[MLIR][XeGPU] XeVM lowering support for load_matrix/store_matrix (#162780)
This PR adds lowering of xegpu.load_matrix/store_matrix to
xevm.blockload/blockstore or and llvm.load/store, depending on wi level
attributes.
It includes a few components:
1. adds wi-level attributes: subgroup_block_io.
2. expand load_matrix/store_matrix op definition to support scalar data
(besides vector data).
2. adds a member function to mem_desc to compute the linearized address
for a nd offsets.
3. add lowering depending on wi-level attributes:
a) if subgroup_block_io attribute presents, lower to
xevm.blockload/blockstore
c) else lower to llvm.load/store. If result is a vector, lower to
llvm.load/store with vector operand.
llvm-project
6cae29fb - [MLIR][XeGPU] XeVM lowering support for load_matrix/store_matrix (#162780)
