Addresses: https://github.com/llvm/llvm-project/issues/115653
We already have utilities to flatten memrefs into 1-D. This change makes
memref flattening a prerequisite for vector narrow type emulation,
ensuring that emulation patterns only need to handle 1-D scenarios.
These are identified by misc-include-cleaner. I've filtered out those
that break builds. Also, I'm staying away from llvm-config.h,
config.h, and Compiler.h, which likely cause platform- or
compiler-specific build failures.
To add a transformation that simplifies memory access patterns, this PR
adds a memref linearizer which is based on the GPU/DecomposeMemRefs
pass, with the following changes:
* support vector dialect ops
* instead of decompose memrefs to rank-0 memrefs, flatten higher-ranked
memrefs to rank-1.
Notes:
* After the linearization, a MemRef's offset is kept, so a
`memref<4x8xf32, strided<[8, 1], offset: 100>>` becomes `memref<32xf32,
strided<[1], offset: 100>>`.
* It also works with dynamic shapes and strides and offsets (see test
cases for details).
* The shape of the casted memref is computed as 1d, flattened.
