Fixed bug in basic gshare implementation. Should be a better comparison to the speculative versions now.

This commit is contained in:
Ross Thompson 2023-02-13 17:57:05 -06:00
parent b298a8afc5
commit 9f25b53b36
2 changed files with 13 additions and 11 deletions

View File

@ -48,8 +48,8 @@ module gshare #(parameter k = 10) (
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 = GHRE ^ {PCE[k+1] ^ PCE[1], PCE[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),

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@ -31,16 +31,16 @@
module gshare_copy #(parameter k = 10) ( module gshare_copy #(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
); );
logic [k-1:0] IndexNextF, IndexE; logic [k-1:0] IndexNextF, IndexM;
logic [1:0] DirPredictionD, DirPredictionE; logic [1:0] DirPredictionD, DirPredictionE;
logic [1:0] NewDirPredictionE, NewDirPredictionM; logic [1:0] NewDirPredictionE, NewDirPredictionM;
@ -48,16 +48,16 @@ module gshare_copy #(parameter k = 10) (
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 = GHRNext ^ {PCNextF[k+1] ^ PCNextF[1], PCNextF[k:2]};
assign IndexE = GHRE & {PCE[k+1] ^ PCE[1], PCE[k:2]}; assign IndexM = GHR ^ {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(IndexM),
.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);
@ -72,9 +72,11 @@ module gshare_copy #(parameter k = 10) (
flopenr #(k) GHRReg(clk, reset, ~StallM & ~FlushM & BranchInstrM, GHRNext, GHR); flopenr #(k) GHRReg(clk, reset, ~StallM & ~FlushM & BranchInstrM, GHRNext, GHR);
flopenrc #(1) PCSrcMReg(clk, reset, FlushM, ~StallM, PCSrcE, PCSrcM); flopenrc #(1) PCSrcMReg(clk, reset, FlushM, ~StallM, PCSrcE, PCSrcM);
/* -----\/----- EXCLUDED -----\/-----
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);
-----/\----- EXCLUDED -----/\----- */
endmodule endmodule