--trust-primitives: Remove bounds checks and receiver and argument type checks

pkg/compiler/lib/src/ssa/codegen_helpers.dart

 // Copyright (c) 2012, 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.
 
 part of ssa;
 
 /**
  * Replaces some instructions with specialized versions to make codegen easier.
  * Caches codegen information on nodes.
  */
@@ skipping 255 matching lines @@
     }
   }
 
   void visitTypeKnown(HTypeKnown instruction) {
     instruction.block.rewrite(instruction, instruction.checkedInput);
     instruction.block.remove(instruction);
   }
 }
 
 /**
+ * Remove [HTypeConversion] instructions from the graph in '--trust-primitives'
+ * mode.
+ */
+class SsaTrustedCheckRemover extends HBaseVisitor {
+
+  Compiler compiler;
+  SsaTrustedCheckRemover(this.compiler);
+
+  void visitGraph(HGraph graph) {
+    if (!compiler.trustPrimitives) return;
+    visitDominatorTree(graph);
+  }
+
+  void visitBasicBlock(HBasicBlock block) {
+    HInstruction instruction = block.first;
+    while (instruction != null) {
+      HInstruction next = instruction.next;
+      instruction.accept(this);
+      instruction = next;
+    }
+  }
+
+  void visitTypeConversion(HTypeConversion instruction) {
+    if (instruction.isReceiverTypeCheck || instruction.isArgumentTypeCheck) {
+      instruction.block.rewrite(instruction, instruction.checkedInput);
+      instruction.block.remove(instruction);
+    }
+  }
+}
+
+/**
  * Instead of emitting each SSA instruction with a temporary variable
  * mark instructions that can be emitted at their use-site.
  * For example, in:
  *   t0 = 4;
  *   t1 = 3;
  *   t2 = add(t0, t1);
  * t0 and t1 would be marked and the resulting code would then be:
  *   t2 = add(4, 3);
  */
 class SsaInstructionMerger extends HBaseVisitor {
@@ skipping 408 matching lines @@
     }
 
     // If [thenInput] is defined in the first predecessor, then it is only used
     // by [phi] and can be generated at use site.
     if (identical(thenInput.block, end.predecessors[0])) {
       assert(thenInput.usedBy.length == 1);
       markAsGenerateAtUseSite(thenInput);
     }
   }
 }