diff --git a/ext/llvm_value.cpp b/ext/llvm_value.cpp
index d914299..b5f7a0d 100644
--- a/ext/llvm_value.cpp
+++ b/ext/llvm_value.cpp
@@ -101,6 +101,68 @@ llvm_value_get_immediate_constant(VALUE self, VALUE v) {
   return llvm_value_wrap(ConstantInt::get(type, (long)v));
 }
 
+VALUE
+llvm_value_is_constant(VALUE self) {
+  Value *v;
+  Data_Get_Struct(self, Value, v);
+  return isa<Constant>(v) ? Qtrue : Qfalse;
+}
+
+VALUE
+llvm_value_is_int_constant(VALUE self) {
+  Value *v;
+  Data_Get_Struct(self, Value, v);
+  return isa<ConstantInt>(v) ? Qtrue : Qfalse;
+}
+
+VALUE
+llvm_value_is_float_constant(VALUE self) {
+  Value *v;
+  Data_Get_Struct(self, Value, v);
+  return isa<ConstantFP>(v) ? Qtrue : Qfalse;
+}
+
+VALUE
+llvm_value_get_int_constant_value(VALUE self) {
+  Value *v;
+  Data_Get_Struct(self, Value, v);
+  if (ConstantInt *C = dyn_cast<ConstantInt>(v)) {
+    APInt val = C->getValue();
+    return LL2NUM(val.getLimitedValue());
+  } else {
+    rb_raise(rb_eTypeError, "Argument not an integer constant");
+  }
+}
+
+VALUE
+llvm_value_get_float_constant_value(VALUE self) {
+  Value *v;
+  Data_Get_Struct(self, Value, v);
+  if (ConstantFP *C = dyn_cast<ConstantFP>(v)) {
+    APFloat val = C->getValueAPF();
+    return rb_float_new(val.convertToFloat());
+  } else {
+    rb_raise(rb_eTypeError, "Argument not a float constant");
+  }
+}
+
+
+VALUE
+llvm_value_is_null(VALUE self) {
+  Value *v;
+  Data_Get_Struct(self, Value, v);
+  if (Constant *C = dyn_cast<Constant>(v))
+    return C->isNullValue() ? Qtrue : Qfalse;
+  return Qfalse;
+}
+
+VALUE
+llvm_value_is_undef(VALUE self) {
+  Value *v;
+  Data_Get_Struct(self, Value, v);
+  return isa<UndefValue>(v) ? Qtrue : Qfalse;
+}
+
 VALUE 
 llvm_type_pointer(VALUE self, VALUE rtype) {
   Type *type;
diff --git a/ext/llvmruby.c b/ext/llvmruby.c
index 36d00e7..8c0fb94 100644
--- a/ext/llvmruby.c
+++ b/ext/llvmruby.c
@@ -129,6 +129,14 @@ VALUE llvm_value_num_uses(VALUE);
 VALUE llvm_value_used_in_basic_block(VALUE, VALUE);
 VALUE llvm_value_replace_all_uses_with(VALUE, VALUE);
 
+VALUE llvm_value_is_constant(VALUE self);
+VALUE llvm_value_is_int_constant(VALUE self);
+VALUE llvm_value_is_float_constant(VALUE self);
+VALUE llvm_value_get_int_constant_value(VALUE self);
+VALUE llvm_value_get_float_constant_value(VALUE self);
+VALUE llvm_value_is_null(VALUE self);
+VALUE llvm_value_is_undef(VALUE self);
+
 VALUE llvm_user_get_operand_list(VALUE);
 VALUE llvm_user_get_num_operands(VALUE);
 VALUE llvm_user_get_operand(VALUE, VALUE);
@@ -209,6 +217,14 @@ void Init_llvmruby() {
   rb_define_method(cLLVMValue, "used_in_basic_block?", llvm_value_used_in_basic_block, 1);
   rb_define_method(cLLVMValue, "replace_all_uses_with", llvm_value_replace_all_uses_with, 1);
 
+  rb_define_method(cLLVMValue, "is_constant", llvm_value_is_constant, 0);
+  rb_define_method(cLLVMValue, "is_int_constant", llvm_value_is_int_constant, 0);
+  rb_define_method(cLLVMValue, "is_float_constant", llvm_value_is_float_constant, 0);
+  rb_define_method(cLLVMValue, "get_int_constant_value", llvm_value_get_int_constant_value, 0);
+  rb_define_method(cLLVMValue, "get_float_constant_value", llvm_value_get_float_constant_value, 0);
+  rb_define_method(cLLVMValue, "is_null", llvm_value_is_null, 0);
+  rb_define_method(cLLVMValue, "is_undef", llvm_value_is_undef, 0);
+
   rb_define_method(cLLVMUser, "get_operand_list", llvm_user_get_operand_list, 0);
   rb_define_method(cLLVMUser, "get_num_operands", llvm_user_get_num_operands, 0);
   rb_define_method(cLLVMUser, "get_operand", llvm_user_get_operand, 1);
diff --git a/test/test_value.rb b/test/test_value.rb
new file mode 100644
index 0000000..da99ee8
--- /dev/null
+++ b/test/test_value.rb
@@ -0,0 +1,63 @@
+require 'test/unit'
+require 'llvm'
+
+include LLVM
+
+class ValueTests < Test::Unit::TestCase
+
+  def setup
+    @assembly=<<-EOF
+    ; ModuleID = 'constants.o'
+    target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
+    target triple = "i386-apple-darwin9"
+    @CONST_PI = constant float 0x400921FA00000000		; <float*> [#uses=0]
+
+    define float @circle_area(float %radius) nounwind {
+    entry:
+    	%tmp2 = mul float %radius, 0x400921FA00000000		; <float> [#uses=1]
+    	%tmp4 = mul float %tmp2, %radius		; <float> [#uses=1]
+    	ret float %tmp4
+    }
+
+    define i32 @add_42(i32 %x) nounwind {
+    entry:
+    	%tmp2 = add i32 %x, 42		; <i32> [#uses=1]
+    	ret i32 %tmp2
+    }
+    EOF
+
+     @m = LLVM::Module.read_assembly(@assembly)
+  end
+
+  def test_check_value_is_constant
+    add42 = @m.get_function("add_42")
+    assert(add42)
+    ins = add42.get_basic_block_list[0].get_instruction_list
+    add_ins = ins[0]
+    assert_equal(false,add_ins.get_operand(0).is_constant())
+    assert_equal(true,add_ins.get_operand(1).is_constant())
+  end
+
+  def test_get_integer_constant_values
+    add42 = @m.get_function("add_42")
+    assert(add42)
+    ins = add42.get_basic_block_list[0].get_instruction_list
+    add_ins = ins[0]
+    assert(add_ins.get_operand(1).is_constant())
+    assert(add_ins.get_operand(1).is_int_constant())
+    assert_equal(42,add_ins.get_operand(1).get_int_constant_value())
+  end
+
+  def test_get_float_constant_values
+    circle_area = @m.get_function("circle_area")
+    assert(circle_area)
+    ins = circle_area.get_basic_block_list[0].get_instruction_list
+    add_ins = ins[0]
+    assert_equal(false,add_ins.get_operand(0).is_constant())
+    assert_equal(true,add_ins.get_operand(1).is_constant())
+    assert_equal(true,add_ins.get_operand(1).is_float_constant())
+    assert_in_delta(3.14159, add_ins.get_operand(1).get_float_constant_value(), 2 ** -20)
+  end
+
+end
+