[Buffer Placement] Add CFDFC Extraction and throughput resutls as attributes of handshake dialect

[qianxu1998]

This PR adds two attributes for the handshake dialect to store the CFDFC extraction and throughput results during the buffer placement pass.

The following two dictionary attributes are defined in HandshakeAttributes.td:

• CFDFCToBBListAttr : Holds a map from CFDFC index to the corresponding list of BB indices. For example {"0" : [1, 2], "1" : [3, 4, 5]}, means CFDFC 0 contains BB 1 and BB 2, and CFDFC 1 contains BB 3, BB 4 and BB 5.

• CFDFCThroughputAttr : Holds a map from CFDFC index to the corresponding throughput value (floating value). For example, {"0" : 0.5, "1": 0.25}. This means CFDFC 0 has a throughput of 0.5 and CFDFC 1 has a throughput of 0.25.

  Buffer placement pass is changed accordingly to add those two attributes directly in the funcop. CFDFCToBBListAttr is named as handshake.cfdfc and CFDFCThroughputAttr is named as handshake.tp. Taking fir as an example, after adding the two attributes the top of the generated handshake_buffered.mlir looks like:

  module {
  handshake.func @fir(%arg0: memref<1000xi32>, %arg1: memref<1000xi32>, %arg2: none, ...) -> i32 attributes {argNames = ["di", "idx", "start"], handshake.cfdfc = #handshake<cfdfcToBBList {"0" = [1 : ui32]}>, handshake.tp = #handshake<cfdfcThroughput {"0" = 5.000000e-01 : f64}>, resNames = ["out0"]} {
  ...
  }}

[Jiahui17]

I did the following:

--- info.funcOp->setAttr("handshake.cfdfc", cfdfcMap);
+++ setUniqueAttr(info.funcOp, cfdfcMap);

This makes it easier to retrieve the value later like the following:

DictionaryAttr dicAttr =
    getUniqueAttr<handshake::CFDFCThroughputAttr>(funcOp)
        .getThroughputMap();
for (const NamedAttribute attr : dicAttr) {
  StringRef cfId = attr.getName();
  FloatAttr cfThroughput = llvm::dyn_cast<FloatAttr>(attr.getValue());
  llvm::errs() << "CFDFC " << cfId << "=" << cfThroughput.getValueAsDouble() << "\n";
}

Otherwise, we need to remember that there is an attribute called "handshake.cfdfc". But here we can get it as a unique attribute.