HIFIVE1-VP/riscv/gen_input/RV32M.core_desc

import "RV32IBase.core_desc"

InsructionSet RV32M extends RV32IBase {
    constants {
        MAXLEN:=128
    }
    instructions{       
        MUL{
            encoding: b0000001 | rs2[4:0] | rs1[4:0] | b000 | rd[4:0] | b0110011;
            args_disass:"x%rd$d, x%rs1$d, x%rs2$d";
            if(rd != 0){
                val res[MAXLEN] <= zext(X[rs1], MAXLEN) * zext(X[rs2], MAXLEN);
                X[rd]<= zext(res , XLEN);
            }
        }
        MULH {
            encoding: b0000001 | rs2[4:0] | rs1[4:0] | b001 | rd[4:0] | b0110011;
            args_disass:"x%rd$d, x%rs1$d, x%rs2$d";
            if(rd != 0){
                val res[MAXLEN] <= sext(X[rs1], MAXLEN) * sext(X[rs2], MAXLEN);
                X[rd]<= zext(res >> XLEN, XLEN);
            }
        }
        MULHSU {
            encoding: b0000001 | rs2[4:0] | rs1[4:0] | b010 | rd[4:0] | b0110011;
            args_disass:"x%rd$d, x%rs1$d, x%rs2$d";
            if(rd != 0){
                val res[MAXLEN] <= sext(X[rs1], MAXLEN) * zext(X[rs2], MAXLEN);
                X[rd]<= zext(res >> XLEN, XLEN);
            }
        }
        MULHU {
            encoding: b0000001 | rs2[4:0] | rs1[4:0] | b011 | rd[4:0] | b0110011;
            args_disass:"x%rd$d, x%rs1$d, x%rs2$d";
            if(rd != 0){
                val res[MAXLEN] <= zext(X[rs1], MAXLEN) * zext(X[rs2], MAXLEN);
                X[rd]<= zext(res >> XLEN, XLEN);
            }
        }
        DIV {
            encoding: b0000001 | rs2[4:0] | rs1[4:0] | b100 | rd[4:0] | b0110011;
            args_disass:"x%rd$d, x%rs1$d, x%rs2$d";
            if(rd != 0){
                if(X[rs2]!=0){
                    val M1[XLEN] <= -1;
                    val MMIN[XLEN] <= -1<<(XLEN-1);
                    if(X[rs1]s==MMIN's)
                        if(X[rs2]s==M1's)
                            X[rd]<=MMIN;
                        else
                            X[rd] <= X[rs1]s / X[rs2]s;
                    else
                        X[rd] <= X[rs1]s / X[rs2]s;
                }else 
                    X[rd] <= -1;
            }
        }
        DIVU {
            encoding: b0000001 | rs2[4:0] | rs1[4:0] | b101 | rd[4:0] | b0110011;
            args_disass:"x%rd$d, x%rs1$d, x%rs2$d";
            if(rd != 0){
                if(X[rs2]!=0)
                    X[rd] <= zext(X[rs1], 32) / zext(X[rs2], 32);
                else 
                    X[rd] <= -1;
            }
        }
        REM {
            encoding: b0000001 | rs2[4:0] | rs1[4:0] | b110 | rd[4:0] | b0110011;
            args_disass:"x%rd$d, x%rs1$d, x%rs2$d";
            if(rd != 0){
                if(X[rs2]!=0) {
                    val M1[XLEN] <= -1;
                    val MMIN[XLEN] <= -1<<(XLEN-1);
                    if(X[rs1]s==MMIN's)
                        if(X[rs2]s==M1's)
                            X[rd] <= 0;
                        else
                            X[rd] <= sext(X[rs1], 32) % sext(X[rs2], 32);
                    else
                        X[rd] <= sext(X[rs1], 32) % sext(X[rs2], 32);
                } else 
                    X[rd] <= X[rs1];
            }
        }
        REMU {
            encoding: b0000001 | rs2[4:0] | rs1[4:0] | b111 | rd[4:0] | b0110011;
            args_disass:"x%rd$d, x%rs1$d, x%rs2$d";
            if(rd != 0){
                if(X[rs2]!=0)
                    X[rd] <= zext(X[rs1], 32) % zext(X[rs2], 32);
                else 
                    X[rd] <= X[rs1];
            }
        }
    }
}