HIFIVE1-VP/riscv/gen_input/RV64M.core_desc

import "RV64IBase.core_desc"

InsructionSet RV64M extends RV64IBase {
    instructions{       
        MULW{
            encoding: b0000001 | rs2[4:0] | rs1[4:0] | b000 | rd[4:0] | b0111011;
            args_disass:"{name(rd)}, {name(rs1)}, {name(rs2)}";
            if(rd != 0){
                X[rd]<= sext(X[rs1]{32} * X[rs2]{32});
            }
        }
        DIVW {
            encoding: b0000001 | rs2[4:0] | rs1[4:0] | b100 | rd[4:0] | b0111011;
            args_disass:"{name(rd)}, {name(rs1)}, {name(rs2)}";
            if(rd != 0){
                if(X[rs2]!=0){
                    val M1[32] <= -1;
                    val ONE[32] <= 1;
                    val MMIN[32] <= ONE<<31;
                    if(X[rs1]{32}==MMIN && X[rs2]{32}==M1)
                        X[rd] <= -1<<31;
                    else
                        X[rd] <= sext(X[rs1]{32}s / X[rs2]{32}s);
                }else 
                    X[rd] <= -1;
            }
        }
        DIVUW {
            encoding: b0000001 | rs2[4:0] | rs1[4:0] | b101 | rd[4:0] | b0111011;
            args_disass:"{name(rd)}, {name(rs1)}, {name(rs2)}";
            if(rd != 0){
	            if(X[rs2]{32}!=0)
	                X[rd] <= sext(X[rs1]{32} / X[rs2]{32});
	            else 
	                X[rd] <= -1;
	        }
        }
        REMW {
            encoding: b0000001 | rs2[4:0] | rs1[4:0] | b110 | rd[4:0] | b0111011;
            args_disass:"{name(rd)}, {name(rs1)}, {name(rs2)}";
            if(rd != 0){
                if(X[rs2]!=0) {
                    val M1[32] <= -1; // constant -1 
                    val ONE[32] <= 1;
                    val MMIN[32] <= ONE<<31; // -2^(XLEN-1)
                    if(X[rs1]{32}==MMIN && X[rs2]==M1)
                        X[rd] <= 0;
                    else
                        X[rd] <= sext(X[rs1]{32}s % X[rs2]{32}s);
                } else 
                    X[rd] <= sext(X[rs1]{32});
            }
        }
        REMUW {
            encoding: b0000001 | rs2[4:0] | rs1[4:0] | b111 | rd[4:0] | b0111011;
            args_disass:"{name(rd)}, {name(rs1)}, {name(rs2)}";
            if(rd != 0){
                if(X[rs2]{32}!=0)
                    X[rd] <= sext(X[rs1]{32} % X[rs2]{32});
                else 
                    X[rd] <= sext(X[rs1]{32});
            }
        }
    }
}