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

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Ross Thompson 2023-02-15 11:28:50 -06:00
commit 9c7339694b
7 changed files with 59 additions and 57 deletions
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7
src/ifu/bpred/RASPredictor.sv
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@ -33,10 +33,10 @@ module RASPredictor #(parameter int StackSize = 16 )(
input logic clk, input logic clk,
input logic reset, input logic reset,
input logic StallF, StallD, StallE, StallM, FlushD, FlushE, FlushM, input logic StallF, StallD, StallE, StallM, FlushD, FlushE, FlushM,
input logic [2:0] WrongPredInstrClassD, // Prediction class is wrong input logic [3:0] WrongPredInstrClassD, // Prediction class is wrong
input logic [3:0] InstrClassD, input logic [3:0] InstrClassD,
input logic [3:0] InstrClassE, // Instr class input logic [3:0] InstrClassE, // Instr class
input logic [2:0] PredInstrClassF, input logic [3:0] PredInstrClassF,
input logic [`XLEN-1:0] PCLinkE, // PC of instruction after a jal input logic [`XLEN-1:0] PCLinkE, // PC of instruction after a jal
output logic [`XLEN-1:0] RASPCF // Top of the stack output logic [`XLEN-1:0] RASPCF // Top of the stack
); );
@ -95,6 +95,3 @@ module RASPredictor #(parameter int StackSize = 16 )(
endmodule endmodule

31
src/ifu/bpred/bpred.sv
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@ -72,11 +72,10 @@ module bpred (
logic PredValidF; logic PredValidF;
logic [1:0] DirPredictionF; logic [1:0] DirPredictionF;
logic [2:0] BTBPredInstrClassF, PredInstrClassF, PredInstrClassD; logic [3:0] BTBPredInstrClassF, PredInstrClassF, PredInstrClassD, PredInstrClassE;
logic [`XLEN-1:0] PredPCF, RASPCF; logic [`XLEN-1:0] PredPCF, RASPCF;
logic PredictionPCWrongE; logic PredictionPCWrongE;
logic AnyWrongPredInstrClassD, AnyWrongPredInstrClassE; logic AnyWrongPredInstrClassD, AnyWrongPredInstrClassE;
logic [2:0] InstrClassF;
logic [3:0] InstrClassD; logic [3:0] InstrClassD;
logic [3:0] InstrClassE; logic [3:0] InstrClassE;
logic DirPredictionWrongE, BTBPredPCWrongE, RASPredPCWrongE; logic DirPredictionWrongE, BTBPredPCWrongE, RASPredPCWrongE;
@ -85,7 +84,7 @@ module bpred (
logic [`XLEN-1:0] BPPredPCF; logic [`XLEN-1:0] BPPredPCF;
logic [`XLEN-1:0] PCNext0F; logic [`XLEN-1:0] PCNext0F;
logic [`XLEN-1:0] PCCorrectE; logic [`XLEN-1:0] PCCorrectE;
logic [2:0] WrongPredInstrClassD; logic [3:0] WrongPredInstrClassD;
logic BTBTargetWrongE; logic BTBTargetWrongE;
logic RASTargetWrongE; logic RASTargetWrongE;
@ -108,17 +107,17 @@ module bpred (
end else if (`BPRED_TYPE == "BPSPECULATIVEGLOBAL") begin:Predictor end else if (`BPRED_TYPE == "BPSPECULATIVEGLOBAL") begin:Predictor
speculativeglobalhistory #(`BPRED_SIZE) DirPredictor(.clk, .reset, .StallF, .StallD, .StallE, .StallM, .StallW, .FlushD, .FlushE, .FlushM, .FlushW, speculativeglobalhistory #(`BPRED_SIZE) DirPredictor(.clk, .reset, .StallF, .StallD, .StallE, .StallM, .StallW, .FlushD, .FlushE, .FlushM, .FlushW,
.DirPredictionF, .DirPredictionWrongE, .DirPredictionF, .DirPredictionWrongE,
.PredInstrClassF, .InstrClassD, .InstrClassE, .WrongPredInstrClassD, .PCSrcE); .PredInstrClassF, .InstrClassD, .InstrClassE, .InstrClassM, .WrongPredInstrClassD, .PCSrcE);
end else if (`BPRED_TYPE == "BPGSHARE") begin:Predictor end else if (`BPRED_TYPE == "BPGSHARE") begin:Predictor
gshare #(`BPRED_SIZE) DirPredictor(.clk, .reset, .StallF, .StallD, .StallE, .StallM, .FlushD, .FlushE, .FlushM, gshare #(`BPRED_SIZE) DirPredictor(.clk, .reset, .StallF, .StallD, .StallE, .StallM, .StallW, .FlushD, .FlushE, .FlushM, .FlushW,
.PCNextF, .PCE, .DirPredictionF, .DirPredictionWrongE, .PCNextF, .PCM, .DirPredictionF, .DirPredictionWrongE,
.BranchInstrE(InstrClassE[0]), .BranchInstrM(InstrClassM[0]), .PCSrcE); .BranchInstrE(InstrClassE[0]), .BranchInstrM(InstrClassM[0]), .PCSrcE);
end else if (`BPRED_TYPE == "BPSPECULATIVEGSHARE") begin:Predictor end else if (`BPRED_TYPE == "BPSPECULATIVEGSHARE") begin:Predictor
speculativegshare #(`BPRED_SIZE) DirPredictor(.clk, .reset, .StallF, .StallD, .StallE, .StallM, .StallW, .FlushD, .FlushE, .FlushM, .FlushW, speculativegshare #(`BPRED_SIZE) DirPredictor(.clk, .reset, .StallF, .StallD, .StallE, .StallM, .StallW, .FlushD, .FlushE, .FlushM, .FlushW,
.PCNextF, .PCF, .PCD, .PCE, .DirPredictionF, .DirPredictionWrongE, .PCNextF, .PCF, .PCD, .PCE, .DirPredictionF, .DirPredictionWrongE,
.PredInstrClassF, .InstrClassD, .InstrClassE, .WrongPredInstrClassD, .PCSrcE); .PredInstrClassF, .InstrClassD, .InstrClassE, .InstrClassM, .WrongPredInstrClassD, .PCSrcE);
end else if (`BPRED_TYPE == "BPLOCALPAg") begin:Predictor end else if (`BPRED_TYPE == "BPLOCALPAg") begin:Predictor
// *** Fix me // *** Fix me
@ -151,7 +150,7 @@ module bpred (
// the branch predictor needs a compact decoding of the instruction class. // the branch predictor needs a compact decoding of the instruction class.
if (`INSTR_CLASS_PRED == 0) begin : DirectClassDecode if (`INSTR_CLASS_PRED == 0) begin : DirectClassDecode
logic [4:0] CompressedOpcF; logic [4:0] CompressedOpcF;
logic [2:0] InstrClassF; logic [3:0] InstrClassF;
logic cjal, cj, cjr, cjalr, CJumpF, CBranchF; logic cjal, cj, cjr, cjalr, CJumpF, CBranchF;
logic JumpF, BranchF; logic JumpF, BranchF;
@ -172,9 +171,8 @@ module bpred (
assign InstrClassF[2] = (JumpF & (PostSpillInstrRawF[19:15] & 5'h1B) == 5'h01) | // return must return to ra or r5 assign InstrClassF[2] = (JumpF & (PostSpillInstrRawF[19:15] & 5'h1B) == 5'h01) | // return must return to ra or r5
(`C_SUPPORTED & (cjalr | cjr) & ((PostSpillInstrRawF[11:7] & 5'h1B) == 5'h01)); (`C_SUPPORTED & (cjalr | cjr) & ((PostSpillInstrRawF[11:7] & 5'h1B) == 5'h01));
//assign InstrClassF[3] = (JumpF & (PostSpillInstrRawF[11:07] & 5'h1B) == 5'h01) | // jal(r) must link to ra or x5 assign InstrClassF[3] = (JumpF & (PostSpillInstrRawF[11:07] & 5'h1B) == 5'h01) | // jal(r) must link to ra or x5
// (`C_SUPPORTED & (cjal | (cjalr & (PostSpillInstrRawF[11:7] & 5'h1b) == 5'h01))); (`C_SUPPORTED & (cjal | (cjalr & (PostSpillInstrRawF[11:7] & 5'h1b) == 5'h01)));
assign PredInstrClassF = InstrClassF; assign PredInstrClassF = InstrClassF;
assign SelBPPredF = (PredInstrClassF[0] & DirPredictionF[1]) | assign SelBPPredF = (PredInstrClassF[0] & DirPredictionF[1]) |
@ -196,8 +194,6 @@ module bpred (
assign InstrClassD[1] = JumpD ; assign InstrClassD[1] = JumpD ;
assign InstrClassD[2] = JumpD & (InstrD[19:15] & 5'h1B) == 5'h01; // return must return to ra or x5 assign InstrClassD[2] = JumpD & (InstrD[19:15] & 5'h1B) == 5'h01; // return must return to ra or x5
assign InstrClassD[3] = JumpD & (InstrD[11:7] & 5'h1B) == 5'h01; // jal(r) must link to ra or x5 assign InstrClassD[3] = JumpD & (InstrD[11:7] & 5'h1B) == 5'h01; // jal(r) must link to ra or x5
flopenrc #(4) InstrClassRegE(clk, reset, FlushE, ~StallE, InstrClassD, InstrClassE); flopenrc #(4) InstrClassRegE(clk, reset, FlushE, ~StallE, InstrClassD, InstrClassE);
flopenrc #(4) InstrClassRegM(clk, reset, FlushM, ~StallM, InstrClassE, InstrClassM); flopenrc #(4) InstrClassRegM(clk, reset, FlushM, ~StallM, InstrClassE, InstrClassM);
@ -209,8 +205,9 @@ module bpred (
{DirPredictionWrongM, BTBPredPCWrongM, RASPredPCWrongM, PredictionInstrClassWrongM}); {DirPredictionWrongM, BTBPredPCWrongM, RASPredPCWrongM, PredictionInstrClassWrongM});
// pipeline the class // pipeline the class
flopenrc #(3) PredInstrClassRegD(clk, reset, FlushD, ~StallD, PredInstrClassF, PredInstrClassD); flopenrc #(4) PredInstrClassRegD(clk, reset, FlushD, ~StallD, PredInstrClassF, PredInstrClassD);
flopenrc #(1) WrongInstrClassRegE(clk, reset, FlushE, ~StallE, AnyWrongPredInstrClassD, AnyWrongPredInstrClassE); flopenrc #(1) WrongInstrClassRegE(clk, reset, FlushE, ~StallE, AnyWrongPredInstrClassD, AnyWrongPredInstrClassE);
flopenrc #(4) PredInstrClassRegE(clk, reset, FlushE, ~StallE, PredInstrClassD, PredInstrClassE);
// Check the prediction // Check the prediction
// if it is a CFI then check if the next instruction address (PCD) matches the branch's target or fallthrough address. // if it is a CFI then check if the next instruction address (PCD) matches the branch's target or fallthrough address.
@ -221,11 +218,12 @@ module bpred (
assign PredictionPCWrongE = PCCorrectE != PCD; assign PredictionPCWrongE = PCCorrectE != PCD;
// branch class prediction wrong. // branch class prediction wrong.
assign WrongPredInstrClassD = PredInstrClassD ^ InstrClassD[2:0]; assign WrongPredInstrClassD = PredInstrClassD ^ InstrClassD[3:0];
assign AnyWrongPredInstrClassD = |WrongPredInstrClassD; assign AnyWrongPredInstrClassD = |WrongPredInstrClassD;
// branch is wrong only if the PC does not match and both the Decode and Fetch stages have valid instructions. // branch is wrong only if the PC does not match and both the Decode and Fetch stages have valid instructions.
assign BPPredWrongE = PredictionPCWrongE & InstrValidE & InstrValidD; assign BPPredWrongE = (PredictionPCWrongE & |InstrClassE | (AnyWrongPredInstrClassE & ~|InstrClassE));
//assign BPPredWrongE = PredictionPCWrongE & InstrValidE & InstrValidD; // this does not work for cubic benchmark
// Output the predicted PC or corrected PC on miss-predict. // Output the predicted PC or corrected PC on miss-predict.
// Selects the BP or PC+2/4. // Selects the BP or PC+2/4.
@ -250,7 +248,6 @@ module bpred (
// could be wrong or the fall through address selected for branch predict not taken. // could be wrong or the fall through address selected for branch predict not taken.
// By pipeline the BTB's PC and RAS address through the pipeline we can measure the accuracy of // By pipeline the BTB's PC and RAS address through the pipeline we can measure the accuracy of
// both without the above inaccuracies. // both without the above inaccuracies.
//assign BTBPredPCWrongE = (PredPCE != IEUAdrE) & (InstrClassE[0] | InstrClassE[1] | InstrClassE[3]) & PCSrcE;
assign BTBPredPCWrongE = (PredPCE != IEUAdrE) & (InstrClassE[0] | InstrClassE[1] & ~InstrClassE[2]) & PCSrcE; assign BTBPredPCWrongE = (PredPCE != IEUAdrE) & (InstrClassE[0] | InstrClassE[1] & ~InstrClassE[2]) & PCSrcE;
assign RASPredPCWrongE = (RASPCE != IEUAdrE) & InstrClassE[2] & PCSrcE; assign RASPredPCWrongE = (RASPCE != IEUAdrE) & InstrClassE[2] & PCSrcE;

16
src/ifu/bpred/btb.sv
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@ -36,7 +36,7 @@ module btb #(parameter int Depth = 10 ) (
input logic StallF, StallD, StallM, FlushD, FlushM, input logic StallF, StallD, StallM, FlushD, FlushM,
input logic [`XLEN-1:0] PCNextF, PCF, PCD, PCE, // PC at various stages input logic [`XLEN-1:0] PCNextF, PCF, PCD, PCE, // PC at various stages
output logic [`XLEN-1:0] PredPCF, // BTB's guess at PC output logic [`XLEN-1:0] PredPCF, // BTB's guess at PC
output logic [2:0] BTBPredInstrClassF, // BTB's guess at instruction class output logic [3:0] BTBPredInstrClassF, // BTB's guess at instruction class
output logic PredValidF, // BTB's guess is valid output logic PredValidF, // BTB's guess is valid
// update // update
input logic AnyWrongPredInstrClassE, // BTB's instruction class guess was wrong input logic AnyWrongPredInstrClassE, // BTB's instruction class guess was wrong
@ -50,8 +50,8 @@ module btb #(parameter int Depth = 10 ) (
logic [Depth-1:0] PCNextFIndex, PCFIndex, PCDIndex, PCEIndex; logic [Depth-1:0] PCNextFIndex, PCFIndex, PCDIndex, PCEIndex;
logic [`XLEN-1:0] ResetPC; logic [`XLEN-1:0] ResetPC;
logic MatchF, MatchD, MatchE, MatchNextX, MatchXF; logic MatchF, MatchD, MatchE, MatchNextX, MatchXF;
logic [`XLEN+3:0] ForwardBTBPrediction, ForwardBTBPredictionF; logic [`XLEN+4:0] ForwardBTBPrediction, ForwardBTBPredictionF;
logic [`XLEN+2:0] TableBTBPredictionF; logic [`XLEN+3:0] TableBTBPredictionF;
logic [`XLEN-1:0] PredPCD; logic [`XLEN-1:0] PredPCD;
logic UpdateEn; logic UpdateEn;
logic TablePredValidF, PredValidD; logic TablePredValidF, PredValidD;
@ -79,10 +79,10 @@ module btb #(parameter int Depth = 10 ) (
flopenr #(1) MatchReg(clk, reset, ~StallF, MatchNextX, MatchXF); flopenr #(1) MatchReg(clk, reset, ~StallF, MatchNextX, MatchXF);
assign ForwardBTBPrediction = MatchF ? {PredValidF, BTBPredInstrClassF, PredPCF} : assign ForwardBTBPrediction = MatchF ? {PredValidF, BTBPredInstrClassF, PredPCF} :
MatchD ? {PredValidD, InstrClassD[2:0], PredPCD} : MatchD ? {PredValidD, InstrClassD, PredPCD} :
{1'b1, InstrClassE[2:0], IEUAdrE} ; {1'b1, InstrClassE, IEUAdrE} ;
flopenr #(`XLEN+4) ForwardBTBPredicitonReg(clk, reset, ~StallF, ForwardBTBPrediction, ForwardBTBPredictionF); flopenr #(`XLEN+5) ForwardBTBPredicitonReg(clk, reset, ~StallF, ForwardBTBPrediction, ForwardBTBPredictionF);
assign {PredValidF, BTBPredInstrClassF, PredPCF} = MatchXF ? ForwardBTBPredictionF : {TablePredValidF, TableBTBPredictionF}; assign {PredValidF, BTBPredInstrClassF, PredPCF} = MatchXF ? ForwardBTBPredictionF : {TablePredValidF, TableBTBPredictionF};
@ -98,9 +98,9 @@ module btb #(parameter int Depth = 10 ) (
assign UpdateEn = |InstrClassE | AnyWrongPredInstrClassE; assign UpdateEn = |InstrClassE | AnyWrongPredInstrClassE;
// An optimization may be using a PC relative address. // An optimization may be using a PC relative address.
ram2p1r1wbe #(2**Depth, `XLEN+3) memory( ram2p1r1wbe #(2**Depth, `XLEN+4) memory(
.clk, .ce1(~StallF | reset), .ra1(PCNextFIndex), .rd1(TableBTBPredictionF), .clk, .ce1(~StallF | reset), .ra1(PCNextFIndex), .rd1(TableBTBPredictionF),
.ce2(~StallM & ~FlushM), .wa2(PCEIndex), .wd2({InstrClassE[2:0], IEUAdrE}), .we2(UpdateEn), .bwe2('1)); .ce2(~StallM & ~FlushM), .wa2(PCEIndex), .wd2({InstrClassE, IEUAdrE}), .we2(UpdateEn), .bwe2('1));
flopenrc #(`XLEN+1) BTBD(clk, reset, FlushD, ~StallD, {PredValidF, PredPCF}, {PredValidD, PredPCD}); flopenrc #(`XLEN+1) BTBD(clk, reset, FlushD, ~StallD, {PredValidF, PredPCF}, {PredValidD, PredPCD});

17
src/ifu/bpred/gshare.sv
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@ -31,12 +31,12 @@
module gshare #(parameter k = 10) ( module gshare #(parameter k = 10) (
input logic clk, input logic clk,
input logic reset, input logic reset,
input logic StallF, StallD, StallE, StallM, input logic StallF, StallD, StallE, StallM, StallW,
input logic FlushD, FlushE, FlushM, input logic FlushD, FlushE, FlushM, FlushW,
output logic [1:0] DirPredictionF, output logic [1:0] DirPredictionF,
output logic DirPredictionWrongE, output logic DirPredictionWrongE,
// update // update
input logic [`XLEN-1:0] PCNextF, PCE, input logic [`XLEN-1:0] PCNextF, PCM,
input logic BranchInstrE, BranchInstrM, PCSrcE input logic BranchInstrE, BranchInstrM, PCSrcE
); );
@ -44,20 +44,20 @@ module gshare #(parameter k = 10) (
logic [1:0] DirPredictionD, DirPredictionE; logic [1:0] DirPredictionD, DirPredictionE;
logic [1:0] NewDirPredictionE, NewDirPredictionM; logic [1:0] NewDirPredictionE, NewDirPredictionM;
logic [k-1:0] GHRF, GHRD, GHRE, GHR; logic [k-1:0] GHRF, GHRD, GHRE, GHRM, GHR;
logic [k-1:0] GHRNext; logic [k-1:0] GHRNext;
logic PCSrcM; logic PCSrcM;
assign IndexNextF = GHR & {PCNextF[k+1] ^ PCNextF[1], PCNextF[k:2]}; assign IndexNextF = GHR ^ {PCNextF[k+1] ^ PCNextF[1], PCNextF[k:2]};
assign IndexE = GHRE & {PCE[k+1] ^ PCE[1], PCE[k:2]}; assign IndexE = GHRM ^ {PCM[k+1] ^ PCM[1], PCM[k:2]};
ram2p1r1wbe #(2**k, 2) PHT(.clk(clk), ram2p1r1wbe #(2**k, 2) PHT(.clk(clk),
.ce1(~StallF), .ce2(~StallM & ~FlushM), .ce1(~StallF), .ce2(~StallM & ~FlushM),
.ra1(IndexNextF), .ra1(IndexNextF),
.rd1(DirPredictionF), .rd1(DirPredictionF),
.wa2(IndexE), .wa2(IndexE),
.wd2(NewDirPredictionE), .wd2(NewDirPredictionM),
.we2(BranchInstrE & ~StallM & ~FlushM), .we2(BranchInstrM & ~StallW & ~FlushW),
.bwe2(1'b1)); .bwe2(1'b1));
flopenrc #(2) PredictionRegD(clk, reset, FlushD, ~StallD, DirPredictionF, DirPredictionD); flopenrc #(2) PredictionRegD(clk, reset, FlushD, ~StallD, DirPredictionF, DirPredictionD);
@ -75,6 +75,7 @@ module gshare #(parameter k = 10) (
flopenrc #(k) GHRFReg(clk, reset, FlushD, ~StallF, GHR, GHRF); flopenrc #(k) GHRFReg(clk, reset, FlushD, ~StallF, GHR, GHRF);
flopenrc #(k) GHRDReg(clk, reset, FlushD, ~StallD, GHRF, GHRD); flopenrc #(k) GHRDReg(clk, reset, FlushD, ~StallD, GHRF, GHRD);
flopenrc #(k) GHREReg(clk, reset, FlushE, ~StallE, GHRD, GHRE); flopenrc #(k) GHREReg(clk, reset, FlushE, ~StallE, GHRD, GHRE);
flopenrc #(k) GHRMReg(clk, reset, FlushM, ~StallM, GHRE, GHRM);
endmodule endmodule

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

19
src/ifu/bpred/speculativegshare.sv
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@ -37,9 +37,9 @@ module speculativegshare #(parameter int k = 10 ) (
output logic DirPredictionWrongE, output logic DirPredictionWrongE,
// update // update
input logic [`XLEN-1:0] PCNextF, PCF, PCD, PCE, input logic [`XLEN-1:0] PCNextF, PCF, PCD, PCE,
input logic [2:0] PredInstrClassF, input logic [3:0] PredInstrClassF,
input logic [3:0] InstrClassD, InstrClassE, input logic [3:0] InstrClassD, InstrClassE, InstrClassM,
input logic [2:0] WrongPredInstrClassD, input logic [3:0] WrongPredInstrClassD,
input logic PCSrcE input logic PCSrcE
); );
@ -49,9 +49,9 @@ module speculativegshare #(parameter int k = 10 ) (
logic [1:0] TableDirPredictionF, DirPredictionD, DirPredictionE; logic [1:0] TableDirPredictionF, DirPredictionD, DirPredictionE;
logic [1:0] NewDirPredictionE; logic [1:0] NewDirPredictionE;
logic [k-1:0] GHRF, GHRD, GHRE; logic [k-1:0] GHRF, GHRD, GHRE, GHRM;
logic GHRLastF; 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 [k-1:0] IndexNextF, IndexF, IndexD, IndexE;
logic [1:0] ForwardNewDirPrediction, ForwardDirPredictionF; logic [1:0] ForwardNewDirPrediction, ForwardDirPredictionF;
@ -113,15 +113,18 @@ module speculativegshare #(parameter int k = 10 ) (
// If it is wrong and branch does exist then shift right and insert the prediction. // 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. // If the branch does not exist then shift left and use GHRLastF to restore the LSB.
logic [k-1:0] GHRClassWrong; 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. // 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); mux3 #(k) GHRDMux(GHRF, GHRClassWrong, GHRNextE, {FlushDOrDirWrong, WrongPredInstrClassD[0]}, GHRNextD);
flopenr #(k) GHRDReg(clk, reset, ~StallD | FlushDOrDirWrong, GHRNextD, GHRD); 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]; assign DirPredictionWrongE = PCSrcE != DirPredictionE[1] & InstrClassE[0];

2
testbench/tests.vh
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@ -50,9 +50,9 @@ string tvpaths[] = '{
string embench[] = '{ string embench[] = '{
`EMBENCH, `EMBENCH,
"bd_speedopt_speed/src/cubic/cubic", // cubic is likely going to removed when embench 2.0 launches
"bd_speedopt_speed/src/aha-mont64/aha-mont64", "bd_speedopt_speed/src/aha-mont64/aha-mont64",
"bd_speedopt_speed/src/crc32/crc32", "bd_speedopt_speed/src/crc32/crc32",
"bd_speedopt_speed/src/cubic/cubic", // cubic is likely going to removed when embench 2.0 launches
"bd_speedopt_speed/src/edn/edn", "bd_speedopt_speed/src/edn/edn",
"bd_speedopt_speed/src/huffbench/huffbench", "bd_speedopt_speed/src/huffbench/huffbench",
"bd_speedopt_speed/src/matmult-int/matmult-int", "bd_speedopt_speed/src/matmult-int/matmult-int",