add tests for bit cast expressions

tests/behavior/success/bit_cast.bz

@@ -0,0 +1,203 @@
+function cast_test(consteval value, T: typename)
+{
+	consteval expected = __builtin_bit_cast(T, value);
+	let v = value;
+	if (__builtin_bit_cast(T, v) != expected) unreachable;
+}
+
+function int_cast_test()
+{
+	cast_test(42i8, int8);
+	cast_test(42i16, int16);
+	cast_test(42i32, int32);
+	cast_test(42i64, int64);
+
+	cast_test(-42i8, int8);
+	cast_test(-42i16, int16);
+	cast_test(-42i32, int32);
+	cast_test(-42i64, int64);
+
+	cast_test(42u8, uint8);
+	cast_test(42u16, uint16);
+	cast_test(42u32, uint32);
+	cast_test(42u64, uint64);
+
+	cast_test(42i8, uint8);
+	cast_test(42i16, uint16);
+	cast_test(42i32, uint32);
+	cast_test(42i64, uint64);
+
+	cast_test(-42i8, uint8);
+	cast_test(-42i16, uint16);
+	cast_test(-42i32, uint32);
+	cast_test(-42i64, uint64);
+
+	cast_test(42u8, int8);
+	cast_test(42u16, int16);
+	cast_test(42u32, int32);
+	cast_test(42u64, int64);
+
+	cast_test(123u32, char);
+	cast_test(123i32, char);
+	cast_test(-123i32, char);
+}
+
+function isnan = __builtin_isnan_f32;
+function isnan = __builtin_isnan_f64;
+
+function float_nan_cast_test(n, T: typename)
+{
+	let x = __builtin_bit_cast(T, n);
+	if (!isnan(x)) unreachable;
+	let new_n = __builtin_bit_cast(typeof n, x);
+	if (new_n != n) unreachable;
+}
+
+function float_cast_test()
+{
+	cast_test(0.0f32, uint32);
+	cast_test(0.0f64, uint64);
+	cast_test(-0.0f32, uint32);
+	cast_test(-0.0f64, uint64);
+	cast_test(42.0f32, uint32);
+	cast_test(42.0f64, uint64);
+	cast_test(-42.0f32, uint32);
+	cast_test(-42.0f64, uint64);
+	cast_test(12412.3523f32, uint32);
+	cast_test(12412.3523f64, uint64);
+	cast_test(-12412.3523f32, uint32);
+	cast_test(-12412.3523f64, uint64);
+
+	cast_test(0u32, float32); // 0.0
+	let n = 0u32;
+	let f = __builtin_bit_cast(float32, n);
+	if (f != 0.0f32) unreachable;
+	if (f != -0.0f32) unreachable;
+	let n = __builtin_bit_cast(uint32, f);
+	if (n != 0u32) unreachable;
+
+	cast_test(1u32 << 31, float32); // -0.0
+	let n = 1u32 << 31;
+	let f = __builtin_bit_cast(float32, n);
+	if (f != 0.0f32) unreachable;
+	if (f != -0.0f32) unreachable;
+	let n = __builtin_bit_cast(uint32, f);
+	if (n != (1u32 << 31)) unreachable;
+
+	cast_test(__builtin_bit_cast(uint32, 0.1f32), float32);
+	cast_test(__builtin_bit_cast(uint32, 123.123f32), float32);
+
+	cast_test(0x7f80'0000u32, float32); // inf
+	cast_test(0xff80'0000u32, float32); // -inf
+
+	float_nan_cast_test(0x7fc0'0000u32, float32);
+	float_nan_cast_test(0xffc0'0000u32, float32);
+	float_nan_cast_test(0x7f80'0100u32, float32);
+	float_nan_cast_test(0xff80'0100u32, float32);
+	float_nan_cast_test(0x7f80'0001u32, float32);
+	float_nan_cast_test(0xff80'0001u32, float32);
+	float_nan_cast_test(0x7f83'9836u32, float32);
+	float_nan_cast_test(0xff83'9836u32, float32);
+
+	cast_test(0u64, float64); // 0.0
+	let n = 0u64;
+	let f = __builtin_bit_cast(float64, n);
+	if (f != 0.0f64) unreachable;
+	if (f != -0.0f64) unreachable;
+	let n = __builtin_bit_cast(uint64, f);
+	if (n != 0u64) unreachable;
+
+	cast_test(1u64 << 31, float64); // -0.0
+	let n = 1u64 << 63;
+	let f = __builtin_bit_cast(float64, n);
+	if (f != 0.0f64) unreachable;
+	if (f != -0.0f64) unreachable;
+	let n = __builtin_bit_cast(uint64, f);
+	if (n != (1u64 << 63)) unreachable;
+
+	cast_test(__builtin_bit_cast(uint64, 0.1f64), float64);
+	cast_test(__builtin_bit_cast(uint64, 123.123f64), float64);
+
+	cast_test(0x7ff0'0000'0000'0000u64, float64); // inf
+	cast_test(0xfff0'0000'0000'0000u64, float64); // -inf
+
+	float_nan_cast_test(0x7ff8'0000'0000'0000u64, float64);
+	float_nan_cast_test(0xfff8'0000'0000'0000u64, float64);
+	float_nan_cast_test(0x7ff1'0000'0000'0000u64, float64);
+	float_nan_cast_test(0xfff1'0000'0000'0000u64, float64);
+	float_nan_cast_test(0x7ff0'0100'0000'0000u64, float64);
+	float_nan_cast_test(0xfff0'0100'0000'0000u64, float64);
+	float_nan_cast_test(0x7ff0'0001'0000'0000u64, float64);
+	float_nan_cast_test(0xfff0'0001'0000'0000u64, float64);
+	float_nan_cast_test(0x7ff0'0000'0100'0000u64, float64);
+	float_nan_cast_test(0xfff0'0000'0100'0000u64, float64);
+	float_nan_cast_test(0x7ff0'0000'0001'0000u64, float64);
+	float_nan_cast_test(0xfff0'0000'0001'0000u64, float64);
+	float_nan_cast_test(0x7ff0'0000'0000'0100u64, float64);
+	float_nan_cast_test(0xfff0'0000'0000'0100u64, float64);
+	float_nan_cast_test(0x7ff0'0000'0000'0001u64, float64);
+	float_nan_cast_test(0xfff0'0000'0000'0001u64, float64);
+	float_nan_cast_test(0x7ff6'2358'fac8'9dabu64, float64);
+	float_nan_cast_test(0xfff6'2358'fac8'9dabu64, float64);
+}
+
+function aggregate_to_int_test()
+{
+	consteval a: [4: uint8] = [ 0xaa, 0xbb, 0xcc, 0xdd ];
+	static_assert(__builtin_bit_cast(uint32, a) == 0xaabbccdd || __builtin_bit_cast(uint32, a) == 0xddccbbaa);
+	cast_test(a, uint32);
+
+	consteval a: [2: uint16] = [ 0xaabb, 0xccdd ];
+	cast_test(a, uint32);
+
+	consteval a: [1: uint32] = [ 0xaabbccdd ];
+	cast_test(a, uint32);
+
+	consteval t: [uint8, uint8, uint8, uint8] = [ 0xaa, 0xbb, 0xcc, 0xdd ];
+	cast_test(t, uint32);
+
+	consteval t: [uint8, uint8, uint16] = [ 0xaa, 0xbb, 0xccdd ];
+	cast_test(t, uint32);
+
+	consteval t: [float32, uint32] = [ 123.123f32, 42 ];
+	cast_test(t, uint64);
+}
+
+function aggregate_test()
+{
+	consteval a: [4: uint8] = [ 0xaa, 0xbb, 0xcc, 0xdd ];
+	cast_test(a, [2: uint16]);
+
+	consteval a: [4: uint8] = [ 0xaa, 0xbb, 0xcc, 0xdd ];
+	consteval expected = __builtin_bit_cast([uint8, uint16], a);
+	let a = a;
+	let t = __builtin_bit_cast([uint8, uint16], a);
+	if (t[0] != expected[0] || t[1] != expected[1]) unreachable;
+
+	consteval a: [2: uint32] = [ 0x00112233, 0x44556677 ];
+	consteval expected = __builtin_bit_cast([float32, uint16, uint8, uint8], a);
+	let a = a;
+	let t = __builtin_bit_cast([float32, uint16, uint8, uint8], a);
+	if (t[0] != expected[0] || t[1] != expected[1] || t[2] != expected[2]) unreachable;
+
+	consteval t: [uint32, uint64, float32, float64] = [ 123, 456, 42.42f32, 42.42f64 ];
+	consteval expected = __builtin_bit_cast([uint16, float64, uint8, uint8, uint16, uint64], t);
+	let t = t;
+	let t = __builtin_bit_cast([uint16, float64, uint8, uint8, uint16, uint64], t);
+	if (
+		t[0] != expected[0]
+		|| t[1] != expected[1]
+		|| t[2] != expected[2]
+		|| t[3] != expected[3]
+		|| t[4] != expected[4]
+		|| t[5] != expected[5]
+	) unreachable;
+}
+
+function main()
+{
+	int_cast_test();
+	float_cast_test();
+	aggregate_to_int_test();
+	aggregate_test();
+}