Merge pull request #775 from davidharrishmc/dev

Shared AND gate for bext and & operations in ALU
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Rose Thompson 2024-05-03 11:22:37 -05:00 committed by GitHub
commit 2bc4e909d7
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2 changed files with 8 additions and 5 deletions

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@ -50,6 +50,7 @@ module alu import cvw::*; #(parameter cvw_t P) (
logic [P.XLEN-1:0] CondMaskB; // Result of B mask select mux
logic [P.XLEN-1:0] CondShiftA; // Result of A shifted select mux
logic [P.XLEN-1:0] ZeroCondMaskInvB; // B input to AND gate, accounting for czero.* instructions
logic [P.XLEN-1:0] AndResult; // AND result
logic Carry, Neg; // Flags: carry out, negative
logic LT, LTU; // Less than, Less than unsigned
logic Asign, Bsign; // Sign bits of A, B
@ -72,6 +73,7 @@ module alu import cvw::*; #(parameter cvw_t P) (
assign Bsign = B[P.XLEN-1];
assign LT = Asign & ~Bsign | Asign & Neg | ~Bsign & Neg;
assign LTU = ~Carry;
assign AndResult = A & ZeroCondMaskInvB;
// Select appropriate ALU Result
always_comb
@ -81,9 +83,10 @@ module alu import cvw::*; #(parameter cvw_t P) (
3'b010: FullResult = {{(P.XLEN-1){1'b0}}, LT}; // slt
3'b011: FullResult = {{(P.XLEN-1){1'b0}}, LTU}; // sltu
3'b100: FullResult = A ^ CondMaskInvB; // xor, xnor, binv
3'b101: FullResult = (P.ZBS_SUPPORTED) ? {{(P.XLEN-1){1'b0}},{|(A & CondMaskB)}} : Shift; // bext (or IEU shift when BMU not supported)
// 3'b101: FullResult = (P.ZBS_SUPPORTED) ? {{(P.XLEN-1){1'b0}},{|(A & CondMaskInvB)}} : Shift; // bext (or IEU shift when BMU not supported)
3'b101: FullResult = (P.ZBS_SUPPORTED) ? {{(P.XLEN-1){1'b0}},{|(AndResult)}} : Shift; // bext (or IEU shift when BMU not supported)
3'b110: FullResult = A | CondMaskInvB; // or, orn, bset
3'b111: FullResult = A & ZeroCondMaskInvB; // and, bclr, czero.*
3'b111: FullResult = AndResult; // and, bclr, czero.*
endcase
// Support RV64I W-type addw/subw/addiw/shifts that discard upper 32 bits and sign-extend 32-bit result to 64 bits

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@ -136,21 +136,21 @@ module bmuctrl import cvw::*; #(parameter cvw_t P) (
if (P.ZBS_SUPPORTED) begin // ZBS
casez({OpD, Funct7D, Funct3D})
17'b0110011_0100100_001: BMUControlsD = `BMUCTRLW'b111_0001_0000_1_0_0_1_1_0_1_0_0; // bclr
17'b0110011_0100100_101: BMUControlsD = `BMUCTRLW'b101_0001_0000_1_0_0_1_1_0_1_0_0; // bext
17'b0110011_0100100_101: BMUControlsD = `BMUCTRLW'b101_0001_0000_1_0_0_1_0_0_1_0_0; // bext
17'b0110011_0110100_001: BMUControlsD = `BMUCTRLW'b100_0001_0000_1_0_0_1_0_0_1_0_0; // binv
17'b0110011_0010100_001: BMUControlsD = `BMUCTRLW'b110_0001_0000_1_0_0_1_0_0_1_0_0; // bset
endcase
if (P.XLEN==32) // ZBS 64-bit
casez({OpD, Funct7D, Funct3D})
17'b0010011_0100100_001: BMUControlsD = `BMUCTRLW'b111_0001_0000_1_1_0_1_1_0_1_0_0; // bclri
17'b0010011_0100100_101: BMUControlsD = `BMUCTRLW'b101_0001_0000_1_1_0_1_1_0_1_0_0; // bexti
17'b0010011_0100100_101: BMUControlsD = `BMUCTRLW'b101_0001_0000_1_1_0_1_0_0_1_0_0; // bexti
17'b0010011_0110100_001: BMUControlsD = `BMUCTRLW'b100_0001_0000_1_1_0_1_0_0_1_0_0; // binvi
17'b0010011_0010100_001: BMUControlsD = `BMUCTRLW'b110_0001_0000_1_1_0_1_0_0_1_0_0; // bseti
endcase
else if (P.XLEN==64) // ZBS 64-bit
casez({OpD, Funct7D, Funct3D})
17'b0010011_010010?_001: BMUControlsD = `BMUCTRLW'b111_0001_0000_1_1_0_1_1_0_1_0_0; // bclri (rv64)
17'b0010011_010010?_101: BMUControlsD = `BMUCTRLW'b101_0001_0000_1_1_0_1_1_0_1_0_0; // bexti (rv64)
17'b0010011_010010?_101: BMUControlsD = `BMUCTRLW'b101_0001_0000_1_1_0_1_0_0_1_0_0; // bexti (rv64)
17'b0010011_011010?_001: BMUControlsD = `BMUCTRLW'b100_0001_0000_1_1_0_1_0_0_1_0_0; // binvi (rv64)
17'b0010011_001010?_001: BMUControlsD = `BMUCTRLW'b110_0001_0000_1_1_0_1_0_0_1_0_0; // bseti (rv64)
endcase