diff --git a/lib/std/core/types.c3 b/lib/std/core/types.c3
index cbdb67657..70780643c 100644
--- a/lib/std/core/types.c3
+++ b/lib/std/core/types.c3
@@ -208,7 +208,7 @@ macro bool may_load_atomic($Type)
 }
 
 macro bool is_promotable_to_floatlike($Type) => types::is_floatlike($Type) || types::is_int($Type);
-
+macro bool is_promotable_to_float($Type) => types::is_float($Type) || types::is_int($Type);
 
 macro bool is_same_vector_type($Type1, $Type2)
 {
diff --git a/lib/std/core/values.c3 b/lib/std/core/values.c3
index 0daa86930..b6a054a46 100644
--- a/lib/std/core/values.c3
+++ b/lib/std/core/values.c3
@@ -8,6 +8,7 @@ macro bool @convertable_to(#a, #b) => $checks($typeof(#b) x = #a);
 macro bool @is_floatlike(#value) => types::is_floatlike($typeof(#value));
 macro bool @is_float(#value) => types::is_float($typeof(#value));
 macro bool @is_promotable_to_floatlike(#value) => types::is_promotable_to_floatlike($typeof(#value));
+macro bool @is_promotable_to_float(#value) => types::is_promotable_to_float($typeof(#value));
 macro bool @is_same_vector_type(#value1, #value2) => types::is_same_vector_type($typeof(#value1), $typeof(#value2));
 macro promote_int(x)
 {
diff --git a/lib/std/math/math.c3 b/lib/std/math/math.c3
index 307fc512c..23a2945d3 100644
--- a/lib/std/math/math.c3
+++ b/lib/std/math/math.c3
@@ -329,15 +329,31 @@ macro pow(x, exp)
 }
 
 /**
- * @require values::@is_float(a) : `The input must be floating type`
+ * @require values::@is_promotable_to_float(x) : `The input must be integer or floating type`
  **/
 macro frexp(x, int* e)
 {
-	$if (@typeis(x, float)):
-		return _frexpf(x, e);
-	$else:
-		return _frexp(x, e);
-	$endif;
+	$switch($typeof(x)):
+	$case float:
+	$case float16:
+		return _frexpf((float)x, e);
+	$default:
+		return _frexp((double)x, e);
+	$endswitch;
+}
+
+/**
+ * @require values::@is_promotable_to_float(x) : `The input must be integer or floating type`
+ **/
+macro int signbit(x)
+{
+	$switch($typeof(x)):
+	$case float:
+	$case float16:
+		return bitcast((float)x, uint) >> 31;
+	$default:
+		return (int)(bitcast((double)x, ulong) >> 63);
+	$endswitch;
 }
 
 /**
@@ -716,4 +732,4 @@ extern fn double _tan(double x) @extern("tan");
 extern fn float _tanf(float x) @extern("tanf");
 extern fn double _scalbn(double x, int n) @extern("scalbn");
 extern fn double _frexp(double x, int* e) @extern("frexp");
-extern fn float _frexpf(float x, int* e) @extern("frexp");
\ No newline at end of file
+extern fn float _frexpf(float x, int* e) @extern("frexpf");
\ No newline at end of file
diff --git a/test/unit/stdlib/math/frexp_signbit.c3 b/test/unit/stdlib/math/frexp_signbit.c3
new file mode 100644
index 000000000..7f6473e4b
--- /dev/null
+++ b/test/unit/stdlib/math/frexp_signbit.c3
@@ -0,0 +1,18 @@
+module std::math @test;
+
+fn void test_frexp()
+{
+	int a;
+	double z = math::frexp(231.23, &a);
+	assert((z - 0.903242187) < 0.0000001 && a == 8);
+	float z2 = math::frexp(231.23f, &a);
+	assert((z2 - 0.903242187) < 0.0000001 && a == 8);
+}
+
+fn void test_signbit()
+{
+	assert(math::signbit(-231.3) == 1);
+	assert(math::signbit(231.3) == 0);
+	assert(math::signbit(float.inf) == 0);
+	assert(math::signbit(-float.inf) == 1);
+}