\n"); | |
| 1361 } | |
| 1362 #endif | |
| 1363 | |
| 1364 // Schedule locally. Right now a simple topological sort. | |
| 1365 // Later, do a real latency aware scheduler. | |
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1366 GrowableArray<int> ready_cnt(C->unique(), C->unique(), -1); |
| 0 | 1367 visited.Clear(); |
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1368 for (uint i = 0; i < number_of_blocks(); i++) { |
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1369 Block* block = get_block(i); |
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1370 if (!block->schedule_local(this, _matcher, ready_cnt, visited)) { |
| 0 | 1371 if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) { |
| 1372 C->record_method_not_compilable("local schedule failed"); | |
| 1373 } | |
| 1374 return; | |
| 1375 } | |
| 1376 } | |
| 1377 | |
| 1378 // If we inserted any instructions between a Call and his CatchNode, | |
| 1379 // clone the instructions on all paths below the Catch. | |
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1380 for (uint i = 0; i < number_of_blocks(); i++) { |
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1381 Block* block = get_block(i); |
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1382 block->call_catch_cleanup(this, C); |
| 12023 | 1383 } |
| 0 | 1384 |
| 1385 #ifndef PRODUCT | |
| 1386 if (trace_opto_pipelining()) { | |
| 1387 tty->print("\n---- After GlobalCodeMotion ----\n"); | |
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1388 for (uint i = 0; i < number_of_blocks(); i++) { |
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1389 Block* block = get_block(i); |
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1390 block->dump(); |
| 0 | 1391 } |
| 1392 } | |
| 1393 #endif | |
| 1685 | 1394 // Dead. |
| 1395 _node_latency = (GrowableArray<uint> *)0xdeadbeef; | |
| 0 | 1396 } |
| 1397 | |
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1398 bool PhaseCFG::do_global_code_motion() { |
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1399 |
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1400 build_dominator_tree(); |
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1401 if (C->failing()) { |
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1402 return false; |
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1403 } |
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1404 |
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1405 NOT_PRODUCT( C->verify_graph_edges(); ) |
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1406 |
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1407 estimate_block_frequency(); |
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1408 |
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1409 global_code_motion(); |
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1410 |
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1411 if (C->failing()) { |
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1412 return false; |
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1413 } |
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1414 |
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1415 return true; |
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1416 } |
| 0 | 1417 |
| 1418 //------------------------------Estimate_Block_Frequency----------------------- | |
| 1419 // Estimate block frequencies based on IfNode probabilities. | |
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1420 void PhaseCFG::estimate_block_frequency() { |
| 418 | 1421 |
| 1422 // Force conditional branches leading to uncommon traps to be unlikely, | |
| 1423 // not because we get to the uncommon_trap with less relative frequency, | |
| 1424 // but because an uncommon_trap typically causes a deopt, so we only get | |
| 1425 // there once. | |
| 1426 if (C->do_freq_based_layout()) { | |
| 1427 Block_List worklist; | |
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1428 Block* root_blk = get_block(0); |
| 418 | 1429 for (uint i = 1; i < root_blk->num_preds(); i++) { |
| 12023 | 1430 Block *pb = get_block_for_node(root_blk->pred(i)); |
| 418 | 1431 if (pb->has_uncommon_code()) { |
| 1432 worklist.push(pb); | |
| 1433 } | |
| 1434 } | |
| 1435 while (worklist.size() > 0) { | |
| 1436 Block* uct = worklist.pop(); | |
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1437 if (uct == get_root_block()) { |
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1438 continue; |
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1439 } |
| 418 | 1440 for (uint i = 1; i < uct->num_preds(); i++) { |
| 12023 | 1441 Block *pb = get_block_for_node(uct->pred(i)); |
| 418 | 1442 if (pb->_num_succs == 1) { |
| 1443 worklist.push(pb); | |
| 1444 } else if (pb->num_fall_throughs() == 2) { | |
| 1445 pb->update_uncommon_branch(uct); | |
| 1446 } | |
| 1447 } | |
| 1448 } | |
| 1449 } | |
| 0 | 1450 |
| 1451 // Create the loop tree and calculate loop depth. | |
| 1452 _root_loop = create_loop_tree(); | |
| 1453 _root_loop->compute_loop_depth(0); | |
| 1454 | |
| 1455 // Compute block frequency of each block, relative to a single loop entry. | |
| 1456 _root_loop->compute_freq(); | |
| 1457 | |
| 1458 // Adjust all frequencies to be relative to a single method entry | |
| 418 | 1459 _root_loop->_freq = 1.0; |
| 0 | 1460 _root_loop->scale_freq(); |
| 1461 | |
| 673 | 1462 // Save outmost loop frequency for LRG frequency threshold |
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1463 _outer_loop_frequency = _root_loop->outer_loop_freq(); |
| 673 | 1464 |
| 0 | 1465 // force paths ending at uncommon traps to be infrequent |
| 418 | 1466 if (!C->do_freq_based_layout()) { |
| 1467 Block_List worklist; | |
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1468 Block* root_blk = get_block(0); |
| 418 | 1469 for (uint i = 1; i < root_blk->num_preds(); i++) { |
| 12023 | 1470 Block *pb = get_block_for_node(root_blk->pred(i)); |
| 418 | 1471 if (pb->has_uncommon_code()) { |
| 1472 worklist.push(pb); | |
| 1473 } | |
| 0 | 1474 } |
| 418 | 1475 while (worklist.size() > 0) { |
| 1476 Block* uct = worklist.pop(); | |
| 1477 uct->_freq = PROB_MIN; | |
| 1478 for (uint i = 1; i < uct->num_preds(); i++) { | |
| 12023 | 1479 Block *pb = get_block_for_node(uct->pred(i)); |
| 418 | 1480 if (pb->_num_succs == 1 && pb->_freq > PROB_MIN) { |
| 1481 worklist.push(pb); | |
| 1482 } | |
| 0 | 1483 } |
| 1484 } | |
| 1485 } | |
| 1486 | |
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1487 #ifdef ASSERT |
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1488 for (uint i = 0; i < number_of_blocks(); i++) { |
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1489 Block* b = get_block(i); |
| 605 | 1490 assert(b->_freq >= MIN_BLOCK_FREQUENCY, "Register Allocator requires meaningful block frequency"); |
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1491 } |
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1492 #endif |
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1493 |
| 0 | 1494 #ifndef PRODUCT |
| 1495 if (PrintCFGBlockFreq) { | |
| 1496 tty->print_cr("CFG Block Frequencies"); | |
| 1497 _root_loop->dump_tree(); | |
| 1498 if (Verbose) { | |
| 1499 tty->print_cr("PhaseCFG dump"); | |
| 1500 dump(); | |
| 1501 tty->print_cr("Node dump"); | |
| 1502 _root->dump(99999); | |
| 1503 } | |
| 1504 } | |
| 1505 #endif | |
| 1506 } | |
| 1507 | |
| 1508 //----------------------------create_loop_tree-------------------------------- | |
| 1509 // Create a loop tree from the CFG | |
| 1510 CFGLoop* PhaseCFG::create_loop_tree() { | |
| 1511 | |
| 1512 #ifdef ASSERT | |
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1513 assert(get_block(0) == get_root_block(), "first block should be root block"); |
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1514 for (uint i = 0; i < number_of_blocks(); i++) { |
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1515 Block* block = get_block(i); |
| 0 | 1516 // Check that _loop field are clear...we could clear them if not. |
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1517 assert(block->_loop == NULL, "clear _loop expected"); |
| 0 | 1518 // Sanity check that the RPO numbering is reflected in the _blocks array. |
| 1519 // It doesn't have to be for the loop tree to be built, but if it is not, | |
| 1520 // then the blocks have been reordered since dom graph building...which | |
| 1521 // may question the RPO numbering | |
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1522 assert(block->_rpo == i, "unexpected reverse post order number"); |
| 0 | 1523 } |
| 1524 #endif | |
| 1525 | |
| 1526 int idct = 0; | |
| 1527 CFGLoop* root_loop = new CFGLoop(idct++); | |
| 1528 | |
| 1529 Block_List worklist; | |
| 1530 | |
| 1531 // Assign blocks to loops | |
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1532 for(uint i = number_of_blocks() - 1; i > 0; i-- ) { // skip Root block |
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1533 Block* block = get_block(i); |
| 0 | 1534 |
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1535 if (block->head()->is_Loop()) { |
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1536 Block* loop_head = block; |
| 0 | 1537 assert(loop_head->num_preds() - 1 == 2, "loop must have 2 predecessors"); |
| 1538 Node* tail_n = loop_head->pred(LoopNode::LoopBackControl); | |
| 12023 | 1539 Block* tail = get_block_for_node(tail_n); |
| 0 | 1540 |
| 1541 // Defensively filter out Loop nodes for non-single-entry loops. | |
| 1542 // For all reasonable loops, the head occurs before the tail in RPO. | |
| 1543 if (i <= tail->_rpo) { | |
| 1544 | |
| 1545 // The tail and (recursive) predecessors of the tail | |
| 1546 // are made members of a new loop. | |
| 1547 | |
| 1548 assert(worklist.size() == 0, "nonempty worklist"); | |
| 1549 CFGLoop* nloop = new CFGLoop(idct++); | |
| 1550 assert(loop_head->_loop == NULL, "just checking"); | |
| 1551 loop_head->_loop = nloop; | |
| 1552 // Add to nloop so push_pred() will skip over inner loops | |
| 1553 nloop->add_member(loop_head); | |
| 12023 | 1554 nloop->push_pred(loop_head, LoopNode::LoopBackControl, worklist, this); |
| 0 | 1555 |
| 1556 while (worklist.size() > 0) { | |
| 1557 Block* member = worklist.pop(); | |
| 1558 if (member != loop_head) { | |
| 1559 for (uint j = 1; j < member->num_preds(); j++) { | |
| 12023 | 1560 nloop->push_pred(member, j, worklist, this); |
| 0 | 1561 } |
| 1562 } | |
| 1563 } | |
| 1564 } | |
| 1565 } | |
| 1566 } | |
| 1567 | |
| 1568 // Create a member list for each loop consisting | |
| 1569 // of both blocks and (immediate child) loops. | |
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1570 for (uint i = 0; i < number_of_blocks(); i++) { |
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1571 Block* block = get_block(i); |
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1572 CFGLoop* lp = block->_loop; |
| 0 | 1573 if (lp == NULL) { |
| 1574 // Not assigned to a loop. Add it to the method's pseudo loop. | |
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1575 block->_loop = root_loop; |
| 0 | 1576 lp = root_loop; |
| 1577 } | |
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1578 if (lp == root_loop || block != lp->head()) { // loop heads are already members |
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1579 lp->add_member(block); |
| 0 | 1580 } |
| 1581 if (lp != root_loop) { | |
| 1582 if (lp->parent() == NULL) { | |
| 1583 // Not a nested loop. Make it a child of the method's pseudo loop. | |
| 1584 root_loop->add_nested_loop(lp); | |
| 1585 } | |
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1586 if (block == lp->head()) { |
| 0 | 1587 // Add nested loop to member list of parent loop. |
| 1588 lp->parent()->add_member(lp); | |
| 1589 } | |
| 1590 } | |
| 1591 } | |
| 1592 | |
| 1593 return root_loop; | |
| 1594 } | |
| 1595 | |
| 1596 //------------------------------push_pred-------------------------------------- | |
| 12023 | 1597 void CFGLoop::push_pred(Block* blk, int i, Block_List& worklist, PhaseCFG* cfg) { |
| 0 | 1598 Node* pred_n = blk->pred(i); |
| 12023 | 1599 Block* pred = cfg->get_block_for_node(pred_n); |
| 0 | 1600 CFGLoop *pred_loop = pred->_loop; |
| 1601 if (pred_loop == NULL) { | |
| 1602 // Filter out blocks for non-single-entry loops. | |
| 1603 // For all reasonable loops, the head occurs before the tail in RPO. | |
| 1604 if (pred->_rpo > head()->_rpo) { | |
| 1605 pred->_loop = this; | |
| 1606 worklist.push(pred); | |
| 1607 } | |
| 1608 } else if (pred_loop != this) { | |
| 1609 // Nested loop. | |
| 1610 while (pred_loop->_parent != NULL && pred_loop->_parent != this) { | |
| 1611 pred_loop = pred_loop->_parent; | |
| 1612 } | |
| 1613 // Make pred's loop be a child | |
| 1614 if (pred_loop->_parent == NULL) { | |
| 1615 add_nested_loop(pred_loop); | |
| 1616 // Continue with loop entry predecessor. | |
| 1617 Block* pred_head = pred_loop->head(); | |
| 1618 assert(pred_head->num_preds() - 1 == 2, "loop must have 2 predecessors"); | |
| 1619 assert(pred_head != head(), "loop head in only one loop"); | |
| 12023 | 1620 push_pred(pred_head, LoopNode::EntryControl, worklist, cfg); |
| 0 | 1621 } else { |
| 1622 assert(pred_loop->_parent == this && _parent == NULL, "just checking"); | |
| 1623 } | |
| 1624 } | |
| 1625 } | |
| 1626 | |
| 1627 //------------------------------add_nested_loop-------------------------------- | |
| 1628 // Make cl a child of the current loop in the loop tree. | |
| 1629 void CFGLoop::add_nested_loop(CFGLoop* cl) { | |
| 1630 assert(_parent == NULL, "no parent yet"); | |
| 1631 assert(cl != this, "not my own parent"); | |
| 1632 cl->_parent = this; | |
| 1633 CFGLoop* ch = _child; | |
| 1634 if (ch == NULL) { | |
| 1635 _child = cl; | |
| 1636 } else { | |
| 1637 while (ch->_sibling != NULL) { ch = ch->_sibling; } | |
| 1638 ch->_sibling = cl; | |
| 1639 } | |
| 1640 } | |
| 1641 | |
| 1642 //------------------------------compute_loop_depth----------------------------- | |
| 1643 // Store the loop depth in each CFGLoop object. | |
| 1644 // Recursively walk the children to do the same for them. | |
| 1645 void CFGLoop::compute_loop_depth(int depth) { | |
| 1646 _depth = depth; | |
| 1647 CFGLoop* ch = _child; | |
| 1648 while (ch != NULL) { | |
| 1649 ch->compute_loop_depth(depth + 1); | |
| 1650 ch = ch->_sibling; | |
| 1651 } | |
| 1652 } | |
| 1653 | |
| 1654 //------------------------------compute_freq----------------------------------- | |
| 1655 // Compute the frequency of each block and loop, relative to a single entry | |
| 1656 // into the dominating loop head. | |
| 1657 void CFGLoop::compute_freq() { | |
| 1658 // Bottom up traversal of loop tree (visit inner loops first.) | |
| 1659 // Set loop head frequency to 1.0, then transitively | |
| 1660 // compute frequency for all successors in the loop, | |
| 1661 // as well as for each exit edge. Inner loops are | |
| 1662 // treated as single blocks with loop exit targets | |
| 1663 // as the successor blocks. | |
| 1664 | |
| 1665 // Nested loops first | |
| 1666 CFGLoop* ch = _child; | |
| 1667 while (ch != NULL) { | |
| 1668 ch->compute_freq(); | |
| 1669 ch = ch->_sibling; | |
| 1670 } | |
| 1671 assert (_members.length() > 0, "no empty loops"); | |
| 1672 Block* hd = head(); | |
| 1673 hd->_freq = 1.0f; | |
| 1674 for (int i = 0; i < _members.length(); i++) { | |
| 1675 CFGElement* s = _members.at(i); | |
| 1676 float freq = s->_freq; | |
| 1677 if (s->is_block()) { | |
| 1678 Block* b = s->as_Block(); | |
| 1679 for (uint j = 0; j < b->_num_succs; j++) { | |
| 1680 Block* sb = b->_succs[j]; | |
| 1681 update_succ_freq(sb, freq * b->succ_prob(j)); | |
| 1682 } | |
| 1683 } else { | |
| 1684 CFGLoop* lp = s->as_CFGLoop(); | |
| 1685 assert(lp->_parent == this, "immediate child"); | |
| 1686 for (int k = 0; k < lp->_exits.length(); k++) { | |
| 1687 Block* eb = lp->_exits.at(k).get_target(); | |
| 1688 float prob = lp->_exits.at(k).get_prob(); | |
| 1689 update_succ_freq(eb, freq * prob); | |
| 1690 } | |
| 1691 } | |
| 1692 } | |
| 1693 | |
| 1694 // For all loops other than the outer, "method" loop, | |
| 1695 // sum and normalize the exit probability. The "method" loop | |
| 1696 // should keep the initial exit probability of 1, so that | |
| 1697 // inner blocks do not get erroneously scaled. | |
| 1698 if (_depth != 0) { | |
| 1699 // Total the exit probabilities for this loop. | |
| 1700 float exits_sum = 0.0f; | |
| 1701 for (int i = 0; i < _exits.length(); i++) { | |
| 1702 exits_sum += _exits.at(i).get_prob(); | |
| 1703 } | |
| 1704 | |
| 1705 // Normalize the exit probabilities. Until now, the | |
| 1706 // probabilities estimate the possibility of exit per | |
| 1707 // a single loop iteration; afterward, they estimate | |
| 1708 // the probability of exit per loop entry. | |
| 1709 for (int i = 0; i < _exits.length(); i++) { | |
| 1710 Block* et = _exits.at(i).get_target(); | |
| 418 | 1711 float new_prob = 0.0f; |
| 1712 if (_exits.at(i).get_prob() > 0.0f) { | |
| 1713 new_prob = _exits.at(i).get_prob() / exits_sum; | |
| 1714 } | |
| 0 | 1715 BlockProbPair bpp(et, new_prob); |
| 1716 _exits.at_put(i, bpp); | |
| 1717 } | |
| 1718 | |
| 418 | 1719 // Save the total, but guard against unreasonable probability, |
| 0 | 1720 // as the value is used to estimate the loop trip count. |
| 1721 // An infinite trip count would blur relative block | |
| 1722 // frequencies. | |
| 1723 if (exits_sum > 1.0f) exits_sum = 1.0; | |
| 1724 if (exits_sum < PROB_MIN) exits_sum = PROB_MIN; | |
| 1725 _exit_prob = exits_sum; | |
| 1726 } | |
| 1727 } | |
| 1728 | |
| 1729 //------------------------------succ_prob------------------------------------- | |
| 1730 // Determine the probability of reaching successor 'i' from the receiver block. | |
| 1731 float Block::succ_prob(uint i) { | |
| 1732 int eidx = end_idx(); | |
| 1733 Node *n = _nodes[eidx]; // Get ending Node | |
| 308 | 1734 |
| 1735 int op = n->Opcode(); | |
| 1736 if (n->is_Mach()) { | |
| 1737 if (n->is_MachNullCheck()) { | |
| 1738 // Can only reach here if called after lcm. The original Op_If is gone, | |
| 1739 // so we attempt to infer the probability from one or both of the | |
| 1740 // successor blocks. | |
| 1741 assert(_num_succs == 2, "expecting 2 successors of a null check"); | |
| 1742 // If either successor has only one predecessor, then the | |
| 605 | 1743 // probability estimate can be derived using the |
| 308 | 1744 // relative frequency of the successor and this block. |
| 1745 if (_succs[i]->num_preds() == 2) { | |
| 1746 return _succs[i]->_freq / _freq; | |
| 1747 } else if (_succs[1-i]->num_preds() == 2) { | |
| 1748 return 1 - (_succs[1-i]->_freq / _freq); | |
| 1749 } else { | |
| 1750 // Estimate using both successor frequencies | |
| 1751 float freq = _succs[i]->_freq; | |
| 1752 return freq / (freq + _succs[1-i]->_freq); | |
| 1753 } | |
| 1754 } | |
| 1755 op = n->as_Mach()->ideal_Opcode(); | |
| 1756 } | |
| 1757 | |
| 0 | 1758 |
| 1759 // Switch on branch type | |
| 1760 switch( op ) { | |
| 1761 case Op_CountedLoopEnd: | |
| 1762 case Op_If: { | |
| 1763 assert (i < 2, "just checking"); | |
| 1764 // Conditionals pass on only part of their frequency | |
| 1765 float prob = n->as_MachIf()->_prob; | |
| 1766 assert(prob >= 0.0 && prob <= 1.0, "out of range probability"); | |
| 1767 // If succ[i] is the FALSE branch, invert path info | |
| 1768 if( _nodes[i + eidx + 1]->Opcode() == Op_IfFalse ) { | |
| 1769 return 1.0f - prob; // not taken | |
| 1770 } else { | |
| 1771 return prob; // taken | |
| 1772 } | |
| 1773 } | |
| 1774 | |
| 1775 case Op_Jump: | |
| 1776 // Divide the frequency between all successors evenly | |
| 1777 return 1.0f/_num_succs; | |
| 1778 | |
| 1779 case Op_Catch: { | |
| 1780 const CatchProjNode *ci = _nodes[i + eidx + 1]->as_CatchProj(); | |
| 1781 if (ci->_con == CatchProjNode::fall_through_index) { | |
| 1782 // Fall-thru path gets the lion's share. | |
| 1783 return 1.0f - PROB_UNLIKELY_MAG(5)*_num_succs; | |
| 1784 } else { | |
| 1785 // Presume exceptional paths are equally unlikely | |
| 1786 return PROB_UNLIKELY_MAG(5); | |
| 1787 } | |
| 1788 } | |
| 1789 | |
| 1790 case Op_Root: | |
| 1791 case Op_Goto: | |
| 1792 // Pass frequency straight thru to target | |
| 1793 return 1.0f; | |
| 1794 | |
| 1795 case Op_NeverBranch: | |
| 1796 return 0.0f; | |
| 1797 | |
| 1798 case Op_TailCall: | |
| 1799 case Op_TailJump: | |
| 1800 case Op_Return: | |
| 1801 case Op_Halt: | |
| 1802 case Op_Rethrow: | |
| 1803 // Do not push out freq to root block | |
| 1804 return 0.0f; | |
| 1805 | |
| 1806 default: | |
| 1807 ShouldNotReachHere(); | |
| 1808 } | |
| 1809 | |
| 1810 return 0.0f; | |
| 1811 } | |
| 1812 | |
| 418 | 1813 //------------------------------num_fall_throughs----------------------------- |
| 1814 // Return the number of fall-through candidates for a block | |
| 1815 int Block::num_fall_throughs() { | |
| 1816 int eidx = end_idx(); | |
| 1817 Node *n = _nodes[eidx]; // Get ending Node | |
| 1818 | |
| 1819 int op = n->Opcode(); | |
| 1820 if (n->is_Mach()) { | |
| 1821 if (n->is_MachNullCheck()) { | |
| 1822 // In theory, either side can fall-thru, for simplicity sake, | |
| 1823 // let's say only the false branch can now. | |
| 1824 return 1; | |
| 1825 } | |
| 1826 op = n->as_Mach()->ideal_Opcode(); | |
| 1827 } | |
| 1828 | |
| 1829 // Switch on branch type | |
| 1830 switch( op ) { | |
| 1831 case Op_CountedLoopEnd: | |
| 1832 case Op_If: | |
| 1833 return 2; | |
| 1834 | |
| 1835 case Op_Root: | |
| 1836 case Op_Goto: | |
| 1837 return 1; | |
| 1838 | |
| 1839 case Op_Catch: { | |
| 1840 for (uint i = 0; i < _num_succs; i++) { | |
| 1841 const CatchProjNode *ci = _nodes[i + eidx + 1]->as_CatchProj(); | |
| 1842 if (ci->_con == CatchProjNode::fall_through_index) { | |
| 1843 return 1; | |
| 1844 } | |
| 1845 } | |
| 1846 return 0; | |
| 1847 } | |
| 1848 | |
| 1849 case Op_Jump: | |
| 1850 case Op_NeverBranch: | |
| 1851 case Op_TailCall: | |
| 1852 case Op_TailJump: | |
| 1853 case Op_Return: | |
| 1854 case Op_Halt: | |
| 1855 case Op_Rethrow: | |
| 1856 return 0; | |
| 1857 | |
| 1858 default: | |
| 1859 ShouldNotReachHere(); | |
| 1860 } | |
| 1861 | |
| 1862 return 0; | |
| 1863 } | |
| 1864 | |
| 1865 //------------------------------succ_fall_through----------------------------- | |
| 1866 // Return true if a specific successor could be fall-through target. | |
| 1867 bool Block::succ_fall_through(uint i) { | |
| 1868 int eidx = end_idx(); | |
| 1869 Node *n = _nodes[eidx]; // Get ending Node | |
| 1870 | |
| 1871 int op = n->Opcode(); | |
| 1872 if (n->is_Mach()) { | |
| 1873 if (n->is_MachNullCheck()) { | |
| 1874 // In theory, either side can fall-thru, for simplicity sake, | |
| 1875 // let's say only the false branch can now. | |
| 1876 return _nodes[i + eidx + 1]->Opcode() == Op_IfFalse; | |
| 1877 } | |
| 1878 op = n->as_Mach()->ideal_Opcode(); | |
| 1879 } | |
| 1880 | |
| 1881 // Switch on branch type | |
| 1882 switch( op ) { | |
| 1883 case Op_CountedLoopEnd: | |
| 1884 case Op_If: | |
| 1885 case Op_Root: | |
| 1886 case Op_Goto: | |
| 1887 return true; | |
| 1888 | |
| 1889 case Op_Catch: { | |
| 1890 const CatchProjNode *ci = _nodes[i + eidx + 1]->as_CatchProj(); | |
| 1891 return ci->_con == CatchProjNode::fall_through_index; | |
| 1892 } | |
| 1893 | |
| 1894 case Op_Jump: | |
| 1895 case Op_NeverBranch: | |
| 1896 case Op_TailCall: | |
| 1897 case Op_TailJump: | |
| 1898 case Op_Return: | |
| 1899 case Op_Halt: | |
| 1900 case Op_Rethrow: | |
| 1901 return false; | |
| 1902 | |
| 1903 default: | |
| 1904 ShouldNotReachHere(); | |
| 1905 } | |
| 1906 | |
| 1907 return false; | |
| 1908 } | |
| 1909 | |
| 1910 //------------------------------update_uncommon_branch------------------------ | |
| 1911 // Update the probability of a two-branch to be uncommon | |
| 1912 void Block::update_uncommon_branch(Block* ub) { | |
| 1913 int eidx = end_idx(); | |
| 1914 Node *n = _nodes[eidx]; // Get ending Node | |
| 1915 | |
| 1916 int op = n->as_Mach()->ideal_Opcode(); | |
| 1917 | |
| 1918 assert(op == Op_CountedLoopEnd || op == Op_If, "must be a If"); | |
| 1919 assert(num_fall_throughs() == 2, "must be a two way branch block"); | |
| 1920 | |
| 1921 // Which successor is ub? | |
| 1922 uint s; | |
| 1923 for (s = 0; s <_num_succs; s++) { | |
| 1924 if (_succs[s] == ub) break; | |
| 1925 } | |
| 1926 assert(s < 2, "uncommon successor must be found"); | |
| 1927 | |
| 1928 // If ub is the true path, make the proability small, else | |
| 1929 // ub is the false path, and make the probability large | |
| 1930 bool invert = (_nodes[s + eidx + 1]->Opcode() == Op_IfFalse); | |
| 1931 | |
| 1932 // Get existing probability | |
| 1933 float p = n->as_MachIf()->_prob; | |
| 1934 | |
| 1935 if (invert) p = 1.0 - p; | |
| 1936 if (p > PROB_MIN) { | |
| 1937 p = PROB_MIN; | |
| 1938 } | |
| 1939 if (invert) p = 1.0 - p; | |
| 1940 | |
| 1941 n->as_MachIf()->_prob = p; | |
| 1942 } | |
| 1943 | |
| 0 | 1944 //------------------------------update_succ_freq------------------------------- |
| 605 | 1945 // Update the appropriate frequency associated with block 'b', a successor of |
| 0 | 1946 // a block in this loop. |
| 1947 void CFGLoop::update_succ_freq(Block* b, float freq) { | |
| 1948 if (b->_loop == this) { | |
| 1949 if (b == head()) { | |
| 1950 // back branch within the loop | |
| 1951 // Do nothing now, the loop carried frequency will be | |
| 1952 // adjust later in scale_freq(). | |
| 1953 } else { | |
| 1954 // simple branch within the loop | |
| 1955 b->_freq += freq; | |
| 1956 } | |
| 1957 } else if (!in_loop_nest(b)) { | |
| 1958 // branch is exit from this loop | |
| 1959 BlockProbPair bpp(b, freq); | |
| 1960 _exits.append(bpp); | |
| 1961 } else { | |
| 1962 // branch into nested loop | |
| 1963 CFGLoop* ch = b->_loop; | |
| 1964 ch->_freq += freq; | |
| 1965 } | |
| 1966 } | |
| 1967 | |
| 1968 //------------------------------in_loop_nest----------------------------------- | |
| 1969 // Determine if block b is in the receiver's loop nest. | |
| 1970 bool CFGLoop::in_loop_nest(Block* b) { | |
| 1971 int depth = _depth; | |
| 1972 CFGLoop* b_loop = b->_loop; | |
| 1973 int b_depth = b_loop->_depth; | |
| 1974 if (depth == b_depth) { | |
| 1975 return true; | |
| 1976 } | |
| 1977 while (b_depth > depth) { | |
| 1978 b_loop = b_loop->_parent; | |
| 1979 b_depth = b_loop->_depth; | |
| 1980 } | |
| 1981 return b_loop == this; | |
| 1982 } | |
| 1983 | |
| 1984 //------------------------------scale_freq------------------------------------- | |
| 1985 // Scale frequency of loops and blocks by trip counts from outer loops | |
| 1986 // Do a top down traversal of loop tree (visit outer loops first.) | |
| 1987 void CFGLoop::scale_freq() { | |
| 1988 float loop_freq = _freq * trip_count(); | |
| 673 | 1989 _freq = loop_freq; |
| 0 | 1990 for (int i = 0; i < _members.length(); i++) { |
| 1991 CFGElement* s = _members.at(i); | |
|
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1992 float block_freq = s->_freq * loop_freq; |
| 621 | 1993 if (g_isnan(block_freq) || block_freq < MIN_BLOCK_FREQUENCY) |
| 1994 block_freq = MIN_BLOCK_FREQUENCY; | |
|
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1995 s->_freq = block_freq; |
| 0 | 1996 } |
| 1997 CFGLoop* ch = _child; | |
| 1998 while (ch != NULL) { | |
| 1999 ch->scale_freq(); | |
| 2000 ch = ch->_sibling; | |
| 2001 } | |
| 2002 } | |
| 2003 | |
| 673 | 2004 // Frequency of outer loop |
| 2005 float CFGLoop::outer_loop_freq() const { | |
| 2006 if (_child != NULL) { | |
| 2007 return _child->_freq; | |
| 2008 } | |
| 2009 return _freq; | |
| 2010 } | |
| 2011 | |
| 0 | 2012 #ifndef PRODUCT |
| 2013 //------------------------------dump_tree-------------------------------------- | |
| 2014 void CFGLoop::dump_tree() const { | |
| 2015 dump(); | |
| 2016 if (_child != NULL) _child->dump_tree(); | |
| 2017 if (_sibling != NULL) _sibling->dump_tree(); | |
| 2018 } | |
| 2019 | |
| 2020 //------------------------------dump------------------------------------------- | |
| 2021 void CFGLoop::dump() const { | |
| 2022 for (int i = 0; i < _depth; i++) tty->print(" "); | |
| 2023 tty->print("%s: %d trip_count: %6.0f freq: %6.0f\n", | |
| 2024 _depth == 0 ? "Method" : "Loop", _id, trip_count(), _freq); | |
| 2025 for (int i = 0; i < _depth; i++) tty->print(" "); | |
| 2026 tty->print(" members:", _id); | |
| 2027 int k = 0; | |
| 2028 for (int i = 0; i < _members.length(); i++) { | |
| 2029 if (k++ >= 6) { | |
| 2030 tty->print("\n "); | |
| 2031 for (int j = 0; j < _depth+1; j++) tty->print(" "); | |
| 2032 k = 0; | |
| 2033 } | |
| 2034 CFGElement *s = _members.at(i); | |
| 2035 if (s->is_block()) { | |
| 2036 Block *b = s->as_Block(); | |
| 2037 tty->print(" B%d(%6.3f)", b->_pre_order, b->_freq); | |
| 2038 } else { | |
| 2039 CFGLoop* lp = s->as_CFGLoop(); | |
| 2040 tty->print(" L%d(%6.3f)", lp->_id, lp->_freq); | |
| 2041 } | |
| 2042 } | |
| 2043 tty->print("\n"); | |
| 2044 for (int i = 0; i < _depth; i++) tty->print(" "); | |
| 2045 tty->print(" exits: "); | |
| 2046 k = 0; | |
| 2047 for (int i = 0; i < _exits.length(); i++) { | |
| 2048 if (k++ >= 7) { | |
| 2049 tty->print("\n "); | |
| 2050 for (int j = 0; j < _depth+1; j++) tty->print(" "); | |
| 2051 k = 0; | |
| 2052 } | |
| 2053 Block *blk = _exits.at(i).get_target(); | |
| 2054 float prob = _exits.at(i).get_prob(); | |
| 2055 tty->print(" ->%d@%d%%", blk->_pre_order, (int)(prob*100)); | |
| 2056 } | |
| 2057 tty->print("\n"); | |
| 2058 } | |
| 2059 #endif |