[TIR] [Script] tir.buffer.vstore in script not found in prim_func.body

Questions
1

Here is my code:

@T.prim_func
def func(A:T.handle,B:T.handle, C:T.handle):
    a = T.match_buffer(A,shape=(16,), dtype="float32")
    b = T.match_buffer(B,shape=(16,), dtype="float32")
    c = T.match_buffer(C,shape=(16,), dtype="float32")
    for i in range(16//4):
        va = a.vload(i*4,"float32x4")
        vb = b.vload(i*4,"float32x4")
        vc = va + vb
        # c[i*4:i*4+4]=vc
        c.vstore(i*4,vc)

If I run

func.show()

Here is the output:

@T.prim_func
def main(a: T.Buffer((16,), "float32"), b: T.Buffer((16,), "float32"), c: T.Buffer((16,), "float32")):
    for i in range(4):
        va: T.float32x4 = a[i * 4:i * 4 + 4]
        vb: T.float32x4 = b[i * 4:i * 4 + 4]
        vc: T.float32x4 = va + vb
        T.evaluate(0)

We can see that the statement c.vstore is not in the body of prim_func!!!

Of course, we can write in another way like c[i4:i4+4]=vc.

My question is: if I use tir.buffer.vload in script, how to handle the problem of “vstore stmt not in prim_func’s body”?

2

It looks like the last expression be considered as a dead code, and because tvm doesn’t analyze whether vstore is going to change something internally, so it simplifies this expression, and by the way, I don’t know why you would do vectorize in this vstore way, you may have a look at sch.vectorize, I hope this can help.