vmois Posts - Answer Overflow

vmois

•Created by vmois on 3/29/2024 in #questions

When do you plan to open-source "algorithms" module?

At this moment, "algorithms" module is not available yet in the open-sourced code (source). Do you have an approximate plan when it will be open-sourced? For example, being able to extend sort to work with strings would be an amazing thing. Thank you.

1 replies

MModular

•Created by vmois on 12/30/2023 in #questions

Owned convention does not destroy variable after transferring ownership

Hello everybody! I am working on a project that has a small exercises to learn Mojo. Currently, I am working on value ownership section and was playing with a code below.

# TASK
# Make file compile with no errors

# I AM NOT DONE

fn take_ptr(owned array: Pointer[Int]):
    array.store(2, 23)


fn main():
    # this line just allocates pointer for 3 integers
    var array = Pointer[Int].alloc(3)

    array.store(0, 1)
    array.store(1, 2)

    # this function call does not need any changes
    take_ptr(array^)

    array.store(2, 2)
    print(array[2])

# TASK
# Make file compile with no errors

# I AM NOT DONE

fn take_ptr(owned array: Pointer[Int]):
    array.store(2, 23)


fn main():
    # this line just allocates pointer for 3 integers
    var array = Pointer[Int].alloc(3)

    array.store(0, 1)
    array.store(1, 2)

    # this function call does not need any changes
    take_ptr(array^)

    array.store(2, 2)
    print(array[2])

The issue I have is that this code compiles but to my understanding of owned and ownership operator it shouldn't. If you take equivalent code for string, it has an error "a is not initialized":

fn take_text(owned text: String):
    text += "🔥"
    return text


fn main():
    var a: String = "mojo"

    take_text(a^)
    print(a)

fn take_text(owned text: String):
    text += "🔥"
    return text


fn main():
    var a: String = "mojo"

    take_text(a^)
    print(a)

For equivalent integer code:

fn take_value(owned x: Int):
    x += 2


fn main():
    var x: Int = 1
    take_value(x^)
    print(x)

fn take_value(owned x: Int):
    x += 2


fn main():
    var x: Int = 1
    take_value(x^)
    print(x)

It throws no error, and value of x is 1. Can someone please explain if this behaviour is correct or am I missing something? Thank you.

5 replies

MModular

•Created by vmois on 10/22/2023 in #questions

SIMD produces weird results without print statement at the end

The code below produces weird results:

from algorithm import vectorize
from tensor import Tensor

alias type = DType.int64
alias nelts = simdwidthof[type]()

def main():
    let size = 10
    var a = Tensor[type](size)
    var b = Tensor[type](size)
    var c = Tensor[type](size)

    for i in range(size):
        a[i] = i + 1
        b[i] = i
    
    @parameter
    fn diff[nelts : Int](x : Int):
        #print(a.simd_load[nelts](x))
        c.simd_store[nelts](x, a.simd_load[nelts](x) - b.simd_load[nelts](x))
        #print(nelts, x)
    vectorize[nelts, diff](size)

    for i in range(size):
        print(c[i])

    #print(a.simd_load[nelts](0))

from algorithm import vectorize
from tensor import Tensor

alias type = DType.int64
alias nelts = simdwidthof[type]()

def main():
    let size = 10
    var a = Tensor[type](size)
    var b = Tensor[type](size)
    var c = Tensor[type](size)

    for i in range(size):
        a[i] = i + 1
        b[i] = i
    
    @parameter
    fn diff[nelts : Int](x : Int):
        #print(a.simd_load[nelts](x))
        c.simd_store[nelts](x, a.simd_load[nelts](x) - b.simd_load[nelts](x))
        #print(nelts, x)
    vectorize[nelts, diff](size)

    for i in range(size):
        print(c[i])

    #print(a.simd_load[nelts](0))

For example:

2305843009213693952
4611686018780248321
3
1
1
1
1
1
1
1407374883553281

2305843009213693952
4611686018780248321
3
1
1
1
1
1
1
1407374883553281

If I uncomment last print statement, suddenly results are correct:

Can someone please explain this behaviour? Am I doing something wrong with SIMD?

24 replies

MModular

•Created by vmois on 9/12/2023 in #questions

Add documentation for Runtime

In a Mandelbrot notebook, we have seen examples of using Runtime, but as for now there is no documentations about arguments, use cases, etc. Any plans to provide more information? Thank you.

2 replies

Gaming

Programming