Make special RPO computation iterative during scheduling.

test/cctest/compiler/test-scheduler.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 #include "test/cctest/cctest.h"
 
 #include "src/compiler/access-builder.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/generic-node-inl.h"
@@ skipping 12 matching lines @@
 using namespace v8::internal;
 using namespace v8::internal::compiler;
 
 // TODO(titzer): pull RPO tests out to their own file.
 static void CheckRPONumbers(BasicBlockVector* order, size_t expected,
                             bool loops_allowed) {
   CHECK(expected == order->size());
   for (int i = 0; i < static_cast<int>(order->size()); i++) {
     CHECK(order->at(i)->rpo_number() == i);
     if (!loops_allowed) {
-      CHECK_LT(order->at(i)->loop_end(), 0);
+      CHECK_EQ(NULL, order->at(i)->loop_end());
       CHECK_EQ(NULL, order->at(i)->loop_header());
     }
   }
 }
 
 
 static void CheckLoop(BasicBlockVector* order, BasicBlock** blocks,
                       int body_size) {
   BasicBlock* header = blocks[0];
-  CHECK_GT(header->loop_end(), 0);
-  CHECK_EQ(body_size, (header->loop_end() - header->rpo_number()));
+  BasicBlock* end = header->loop_end();
+  CHECK_NE(NULL, end);
+  CHECK_GT(end->rpo_number(), 0);
+  CHECK_EQ(body_size, end->rpo_number() - header->rpo_number());
   for (int i = 0; i < body_size; i++) {
-    int num = blocks[i]->rpo_number();
-    CHECK(num >= header->rpo_number() && num < header->loop_end());
+    CHECK_GE(blocks[i]->rpo_number(), header->rpo_number());
+    CHECK_LT(blocks[i]->rpo_number(), end->rpo_number());
     CHECK(header->LoopContains(blocks[i]));
     CHECK(header->IsLoopHeader() || blocks[i]->loop_header() == header);
   }
   if (header->rpo_number() > 0) {
     CHECK_NE(order->at(header->rpo_number() - 1)->loop_header(), header);
   }
-  if (header->loop_end() < static_cast<int>(order->size())) {
-    CHECK_NE(order->at(header->loop_end())->loop_header(), header);
+  if (end->rpo_number() < static_cast<int>(order->size())) {
+    CHECK_NE(order->at(end->rpo_number())->loop_header(), header);
   }
 }
 
 
 struct TestLoop {
   int count;
   BasicBlock** nodes;
   BasicBlock* header() { return nodes[0]; }
   BasicBlock* last() { return nodes[count - 1]; }
   ~TestLoop() { delete[] nodes; }
@@ skipping 1890 matching lines @@
   graph.SetEnd(end);
 
   Schedule* schedule = ComputeAndVerifySchedule(6, &graph);
   BasicBlock* block = schedule->block(loop);
   CHECK_NE(NULL, loop);
   CHECK_EQ(block, schedule->block(effect));
   CHECK_GE(block->rpo_number(), 0);
 }
 
 #endif