Layout Rewriting: Suggest-Index-Map

[junrushao]

No description provided.

[junrushao]

@jinhongyii Would love to have you review this algorithm. Thanks in advance!

[jinhongyii]

this function can't handle nested patterns like (i//4*2+j)//4. In this example, the iter map is like split(sum(split, ..., split))), so it will not throw error. The expected SplitExpr about i should be lower_factor = 8, but in your function it will have lower_factor =4

[jinhongyii]

@junrushao1994 I don't know why you modified tensorize-related functions. Is that a mistake?

[junrushao]

@jinhongyii tensorize related change is mainly formatting to help pass cpplint

[jinhongyii]

ok, I get it.

[junrushao]

@jinhongyii would you mind helping me drafting some unittests?

[jinhongyii]

test1.

normal input:

//shape: A[8, 256]
for i in range(0,32):
	for j in range(0,64):
		A[i//16*4+j//16, i%16*16+j%16]

expected output:

IndexMap{
	{x,y}, {x//4, y//16, x%4, y%16} 
}

test 2.

nested input

//shape: A[8]
for i in range(0,32):
	for j in range(0,2):
		A[ (j*8 + i//4)//4*2 + i//8%2]

expected output:

IndexMap{
	{x}, {x//2%2, x%2, x//4} 
}

test 3.

test bijective

//shape: A[8]
for j in range(0,2):
	for i in range(0,32):
		A[i%4*2+j]

expected output:

IndexMap{
	{x}, {x%2, x//2} 
}

Do they make sense to you?

[junrushao]

Thanks @jinhongyii! I will work on integrating into the unittests!

[jinhongyii]

buffer shape updated in the test.

[junrushao]

Per discussion with @jinhongyii, I'm going to merge this in and handle the nest case in a follow-up PR