CascadeFlowOp and ConfigureCascadeOp

[AndraBisca]

This PR adds two new operations to the AIE dialect, CascadeFlowOp and ConfigureCascadeOp.

CascadeFlowOp represents a cascade stream flow between the two input tiles. The op is used like in the example below:

module @test {
  aie.device(xcve2802) {
    %t13 = aie.tile(1, 3)
    %t23 = aie.tile(2, 3)
    aie.cascade_flow(%t13, %t23)
  }
}

Each CascadeFlowOp is lowered into a ConfigureCascadeOp which takes as input a tile, an input cascade direction and an output cascade direction. The input and output directions of the cascade for that tile are based on the relative positions of the tiles in the CascadeFlowOp. Unless specified otherwise, the default input and output directions for the cascade are North and South respectively. The lowering is implemented in AIELowerCascadeFlows.cpp and is called using aie-opt --aie-lower-cascade-flows <path to mlir code>. As an example, the code above lowers to:

module @test {
  aie.device(xcve2802) {
    %tile_1_3 = aie.tile(1, 3)
    %tile_2_3 = aie.tile(2, 3)
    aie.configure_cascade(%tile_1_3, North, East)
    aie.configure_cascade(%tile_2_3, West, South)
  }
}

Additionally, this PR adds a new configuration function, mlir_aie_configure_cascade, to AIETargetXAIEV2.cpp that generates libXAIE calls to XAie_CoreConfigAccumulatorControl for each ConfigureCascadeOp. This new target should be called from the host code at the beginning of execution to properly setup the registers for each tile. Similar configuration functions have been added to AIETargetCDODirect.cpp and AIETargetAirbin.cpp.

[AndraBisca]

Related to #517.

[github-actions]

Coverage Report

Created: 2024-02-19 15:45

Click here for information about interpreting this report.

Filename	Function Coverage	Line Coverage	Region Coverage	Branch Coverage
include/aie/Dialect/AIE/Transforms/AIEPasses.h	50.00%	50.00%	50.00%	-
lib/Dialect/AIE/IR/AIEDialect.cpp	90.91%	82.31%	84.83%	74.62%
lib/Dialect/AIE/Transforms/AIECoreToStandard.cpp	93.10%	77.52%	76.52%	61.96%
lib/Dialect/AIE/Transforms/AIELowerCascadeFlows.cpp	100.00%	93.55%	95.83%	93.75%
Totals	91.03%	81.62%	83.96%	73.51%

Generated by llvm-cov -- llvm version 14.0.0

[makslevental]

Is this not supported on IPU? Ie shouldn't CDODirect also be extended to support?

[AndraBisca]

Is this not supported on IPU? Ie shouldn't CDODirect also be extended to support?

Yes, it is. I'm working on modifying CDODirect.

[keryell]

Would it be possible to make clearer in the operation what is the input and what is the output. Perhaps if runing an LSP server knowing the dialect the IDE could display it as when the mouse is above it, but that does not seem super clear in other context, such as reading slides or random code samples. :-)

[makslevental]

Perhaps if runing an LSP server knowing the dialect

We don't have such functionality.

[denolf]

Looking great!