diff --git a/runtime/verifier/method_verifier.cc b/runtime/verifier/method_verifier.cc
index c4c3082..fb2d29f 100644
--- a/runtime/verifier/method_verifier.cc
+++ b/runtime/verifier/method_verifier.cc
@@ -3905,6 +3905,7 @@
 
 std::vector<int32_t> MethodVerifier::DescribeVRegs(uint32_t dex_pc) {
   RegisterLine* line = reg_table_.GetLine(dex_pc);
+  DCHECK(line != nullptr) << "No register line at DEX pc " << StringPrintf("0x%x", dex_pc);
   std::vector<int32_t> result;
   for (size_t i = 0; i < line->NumRegs(); ++i) {
     const RegType& type = line->GetRegisterType(i);
diff --git a/runtime/verifier/reg_type.cc b/runtime/verifier/reg_type.cc
index 63f0ff4..c6f3e5c 100644
--- a/runtime/verifier/reg_type.cc
+++ b/runtime/verifier/reg_type.cc
@@ -777,7 +777,7 @@
 }
 
 static const RegType& SelectNonConstant(const RegType& a, const RegType& b) {
-  return a.IsConstant() ? b : a;
+  return a.IsConstantTypes() ? b : a;
 }
 
 const RegType& RegType::Merge(const RegType& incoming_type, RegTypeCache* reg_types) const {
diff --git a/runtime/verifier/reg_type_test.cc b/runtime/verifier/reg_type_test.cc
index 1a64c00..1695fc5 100644
--- a/runtime/verifier/reg_type_test.cc
+++ b/runtime/verifier/reg_type_test.cc
@@ -335,7 +335,6 @@
   EXPECT_FALSE(double_reg_type.IsNonZeroReferenceTypes());
 }
 
-
 class RegTypeReferenceTest : public CommonRuntimeTest {};
 
 TEST_F(RegTypeReferenceTest, JavalangObjectImprecise) {
@@ -472,6 +471,144 @@
   EXPECT_EQ(ref_type_1.GetId(), *((++merged_ids.begin())));
 }
 
+TEST_F(RegTypeReferenceTest, MergingFloat) {
+  // Testing merging logic with float and float constants.
+  ScopedObjectAccess soa(Thread::Current());
+  RegTypeCache cache_new(true);
+
+  constexpr int32_t kTestConstantValue = 10;
+  const RegType& float_type = cache_new.Float();
+  const RegType& precise_cst = cache_new.FromCat1Const(kTestConstantValue, true);
+  const RegType& imprecise_cst = cache_new.FromCat1Const(kTestConstantValue, false);
+  {
+    // float MERGE precise cst => float.
+    const RegType& merged = float_type.Merge(precise_cst, &cache_new);
+    EXPECT_TRUE(merged.IsFloat());
+  }
+  {
+    // precise cst MERGE float => float.
+    const RegType& merged = precise_cst.Merge(float_type, &cache_new);
+    EXPECT_TRUE(merged.IsFloat());
+  }
+  {
+    // float MERGE imprecise cst => float.
+    const RegType& merged = float_type.Merge(imprecise_cst, &cache_new);
+    EXPECT_TRUE(merged.IsFloat());
+  }
+  {
+    // imprecise cst MERGE float => float.
+    const RegType& merged = imprecise_cst.Merge(float_type, &cache_new);
+    EXPECT_TRUE(merged.IsFloat());
+  }
+}
+
+TEST_F(RegTypeReferenceTest, MergingLong) {
+  // Testing merging logic with long and long constants.
+  ScopedObjectAccess soa(Thread::Current());
+  RegTypeCache cache_new(true);
+
+  constexpr int32_t kTestConstantValue = 10;
+  const RegType& long_lo_type = cache_new.LongLo();
+  const RegType& long_hi_type = cache_new.LongHi();
+  const RegType& precise_cst_lo = cache_new.FromCat2ConstLo(kTestConstantValue, true);
+  const RegType& imprecise_cst_lo = cache_new.FromCat2ConstLo(kTestConstantValue, false);
+  const RegType& precise_cst_hi = cache_new.FromCat2ConstHi(kTestConstantValue, true);
+  const RegType& imprecise_cst_hi = cache_new.FromCat2ConstHi(kTestConstantValue, false);
+  {
+    // lo MERGE precise cst lo => lo.
+    const RegType& merged = long_lo_type.Merge(precise_cst_lo, &cache_new);
+    EXPECT_TRUE(merged.IsLongLo());
+  }
+  {
+    // precise cst lo MERGE lo => lo.
+    const RegType& merged = precise_cst_lo.Merge(long_lo_type, &cache_new);
+    EXPECT_TRUE(merged.IsLongLo());
+  }
+  {
+    // lo MERGE imprecise cst lo => lo.
+    const RegType& merged = long_lo_type.Merge(imprecise_cst_lo, &cache_new);
+    EXPECT_TRUE(merged.IsLongLo());
+  }
+  {
+    // imprecise cst lo MERGE lo => lo.
+    const RegType& merged = imprecise_cst_lo.Merge(long_lo_type, &cache_new);
+    EXPECT_TRUE(merged.IsLongLo());
+  }
+  {
+    // hi MERGE precise cst hi => hi.
+    const RegType& merged = long_hi_type.Merge(precise_cst_hi, &cache_new);
+    EXPECT_TRUE(merged.IsLongHi());
+  }
+  {
+    // precise cst hi MERGE hi => hi.
+    const RegType& merged = precise_cst_hi.Merge(long_hi_type, &cache_new);
+    EXPECT_TRUE(merged.IsLongHi());
+  }
+  {
+    // hi MERGE imprecise cst hi => hi.
+    const RegType& merged = long_hi_type.Merge(imprecise_cst_hi, &cache_new);
+    EXPECT_TRUE(merged.IsLongHi());
+  }
+  {
+    // imprecise cst hi MERGE hi => hi.
+    const RegType& merged = imprecise_cst_hi.Merge(long_hi_type, &cache_new);
+    EXPECT_TRUE(merged.IsLongHi());
+  }
+}
+
+TEST_F(RegTypeReferenceTest, MergingDouble) {
+  // Testing merging logic with double and double constants.
+  ScopedObjectAccess soa(Thread::Current());
+  RegTypeCache cache_new(true);
+
+  constexpr int32_t kTestConstantValue = 10;
+  const RegType& double_lo_type = cache_new.DoubleLo();
+  const RegType& double_hi_type = cache_new.DoubleHi();
+  const RegType& precise_cst_lo = cache_new.FromCat2ConstLo(kTestConstantValue, true);
+  const RegType& imprecise_cst_lo = cache_new.FromCat2ConstLo(kTestConstantValue, false);
+  const RegType& precise_cst_hi = cache_new.FromCat2ConstHi(kTestConstantValue, true);
+  const RegType& imprecise_cst_hi = cache_new.FromCat2ConstHi(kTestConstantValue, false);
+  {
+    // lo MERGE precise cst lo => lo.
+    const RegType& merged = double_lo_type.Merge(precise_cst_lo, &cache_new);
+    EXPECT_TRUE(merged.IsDoubleLo());
+  }
+  {
+    // precise cst lo MERGE lo => lo.
+    const RegType& merged = precise_cst_lo.Merge(double_lo_type, &cache_new);
+    EXPECT_TRUE(merged.IsDoubleLo());
+  }
+  {
+    // lo MERGE imprecise cst lo => lo.
+    const RegType& merged = double_lo_type.Merge(imprecise_cst_lo, &cache_new);
+    EXPECT_TRUE(merged.IsDoubleLo());
+  }
+  {
+    // imprecise cst lo MERGE lo => lo.
+    const RegType& merged = imprecise_cst_lo.Merge(double_lo_type, &cache_new);
+    EXPECT_TRUE(merged.IsDoubleLo());
+  }
+  {
+    // hi MERGE precise cst hi => hi.
+    const RegType& merged = double_hi_type.Merge(precise_cst_hi, &cache_new);
+    EXPECT_TRUE(merged.IsDoubleHi());
+  }
+  {
+    // precise cst hi MERGE hi => hi.
+    const RegType& merged = precise_cst_hi.Merge(double_hi_type, &cache_new);
+    EXPECT_TRUE(merged.IsDoubleHi());
+  }
+  {
+    // hi MERGE imprecise cst hi => hi.
+    const RegType& merged = double_hi_type.Merge(imprecise_cst_hi, &cache_new);
+    EXPECT_TRUE(merged.IsDoubleHi());
+  }
+  {
+    // imprecise cst hi MERGE hi => hi.
+    const RegType& merged = imprecise_cst_hi.Merge(double_hi_type, &cache_new);
+    EXPECT_TRUE(merged.IsDoubleHi());
+  }
+}
 
 TEST_F(RegTypeTest, ConstPrecision) {
   // Tests creating primitive types types.