95 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
			
		
		
	
	
			95 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
| import "RV32IBase.core_desc"
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| 
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| InsructionSet RV32M extends RV32IBase {
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|     constants {
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|         MAXLEN:=128
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|     }
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|     instructions{       
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|         MUL{
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|             encoding: b0000001 | rs2[4:0] | rs1[4:0] | b000 | rd[4:0] | b0110011;
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|             args_disass:"{name(rd)}, {name(rs1)}, {name(rs2)}";
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|             if(rd != 0){
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|                 val res[MAXLEN] <= zext(X[rs1], MAXLEN) * zext(X[rs2], MAXLEN);
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|                 X[rd]<= zext(res , XLEN);
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|             }
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|         }
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|         MULH {
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|             encoding: b0000001 | rs2[4:0] | rs1[4:0] | b001 | rd[4:0] | b0110011;
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|             args_disass:"{name(rd)}, {name(rs1)}, {name(rs2)}";
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|             if(rd != 0){
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|                 val res[MAXLEN] <= sext(X[rs1], MAXLEN) * sext(X[rs2], MAXLEN);
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|                 X[rd]<= zext(res >> XLEN, XLEN);
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|             }
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|         }
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|         MULHSU {
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|             encoding: b0000001 | rs2[4:0] | rs1[4:0] | b010 | rd[4:0] | b0110011;
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|             args_disass:"{name(rd)}, {name(rs1)}, {name(rs2)}";
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|             if(rd != 0){
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|                 val res[MAXLEN] <= sext(X[rs1], MAXLEN) * zext(X[rs2], MAXLEN);
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|                 X[rd]<= zext(res >> XLEN, XLEN);
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|             }
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|         }
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|         MULHU {
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|             encoding: b0000001 | rs2[4:0] | rs1[4:0] | b011 | rd[4:0] | b0110011;
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|             args_disass:"{name(rd)}, {name(rs1)}, {name(rs2)}";
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|             if(rd != 0){
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|                 val res[MAXLEN] <= zext(X[rs1], MAXLEN) * zext(X[rs2], MAXLEN);
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|                 X[rd]<= zext(res >> XLEN, XLEN);
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|             }
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|         }
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|         DIV {
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|             encoding: b0000001 | rs2[4:0] | rs1[4:0] | b100 | rd[4:0] | b0110011;
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|             args_disass:"{name(rd)}, {name(rs1)}, {name(rs2)}";
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|             if(rd != 0){
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|                 if(X[rs2]!=0){
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|                     val M1[XLEN] <= -1;
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|                     val XLM1[8] <= XLEN-1;
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|                     val ONE[XLEN] <= 1;
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|                     val MMIN[XLEN] <= ONE<<XLM1;
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|                     if(X[rs1]==MMIN && X[rs2]==M1)
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|                         X[rd] <= MMIN;
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|                     else
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|                         X[rd] <= X[rs1]s / X[rs2]s;
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|                 }else 
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|                     X[rd] <= -1;
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|             }
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|         }
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|         DIVU {
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|             encoding: b0000001 | rs2[4:0] | rs1[4:0] | b101 | rd[4:0] | b0110011;
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|             args_disass:"{name(rd)}, {name(rs1)}, {name(rs2)}";
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|             if(rd != 0){
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|                 if(X[rs2]!=0)
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|                     X[rd] <= X[rs1] / X[rs2];
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|                 else 
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|                     X[rd] <= -1;
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|             }
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|         }
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|         REM {
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|             encoding: b0000001 | rs2[4:0] | rs1[4:0] | b110 | rd[4:0] | b0110011;
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|             args_disass:"{name(rd)}, {name(rs1)}, {name(rs2)}";
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|             if(rd != 0){
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|                 if(X[rs2]!=0) {
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|                     val M1[XLEN] <= -1; // constant -1 
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|                     val XLM1[32] <= XLEN-1;
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|                     val ONE[XLEN] <= 1;
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|                     val MMIN[XLEN] <= ONE<<XLM1; // -2^(XLEN-1)
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|                     if(X[rs1]==MMIN && X[rs2]==M1)
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|                         X[rd] <= 0;
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|                     else
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|                         X[rd] <= X[rs1]'s % X[rs2]'s;
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|                 } else 
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|                     X[rd] <= X[rs1];
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|             }
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|         }
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|         REMU {
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|             encoding: b0000001 | rs2[4:0] | rs1[4:0] | b111 | rd[4:0] | b0110011;
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|             args_disass:"{name(rd)}, {name(rs1)}, {name(rs2)}";
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|             if(rd != 0){
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|                 if(X[rs2]!=0)
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|                     X[rd] <= X[rs1] % X[rs2];
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|                 else 
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|                     X[rd] <= X[rs1];
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|             }
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|         }
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|     }
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| } | 
