From eba7ce64f56fc49a2fb4017290af23ac9a820712 Mon Sep 17 00:00:00 2001 From: "James E. Stine" Date: Tue, 1 Jun 2021 17:39:54 -0400 Subject: [PATCH] delete div.bak --- wally-pipelined/src/muldiv/div.bak | 1560 ---------------------------- 1 file changed, 1560 deletions(-) delete mode 100755 wally-pipelined/src/muldiv/div.bak diff --git a/wally-pipelined/src/muldiv/div.bak b/wally-pipelined/src/muldiv/div.bak deleted file mode 100755 index 4266ae61a..000000000 --- a/wally-pipelined/src/muldiv/div.bak +++ /dev/null @@ -1,1560 +0,0 @@ -/////////////////////////////////////////// -// mul.sv -// -// Written: James.Stine@okstate.edu 1 February 2021 -// Modified: -// -// Purpose: Integer Divide instructions -// -// A component of the Wally configurable RISC-V project. -// -// Copyright (C) 2021 Harvey Mudd College & Oklahoma State University -// -// Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation -// files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, -// modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software -// is furnished to do so, subject to the following conditions: -// -// The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. -// -// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES -// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS -// BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT -// OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. -/////////////////////////////////////////// - -// *** I added these verilator controls to clean up the -// lint output. The linter warnings should be fixed, but now the output is at -// least readable. -/* verilator lint_off COMBDLY */ -/* verilator lint_off IMPLICIT */ - -`include "wally-config.vh" - -module div (Qf, remf, done, divBusy, div0, N, D, clk, reset, start, S); - - input logic [63:0] N, D; - input logic clk; - input logic reset; - input logic start; - input logic S; - - output logic [63:0] Qf; - output logic [63:0] remf; - output logic div0; - output logic done; - output logic divBusy; - - logic divdone; - logic enable; - logic state0; - logic V; - logic [7:0] Num; - logic [5:0] P, NumIter, RemShift; - logic [63:0] op1, op2, op1shift, Rem5; - logic [64:0] Qd, Rd, Qd2, Rd2; - logic [63:0] Q, rem0; - logic [3:0] quotient; - logic otfzero; - logic shiftResult; - logic enablev, state0v, donev, divdonev, oftzerov, divBusyv, ulp; - - logic [63:0] twoD; - logic [63:0] twoN; - logic SignD; - logic SignN; - logic [63:0] QT, remT; - logic D_NegOne; - logic Max_N; - - // Check if negative (two's complement) - // If so, convert to positive - adder #(64) cpa1 ((D ^ {64{D[63]&S}}), {63'h0, D[63]&S}, twoD); - adder #(64) cpa2 ((N ^ {64{N[63]&S}}), {63'h0, N[63]&S}, twoN); - assign SignD = D[63]; - assign SignN = N[63]; - // Max N and D = -1 (Overflow) - assign Max_N = (~|N[62:0]) & N[63]; - assign D_NegOne = &D; - - // Divider goes the distance to 37 cycles - // (thanks to the evil divisor for D = 0x1) - - // Shift D, if needed (for integer) - // needed to allow qst to be in range for integer - // division [1,2) and allow integer divide to work. - // - // The V or valid bit can be used to determine if D - // is 0 and thus a divide by 0 exception. This div0 - // exception is given to FSM to tell the operation to - // quit gracefully. - - lzd_hier #(64) p1 (.ZP(P), .ZV(V), .B(twoD)); - shift_left #(64) p2 (twoD, P, op2); - assign op1 = twoN; - assign div0 = ~V; - - // #iter: N = m+v+s = m+(s+2) = m+2+s (mod k = 0) - // v = 2 since \rho < 1 (add 4 to make sure its a ceil) - adder #(8) cpa3 ({2'b0, P}, - {5'h0, shiftResult, ~shiftResult, 1'b0}, - Num); - - // Determine whether need to add just Q/Rem - assign shiftResult = P[0]; - // div by 2 (ceil) - assign NumIter = Num[6:1]; - assign RemShift = P; - - // FSM to control integer divider - // assume inputs are postive edge and - // datapath (divider) is negative edge - fsm64 fsm1 (enablev, state0v, donev, divdonev, otfzerov, divBusyv, - start, div0, NumIter, ~clk, reset); - - flopr #(1) rega (~clk, reset, donev, done); - flopr #(1) regb (~clk, reset, divdonev, divdone); - flopr #(1) regc (~clk, reset, otfzerov, otfzero); - flopr #(1) regd (~clk, reset, enablev, enable); - flopr #(1) rege (~clk, reset, state0v, state0); - flopr #(1) regf (~clk, reset, divBusyv, divBusy); - - // To obtain a correct remainder the last bit of the - // quotient has to be aligned with a radix-r boundary. - // Since the quotient is in the range 1/2 < q < 2 (one - // integer bit and m fractional bits), this is achieved by - // shifting N right by v+s so that (m+v+s) mod k = 0. And, - // the quotient has to be aligned to the integer position. - - divide4x64 p3 (Qd, Rd, quotient, op1, op2, clk, reset, state0, - enable, otfzero, shiftResult); - - // Storage registers to hold contents stable - flopenr #(65) reg3 (clk, reset, enable, Rd, Rd2); - flopenr #(65) reg4 (clk, reset, enable, Qd, Qd2); - - // Probably not needed - just assigns results - assign Q = Qd2[63:0]; - assign Rem5 = Rd2[64:1]; - - // Adjust remainder by m - shift_right #(64) p4 (Rem5, RemShift, rem0); - - // Adjust Q/Rem for Signed - assign tcQ = (SignN ^ SignD) & S; - assign tcR = SignN & S; - // Signed Divide - // - When N and D are negative: Remainder is negative (undergoes a two's complement). - // - When N is negative: Quotient and Remainder are both negative (undergo a two's complement). - // - When D is negative: Quotient is negative (undergoes a two's complement). - adder #(64) cpa4 ((rem0 ^ {64{tcR}}), {63'h0, tcR}, remT); - adder #(64) cpa5 ((Q ^ {64{tcQ}}), {63'h0, tcQ}, QT); - - // RISC-V has exceptions for divide by 0 and overflow (see Table 6.1 of spec) - exception_int exc (QT, remT, N, S, div0, Max_N, D_NegOne, Qf, remf); - -endmodule // int32div - -module divide4x64 (Q, rem0, quotient, op1, op2, clk, reset, state0, - enable, otfzero, shiftResult); - - input logic [63:0] op1, op2; - input logic clk, state0; - input logic reset; - input logic enable; - input logic otfzero; - input logic shiftResult; - - output logic [64:0] rem0; - output logic [64:0] Q; - output logic [3:0] quotient; - - logic [67:0] Sum, Carry; - logic [64:0] Qstar; - logic [64:0] QMstar; - logic [7:0] qtotal; - logic [67:0] SumN, CarryN, SumN2, CarryN2; - logic [67:0] divi1, divi2, divi1c, divi2c, dive1; - logic [67:0] mdivi_temp, mdivi; - logic zero; - logic [1:0] qsel; - logic [1:0] Qin, QMin; - logic CshiftQ, CshiftQM; - logic [67:0] rem1, rem2, rem3; - logic [67:0] SumR, CarryR; - logic [64:0] Qt; - - // Create one's complement values of Divisor (for q*D) - assign divi1 = {3'h0, op2, 1'b0}; - assign divi2 = {2'h0, op2, 2'b0}; - assign divi1c = ~divi1; - assign divi2c = ~divi2; - // Shift x1 if not mod k - mux2 #(68) mx1 ({3'b000, op1, 1'b0}, {4'h0, op1}, shiftResult, dive1); - - // I I I . F F F F F ... (Robertson Criteria - \rho * qmax * D) - mux2 #(68) mx2 ({CarryN2[65:0], 2'h0}, 68'h0, state0, CarryN); - mux2 #(68) mx3 ({SumN2[65:0], 2'h0}, dive1, state0, SumN); - // Simplify QST - adder #(8) cpa1 (SumN[67:60], CarryN[67:60], qtotal); - // q = {+2, +1, -1, -2} else q = 0 - qst4 pd1 (qtotal[7:1], divi1[63:61], quotient); - assign ulp = quotient[2]|quotient[3]; - assign zero = ~(quotient[3]|quotient[2]|quotient[1]|quotient[0]); - // Map to binary encoding - assign qsel[1] = quotient[3]|quotient[2]; - assign qsel[0] = quotient[3]|quotient[1]; - mux4 #(68) mx4 (divi2, divi1, divi1c, divi2c, qsel, mdivi_temp); - mux2 #(68) mx5 (mdivi_temp, 68'h0, zero, mdivi); - csa #(68) csa1 (mdivi, SumN, {CarryN[67:1], ulp}, Sum, Carry); - // regs : save CSA - flopenr #(68) reg1 (clk, reset, enable, Sum, SumN2); - flopenr #(68) reg2 (clk, reset, enable, Carry, CarryN2); - // OTF - ls_control otf1 (quotient, Qin, QMin, CshiftQ, CshiftQM); - otf #(65) otf2 (Qin, QMin, CshiftQ, CshiftQM, clk, - otfzero, enable, Qstar, QMstar); - - // Correction and generation of Remainder - adder #(68) cpa2 (SumN2[67:0], CarryN2[67:0], rem1); - // Add back +D as correction - csa #(68) csa2 (CarryN2[67:0], SumN2[67:0], divi1, SumR, CarryR); - adder #(68) cpa3 (SumR, CarryR, rem2); - // Choose remainder (Rem or Rem+D) - mux2 #(68) mx6 (rem1, rem2, rem1[67], rem3); - // Choose correct Q or QM - mux2 #(65) mx7 (Qstar, QMstar, rem1[67], Qt); - // Final results - assign rem0 = rem3[64:0]; - assign Q = Qt; - -endmodule // divide4x64 - -module ls_control (quot, Qin, QMin, CshiftQ, CshiftQM); - - input logic [3:0] quot; - - output logic [1:0] Qin; - output logic [1:0] QMin; - output logic CshiftQ; - output logic CshiftQM; - - // Load/Store Control for OTF - assign Qin[1] = (quot[1]) | (quot[3]) | (quot[0]); - assign Qin[0] = (quot[1]) | (quot[2]); - assign QMin[1] = (quot[1]) | (!quot[3]&!quot[2]&!quot[1]&!quot[0]); - assign QMin[0] = (quot[3]) | (quot[0]) | - (!quot[3]&!quot[2]&!quot[1]&!quot[0]); - assign CshiftQ = (quot[1]) | (quot[0]); - assign CshiftQM = (quot[3]) | (quot[2]); - -endmodule - -// On-the-fly Conversion per Ercegovac/Lang - -module otf #(parameter WIDTH=8) - (Qin, QMin, CshiftQ, CshiftQM, clk, reset, enable, R2Q, R1Q); - - input logic [1:0] Qin, QMin; - input logic CshiftQ, CshiftQM; - input logic clk; - input logic reset; - input logic enable; - - output logic [WIDTH-1:0] R2Q; - output logic [WIDTH-1:0] R1Q; - - logic [WIDTH-1:0] Qstar, QMstar; - logic [WIDTH-1:0] M1Q, M2Q; - - // QM - mux2 #(WIDTH) m1 (QMstar, Qstar, CshiftQM, M1Q); - flopenr #(WIDTH) r1 (clk, reset, enable, {M1Q[WIDTH-3:0], QMin}, R1Q); - // Q - mux2 #(WIDTH) m2 (Qstar, QMstar, CshiftQ, M2Q); - flopenr #(WIDTH) r2 (clk, reset, enable, {M2Q[WIDTH-3:0], Qin}, R2Q); - - assign Qstar = R2Q; - assign QMstar = R1Q; - -endmodule // otf8 - -module adder #(parameter WIDTH=8) (input logic [WIDTH-1:0] a, b, - output logic [WIDTH-1:0] y); - - assign y = a + b; - -endmodule // adder - -module fa (input logic a, b, c, output logic sum, carry); - - assign sum = a^b^c; - assign carry = a&b|a&c|b&c; - -endmodule // fa - -module csa #(parameter WIDTH=8) (input logic [WIDTH-1:0] a, b, c, - output logic [WIDTH-1:0] sum, carry); - - logic [WIDTH:0] carry_temp; - genvar i; - generate - for (i=0;i B. LT and GT are both '0' if A = B. - -module magcompare2b (LT, GT, A, B); - - input logic [1:0] A; - input logic [1:0] B; - - output logic LT; - output logic GT; - - // Determine if A < B using a minimized sum-of-products expression - assign LT = ~A[1]&B[1] | ~A[1]&~A[0]&B[0] | ~A[0]&B[1]&B[0]; - // Determine if A > B using a minimized sum-of-products expression - assign GT = A[1]&~B[1] | A[1]&A[0]&~B[0] | A[0]&~B[1]&~B[0]; - -endmodule // magcompare2b - -// J. E. Stine and M. J. Schulte, "A combined two's complement and -// floating-point comparator," 2005 IEEE International Symposium on -// Circuits and Systems, Kobe, 2005, pp. 89-92 Vol. 1. -// doi: 10.1109/ISCAS.2005.1464531 - -module magcompare8 (LT, EQ, A, B); - - input logic [7:0] A; - input logic [7:0] B; - - logic [3:0] s; - logic [3:0] t; - logic [1:0] u; - logic [1:0] v; - logic GT; - //wire LT; - - output logic EQ; - output logic LT; - - magcompare2b mag1 (s[0], t[0], A[1:0], B[1:0]); - magcompare2b mag2 (s[1], t[1], A[3:2], B[3:2]); - magcompare2b mag3 (s[2], t[2], A[5:4], B[5:4]); - magcompare2b mag4 (s[3], t[3], A[7:6], B[7:6]); - - magcompare2b mag5 (u[0], v[0], t[1:0], s[1:0]); - magcompare2b mag6 (u[1], v[1], t[3:2], s[3:2]); - - magcompare2b mag7 (LT, GT, v[1:0], u[1:0]); - - assign EQ = ~(GT | LT); - -endmodule // magcompare8 - -module exception_int (Q, rem, op1, S, div0, Max_N, D_NegOne, Qf, remf); - - input logic [63:0] Q; - input logic [63:0] rem; - input logic [63:0] op1; - input logic S; - input logic div0; - input logic Max_N; - input logic D_NegOne; - - output logic [63:0] Qf; - output logic [63:0] remf; - - // Needs to be optimized - always_comb - case ({div0, S, Max_N, D_NegOne}) - 4'b0000 : Qf = Q; - 4'b0001 : Qf = Q; - 4'b0010 : Qf = Q; - 4'b0011 : Qf = Q; - 4'b0100 : Qf = Q; - 4'b0101 : Qf = Q; - 4'b0110 : Qf = Q; - 4'b0111 : Qf = {1'b1, 31'h0}; - 4'b1000 : Qf = {64{1'b1}}; - 4'b1001 : Qf = {64{1'b1}}; - 4'b1010 : Qf = {64{1'b1}}; - 4'b1011 : Qf = {64{1'b1}}; - 4'b1100 : Qf = {64{1'b1}}; - 4'b1101 : Qf = {64{1'b1}}; - 4'b1110 : Qf = {64{1'b1}}; - 4'b1111 : Qf = {64{1'b1}}; - default: Qf = Q; - endcase - - always_comb - case ({div0, S, Max_N, D_NegOne}) - 4'b0000 : remf = rem; - 4'b0001 : remf = rem; - 4'b0010 : remf = rem; - 4'b0011 : remf = rem; - 4'b0100 : remf = rem; - 4'b0101 : remf = rem; - 4'b0110 : remf = rem; - 4'b0111 : remf = 64'h0; - 4'b1000 : remf = op1; - 4'b1001 : remf = op1; - 4'b1010 : remf = op1; - 4'b1011 : remf = op1; - 4'b1100 : remf = op1; - 4'b1101 : remf = op1; - 4'b1110 : remf = op1; - 4'b1111 : remf = op1; - default: remf = rem; - endcase - -endmodule // exception_int - -/* verilator lint_on COMBDLY */ -/* verilator lint_on IMPLICIT */ -