Strengthen type assertions post-dominated by checks during type propagation.

runtime/vm/flow_graph_compiler_x64.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/flow_graph_compiler.h"
 
 #include "lib/error.h"
 #include "vm/ast_printer.h"
 #include "vm/dart_entry.h"
 #include "vm/il_printer.h"
 #include "vm/locations.h"
 #include "vm/object_store.h"
 #include "vm/parser.h"
 #include "vm/stub_code.h"
 #include "vm/symbols.h"
 
 namespace dart {
 
 DEFINE_FLAG(bool, trap_on_deoptimization, false, "Trap on deoptimization.");
 DECLARE_FLAG(int, optimization_counter_threshold);
 DECLARE_FLAG(bool, print_ast);
 DECLARE_FLAG(bool, print_scopes);
+DECLARE_FLAG(bool, enable_type_checks);
 DECLARE_FLAG(bool, eliminate_type_checks);
 
 
 FlowGraphCompiler::~FlowGraphCompiler() {
   // BlockInfos are zone-allocated, so their destructors are not called.
   // Verify the labels explicitly here.
   for (int i = 0; i < block_info_.length(); ++i) {
     ASSERT(!block_info_[i]->label.IsLinked());
     ASSERT(!block_info_[i]->label.HasNear());
   }
@@ skipping 577 matching lines @@
   __ popq(RAX);
 
   __ Bind(&is_assignable);
   __ popq(RDX);  // Remove pushed instantiator type arguments.
   __ popq(RCX);  // Remove pushed instantiator.
 }
 
 
 void FlowGraphCompiler::EmitInstructionPrologue(Instruction* instr) {
   if (!is_optimizing()) {
+    if (FLAG_enable_type_checks && instr->IsAssertAssignable()) {
+      AssertAssignableInstr* assert = instr->AsAssertAssignable();
+      AddCurrentDescriptor(PcDescriptors::kDeoptBefore,
+                           assert->deopt_id(),
+                           assert->token_pos());
+    }
     AllocateRegistersLocally(instr);
   }
 }
 
 
 void FlowGraphCompiler::EmitInstructionEpilogue(Instruction* instr) {
   if (is_optimizing()) return;
   Definition* defn = instr->AsDefinition();
   if ((defn != NULL) && defn->is_used()) {
     __ pushq(defn->locs()->out().reg());
@@ skipping 1055 matching lines @@
 void ParallelMoveResolver::Exchange(const Address& mem1, const Address& mem2) {
   __ Exchange(mem1, mem2);
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64