import "RISCVBase.core_desc"

InsructionSet RV32I extends RISCVBase{
     
    instructions { 
        LUI{
            encoding: imm[31:12]s | rd[4:0] | b0110111;
            args_disass: "{name(rd)}, {imm:#05x}";
            if(rd!=0) X[rd] <= imm;
        }
        AUIPC{
            encoding: imm[31:12]s | rd[4:0] | b0010111;
            args_disass: "{name(rd)}, {imm:#08x}";
            if(rd!=0) X[rd] <= PC's+imm;
        }
        JAL(no_cont){
            encoding: imm[20:20]s | imm[10:1]s | imm[11:11]s | imm[19:12]s | rd[4:0] | b1101111;
            args_disass: "{name(rd)}, {imm:#0x}";
            if(rd!=0) X[rd] <= PC+4;
            PC<=PC's+imm;
        }
        JALR(no_cont){
            encoding: imm[11:0]s | rs1[4:0] | b000 | rd[4:0] | b1100111;
            args_disass: "{name(rd)}, {name(rs1)}, {imm:#0x}";
            val new_pc[XLEN] <= X[rs1]'s+ imm;
            val align[XLEN] <= new_pc & 0x2;
            if(align != 0){
                raise(0, 0);
            } else {
                if(rd!=0) X[rd] <= PC+4;
                PC<=new_pc & ~0x1;
            }
        }
        BEQ(no_cont,cond){
            encoding: imm[12:12]s |imm[10:5]s | rs2[4:0] | rs1[4:0] | b000 | imm[4:1]s | imm[11:11]s | b1100011;
            args_disass:"{name(rs1)}, {name(rs2)}, {imm:#0x}";
            PC<=choose(X[rs1]==X[rs2], PC's+imm, PC+4);
        }
        BNE(no_cont,cond){
            encoding: imm[12:12]s |imm[10:5]s | rs2[4:0] | rs1[4:0] | b001 | imm[4:1]s | imm[11:11]s | b1100011;
            args_disass:"{name(rs1)}, {name(rs2)}, {imm:#0x}";
            PC<=choose(X[rs1]!=X[rs2], PC's+imm, PC+4);
        }
        BLT(no_cont,cond){
            encoding: imm[12:12]s |imm[10:5]s | rs2[4:0] | rs1[4:0] | b100 | imm[4:1]s | imm[11:11]s | b1100011;
            args_disass:"{name(rs1)}, {name(rs2)}, {imm:#0x}";
            PC<=choose(X[rs1]s<X[rs2]s, PC's+imm, PC+4);
        }
        BGE(no_cont,cond) {
            encoding: imm[12:12]s |imm[10:5]s | rs2[4:0] | rs1[4:0] | b101 | imm[4:1]s | imm[11:11]s | b1100011;
            args_disass:"{name(rs1)}, {name(rs2)}, {imm:#0x}";
            PC<=choose(X[rs1]s>=X[rs2]s, PC's+imm, PC+4);
        }
        BLTU(no_cont,cond) {
            encoding: imm[12:12]s |imm[10:5]s | rs2[4:0] | rs1[4:0] | b110 | imm[4:1]s | imm[11:11]s | b1100011;
            args_disass:"{name(rs1)}, {name(rs2)}, {imm:#0x}";
            PC<=choose(X[rs1]<X[rs2],PC's+imm, PC+4);
        }
        BGEU(no_cont,cond) {
            encoding: imm[12:12]s |imm[10:5]s | rs2[4:0] | rs1[4:0] | b111 | imm[4:1]s | imm[11:11]s | b1100011;
            args_disass:"{name(rs1)}, {name(rs2)}, {imm:#0x}";
            PC<=choose(X[rs1]>=X[rs2], PC's+imm, PC+4);
        }
        LB {
            encoding: imm[11:0]s | rs1[4:0] | b000 | rd[4:0] | b0000011;
            args_disass:"{name(rd)}, {imm}({name(rs1)})";
            val offs[XLEN] <= X[rs1]'s+imm;
            if(rd!=0) X[rd]<=sext(MEM[offs]);
        }
        LH {
            encoding: imm[11:0]s | rs1[4:0] | b001 | rd[4:0] | b0000011;
            args_disass:"{name(rd)}, {imm}({name(rs1)})";
            val offs[XLEN] <= X[rs1]'s+imm;
            if(rd!=0) X[rd]<=sext(MEM[offs]{16});            
        }
        LW {
            encoding: imm[11:0]s | rs1[4:0] | b010 | rd[4:0] | b0000011;
            args_disass:"{name(rd)}, {imm}({name(rs1)})";
            val offs[XLEN] <= X[rs1]'s+imm;
            if(rd!=0) X[rd]<=sext(MEM[offs]{32});
        }
        LBU {
            encoding: imm[11:0]s | rs1[4:0] | b100 | rd[4:0] | b0000011;
            args_disass:"{name(rd)}, {imm}({name(rs1)})";
            val offs[XLEN] <= X[rs1]'s+imm;
            if(rd!=0) X[rd]<=zext(MEM[offs]);
        }
        LHU {
            encoding: imm[11:0]s | rs1[4:0] | b101 | rd[4:0] | b0000011;
            args_disass:"{name(rd)}, {imm}({name(rs1)})";
            val offs[XLEN] <= X[rs1]'s+imm;
            if(rd!=0) X[rd]<=zext(MEM[offs]{16});            
        }
        SB {
            encoding: imm[11:5]s | rs2[4:0] | rs1[4:0] | b000 | imm[4:0]s | b0100011;
            args_disass:"{name(rs2)}, {imm}({name(rs1)})";
            val offs[XLEN] <= X[rs1]'s + imm;
            MEM[offs] <= X[rs2];
        }
        SH {
            encoding: imm[11:5]s | rs2[4:0] | rs1[4:0] | b001 | imm[4:0]s | b0100011;
            args_disass:"{name(rs2)}, {imm}({name(rs1)})";
            val offs[XLEN] <= X[rs1]'s + imm;
            MEM[offs]{16} <= X[rs2];
        }
        SW {
            encoding: imm[11:5]s | rs2[4:0] | rs1[4:0] | b010 | imm[4:0]s | b0100011;
            args_disass:"{name(rs2)}, {imm}({name(rs1)})";
            val offs[XLEN] <= X[rs1]'s + imm;
            MEM[offs]{32} <= X[rs2];
        }
        ADDI {
            encoding: imm[11:0]s | rs1[4:0] | b000 | rd[4:0] | b0010011;
            args_disass:"{name(rd)}, {name(rs1)}, {imm}";
            if(rd != 0) X[rd] <= X[rs1]'s + imm;
        }
        SLTI {
            encoding: imm[11:0]s | rs1[4:0] | b010 | rd[4:0] | b0010011;
            args_disass:"{name(rd)}, {name(rs1)}, {imm}";
            if (rd != 0) X[rd] <= choose(X[rs1]s < imm's, 1, 0);
        }
        SLTIU {
            encoding: imm[11:0]s | rs1[4:0] | b011 | rd[4:0] | b0010011;
            args_disass:"{name(rd)}, {name(rs1)}, {imm}";
            val full_imm[XLEN] <= imm's;
            if (rd != 0) X[rd] <= choose(X[rs1]'u < full_imm'u, 1, 0);
        }
        XORI {
            encoding: imm[11:0]s | rs1[4:0] | b100 | rd[4:0] | b0010011;
            args_disass:"{name(rd)}, {name(rs1)}, {imm}";
            if(rd != 0) X[rd] <= X[rs1]s ^ imm;
        }
        ORI {
            encoding: imm[11:0]s | rs1[4:0] | b110 | rd[4:0] | b0010011;
            args_disass:"{name(rd)}, {name(rs1)}, {imm}";
            if(rd != 0) X[rd] <= X[rs1]s | imm;
        }
        ANDI {
            encoding: imm[11:0]s | rs1[4:0] | b111 | rd[4:0] | b0010011;
            args_disass:"{name(rd)}, {name(rs1)}, {imm}";
            if(rd != 0) X[rd] <= X[rs1]s & imm;
        }
        SLLI {
            encoding: b0000000 | shamt[4:0] | rs1[4:0] | b001 | rd[4:0] | b0010011;
            args_disass:"{name(rd)}, {name(rs1)}, {shamt}";
            if(shamt > 31){
                raise(0,0);
            } else {
                if(rd != 0) X[rd] <= shll(X[rs1], shamt);
            }
        }
        SRLI {
            encoding: b0000000 | shamt[4:0] | rs1[4:0] | b101 | rd[4:0] | b0010011;
            args_disass:"{name(rd)}, {name(rs1)}, {shamt}";
            if(shamt > 31){
                raise(0,0);
            } else {
                if(rd != 0) X[rd] <= shrl(X[rs1], shamt);
            }
        }
        SRAI {
            encoding: b0100000 | shamt[4:0] | rs1[4:0] | b101 | rd[4:0] | b0010011;
            args_disass:"{name(rd)}, {name(rs1)}, {shamt}";
            if(shamt > 31){
                raise(0,0);
            } else {
                if(rd != 0) X[rd] <= shra(X[rs1], shamt);
            }
        }
        ADD {
            encoding: b0000000 | rs2[4:0] | rs1[4:0] | b000 | rd[4:0] | b0110011;
            args_disass:"{name(rd)}, {name(rs1)}, {name(rs2)}";
            if(rd != 0) X[rd] <= X[rs1] + X[rs2];
        }
        SUB {
            encoding: b0100000 | rs2[4:0] | rs1[4:0] | b000 | rd[4:0] | b0110011;
            args_disass:"{name(rd)}, {name(rs1)}, {name(rs2)}";
            if(rd != 0) X[rd] <= X[rs1] - X[rs2];
        }
        SLL {
            encoding: b0000000 | rs2[4:0] | rs1[4:0] | b001 | rd[4:0] | b0110011;
            args_disass:"{name(rd)}, {name(rs1)}, {name(rs2)}";
            if(rd != 0) X[rd] <= shll(X[rs1], X[rs2]&(XLEN-1));
        }
        SLT {
            encoding: b0000000 | rs2[4:0] | rs1[4:0] | b010 | rd[4:0] | b0110011;
            args_disass:"{name(rd)}, {name(rs1)}, {name(rs2)}";
            if (rd != 0) X[rd] <= choose(X[rs1]s < X[rs2]s, 1, 0);
        }
        SLTU {
            encoding: b0000000 | rs2[4:0] | rs1[4:0] | b011 | rd[4:0] | b0110011;
            args_disass:"{name(rd)}, {name(rs1)}, {name(rs2)}";
            if (rd != 0) X[rd] <= choose(zext(X[rs1]) < zext(X[rs2]), 1, 0);
        }
        XOR {
            encoding: b0000000 | rs2[4:0] | rs1[4:0] | b100 | rd[4:0] | b0110011;
            args_disass:"{name(rd)}, {name(rs1)}, {name(rs2)}";
            if(rd != 0) X[rd] <= X[rs1] ^ X[rs2];
        }
        SRL {
            encoding: b0000000 | rs2[4:0] | rs1[4:0] | b101 | rd[4:0] | b0110011;
            args_disass:"{name(rd)}, {name(rs1)}, {name(rs2)}";
            if(rd != 0) X[rd] <= shrl(X[rs1], X[rs2]&(XLEN-1));
        }
        SRA {
            encoding: b0100000 | rs2[4:0] | rs1[4:0] | b101 | rd[4:0] | b0110011;
            args_disass:"{name(rd)}, {name(rs1)}, {name(rs2)}";
            if(rd != 0) X[rd] <= shra(X[rs1], X[rs2]&(XLEN-1));
        }
        OR {
            encoding: b0000000 | rs2[4:0] | rs1[4:0] | b110 | rd[4:0] | b0110011;
            args_disass:"{name(rd)}, {name(rs1)}, {name(rs2)}";
            if(rd != 0) X[rd] <= X[rs1] | X[rs2];
        }
        AND {
            encoding: b0000000 | rs2[4:0] | rs1[4:0] | b111 | rd[4:0] | b0110011;
            args_disass:"{name(rd)}, {name(rs1)}, {name(rs2)}";
            if(rd != 0) X[rd] <= X[rs1] & X[rs2];
        }
        FENCE {
            encoding: b0000 | pred[3:0] | succ[3:0] | rs1[4:0] | b000 | rd[4:0] | b0001111;
            FENCE[fence] <= pred<<4 | succ;
        }
        FENCE_I(flush) {
            encoding: imm[11:0] | rs1[4:0] | b001 | rd[4:0] | b0001111 ;
            FENCE[fencei] <= imm;
        }
        ECALL(no_cont) {
            encoding: b000000000000 | b00000 | b000 | b00000 | b1110011;
            raise(0, 11);
        }
        EBREAK(no_cont) {
            encoding: b000000000001 | b00000 | b000 | b00000 | b1110011;
            raise(0, 3);
        }
        URET(no_cont) {
            encoding: b0000000 | b00010 | b00000 | b000 | b00000 | b1110011;
            leave(0);
        }
        SRET(no_cont)  {
            encoding: b0001000 | b00010 | b00000 | b000 | b00000 | b1110011;
            leave(1);
        }
        MRET(no_cont) {
            encoding: b0011000 | b00010 | b00000 | b000 | b00000 | b1110011;
            leave(3);
        }
        WFI  {
            encoding: b0001000 | b00101 | b00000 | b000 | b00000 | b1110011;
            wait(1);
        }
        SFENCE.VMA {
            encoding: b0001001 | rs2[4:0] | rs1[4:0] | b000 | b00000 | b1110011;
            FENCE[fencevmal] <= rs1;
            FENCE[fencevmau] <= rs2;
        }
        CSRRW {
            encoding: csr[11:0] | rs1[4:0] | b001 | rd[4:0] | b1110011;
            args_disass:"{name(rd)}, {csr}, {name(rs1)}";
            val rs_val[XLEN] <= X[rs1];
            if(rd!=0){
                val csr_val[XLEN] <= CSR[csr];
                CSR[csr] <= rs_val; 
                // make sure Xrd is updated once CSR write succeeds
                X[rd] <= csr_val;
            } else {
                CSR[csr] <= rs_val;
            }
        }
        CSRRS {
            encoding: csr[11:0] | rs1[4:0] | b010 | rd[4:0] | b1110011;
            args_disass:"{name(rd)}, {csr}, {name(rs1)}";
            val xrd[XLEN] <= CSR[csr];
            val xrs1[XLEN] <= X[rs1];
            if(rd!=0) X[rd] <= xrd;
            if(rs1!=0) CSR[csr] <= xrd | xrs1;    
        }
        CSRRC {
            encoding: csr[11:0] | rs1[4:0] | b011 | rd[4:0] | b1110011;
            args_disass:"{name(rd)}, {csr}, {name(rs1)}";
            val xrd[XLEN] <= CSR[csr];
            val xrs1[XLEN] <= X[rs1];
            if(rd!=0) X[rd] <= xrd;
            if(rs1!=0) CSR[csr] <= xrd & ~xrs1;    
        }
        CSRRWI {
            encoding: csr[11:0] | zimm[4:0] | b101 | rd[4:0] | b1110011;
            args_disass:"{name(rd)}, {csr}, {zimm:#0x}";
            if(rd!=0) X[rd] <= CSR[csr];
            CSR[csr] <= zext(zimm);    
        }
        CSRRSI {
            encoding: csr[11:0] | zimm[4:0] | b110 | rd[4:0] | b1110011;
            args_disass:"{name(rd)}, {csr}, {zimm:#0x}";
            val res[XLEN] <= CSR[csr];
            if(zimm!=0) CSR[csr] <= res | zext(zimm);
            // make sure rd is written after csr write succeeds    
            if(rd!=0) X[rd] <= res;
        }
        CSRRCI {
            encoding: csr[11:0] | zimm[4:0] | b111 | rd[4:0] | b1110011;
            args_disass:"{name(rd)}, {csr}, {zimm:#0x}";
            val res[XLEN] <= CSR[csr];
            if(rd!=0) X[rd] <= res;
            if(zimm!=0) CSR[csr] <= res & ~zext(zimm, XLEN);    
        }   
    }
}