Cheri-research/Toooba
1
0
Fork 0
Code Issues 1 Pull Requests Actions Packages Projects Releases Wiki Activity

FIFO optimisation both for build time (and possibly condition

Browse Source 
complexity?) and for throughput.
This commit is contained in:
jon
2020-08-13 17:33:46 +01:00
parent 4c74d27e4e
commit 96afb0a7f5
2 changed files with 36 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
src_Core/RISCY_OOO/procs/RV64G_OOO/FetchStage.bsv
View File

@@ -343,8 +343,9 @@ module mkFetchStage(FetchStage);
// Pipeline Stage FIFOs
Fifo#(2, Tuple2#(Bit#(TLog#(SupSizeX2)),Fetch1ToFetch2)) f12f2 <- mkCFFifo;
Fifo#(4, Tuple2#(Bit#(TLog#(SupSizeX2)),Fetch2ToFetch3)) f22f3 <- mkCFFifo; // FIFO should match I$ latency
SupFifo#(SupSizeX2, 3, Fetch3ToDecode) f32d <- mkSupFifo; // This fifo needs a capacity of 3 for full throughput. Unknown why.
SupFifo#(SupSize, 2, FromFetchStage) out_fifo <- mkSupFifo;
// These two fifos needs a capacity of 3 for full throughput if we fire only when we can enq on on channels.
SupFifo#(SupSizeX2, 3, Fetch3ToDecode) f32d <- mkUGSupFifo; // Unguarded to prevent the static analyser from exploding.
SupFifo#(SupSize, 3, FromFetchStage) out_fifo <- mkSupFifo;
// Can the fifo size be smaller?
// Branch Predictors

37
src_Core/RISCY_OOO/procs/lib/Fifos.bsv
View File

@@ -160,7 +160,7 @@ endinstance
// endfunction
// endinstance
module mkSupFifo(SupFifo#(k,n,t)) provisos (
module mkUGSupFifo(SupFifo#(k,n,t)) provisos (
Bits#(t,tSz),
FShow#(t),
Add#(TExp#(TLog#(k)), 0, k) // k must be power of 2
@@ -177,7 +177,7 @@ module mkSupFifo(SupFifo#(k,n,t)) provisos (
Bool can_enq = internalFifos[fifoIdx].notFull;
return (interface SupFifoEnq;
method Bool canEnq = can_enq;
method Action enq(t x) if(can_enq);
method Action enq(t x);
enqueueElement[i][0] <= tagged Valid x;
endmethod
endinterface);
@@ -188,10 +188,10 @@ module mkSupFifo(SupFifo#(k,n,t)) provisos (
Bool can_deq = internalFifos[fifoIdx].notEmpty;
return (interface SupFifoDeq;
method Bool canDeq = can_deq;
method t first if(can_deq);
method t first;
return internalFifos[fifoIdx].first;
endmethod
method Action deq if(can_deq);
method Action deq;
willDequeue[i][0] <= True;
endmethod
endinterface);
@@ -231,6 +231,35 @@ module mkSupFifo(SupFifo#(k,n,t)) provisos (
endmethod
endmodule
module mkSupFifo(SupFifo#(k,n,t)) provisos (
Bits#(t,tSz),
FShow#(t),
Add#(TExp#(TLog#(k)), 0, k) // k must be power of 2
);
SupFifo#(k,n,t) ugf <- mkUGSupFifo;
function SupFifoEnq#(t) getEnqIfc(Integer i);
return (interface SupFifoEnq;
method Bool canEnq = ugf.enqS[i].canEnq;
method Action enq(t x) if(ugf.enqS[i].canEnq) = ugf.enqS[i].enq(x);
endinterface);
endfunction
function SupFifoDeq#(t) getDeqIfc(Integer i);
return (interface SupFifoDeq;
method Bool canDeq = ugf.deqS[i].canDeq;
method t first if(ugf.deqS[i].canDeq) = ugf.deqS[i].first;
method Action deq if(ugf.deqS[i].canDeq) = ugf.deqS[i].deq;
endinterface);
endfunction
Vector#(k,Integer) indexes = genVector;
interface Vector enqS = map(getEnqIfc, indexes);
interface Vector deqS = map(getDeqIfc, indexes);
method Bool internalEmpty = ugf.internalEmpty;
endmodule
// A Conflict free implementation of n element FIFO