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LibWasm: Properly check for indeterminate NaNs in SIMD tests
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Because `nan:arithmetic` and `nan:canonical` aren't bound to a single
bit pattern, we cannot check against a float-containing SIMD vector
against a single value in the tests. Now, we represent `v128`s as
`TypedArray`s in `testjs` (as opposed to using `BigInt`s), allowing us
to properly check `NaN` bit patterns.
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@dzfrias @alimpfard
dzfrias authored and alimpfard committed Jul 12, 2024
1 parent 524e09d commit 906fa04
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Showing 2 changed files with 127 additions and 50 deletions.
93 changes: 62 additions & 31 deletions Meta/generate-libwasm-spec-test.py
View file
Original file line number Diff line number Diff line change
Expand Up @@ -16,11 +16,20 @@ class GenerateException(Exception):


@dataclass
class WasmValue:
kind: Literal["i32", "i64", "f32", "f64", "externref", "funcref", "v128"]
class WasmPrimitiveValue:
kind: Literal["i32", "i64", "f32", "f64", "externref", "funcref"]
value: str


@dataclass
class WasmVector:
lanes: list[str]
num_bits: int


WasmValue = Union[WasmPrimitiveValue, WasmVector]


@dataclass
class ModuleCommand:
line: int
Expand Down Expand Up @@ -98,7 +107,13 @@ class CanonicalNan:
num_bits: int


GeneratedValue = Union[str, ArithmeticNan, CanonicalNan]
@dataclass
class GeneratedVector:
repr: str
num_bits: int


GeneratedValue = Union[str, ArithmeticNan, CanonicalNan, GeneratedVector]


@dataclass
Expand All @@ -117,33 +132,14 @@ def parse_value(arg: dict[str, str]) -> WasmValue:
type_ = arg["type"]
match type_:
case "i32" | "i64" | "f32" | "f64" | "externref" | "funcref":
payload = arg["value"]
return WasmPrimitiveValue(type_, arg["value"])
case "v128":

def reverse_endianness(hex_str):
if len(hex_str) % 2 != 0:
hex_str = "0" + hex_str
bytes_list = [hex_str[i:i + 2] for i in range(0, len(hex_str), 2)]
reversed_hex_str = "".join(bytes_list[::-1])
return reversed_hex_str

size = int(arg["lane_type"][1:]) // 4
parts = []
for raw_val in arg["value"]:
match raw_val:
case "nan:canonical":
hex_repr = "7fc".ljust(size, "0")
case "nan:arithmetic":
hex_repr = "7ff".ljust(size, "0")
case "nan:signaling":
hex_repr = "7ff8".ljust(size, "0")
case _:
hex_repr = hex(int(raw_val))[2:].zfill(size)
parts.append(hex_repr)
payload = "0x" + reverse_endianness("".join(reversed(parts))) + "n"
if not isinstance(arg["value"], list):
raise ParseException("Got unknown type for Wasm value")
num_bits = int(arg["lane_type"][1:])
return WasmVector(arg["value"], num_bits)
case _:
raise ParseException(f"Unknown value type: {type_}")
return WasmValue(type_, payload)


def parse_args(raw_args: list[dict[str, str]]) -> list[WasmValue]:
Expand Down Expand Up @@ -212,7 +208,19 @@ def make_description(input_path: Path, name: str, out_path: Path) -> WastDescrip
return parse(description)


def gen_vector(vec: WasmVector, *, array=False) -> str:
addition = "n" if vec.num_bits == 64 else ""
vals = ", ".join(v + addition if v.isdigit() else f'"{v}"' for v in vec.lanes)
if not array:
type_ = "BigUint64Array" if vec.num_bits == 64 else f"Uint{vec.num_bits}Array"
return f"new {type_}([{vals}])"
return f"[{vals}]"


def gen_value_arg(value: WasmValue) -> str:
if isinstance(value, WasmVector):
return gen_vector(value)

def unsigned_to_signed(uint: int, bits: int) -> int:
max_value = 2**bits
if uint >= 2 ** (bits - 1):
Expand Down Expand Up @@ -263,6 +271,9 @@ def float_to_str(bits: int, *, double=False) -> str:


def gen_value_result(value: WasmValue) -> GeneratedValue:
if isinstance(value, WasmVector):
return GeneratedVector(gen_vector(value, array=True), value.num_bits)

if (value.kind == "f32" or value.kind == "f64") and value.value.startswith("nan"):
num_bits = int(value.kind[1:])
match value.value:
Expand Down Expand Up @@ -319,6 +330,12 @@ def gen_invalid(invalid: AssertInvalid, ctx: Context):
)


def gen_pretty_expect(expr: str, got: str, expect: str):
print(
f"if (!{expr}) {{ expect().fail(`Failed with ${{{got}}}, expected {expect}`); }}"
)


def gen_invoke(
line: int,
invoke: Invoke,
Expand Down Expand Up @@ -352,12 +369,26 @@ def gen_invoke(
case str():
print(f"expect(_result).toBe({gen_result});")
case ArithmeticNan():
print(
f"expect(isArithmeticNaN{gen_result.num_bits}(_result)).toBe(true);"
gen_pretty_expect(
f"isArithmeticNaN{gen_result.num_bits}(_result)",
"_result",
"nan:arithmetic",
)
case CanonicalNan():
print(
f"expect(isCanonicalNaN{gen_result.num_bits}(_result)).toBe(true);"
gen_pretty_expect(
f"isCanonicalNaN{gen_result.num_bits}(_result)",
"_result",
"nan:canonical",
)
case GeneratedVector():
if gen_result.num_bits == 64:
array = "new BigUint64Array(_result)"
else:
array = f"new Uint{gen_result.num_bits}Array(_result)"
gen_pretty_expect(
f"testSIMDVector({gen_result.repr}, {array})",
array,
gen_result.repr,
)
print("});")
if not ctx.has_unclosed:
Expand Down
84 changes: 65 additions & 19 deletions Tests/LibWasm/test-wasm.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -199,16 +199,26 @@ TESTJS_GLOBAL_FUNCTION(compare_typed_arrays, compareTypedArrays)
return JS::Value(lhs_array.viewed_array_buffer()->buffer() == rhs_array.viewed_array_buffer()->buffer());
}

bool _is_canonical_nan32(u32 value)
{
return value == 0x7FC00000 || value == 0xFFC00000;
}

bool _is_canonical_nan64(u64 value)
{
return value == 0x7FF8000000000000 || value == 0xFFF8000000000000;
}

TESTJS_GLOBAL_FUNCTION(is_canonical_nan32, isCanonicalNaN32)
{
auto value = TRY(vm.argument(0).to_u32(vm));
return value == 0x7FC00000 || value == 0xFFC00000;
return _is_canonical_nan32(value);
}

TESTJS_GLOBAL_FUNCTION(is_canonical_nan64, isCanonicalNaN64)
{
auto value = TRY(vm.argument(0).to_bigint_uint64(vm));
return value == 0x7FF8000000000000 || value == 0xFFF8000000000000;
return _is_canonical_nan64(value);
}

TESTJS_GLOBAL_FUNCTION(is_arithmetic_nan32, isArithmeticNaN32)
Expand All @@ -223,6 +233,47 @@ TESTJS_GLOBAL_FUNCTION(is_arithmetic_nan64, isArithmeticNaN64)
return isnan(value);
}

TESTJS_GLOBAL_FUNCTION(test_simd_vector, testSIMDVector)
{
auto expected = TRY(vm.argument(0).to_object(vm));
if (!is<JS::Array>(*expected))
return vm.throw_completion<JS::TypeError>("Expected an Array"sv);
auto& expected_array = static_cast<JS::Array&>(*expected);
auto got = TRY(vm.argument(1).to_object(vm));
if (!is<JS::TypedArrayBase>(*got))
return vm.throw_completion<JS::TypeError>("Expected a TypedArray"sv);
auto& got_array = static_cast<JS::TypedArrayBase&>(*got);
auto element_size = 128 / TRY(TRY(expected_array.get("length")).to_u32(vm));
size_t i = 0;
for (auto it = expected_array.indexed_properties().begin(false); it != expected_array.indexed_properties().end(); ++it) {
auto got_value = TRY(got_array.get(i++));
u64 got = got_value.is_bigint() ? TRY(got_value.to_bigint_uint64(vm)) : (u64)TRY(got_value.to_index(vm));
auto expect = TRY(expected_array.get(it.index()));
if (expect.is_string()) {
if (element_size != 32 && element_size != 64)
return vm.throw_completion<JS::TypeError>("Expected element of size 32 or 64"sv);
auto string = expect.as_string().utf8_string();
if (string == "nan:canonical") {
auto is_canonical = element_size == 32 ? _is_canonical_nan32(got) : _is_canonical_nan64(got);
if (!is_canonical)
return false;
continue;
}
if (string == "nan:arithmetic") {
auto is_arithmetic = element_size == 32 ? isnan(bit_cast<float>((u32)got)) : isnan(bit_cast<double>((u64)got));
if (!is_arithmetic)
return false;
continue;
}
return vm.throw_completion<JS::TypeError>(ByteString::formatted("Bad SIMD float expectation: {}"sv, string));
}
u64 expect_value = expect.is_bigint() ? TRY(expect.to_bigint_uint64(vm)) : (u64)TRY(expect.to_index(vm));
if (got != expect_value)
return false;
}
return true;
}

void WebAssemblyModule::initialize(JS::Realm& realm)
{
Base::initialize(realm);
Expand Down Expand Up @@ -281,7 +332,7 @@ JS_DEFINE_NATIVE_FUNCTION(WebAssemblyModule::wasm_invoke)
for (auto& param : type->parameters()) {
auto argument = vm.argument(index++);
double double_value = 0;
if (!argument.is_bigint())
if (!argument.is_bigint() && !argument.is_object())
double_value = TRY(argument.to_double(vm));
switch (param.kind()) {
case Wasm::ValueType::Kind::I32:
Expand All @@ -307,21 +358,14 @@ JS_DEFINE_NATIVE_FUNCTION(WebAssemblyModule::wasm_invoke)
}
break;
case Wasm::ValueType::Kind::V128: {
if (!argument.is_bigint()) {
if (argument.is_number())
argument = JS::BigInt::create(vm, Crypto::SignedBigInteger { TRY(argument.to_double(vm)) });
else
argument = TRY(argument.to_bigint(vm));
}

auto object = MUST(argument.to_object(vm));
if (!is<JS::TypedArrayBase>(*object))
return vm.throw_completion<JS::TypeError>("Expected typed array"sv);
auto& array = static_cast<JS::TypedArrayBase&>(*object);
u128 bits = 0;
auto bytes = argument.as_bigint().big_integer().unsigned_value().export_data({ bit_cast<u8*>(&bits), sizeof(bits) });
VERIFY(!argument.as_bigint().big_integer().is_negative());

if constexpr (AK::HostIsLittleEndian)
arguments.append(Wasm::Value(bits << (128 - bytes * 8)));
else
arguments.append(Wasm::Value(bits >> (128 - bytes * 8)));
auto* ptr = bit_cast<u8*>(&bits);
memcpy(ptr, array.viewed_array_buffer()->buffer().data(), 16);
arguments.append(Wasm::Value(bits));
break;
}
case Wasm::ValueType::Kind::FunctionReference:
Expand Down Expand Up @@ -359,8 +403,10 @@ JS_DEFINE_NATIVE_FUNCTION(WebAssemblyModule::wasm_invoke)
[](i32 value) { return JS::Value(static_cast<double>(value)); },
[&](i64 value) { return JS::Value(JS::BigInt::create(vm, Crypto::SignedBigInteger { value })); },
[&](u128 value) {
auto unsigned_bigint_value = Crypto::UnsignedBigInteger::import_data(bit_cast<u8 const*>(&value), sizeof(value));
return JS::Value(JS::BigInt::create(vm, Crypto::SignedBigInteger(move(unsigned_bigint_value), false)));
// FIXME: remove the MUST here
auto buf = MUST(JS::ArrayBuffer::create(*vm.current_realm(), 16));
memcpy(buf->buffer().data(), value.bytes().data(), 16);
return JS::Value(buf);
},
[](Wasm::Reference const& reference) {
return reference.ref().visit(
Expand Down

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