forked from Github_Repos/cvw
		
	Cleanup branch predictor files.
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				@ -1,146 +0,0 @@
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///////////////////////////////////////////
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// gsharePredictor.sv
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//
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// Written: Shreya Sanghai
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// Email: ssanghai@hmc.edu
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// Created: March 16, 2021
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// Modified: 
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//
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// Purpose: Global History Branch predictor with parameterized global history register
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// 
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// A component of the CORE-V-WALLY configurable RISC-V project.
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// 
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// Copyright (C) 2021-23 Harvey Mudd College & Oklahoma State University
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//
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// SPDX-License-Identifier: Apache-2.0 WITH SHL-2.1
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//
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// Licensed under the Solderpad Hardware License v 2.1 (the “License”); you may not use this file 
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// except in compliance with the License, or, at your option, the Apache License version 2.0. You 
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// may obtain a copy of the License at
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//
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// https://solderpad.org/licenses/SHL-2.1/
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//
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// Unless required by applicable law or agreed to in writing, any work distributed under the 
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// License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, 
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// either express or implied. See the License for the specific language governing permissions 
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// and limitations under the License.
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////////////////////////////////////////////////////////////////////////////////////////////////
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`include "wally-config.vh"
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module foldedgshare #(parameter k = 16, depth = 10) (
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  input logic             clk,
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  input logic             reset,
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  input logic             StallF, StallD, StallE, StallM, StallW, 
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  input logic             FlushD, FlushE, FlushM, FlushW,
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//   input logic [`XLEN-1:0] LookUpPC,
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  output logic [1:0]      DirPredictionF, 
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  output logic            DirPredictionWrongE,
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  // update
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  input logic [`XLEN-1:0] PCNextF, PCF, PCD, PCE, PCM,
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  input logic             BranchInstrF, BranchInstrD, BranchInstrE, BranchInstrM, BranchInstrW, 
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  input logic             PCSrcE
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);
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  logic                    MatchF, MatchD, MatchE, MatchM, MatchW;
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  logic                    MatchNextX, MatchXF;
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  logic [1:0]              TableDirPredictionF, DirPredictionD, DirPredictionE;
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  logic [1:0]              NewDirPredictionF, NewDirPredictionD, NewDirPredictionE, NewDirPredictionM, NewDirPredictionW;
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  logic [k-1:0]            GHRF;
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  logic [k:0]              GHRD, OldGHRE, GHRE, GHRM, GHRW;
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  logic [k-1:0]            GHRNextF;
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  logic [k:0]              GHRNextD, GHRNextE, GHRNextM, GHRNextW;
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  logic [k-1:0]            IndexNextF, IndexF;
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  logic [k-1:0]            IndexD, IndexE, IndexM, IndexW;
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  logic [depth-1:0] 	     FinalIndexNextF, FinalIndexW;
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  logic                    PCSrcM, PCSrcW;
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  logic [`XLEN-1:0]        PCW;
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  logic [1:0]              ForwardNewDirPrediction, ForwardDirPredictionF;
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  localparam        		   delta = 2 * depth - k;
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  assign IndexNextF = GHRNextF ^ {PCNextF[k+1] ^ PCNextF[1], PCNextF[k:2]};
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  assign IndexF = GHRF        ^ {PCF[k+1] ^ PCF[1], PCF[k:2]};
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  assign IndexD = GHRD[k-1:0] ^ {PCD[k+1] ^ PCD[1], PCD[k:2]};
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  assign IndexE = GHRE[k-1:0] ^ {PCE[k+1] ^ PCE[1], PCE[k:2]};
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  assign IndexM = GHRM[k-1:0] ^ {PCM[k+1] ^ PCM[1], PCM[k:2]};
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  assign IndexW = GHRW[k-1:0] ^ {PCW[k+1] ^ PCW[1], PCW[k:2]};
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  // just be dumb for now.
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  //localparam int kToDepthRatio = (k+depth) / depth;
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  assign FinalIndexNextF = IndexNextF[depth-1:0] ^ {{delta{1'b0}} , IndexNextF[k-1:depth]};
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  assign FinalIndexW = IndexW[depth-1:0] ^ {{delta{1'b0}} , IndexW[k-1:depth]};
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  ram2p1r1wbe #(2**depth, 2) PHT(.clk(clk),
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    .ce1(~StallF | reset), .ce2(~StallW & ~FlushW),
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    .ra1(FinalIndexNextF),
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    .rd1(TableDirPredictionF),
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    .wa2(FinalIndexW),
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    .wd2(NewDirPredictionW),
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    .we2(BranchInstrW & ~StallW & ~FlushW),
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    .bwe2(1'b1));
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  // if there are non-flushed branches in the pipeline we need to forward the prediction from that stage to the NextF demi stage
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  //  and then register for use in the Fetch stage.
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  assign MatchF = BranchInstrF & ~FlushD & (IndexNextF == IndexF);
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  assign MatchD = BranchInstrD & ~FlushE & (IndexNextF == IndexD);
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  assign MatchE = BranchInstrE & ~FlushM & (IndexNextF == IndexE);
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  assign MatchM = BranchInstrM & ~FlushW & (IndexNextF == IndexM);
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  assign MatchW = BranchInstrW & (IndexNextF == IndexW);
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  assign MatchNextX = MatchF | MatchD | MatchE | MatchM | MatchW;
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  flopenr #(1) MatchReg(clk, reset, ~StallF, MatchNextX, MatchXF);
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  assign ForwardNewDirPrediction = MatchF ? NewDirPredictionF :
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                                   MatchD ? NewDirPredictionD :
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                                   MatchE ? NewDirPredictionE :
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                                   MatchM ? NewDirPredictionM :
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                                   NewDirPredictionW;
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  flopenr #(2) ForwardDirPredicitonReg(clk, reset, ~StallF, ForwardNewDirPrediction, ForwardDirPredictionF);
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  assign DirPredictionF = MatchXF ? ForwardDirPredictionF : TableDirPredictionF;
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  // DirPrediction pipeline
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  flopenr #(2) PredictionRegD(clk, reset, ~StallD, DirPredictionF, DirPredictionD);
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  flopenr #(2) PredictionRegE(clk, reset, ~StallE, DirPredictionD, DirPredictionE);
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  // New prediction pipeline
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  satCounter2 BPDirUpdateF(.BrDir(DirPredictionF[1]), .OldState(DirPredictionF), .NewState(NewDirPredictionF));
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  flopenr #(2) NewPredDReg(clk, reset, ~StallD, NewDirPredictionF, NewDirPredictionD);
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  satCounter2 BPDirUpdateE(.BrDir(PCSrcE), .OldState(DirPredictionE), .NewState(NewDirPredictionE));
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  flopenr #(2) NewPredMReg(clk, reset, ~StallM, NewDirPredictionE, NewDirPredictionM);
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  flopenr #(2) NewPredWReg(clk, reset, ~StallW, NewDirPredictionM, NewDirPredictionW);
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  // PCSrc pipeline
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  flopenrc #(1) PCSrcMReg(clk, reset, FlushM, ~StallM, PCSrcE, PCSrcM);
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  flopenrc #(1) PCSrcWReg(clk, reset, FlushW, ~StallW, PCSrcM, PCSrcW);
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  // GHR pipeline
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  assign GHRNextF = FlushD ?  GHRNextD[k:1] :
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                    BranchInstrF ? {DirPredictionF[1], GHRF[k-1:1]} :
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                    GHRF;
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  flopenr  #(k) GHRFReg(clk, reset, (~StallF) | FlushD, GHRNextF, GHRF);
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  assign GHRNextD = FlushD ? GHRNextE : {DirPredictionF[1], GHRF};
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  flopenr  #(k+1) GHRDReg(clk, reset, (~StallD) | FlushD, GHRNextD, GHRD);
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  assign GHRNextE = FlushE ? GHRNextM : GHRD;
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  flopenr  #(k+1) GHREReg(clk, reset, (~StallE) | FlushE, GHRNextE, OldGHRE);
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  assign GHRE = BranchInstrE ? {PCSrcE, OldGHRE[k-1:0]} : OldGHRE;
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  assign GHRNextM = FlushM ? GHRNextW : GHRE;
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  flopenr  #(k+1) GHRMReg(clk, reset, (~StallM) | FlushM, GHRNextM, GHRM);
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  assign GHRNextW = FlushW ? GHRW : GHRM;
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  flopenr  #(k+1) GHRWReg(clk, reset, (BranchInstrM & ~StallW) | FlushW, GHRNextW, GHRW);
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  assign DirPredictionWrongE = PCSrcE != DirPredictionE[1] & BranchInstrE;
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  flopenr #(`XLEN) PCWReg(clk, reset, ~StallW, PCM, PCW);
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endmodule
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@ -1,80 +0,0 @@
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///////////////////////////////////////////
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// globalHistoryPredictor.sv
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//
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// Written: Shreya Sanghai
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// Email: ssanghai@hmc.edu
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// Created: March 16, 2021
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// Modified: 
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//
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// Purpose: Global History Branch predictor with parameterized global history register
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// 
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// A component of the CORE-V-WALLY configurable RISC-V project.
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// 
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// Copyright (C) 2021-23 Harvey Mudd College & Oklahoma State University
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//
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// SPDX-License-Identifier: Apache-2.0 WITH SHL-2.1
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//
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// Licensed under the Solderpad Hardware License v 2.1 (the “License”); you may not use this file 
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// except in compliance with the License, or, at your option, the Apache License version 2.0. You 
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// may obtain a copy of the License at
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//
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// https://solderpad.org/licenses/SHL-2.1/
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//
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// Unless required by applicable law or agreed to in writing, any work distributed under the 
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// License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, 
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// either express or implied. See the License for the specific language governing permissions 
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// and limitations under the License.
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////////////////////////////////////////////////////////////////////////////////////////////////
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`include "wally-config.vh"
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module globalhistory #(parameter k = 10) (
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  input logic             clk,
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  input logic             reset,
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  input logic             StallF, StallD, StallE, StallM, StallW,
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  input logic             FlushD, FlushE, FlushM, FlushW,
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  output logic [1:0]      DirPredictionF, 
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  output logic            DirPredictionWrongE,
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  // update
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  input logic             BranchInstrE, BranchInstrM, PCSrcE
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);
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  logic [k-1:0]            IndexNextF, IndexE;
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  logic [1:0]              DirPredictionD, DirPredictionE;
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  logic [1:0]              NewDirPredictionE, NewDirPredictionM;
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  logic [k-1:0]            GHRF, GHRD, GHRE, GHRM, GHR;
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  logic [k-1:0]            GHRNext;
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  logic                    PCSrcM;
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  assign IndexNextF = GHR;
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  assign IndexE = GHRM;
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  ram2p1r1wbe #(2**k, 2) PHT(.clk(clk),
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    .ce1(~StallF), .ce2(~StallM & ~FlushM),
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    .ra1(IndexNextF),
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    .rd1(DirPredictionF),
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    .wa2(IndexE),
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    .wd2(NewDirPredictionM),
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    .we2(BranchInstrM & ~StallW & ~FlushW),
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    .bwe2(1'b1));
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  flopenrc #(2) PredictionRegD(clk, reset,  FlushD, ~StallD, DirPredictionF, DirPredictionD);
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  flopenrc #(2) PredictionRegE(clk, reset,  FlushE, ~StallE, DirPredictionD, DirPredictionE);
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  satCounter2 BPDirUpdateE(.BrDir(PCSrcE), .OldState(DirPredictionE), .NewState(NewDirPredictionE));
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  flopenrc #(2) NewPredictionRegM(clk, reset,  FlushM, ~StallM, NewDirPredictionE, NewDirPredictionM);
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  assign DirPredictionWrongE = PCSrcE != DirPredictionE[1] & BranchInstrE;
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  assign GHRNext = BranchInstrM ? {PCSrcM, GHR[k-1:1]} : GHR;
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  flopenr #(k) GHRReg(clk, reset, ~StallM & ~FlushM & BranchInstrM, GHRNext, GHR);
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  flopenrc #(1) PCSrcMReg(clk, reset, FlushM, ~StallM, PCSrcE, PCSrcM);
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  flopenrc #(k) GHRFReg(clk, reset, FlushD, ~StallF, GHR, GHRF);
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  flopenrc #(k) GHRDReg(clk, reset, FlushD, ~StallD, GHRF, GHRD);
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  flopenrc #(k) GHREReg(clk, reset, FlushE, ~StallE, GHRD, GHRE);
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  flopenrc #(k) GHRMReg(clk, reset, FlushM, ~StallM, GHRE, GHRM);
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endmodule
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@ -1,12 +1,13 @@
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///////////////////////////////////////////
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// globalHistoryPredictor.sv
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// gshare.sv
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//
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// Written: Shreya Sanghai
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// Email: ssanghai@hmc.edu
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// Created: March 16, 2021
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// Modified: 
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// Written: Ross Thompson
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// Email: ross1728@gmail.com
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// Created: 16 March 2021
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// Adapted from ssanghai@hmc.edu (Shreya Sanghai)
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// Modified: 20 February 2023
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//
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// Purpose: Global History Branch predictor with parameterized global history register
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// Purpose: gshare and Global History Branch predictors
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// 
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// A component of the CORE-V-WALLY configurable RISC-V project.
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// 
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@ -1,10 +1,11 @@
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///////////////////////////////////////////
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// globalHistoryPredictor.sv
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// gsharebasic.sv
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//
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// Written: Shreya Sanghai
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// Email: ssanghai@hmc.edu
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// Created: March 16, 2021
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// Modified: 
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// Written: Ross Thompson
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// Email: ross1728@gmail.com
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// Created: 16 March 2021
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// Adapted from ssanghai@hmc.edu (Shreya Sanghai) global history predictor implementation.
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// Modified: 20 February 2023 
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//
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// Purpose: Global History Branch predictor with parameterized global history register
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// 
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@ -1,219 +0,0 @@
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///////////////////////////////////////////
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// gsharePredictor.sv
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//
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// Written: Shreya Sanghai
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// Email: ssanghai@hmc.edu
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// Created: March 16, 2021
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// Modified: 
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//
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// Purpose: Global History Branch predictor with parameterized global history register
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// 
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// A component of the Wally configurable RISC-V project.
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		||||
// 
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// Copyright (C) 2021 Harvey Mudd College & Oklahoma State University
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//
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// SPDX-License-Identifier: Apache-2.0 WITH SHL-2.1
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//
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		||||
// Licensed under the Solderpad Hardware License v 2.1 (the “License”); you may not use this file 
 | 
			
		||||
// except in compliance with the License, or, at your option, the Apache License version 2.0. You 
 | 
			
		||||
// may obtain a copy of the License at
 | 
			
		||||
//
 | 
			
		||||
// https://solderpad.org/licenses/SHL-2.1/
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		||||
//
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		||||
// Unless required by applicable law or agreed to in writing, any work distributed under the 
 | 
			
		||||
// License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, 
 | 
			
		||||
// either express or implied. See the License for the specific language governing permissions 
 | 
			
		||||
// and limitations under the License.
 | 
			
		||||
////////////////////////////////////////////////////////////////////////////////////////////////
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`include "wally-config.vh"
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module optgshare #(parameter k = 10) (
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  input  logic             clk,
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  input  logic             reset,
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  input  logic             StallF, StallD, StallE, StallM, StallW, 
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  input  logic             FlushD, FlushE, FlushM, FlushW,
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//   input logic [`XLEN-1:0] LookUpPC,
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  output logic [1:0]       DirPredictionF, 
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  output logic             DirPredictionWrongE,
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  // update
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  input  logic [`XLEN-1:0] PCNextF, PCF, PCD, PCE, PCM,
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  input  logic             BranchInstrF, BranchInstrD, BranchInstrE, BranchInstrM, BranchInstrW, 
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  input  logic             PCSrcE
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);
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  logic                    MatchF, MatchD, MatchE, MatchM, MatchW;
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  logic                    MatchNextX, MatchXF;
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  logic [1:0]              TableDirPredictionF, DirPredictionD, DirPredictionE;
 | 
			
		||||
  logic [1:0]              NewDirPredictionF, NewDirPredictionD, NewDirPredictionE, NewDirPredictionM, NewDirPredictionW;
 | 
			
		||||
 | 
			
		||||
  logic [k-1:0]            GHRF;
 | 
			
		||||
  logic [k:0]              GHRD, OldGHRE, GHRE, GHRM, GHRW;
 | 
			
		||||
  logic [k-1:0]            GHRNextF;
 | 
			
		||||
  logic [k:0]              GHRNextD, GHRNextE, GHRNextM, GHRNextW;
 | 
			
		||||
  logic [k-1:0]            IndexNextF, IndexF;
 | 
			
		||||
  logic [k-1:0]            IndexD, IndexE, IndexM, IndexW;
 | 
			
		||||
  
 | 
			
		||||
  logic                    PCSrcM, PCSrcW;
 | 
			
		||||
  logic [`XLEN-1:0]        PCW;
 | 
			
		||||
 | 
			
		||||
  logic [1:0]              ForwardNewDirPrediction, ForwardDirPredictionF;
 | 
			
		||||
 | 
			
		||||
  logic [k+4:0]            GHRNext, GHR;
 | 
			
		||||
  logic                    GHRUpdateEn;
 | 
			
		||||
  
 | 
			
		||||
  assign GHRUpdateEn = BranchInstrF | (DirPredictionWrongE & BranchInstrE) |
 | 
			
		||||
                       FlushD | FlushE | FlushM | FlushW;
 | 
			
		||||
 | 
			
		||||
  // it doesn't work this way.  Instead we need to see how many branch instructions are flushed.
 | 
			
		||||
  // then shift over by that amount.
 | 
			
		||||
  logic                    RemoveBrW, RemoveBrM, RemoveBrE, RemoveBrD, RemoveBrF, RemoveBrNextF;
 | 
			
		||||
  
 | 
			
		||||
  assign RemoveBrW = '0;
 | 
			
		||||
  assign RemoveBrM = BranchInstrM & FlushW;
 | 
			
		||||
  assign RemoveBrE = BranchInstrE & FlushM;
 | 
			
		||||
  assign RemoveBrD = BranchInstrD & FlushE;
 | 
			
		||||
  assign RemoveBrF = BranchInstrF & FlushD;
 | 
			
		||||
  assign RemoveBrNextF = BranchInstrF & FlushD;
 | 
			
		||||
  
 | 
			
		||||
  always_comb begin
 | 
			
		||||
    casez ({BranchInstrF, DirPredictionWrongE, RemoveBrF, RemoveBrD, RemoveBrE, RemoveBrM}) 
 | 
			
		||||
      6'b00_0000: GHRNext = GHR;  // no change
 | 
			
		||||
      6'b00_0001: GHRNext = {GHR[k+4:k+1], GHR[k-1:0], 1'b0}; // RemoveBrM
 | 
			
		||||
      6'b0?_0010: GHRNext = {GHR[k+4:k+2], GHR[k:0], 1'b0};   // RemoveBrE
 | 
			
		||||
      6'b0?_0011: GHRNext = {GHR[k+4:k+2], GHR[k-1:0], 2'b0};   // RemoveBrE, RemoveBrM
 | 
			
		||||
 | 
			
		||||
      6'b00_0100: GHRNext = {GHR[k+4:k+2], GHR[k-1:0], 2'b0}; // RemoveBrD
 | 
			
		||||
      6'b00_0101: GHRNext = {GHR[k+4:k+3], GHR[k+1:0], 1'b0}; // RemoveBrD, RemoveBrM
 | 
			
		||||
      6'b0?_0110: GHRNext = {GHR[k+4:k+3], GHR[k+1], GHR[k-1:0], 2'b0}; // RemoveBrD, RemoveBrE
 | 
			
		||||
      6'b0?_0111: GHRNext = {GHR[k+4:k+3], GHR[k-1:0], 3'b0}; // RemoveBrD, RemoveBrE, RemoveBrM
 | 
			
		||||
 | 
			
		||||
      6'b?0_1000: GHRNext = {GHR[k+2:0],   2'b0}; // RemoveBrF, 
 | 
			
		||||
      6'b?0_1001: GHRNext = {GHR[k+2:k+1], GHR[k-1:0],  3'b0}; // RemoveBrF, RemoveBrM
 | 
			
		||||
      6'b??_1010: GHRNext = {GHR[k+2], GHR[k:0],  3'b0}; // RemoveBrF, RemoveBrE
 | 
			
		||||
      6'b??_1011: GHRNext = {GHR[k+2], GHR[k-1:0],  4'b0}; // RemoveBrF, RemoveBrE, RemoveBrM
 | 
			
		||||
 | 
			
		||||
      6'b?0_1100: GHRNext = {GHR[k+1:0],  3'b0}; // RemoveBrF, RemoveBrD
 | 
			
		||||
      6'b?0_1101: GHRNext = {GHR[k+1], GHR[k-1:0], 4'b0}; // RemoveBrF, RemoveBrD, RemoveBrM
 | 
			
		||||
      6'b??_1110: GHRNext = {GHR[k:0], 4'b0}; // RemoveBrF, RemoveBrD, RemoveBrE
 | 
			
		||||
      6'b??_1111: GHRNext = {GHR[k-1:0], 5'b0}; // RemoveBrF, RemoveBrD, RemoveBrE, RemoveBrM
 | 
			
		||||
 | 
			
		||||
      6'b?1_0000: GHRNext = {PCSrcE, GHR[k+3:0]}; // Miss prediction, no branches to flushes
 | 
			
		||||
      6'b?1_0001: GHRNext = {PCSrcE, GHR[k+3:k], GHR[k-1:1], 1'b0}; // Miss prediction, branch in Memory stage dropped
 | 
			
		||||
 | 
			
		||||
      6'b?1_1100: GHRNext = {PCSrcE, GHR[k+1:0], 2'b00}; // Miss prediction, cannot have RemoveBrE
 | 
			
		||||
      6'b?1_1101: GHRNext = {PCSrcE, GHR[k+1], GHR[k-1:0], 3'b0}; // Miss prediction, cannot have RemoveBrE
 | 
			
		||||
      6'b10_0000: GHRNext = {DirPredictionF[1], GHR[k+4:1]};
 | 
			
		||||
      6'b10_0001: GHRNext = {DirPredictionF[1], GHR[k+4:k+1], GHR[k-1:1], 1'b0};
 | 
			
		||||
      6'b10_0010: GHRNext = {DirPredictionF[1], GHR[k+4:k+2], GHR[k:1], 1'b0};
 | 
			
		||||
      6'b10_0011: GHRNext = {DirPredictionF[1], GHR[k+4:k+2], GHR[k-1:1], 2'b0};
 | 
			
		||||
      6'b10_0100: GHRNext = {DirPredictionF[1], GHR[k+4:k+3], GHR[k+1:1], 1'b0};
 | 
			
		||||
      6'b10_0101: GHRNext = {DirPredictionF[1], GHR[k+4:k+3], GHR[k+1], GHR[k-1:1], 2'b0};
 | 
			
		||||
      6'b10_0110: GHRNext = {DirPredictionF[1], GHR[k+4:k+3], GHR[k], GHR[k-1:1], 2'b0};
 | 
			
		||||
      6'b10_0111: GHRNext = {DirPredictionF[1], GHR[k+4:k+3], GHR[k-1:1], 3'b0};
 | 
			
		||||
      
 | 
			
		||||
      default: GHRNext = GHR;
 | 
			
		||||
    endcase
 | 
			
		||||
  end
 | 
			
		||||
 | 
			
		||||
  flopenr  #(k+5) GHRReg(clk, reset, GHRUpdateEn,  GHRNext, GHR);
 | 
			
		||||
  logic [k-1:0] GHRNextF_temp, GHRF_temp;
 | 
			
		||||
  logic [k:0]   GHRD_temp, GHRE_temp, GHRM_temp, GHRW_temp;
 | 
			
		||||
  logic         GHRFExtra_temp;
 | 
			
		||||
 | 
			
		||||
  // these are also in the ieu controller.  should create inputs.
 | 
			
		||||
  logic         InstrValidF, InstrValidD, InstrValidE, InstrValidM, InstrValidW;
 | 
			
		||||
  flopenrc #(1)  InstrValidFReg(clk, reset, FlushD, ~StallF, 1'b1, InstrValidF);
 | 
			
		||||
  flopenrc #(1)  InstrValidDReg(clk, reset, FlushD, ~StallD, InstrValidF, InstrValidD);
 | 
			
		||||
  flopenrc #(1)  InstrValidEReg(clk, reset, FlushE, ~StallE, InstrValidD, InstrValidE);
 | 
			
		||||
  flopenrc #(1)  InstrValidMReg(clk, reset, FlushM, ~StallM, InstrValidE, InstrValidM);
 | 
			
		||||
  flopenrc #(1)  InstrValidWReg(clk, reset, FlushW, ~StallW, InstrValidM, InstrValidW);
 | 
			
		||||
 | 
			
		||||
  
 | 
			
		||||
  assign GHRNextF_temp = GHRNext[k+4:5];
 | 
			
		||||
  assign GHRF_temp = InstrValidF ? GHR[k+3:4] : GHRNextF_temp;
 | 
			
		||||
  assign GHRFExtra_temp = InstrValidF ? 1'b0 : GHR[k+4];
 | 
			
		||||
  assign GHRD_temp = InstrValidD ? GHR[k+3:3] : {GHRFExtra_temp, GHRF_temp};
 | 
			
		||||
  assign GHRE_temp = InstrValidE ?  GHR[k+2:2] : GHRD_temp;
 | 
			
		||||
  assign GHRM_temp = InstrValidM ? GHR[k+1:1] : GHRE_temp;
 | 
			
		||||
  assign GHRW_temp = InstrValidW ? GHR[k:0] : GHRM_temp;
 | 
			
		||||
  
 | 
			
		||||
  
 | 
			
		||||
  assign IndexNextF = GHRNextF ^ {PCNextF[k+1] ^ PCNextF[1], PCNextF[k:2]};
 | 
			
		||||
  assign IndexF = GHRF        ^ {PCF[k+1] ^ PCF[1], PCF[k:2]};
 | 
			
		||||
  assign IndexD = GHRD[k-1:0] ^ {PCD[k+1] ^ PCD[1], PCD[k:2]};
 | 
			
		||||
  assign IndexE = GHRE[k-1:0] ^ {PCE[k+1] ^ PCE[1], PCE[k:2]};
 | 
			
		||||
  assign IndexM = GHRM[k-1:0] ^ {PCM[k+1] ^ PCM[1], PCM[k:2]};
 | 
			
		||||
  assign IndexW = GHRW[k-1:0] ^ {PCW[k+1] ^ PCW[1], PCW[k:2]};
 | 
			
		||||
      
 | 
			
		||||
  ram2p1r1wbe #(2**k, 2) PHT(.clk(clk),
 | 
			
		||||
    .ce1(~StallF | reset), .ce2(~StallW & ~FlushW),
 | 
			
		||||
    .ra1(IndexNextF),
 | 
			
		||||
    .rd1(TableDirPredictionF),
 | 
			
		||||
    .wa2(IndexW),
 | 
			
		||||
    .wd2(NewDirPredictionW),
 | 
			
		||||
    .we2(BranchInstrW & ~StallW & ~FlushW),
 | 
			
		||||
    .bwe2(1'b1));
 | 
			
		||||
 | 
			
		||||
  // if there are non-flushed branches in the pipeline we need to forward the prediction from that stage to the NextF demi stage
 | 
			
		||||
  //  and then register for use in the Fetch stage.
 | 
			
		||||
  assign MatchF = BranchInstrF & ~FlushD & (IndexNextF == IndexF);
 | 
			
		||||
  assign MatchD = BranchInstrD & ~FlushE & (IndexNextF == IndexD);
 | 
			
		||||
  assign MatchE = BranchInstrE & ~FlushM & (IndexNextF == IndexE);
 | 
			
		||||
  assign MatchM = BranchInstrM & ~FlushW & (IndexNextF == IndexM);
 | 
			
		||||
  assign MatchW = BranchInstrW & (IndexNextF == IndexW);
 | 
			
		||||
  assign MatchNextX = MatchF | MatchD | MatchE | MatchM | MatchW;
 | 
			
		||||
 | 
			
		||||
  flopenr #(1) MatchReg(clk, reset, ~StallF, MatchNextX, MatchXF);
 | 
			
		||||
 | 
			
		||||
  assign ForwardNewDirPrediction = MatchF ? NewDirPredictionF :
 | 
			
		||||
                                   MatchD ? NewDirPredictionD :
 | 
			
		||||
                                   MatchE ? NewDirPredictionE :
 | 
			
		||||
                                   MatchM ? NewDirPredictionM :
 | 
			
		||||
                                   NewDirPredictionW;
 | 
			
		||||
 | 
			
		||||
  flopenr #(2) ForwardDirPredicitonReg(clk, reset, ~StallF, ForwardNewDirPrediction, ForwardDirPredictionF);
 | 
			
		||||
 | 
			
		||||
  assign DirPredictionF = MatchXF ? ForwardDirPredictionF : TableDirPredictionF;
 | 
			
		||||
 | 
			
		||||
  // DirPrediction pipeline
 | 
			
		||||
  flopenr #(2) PredictionRegD(clk, reset, ~StallD, DirPredictionF, DirPredictionD);
 | 
			
		||||
  flopenr #(2) PredictionRegE(clk, reset, ~StallE, DirPredictionD, DirPredictionE);
 | 
			
		||||
 | 
			
		||||
  // New prediction pipeline
 | 
			
		||||
  satCounter2 BPDirUpdateF(.BrDir(DirPredictionF[1]), .OldState(DirPredictionF), .NewState(NewDirPredictionF));
 | 
			
		||||
  flopenr #(2) NewPredDReg(clk, reset, ~StallD, NewDirPredictionF, NewDirPredictionD);
 | 
			
		||||
  satCounter2 BPDirUpdateE(.BrDir(PCSrcE), .OldState(DirPredictionE), .NewState(NewDirPredictionE));
 | 
			
		||||
  flopenr #(2) NewPredMReg(clk, reset, ~StallM, NewDirPredictionE, NewDirPredictionM);
 | 
			
		||||
  flopenr #(2) NewPredWReg(clk, reset, ~StallW, NewDirPredictionM, NewDirPredictionW);
 | 
			
		||||
 | 
			
		||||
  // PCSrc pipeline
 | 
			
		||||
  flopenrc #(1) PCSrcMReg(clk, reset, FlushM, ~StallM, PCSrcE, PCSrcM);
 | 
			
		||||
  flopenrc #(1) PCSrcWReg(clk, reset, FlushW, ~StallW, PCSrcM, PCSrcW);
 | 
			
		||||
  
 | 
			
		||||
  // GHR pipeline
 | 
			
		||||
  assign GHRNextF = FlushD ?  GHRNextD[k:1] :
 | 
			
		||||
                    BranchInstrF ? {DirPredictionF[1], GHRF[k-1:1]} :
 | 
			
		||||
                    GHRF;
 | 
			
		||||
 | 
			
		||||
  flopenr  #(k) GHRFReg(clk, reset, (~StallF) | FlushD, GHRNextF, GHRF);
 | 
			
		||||
  
 | 
			
		||||
  assign GHRNextD = FlushD ? GHRNextE : {DirPredictionF[1], GHRF};
 | 
			
		||||
  flopenr  #(k+1) GHRDReg(clk, reset, (~StallD) | FlushD, GHRNextD, GHRD);
 | 
			
		||||
 | 
			
		||||
  assign GHRNextE = FlushE ? GHRNextM : GHRD;
 | 
			
		||||
  flopenr  #(k+1) GHREReg(clk, reset, (~StallE) | FlushE, GHRNextE, OldGHRE);
 | 
			
		||||
  assign GHRE = BranchInstrE ? {PCSrcE, OldGHRE[k-1:0]} : OldGHRE;
 | 
			
		||||
 | 
			
		||||
  assign GHRNextM = FlushM ? GHRNextW : GHRE;
 | 
			
		||||
  flopenr  #(k+1) GHRMReg(clk, reset, (~StallM) | FlushM, GHRNextM, GHRM);
 | 
			
		||||
 | 
			
		||||
  assign GHRNextW = FlushW ? GHRW : GHRM;
 | 
			
		||||
  flopenr  #(k+1) GHRWReg(clk, reset, (BranchInstrM & ~StallW) | FlushW, GHRNextW, GHRW);
 | 
			
		||||
  
 | 
			
		||||
  assign DirPredictionWrongE = PCSrcE != DirPredictionE[1] & BranchInstrE;
 | 
			
		||||
 | 
			
		||||
  flopenr #(`XLEN) PCWReg(clk, reset, ~StallW, PCM, PCW);
 | 
			
		||||
 | 
			
		||||
endmodule
 | 
			
		||||
@ -1,136 +0,0 @@
 | 
			
		||||
///////////////////////////////////////////
 | 
			
		||||
// speculativeglobalhistory.sv
 | 
			
		||||
//
 | 
			
		||||
// Written: Shreya Sanghai
 | 
			
		||||
// Email: ssanghai@hmc.edu
 | 
			
		||||
// Created: March 16, 2021
 | 
			
		||||
// Modified: 
 | 
			
		||||
//
 | 
			
		||||
// Purpose: Global History Branch predictor with parameterized global history register
 | 
			
		||||
// 
 | 
			
		||||
// A component of the CORE-V-WALLY configurable RISC-V project.
 | 
			
		||||
// 
 | 
			
		||||
// Copyright (C) 2021-23 Harvey Mudd College & Oklahoma State University
 | 
			
		||||
//
 | 
			
		||||
// SPDX-License-Identifier: Apache-2.0 WITH SHL-2.1
 | 
			
		||||
//
 | 
			
		||||
// Licensed under the Solderpad Hardware License v 2.1 (the “License”); you may not use this file 
 | 
			
		||||
// except in compliance with the License, or, at your option, the Apache License version 2.0. You 
 | 
			
		||||
// may obtain a copy of the License at
 | 
			
		||||
//
 | 
			
		||||
// https://solderpad.org/licenses/SHL-2.1/
 | 
			
		||||
//
 | 
			
		||||
// Unless required by applicable law or agreed to in writing, any work distributed under the 
 | 
			
		||||
// License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, 
 | 
			
		||||
// either express or implied. See the License for the specific language governing permissions 
 | 
			
		||||
// and limitations under the License.
 | 
			
		||||
////////////////////////////////////////////////////////////////////////////////////////////////
 | 
			
		||||
 | 
			
		||||
`include "wally-config.vh"
 | 
			
		||||
 | 
			
		||||
module speculativeglobalhistory #(parameter int k = 10 ) (
 | 
			
		||||
  input logic 			  clk,
 | 
			
		||||
  input logic 			  reset,
 | 
			
		||||
  input logic 			  StallF, StallD, StallE, StallM, StallW, 
 | 
			
		||||
  input logic 			  FlushD, FlushE, FlushM, FlushW,
 | 
			
		||||
  output logic [1:0] 	  DirPredictionF, 
 | 
			
		||||
  output logic 			  DirPredictionWrongE,
 | 
			
		||||
  // update
 | 
			
		||||
  input logic [3:0] 	  PredInstrClassF,
 | 
			
		||||
  input logic [3:0]       InstrClassD, InstrClassE, InstrClassM,
 | 
			
		||||
  input logic [3:0] 	  WrongPredInstrClassD, 
 | 
			
		||||
  input logic 			  PCSrcE
 | 
			
		||||
);
 | 
			
		||||
 | 
			
		||||
  logic                    MatchF, MatchD, MatchE;
 | 
			
		||||
  logic                    MatchNextX, MatchXF;
 | 
			
		||||
 | 
			
		||||
  logic [1:0]              TableDirPredictionF, DirPredictionD, DirPredictionE;
 | 
			
		||||
  logic [1:0]              NewDirPredictionE;
 | 
			
		||||
 | 
			
		||||
  logic [k-1:0] 		   GHRF, GHRD, GHRE, GHRM;
 | 
			
		||||
  logic 				   GHRLastF;
 | 
			
		||||
  logic [k-1:0] 		   GHRNextF, GHRNextD, GHRNextE, GHRNextM;
 | 
			
		||||
  logic [k-1:0]            IndexNextF, IndexF, IndexD, IndexE;
 | 
			
		||||
  logic [1:0]              ForwardNewDirPrediction, ForwardDirPredictionF;
 | 
			
		||||
 | 
			
		||||
  logic 				   FlushDOrDirWrong;
 | 
			
		||||
  
 | 
			
		||||
  assign IndexNextF = GHRNextF;
 | 
			
		||||
  assign IndexF = GHRF        ;
 | 
			
		||||
  assign IndexD = GHRD[k-1:0] ;
 | 
			
		||||
  assign IndexE = GHRE[k-1:0] ;
 | 
			
		||||
      
 | 
			
		||||
  ram2p1r1wbe #(2**k, 2) PHT(.clk(clk),
 | 
			
		||||
    .ce1(~StallF | reset), .ce2(~StallM & ~FlushM),
 | 
			
		||||
    .ra1(IndexNextF),
 | 
			
		||||
    .rd1(TableDirPredictionF),
 | 
			
		||||
    .wa2(IndexE),
 | 
			
		||||
    .wd2(NewDirPredictionE),
 | 
			
		||||
    .we2(InstrClassE[0]),
 | 
			
		||||
    .bwe2(1'b1));
 | 
			
		||||
 | 
			
		||||
  // if there are non-flushed branches in the pipeline we need to forward the prediction from that stage to the NextF demi stage
 | 
			
		||||
  // and then register for use in the Fetch stage.
 | 
			
		||||
  assign MatchF = PredInstrClassF[0] & ~FlushD & (IndexNextF == IndexF);
 | 
			
		||||
  assign MatchD = InstrClassD[0] & ~FlushE & (IndexNextF == IndexD);
 | 
			
		||||
  assign MatchE = InstrClassE[0] & ~FlushM & (IndexNextF == IndexE);
 | 
			
		||||
  assign MatchNextX = MatchF | MatchD | MatchE;
 | 
			
		||||
 | 
			
		||||
  flopenr #(1) MatchReg(clk, reset, ~StallF, MatchNextX, MatchXF);
 | 
			
		||||
 | 
			
		||||
  assign ForwardNewDirPrediction = MatchF ? {2{DirPredictionF[1]}} :
 | 
			
		||||
                                   MatchD ? {2{DirPredictionD[1]}} :
 | 
			
		||||
                                   NewDirPredictionE ;
 | 
			
		||||
  
 | 
			
		||||
  flopenr #(2) ForwardDirPredicitonReg(clk, reset, ~StallF, ForwardNewDirPrediction, ForwardDirPredictionF);
 | 
			
		||||
 | 
			
		||||
  assign DirPredictionF = MatchXF ? ForwardDirPredictionF : TableDirPredictionF;
 | 
			
		||||
 | 
			
		||||
  // DirPrediction pipeline
 | 
			
		||||
  flopenr #(2) PredictionRegD(clk, reset, ~StallD, DirPredictionF, DirPredictionD);
 | 
			
		||||
  flopenr #(2) PredictionRegE(clk, reset, ~StallE, DirPredictionD, DirPredictionE);
 | 
			
		||||
 | 
			
		||||
  
 | 
			
		||||
  satCounter2 BPDirUpdateE(.BrDir(PCSrcE), .OldState(DirPredictionE), .NewState(NewDirPredictionE));
 | 
			
		||||
 | 
			
		||||
  // GHR pipeline
 | 
			
		||||
 | 
			
		||||
  // If Fetch has a branch, speculatively insert prediction into the GHR
 | 
			
		||||
  // If the front end is flushed or the direction prediction is wrong, reset to
 | 
			
		||||
  // most recent valid GHR.  For a BP wrong this is GHRD with the correct prediction shifted in.
 | 
			
		||||
  // For FlushE this is GHRE.  GHRNextE is both.
 | 
			
		||||
  logic [k-1:0] 		   GHRClassWrongAndPredF;
 | 
			
		||||
  logic [k-1:0] 		   GHRClassWrong;
 | 
			
		||||
  mux2 #(k) GHRClassWrongAndPredFMux({DirPredictionF[1], DirPredictionD[1], GHRF[k-1:2]}, {DirPredictionF[1], GHRF[k-2:0]}, ~InstrClassD[0], GHRClassWrongAndPredF);
 | 
			
		||||
 | 
			
		||||
  assign FlushDOrDirWrong = FlushD | DirPredictionWrongE;
 | 
			
		||||
//  mux3 #(k) GHRFMux(GHRF, {DirPredictionF[1], GHRF[k-1:1]}, GHRNextE[k-1:0], 
 | 
			
		||||
//					{FlushDOrDirWrong, PredInstrClassF[0]}, GHRNextF);
 | 
			
		||||
 | 
			
		||||
  mux5 #(k) GHRFMux(GHRF, {DirPredictionF[1], GHRF[k-1:1]}, GHRClassWrong, GHRClassWrongAndPredF, GHRNextE[k-1:0], 
 | 
			
		||||
					{FlushDOrDirWrong, WrongPredInstrClassD[0], PredInstrClassF[0]}, GHRNextF);  
 | 
			
		||||
 | 
			
		||||
  // Need 1 extra bit to store the shifted out GHRF if repair needs to back shift.
 | 
			
		||||
  flopenr  #(k) GHRFReg(clk, reset, ~StallF | FlushDOrDirWrong, GHRNextF, GHRF);	
 | 
			
		||||
  flopenr  #(1) GHRFLastReg(clk, reset, ~StallF | FlushDOrDirWrong, GHRF[0], GHRLastF);
 | 
			
		||||
 | 
			
		||||
  // With instruction class prediction, the class could be wrong and is checked in Decode.
 | 
			
		||||
  // 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.
 | 
			
		||||
  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, GHRNextM, {PCSrcE, GHRD[k-2:0]}, {InstrClassE[0] & ~FlushM, FlushE}, GHRNextE);
 | 
			
		||||
 | 
			
		||||
  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];
 | 
			
		||||
 | 
			
		||||
endmodule
 | 
			
		||||
@ -1,137 +0,0 @@
 | 
			
		||||
///////////////////////////////////////////
 | 
			
		||||
// gsharePredictor.sv
 | 
			
		||||
//
 | 
			
		||||
// Written: Shreya Sanghai
 | 
			
		||||
// Email: ssanghai@hmc.edu
 | 
			
		||||
// Created: March 16, 2021
 | 
			
		||||
// Modified: 
 | 
			
		||||
//
 | 
			
		||||
// Purpose: Global History Branch predictor with parameterized global history register
 | 
			
		||||
// 
 | 
			
		||||
// A component of the CORE-V-WALLY configurable RISC-V project.
 | 
			
		||||
// 
 | 
			
		||||
// Copyright (C) 2021-23 Harvey Mudd College & Oklahoma State University
 | 
			
		||||
//
 | 
			
		||||
// SPDX-License-Identifier: Apache-2.0 WITH SHL-2.1
 | 
			
		||||
//
 | 
			
		||||
// Licensed under the Solderpad Hardware License v 2.1 (the “License”); you may not use this file 
 | 
			
		||||
// except in compliance with the License, or, at your option, the Apache License version 2.0. You 
 | 
			
		||||
// may obtain a copy of the License at
 | 
			
		||||
//
 | 
			
		||||
// https://solderpad.org/licenses/SHL-2.1/
 | 
			
		||||
//
 | 
			
		||||
// Unless required by applicable law or agreed to in writing, any work distributed under the 
 | 
			
		||||
// License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, 
 | 
			
		||||
// either express or implied. See the License for the specific language governing permissions 
 | 
			
		||||
// and limitations under the License.
 | 
			
		||||
////////////////////////////////////////////////////////////////////////////////////////////////
 | 
			
		||||
 | 
			
		||||
`include "wally-config.vh"
 | 
			
		||||
 | 
			
		||||
module speculativegshare #(parameter int k = 10 ) (
 | 
			
		||||
  input logic 			  clk,
 | 
			
		||||
  input logic 			  reset,
 | 
			
		||||
  input logic 			  StallF, StallD, StallE, StallM, StallW, 
 | 
			
		||||
  input logic 			  FlushD, FlushE, FlushM, FlushW,
 | 
			
		||||
  output logic [1:0] 	  DirPredictionF, 
 | 
			
		||||
  output logic 			  DirPredictionWrongE,
 | 
			
		||||
  // update
 | 
			
		||||
  input logic [`XLEN-1:0] PCNextF, PCF, PCD, PCE,
 | 
			
		||||
  input logic [3:0] 	  PredInstrClassF,
 | 
			
		||||
  input logic [3:0]       InstrClassD, InstrClassE, InstrClassM,
 | 
			
		||||
  input logic [3:0] 	  WrongPredInstrClassD, 
 | 
			
		||||
  input logic 			  PCSrcE
 | 
			
		||||
);
 | 
			
		||||
 | 
			
		||||
  logic                    MatchF, MatchD, MatchE;
 | 
			
		||||
  logic                    MatchNextX, MatchXF;
 | 
			
		||||
 | 
			
		||||
  logic [1:0]              TableDirPredictionF, DirPredictionD, DirPredictionE;
 | 
			
		||||
  logic [1:0]              NewDirPredictionE;
 | 
			
		||||
 | 
			
		||||
  logic [k-1:0] 		   GHRF, GHRD, GHRE, GHRM;
 | 
			
		||||
  logic 				   GHRLastF;
 | 
			
		||||
  logic [k-1:0] 		   GHRNextF, GHRNextD, GHRNextE, GHRNextM;
 | 
			
		||||
  logic [k-1:0]            IndexNextF, IndexF, IndexD, IndexE;
 | 
			
		||||
  logic [1:0]              ForwardNewDirPrediction, ForwardDirPredictionF;
 | 
			
		||||
 | 
			
		||||
  logic 				   FlushDOrDirWrong;
 | 
			
		||||
  
 | 
			
		||||
  assign IndexNextF = GHRNextF ^ {PCNextF[k+1] ^ PCNextF[1], PCNextF[k:2]};
 | 
			
		||||
  assign IndexF = GHRF        ^ {PCF[k+1] ^ PCF[1], PCF[k:2]};
 | 
			
		||||
  assign IndexD = GHRD[k-1:0] ^ {PCD[k+1] ^ PCD[1], PCD[k:2]};
 | 
			
		||||
  assign IndexE = GHRE[k-1:0] ^ {PCE[k+1] ^ PCE[1], PCE[k:2]};
 | 
			
		||||
      
 | 
			
		||||
  ram2p1r1wbe #(2**k, 2) PHT(.clk(clk),
 | 
			
		||||
    .ce1(~StallF | reset), .ce2(~StallM & ~FlushM),
 | 
			
		||||
    .ra1(IndexNextF),
 | 
			
		||||
    .rd1(TableDirPredictionF),
 | 
			
		||||
    .wa2(IndexE),
 | 
			
		||||
    .wd2(NewDirPredictionE),
 | 
			
		||||
    .we2(InstrClassE[0]),
 | 
			
		||||
    .bwe2(1'b1));
 | 
			
		||||
 | 
			
		||||
  // if there are non-flushed branches in the pipeline we need to forward the prediction from that stage to the NextF demi stage
 | 
			
		||||
  // and then register for use in the Fetch stage.
 | 
			
		||||
  assign MatchF = PredInstrClassF[0] & ~FlushD & (IndexNextF == IndexF);
 | 
			
		||||
  assign MatchD = InstrClassD[0] & ~FlushE & (IndexNextF == IndexD);
 | 
			
		||||
  assign MatchE = InstrClassE[0] & ~FlushM & (IndexNextF == IndexE);
 | 
			
		||||
  assign MatchNextX = MatchF | MatchD | MatchE;
 | 
			
		||||
 | 
			
		||||
  flopenr #(1) MatchReg(clk, reset, ~StallF, MatchNextX, MatchXF);
 | 
			
		||||
 | 
			
		||||
  assign ForwardNewDirPrediction = MatchF ? {2{DirPredictionF[1]}} :
 | 
			
		||||
                                   MatchD ? {2{DirPredictionD[1]}} :
 | 
			
		||||
                                   NewDirPredictionE ;
 | 
			
		||||
  
 | 
			
		||||
  flopenr #(2) ForwardDirPredicitonReg(clk, reset, ~StallF, ForwardNewDirPrediction, ForwardDirPredictionF);
 | 
			
		||||
 | 
			
		||||
  assign DirPredictionF = MatchXF ? ForwardDirPredictionF : TableDirPredictionF;
 | 
			
		||||
 | 
			
		||||
  // DirPrediction pipeline
 | 
			
		||||
  flopenr #(2) PredictionRegD(clk, reset, ~StallD, DirPredictionF, DirPredictionD);
 | 
			
		||||
  flopenr #(2) PredictionRegE(clk, reset, ~StallE, DirPredictionD, DirPredictionE);
 | 
			
		||||
 | 
			
		||||
  
 | 
			
		||||
  satCounter2 BPDirUpdateE(.BrDir(PCSrcE), .OldState(DirPredictionE), .NewState(NewDirPredictionE));
 | 
			
		||||
 | 
			
		||||
  // GHR pipeline
 | 
			
		||||
 | 
			
		||||
  // If Fetch has a branch, speculatively insert prediction into the GHR
 | 
			
		||||
  // If the front end is flushed or the direction prediction is wrong, reset to
 | 
			
		||||
  // most recent valid GHR.  For a BP wrong this is GHRD with the correct prediction shifted in.
 | 
			
		||||
  // For FlushE this is GHRE.  GHRNextE is both.
 | 
			
		||||
  logic [k-1:0] 		   GHRClassWrongAndPredF;
 | 
			
		||||
  logic [k-1:0] 		   GHRClassWrong;
 | 
			
		||||
  mux2 #(k) GHRClassWrongAndPredFMux({DirPredictionF[1], DirPredictionD[1], GHRF[k-1:2]}, {DirPredictionF[1], GHRF[k-2:0]}, ~InstrClassD[0], GHRClassWrongAndPredF);
 | 
			
		||||
 | 
			
		||||
  assign FlushDOrDirWrong = FlushD | DirPredictionWrongE;
 | 
			
		||||
//  mux3 #(k) GHRFMux(GHRF, {DirPredictionF[1], GHRF[k-1:1]}, GHRNextE[k-1:0], 
 | 
			
		||||
//					{FlushDOrDirWrong, PredInstrClassF[0]}, GHRNextF);
 | 
			
		||||
 | 
			
		||||
  mux5 #(k) GHRFMux(GHRF, {DirPredictionF[1], GHRF[k-1:1]}, GHRClassWrong, GHRClassWrongAndPredF, GHRNextE[k-1:0], 
 | 
			
		||||
					{FlushDOrDirWrong, WrongPredInstrClassD[0], PredInstrClassF[0]}, GHRNextF);  
 | 
			
		||||
 | 
			
		||||
  // Need 1 extra bit to store the shifted out GHRF if repair needs to back shift.
 | 
			
		||||
  flopenr  #(k) GHRFReg(clk, reset, ~StallF | FlushDOrDirWrong, GHRNextF, GHRF);	
 | 
			
		||||
  flopenr  #(1) GHRFLastReg(clk, reset, ~StallF | FlushDOrDirWrong, GHRF[0], GHRLastF);
 | 
			
		||||
 | 
			
		||||
  // With instruction class prediction, the class could be wrong and is checked in Decode.
 | 
			
		||||
  // 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.
 | 
			
		||||
  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, GHRNextM, {PCSrcE, GHRD[k-2:0]}, {InstrClassE[0] & ~FlushM, FlushE}, GHRNextE);
 | 
			
		||||
 | 
			
		||||
  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];
 | 
			
		||||
 | 
			
		||||
endmodule
 | 
			
		||||
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	Block a user