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Merge branch 'main' of github.com:ross144/cvw

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Ross Thompson 2023-02-13 18:54:07 -06:00
commit 094b307724
2 changed files with 15 additions and 11 deletions
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2
src/ifu/bpred/bpred.sv
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@ -107,7 +107,7 @@ module bpred (
end else if (`BPRED_TYPE == "BPSPECULATIVEGLOBAL") begin:Predictor
speculativeglobalhistory #(`BPRED_SIZE) DirPredictor(.clk, .reset, .StallF, .StallD, .StallE, .StallM, .StallW, .FlushD, .FlushE, .FlushM, .FlushW,
.DirPredictionF, .DirPredictionWrongE,
.PredInstrClassF, .InstrClassD, .InstrClassE, .WrongPredInstrClassD, .PCSrcE);
.PredInstrClassF, .InstrClassD, .InstrClassE, .InstrClassM, .WrongPredInstrClassD, .PCSrcE);
end else if (`BPRED_TYPE == "BPGSHARE") begin:Predictor
gshare #(`BPRED_SIZE) DirPredictor(.clk, .reset, .StallF, .StallD, .StallE, .StallM, .StallW, .FlushD, .FlushE, .FlushM, .FlushW,

24
src/ifu/bpred/speculativeglobalhistory.sv
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@ -1,5 +1,5 @@
///////////////////////////////////////////
// speculativeglobalhistory.sv
// gsharePredictor.sv
//
// Written: Shreya Sanghai
// Email: ssanghai@hmc.edu
@ -36,8 +36,9 @@ module speculativeglobalhistory #(parameter int k = 10 ) (
output logic [1:0] DirPredictionF,
output logic DirPredictionWrongE,
// update
input logic [3:0] InstrClassD, InstrClassE,
input logic [2:0] PredInstrClassF, WrongPredInstrClassD,
input logic [3:0] PredInstrClassF,
input logic [3:0] InstrClassD, InstrClassE, InstrClassM,
input logic [3:0] WrongPredInstrClassD,
input logic PCSrcE
);
@ -47,9 +48,9 @@ module speculativeglobalhistory #(parameter int k = 10 ) (
logic [1:0] TableDirPredictionF, DirPredictionD, DirPredictionE;
logic [1:0] NewDirPredictionE;
logic [k-1:0] GHRF, GHRD, GHRE;
logic [k-1:0] GHRF, GHRD, GHRE, GHRM;
logic GHRLastF;
logic [k-1:0] GHRNextF, GHRNextD, GHRNextE;
logic [k-1:0] GHRNextF, GHRNextD, GHRNextE, GHRNextM;
logic [k-1:0] IndexNextF, IndexF, IndexD, IndexE;
logic [1:0] ForwardNewDirPrediction, ForwardDirPredictionF;
@ -57,8 +58,8 @@ module speculativeglobalhistory #(parameter int k = 10 ) (
assign IndexNextF = GHRNextF;
assign IndexF = GHRF;
assign IndexD = GHRD[k-1:0];
assign IndexE = GHRE[k-1:0];
assign IndexD = GHRD;
assign IndexE = GHRE;
ram2p1r1wbe #(2**k, 2) PHT(.clk(clk),
.ce1(~StallF | reset), .ce2(~StallM & ~FlushM),
@ -111,15 +112,18 @@ module speculativeglobalhistory #(parameter int k = 10 ) (
// If it is wrong and branch does exist then shift right and insert the prediction.
// If the branch does not exist then shift left and use GHRLastF to restore the LSB.
logic [k-1:0] GHRClassWrong;
mux2 #(k) GHRClassWrongMux({DirPredictionD[1], GHRF[k-1:1]}, {GHRF[k-2:0], GHRLastF}, InstrClassD[0], GHRClassWrong);
mux2 #(k) GHRClassWrongMux({DirPredictionD[1], GHRF[k-1:1]}, {GHRF[k-2:0], GHRLastF}, ~InstrClassD[0], GHRClassWrong);
// As with GHRF FlushD and wrong direction prediction flushes the pipeline and restores to GHRNextE.
mux3 #(k) GHRDMux(GHRF, GHRClassWrong, GHRNextE, {FlushDOrDirWrong, WrongPredInstrClassD[0]}, GHRNextD);
flopenr #(k) GHRDReg(clk, reset, ~StallD | FlushDOrDirWrong, GHRNextD, GHRD);
mux3 #(k) GHREMux(GHRD, GHRE, {PCSrcE, GHRD[k-2:0]}, {InstrClassE[0] & ~FlushM, FlushE}, GHRNextE);
mux3 #(k) GHREMux(GHRD, GHRNextM, {PCSrcE, GHRD[k-2:0]}, {InstrClassE[0] & ~FlushM, FlushE}, GHRNextE);
flopenr #(k) GHREReg(clk, reset, ((InstrClassE[0] & ~FlushM) & ~StallE) | FlushE, GHRNextE, GHRE);
flopenr #(k) GHREReg(clk, reset, (~StallE) | FlushE, GHRNextE, GHRE);
assign GHRNextM = FlushM ? GHRM : GHRE;
flopenr #(k) GHRMReg(clk, reset, (InstrClassM[0] & ~StallM) | FlushM, GHRNextM, GHRM);
assign DirPredictionWrongE = PCSrcE != DirPredictionE[1] & InstrClassE[0];