2 files changed, 103 insertions, 0 deletions

diff --git a/compiler/dex/mir_graph.cc b/compiler/dex/mir_graph.cc
index 4ba66771b4..1b0c7b0485 100644
--- a/compiler/dex/mir_graph.cc
+++ b/compiler/dex/mir_graph.cc
@@ -1490,4 +1490,57 @@ uint32_t SSARepresentation::GetStartUseIndex(Instruction::Code opcode) {
   return res;
 }
 
+/**
+ * @brief Given a decoded instruction, it checks whether the instruction
+ * sets a constant and if it does, more information is provided about the
+ * constant being set.
+ * @param ptr_value pointer to a 64-bit holder for the constant.
+ * @param wide Updated by function whether a wide constant is being set by bytecode.
+ * @return Returns false if the decoded instruction does not represent a constant bytecode.
+ */
+bool MIR::DecodedInstruction::GetConstant(int64_t* ptr_value, bool* wide) const {
+  bool sets_const = true;
+  int64_t value = vB;
+
+  DCHECK(ptr_value != nullptr);
+  DCHECK(wide != nullptr);
+
+  switch (opcode) {
+    case Instruction::CONST_4:
+    case Instruction::CONST_16:
+    case Instruction::CONST:
+      *wide = false;
+      value <<= 32;      // In order to get the sign extend.
+      value >>= 32;
+      break;
+    case Instruction::CONST_HIGH16:
+      *wide = false;
+      value <<= 48;      // In order to get the sign extend.
+      value >>= 32;
+      break;
+    case Instruction::CONST_WIDE_16:
+    case Instruction::CONST_WIDE_32:
+      *wide = true;
+      value <<= 32;      // In order to get the sign extend.
+      value >>= 32;
+      break;
+    case Instruction::CONST_WIDE:
+      *wide = true;
+      value = vB_wide;
+      break;
+    case Instruction::CONST_WIDE_HIGH16:
+      *wide = true;
+      value <<= 48;      // In order to get the sign extend.
+      break;
+    default:
+      sets_const = false;
+      break;
+  }
+
+  if (sets_const) {
+    *ptr_value = value;
+  }
+
+  return sets_const;
+}
 }  // namespace art
diff --git a/compiler/dex/mir_graph.h b/compiler/dex/mir_graph.h
index 0bb82659a2..73260dfce8 100644
--- a/compiler/dex/mir_graph.h
+++ b/compiler/dex/mir_graph.h
@@ -266,6 +266,56 @@ struct MIR {
 
     explicit DecodedInstruction():vA(0), vB(0), vB_wide(0), vC(0), opcode(Instruction::NOP) {
     }
+
+    /*
+     * Given a decoded instruction representing a const bytecode, it updates
+     * the out arguments with proper values as dictated by the constant bytecode.
+     */
+    bool GetConstant(int64_t* ptr_value, bool* wide) const;
+
+    bool IsStore() const {
+      return ((Instruction::FlagsOf(opcode) & Instruction::kStore) == Instruction::kStore);
+    }
+
+    bool IsLoad() const {
+      return ((Instruction::FlagsOf(opcode) & Instruction::kLoad) == Instruction::kLoad);
+    }
+
+    bool IsConditionalBranch() const {
+      return (Instruction::FlagsOf(opcode) == (Instruction::kContinue | Instruction::kBranch));
+    }
+
+    /**
+     * @brief Is the register C component of the decoded instruction a constant?
+     */
+    bool IsCFieldOrConstant() const {
+      return ((Instruction::FlagsOf(opcode) & Instruction::kRegCFieldOrConstant) == Instruction::kRegCFieldOrConstant);
+    }
+
+    /**
+     * @brief Is the register C component of the decoded instruction a constant?
+     */
+    bool IsBFieldOrConstant() const {
+      return ((Instruction::FlagsOf(opcode) & Instruction::kRegBFieldOrConstant) == Instruction::kRegBFieldOrConstant);
+    }
+
+    bool IsCast() const {
+      return ((Instruction::FlagsOf(opcode) & Instruction::kCast) == Instruction::kCast);
+    }
+
+    /**
+     * @brief Does the instruction clobber memory?
+     * @details Clobber means that the instruction changes the memory not in a punctual way.
+     *          Therefore any supposition on memory aliasing or memory contents should be disregarded
+     *            when crossing such an instruction.
+     */
+    bool Clobbers() const {
+      return ((Instruction::FlagsOf(opcode) & Instruction::kClobber) == Instruction::kClobber);
+    }
+
+    bool IsLinear() const {
+      return (Instruction::FlagsOf(opcode) & (Instruction::kAdd | Instruction::kSubtract)) != 0;
+    }
   } dalvikInsn;
 
   NarrowDexOffset offset;         // Offset of the instruction in code units.