feat: add UInt::reinterpret_as_float() (#1130)

moonbitlang · Oct 17, 2024 · e5edbd4 · e5edbd4
1 parent 6f91a8e
commit e5edbd4
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diff --git a/builtin/builtin.mbti b/builtin/builtin.mbti
@@ -493,6 +493,7 @@ impl UInt {
   op_shr(UInt, Int) -> UInt
   op_sub(UInt, UInt) -> UInt
   popcnt(UInt) -> Int
+  reinterpret_as_float(UInt) -> Float
   reinterpret_as_int(UInt) -> Int
   shl(UInt, Int) -> UInt //deprecated
   shr(UInt, Int) -> UInt //deprecated

diff --git a/builtin/intrinsics.mbt b/builtin/intrinsics.mbt
@@ -307,6 +307,8 @@ pub fn Int::to_float(self : Int) -> Float = "%i32.to_f32"
 
 pub fn Int::reinterpret_as_float(self : Int) -> Float = "%i32.to_f32_reinterpret"
 
+pub fn UInt::reinterpret_as_float(self : UInt) -> Float = "%i32.to_f32_reinterpret"
+
 pub fn Byte::to_float(self : Byte) -> Float = "%byte.to_f32"
 
 pub fn Double::to_float(self : Double) -> Float = "%f64.to_f32"

diff --git a/builtin/intrinsics_test.mbt b/builtin/intrinsics_test.mbt
@@ -412,3 +412,24 @@ test "Int::to_uint64 - Random Values" {
   inspect!(Int::to_uint64(1234567890), content="1234567890")
   inspect!(Int::to_uint64(-1234567890), content="18446744072474983726")
 }
+
+test "UInt::reinterpret_as_float roundtrip" {
+  let values = [
+    0x00000000U, // zero
+     0x80000000U, // negative zero
+     0x3F800000U, // 1.0
+     0xBF800000U, // -1.0
+     0x7F800000U, // positive infinity
+     0xFF800000U, // negative infinity
+     0x7FC00000U, // NaN
+     0x00800000U, // smallest positive normal float
+     0x7F7FFFFFU, // largest positive normal float
+     0x00000001U, // smallest positive subnormal float
+     0x007FFFFFU, // largest positive subnormal float
+  ]
+  for value in values {
+    let float_value = value.reinterpret_as_float()
+    let roundtrip_value = Float::reinterpret_as_uint(float_value)
+    assert_eq!(roundtrip_value, value)
+  }
+}