A new Python DSL frontend for LuisaCompute. Will be integrated into LuisaCompute python package once it's ready.
import luisa_lang as lcFunctions are defined using the @lc.func decorator. The function body can contain any valid LuisaCompute code. You can also include normal Python code that will be executed at DSL comile time using lc.constexpr(). (See Metaprogramming for more details)
@lc.func
def add(a: lc.float, b: lc.float) -> lc.float:
with lc.constexpr():
print('compiliing add function')
return a + bLuisaCompute uses value semantics, which means that all types are passed by value. You can use inout to indicate that a variable can be modified in place.
@luisa.func(a=inout, b=inout)
def swap(a: int, b: int):
a, b = b, a@lc.struct
class Sphere:
center: lc.float3
radius: lc.floatT = TypeVar('T', bound=Any)
@lc.func
def add(a: T, b: T) -> T:
return a + bluisa_lang provides a metaprogramming feature similar to C++ that allows users to generate code at compile time.
# Compile time reflection
@lc.func
def get_x_or_zero(x: Any):
t = lc.constexpr(type(x))
if lc.constexpr(hasattr(t, 'x')):
return x.x
else:
return 0.0
# Lambdas/Function objects
F = TypeVar('F', bound=Callable) # TypeVar bounds facilliatate type inference in Mypy etc. but are not strictly necessary
T = TypeVar('T', bound=Any)
@lc.func
def apply_func(f: F, x: T):
return f(x)
# Generate code at compile time
@lc.func
def call_n_times(f: F):
with lc.constexpr():
n = input('how many times to call?')
for i in range(n):
# lc.embed_code(expr) will generate add expr to the DSL code
lc.embed_code(apply_func(f, i))
# or
lc.embed_code('apply_func(f, i)')
# Hint a parameter is constexpr
@lc.func(n=lc.constexpr) # without this, n will be treated as a runtime variable and result in an error
def pow(x: lc.float, n: int) -> lc.float:
p = 1.0
with lc.constexpr():
for _ in range(n):
lc.embed_code('p *= x')- Lambda and nested function do not support updating nonlocal variables.
- All DSL types have value semantics, which means they are copied when passed around.
lc.embed_codecannot be used to generate a new variable that is referenced in later code. Declare the variable withAnytype prior to usinglc.embed_code.lc.structcan only be used at the top level of a module.
It is possible to retarget luisa_lang to serve as another DSL. For example, one may want to use it as a customized shader language different from what LuisaCompute provides, or use it to generate customized C++/CUDA source. In this case, one can use the standalone compiler to compile the luisa_lang code into a standalone shader file.