[x64/ia32] Deal with the non-transitivity of InstructionSelector::CanCover() when folding loads int…

src/compiler/instruction-selector.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/compiler/instruction-selector.h"
 
 #include <limits>
 
 #include "src/base/adapters.h"
 #include "src/compiler/instruction-selector-impl.h"
@@ skipping 695 matching lines @@
   int effect_level = 0;
   for (Node* const node : *block) {
     if (node->opcode() == IrOpcode::kStore ||
         node->opcode() == IrOpcode::kCheckedStore ||
         node->opcode() == IrOpcode::kCall) {
       ++effect_level;
     }
     SetEffectLevel(node, effect_level);
   }
 
+  // We visit the control first, then the nodes in the block, so the block's
+  // control input should be on the same effect level as the last node.
+  if (block->control_input() != nullptr) {
+    SetEffectLevel(block->control_input(), effect_level);
+  }
+
   // Generate code for the block control "top down", but schedule the code
   // "bottom up".
   VisitControl(block);
   std::reverse(instructions_.begin() + current_block_end, instructions_.end());
 
   // Visit code in reverse control flow order, because architecture-specific
   // matching may cover more than one node at a time.
   for (auto node : base::Reversed(*block)) {
     // Skip nodes that are unused or already defined.
     if (!IsUsed(node) || IsDefined(node)) continue;
@@ skipping 1092 matching lines @@
   return new (instruction_zone()) FrameStateDescriptor(
       instruction_zone(), state_info.type(), state_info.bailout_id(),
       state_info.state_combine(), parameters, locals, stack,
       state_info.shared_info(), outer_state);
 }
 
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8