Rename HNativeDebugInfo to HNop

We can generalize HNativeDebugInfo to be used as a Nop (i.e. no
instructions are generated), and give it the option of having an
environment to keep the current HNativeDebugInfo logic working.

Test: art/test/testrunner/testrunner.py --host --64 --optimizing -b
Change-Id: I06b3a36e8b124bcda858d2c9cd8ff0ab21caea36

1 files changed, 15 insertions, 10 deletions

diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index ed2f2111b2..103d318710 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -1565,10 +1565,10 @@ class HLoopInformationOutwardIterator : public ValueObject {
   M(Min, BinaryOperation)                                               \
   M(MonitorOperation, Instruction)                                      \
   M(Mul, BinaryOperation)                                               \
-  M(NativeDebugInfo, Instruction)                                       \
   M(Neg, UnaryOperation)                                                \
   M(NewArray, Instruction)                                              \
   M(NewInstance, Instruction)                                           \
+  M(Nop, Instruction)                                                   \
   M(Not, UnaryOperation)                                                \
   M(NotEqual, Condition)                                                \
   M(NullConstant, Instruction)                                          \
@@ -2433,7 +2433,7 @@ class HInstruction : public ArenaObject<kArenaAllocInstruction> {
         !CanThrow() &&
         !IsSuspendCheck() &&
         !IsControlFlow() &&
-        !IsNativeDebugInfo() &&
+        !IsNop() &&
         !IsParameterValue() &&
         // If we added an explicit barrier then we should keep it.
         !IsMemoryBarrier() &&
@@ -6783,22 +6783,27 @@ class HSuspendCheck final : public HExpression<0> {
   SlowPathCode* slow_path_;
 };
 
-// Pseudo-instruction which provides the native debugger with mapping information.
-// It ensures that we can generate line number and local variables at this point.
-class HNativeDebugInfo : public HExpression<0> {
+// Pseudo-instruction which doesn't generate any code.
+// If `emit_environment` is true, it can be used to generate an environment. It is used, for
+// example, to provide the native debugger with mapping information. It ensures that we can generate
+// line number and local variables at this point.
+class HNop : public HExpression<0> {
  public:
-  explicit HNativeDebugInfo(uint32_t dex_pc)
-      : HExpression<0>(kNativeDebugInfo, SideEffects::None(), dex_pc) {
+  explicit HNop(uint32_t dex_pc, bool needs_environment)
+      : HExpression<0>(kNop, SideEffects::None(), dex_pc), needs_environment_(needs_environment) {
   }
 
   bool NeedsEnvironment() const override {
-    return true;
+    return needs_environment_;
   }
 
-  DECLARE_INSTRUCTION(NativeDebugInfo);
+  DECLARE_INSTRUCTION(Nop);
 
  protected:
-  DEFAULT_COPY_CONSTRUCTOR(NativeDebugInfo);
+  DEFAULT_COPY_CONSTRUCTOR(Nop);
+
+ private:
+  bool needs_environment_;
 };
 
 /**