| Line 58... |
Line 58... |
//`CHK: IsBranch = TRUE;
|
//`CHK: IsBranch = TRUE;
|
//default: IsBranch = FALSE;
|
//default: IsBranch = FALSE;
|
//endcase
|
//endcase
|
//endfunction
|
//endfunction
|
|
|
|
wire [10:0] brdisp = instr[31:21];
|
|
|
wire iAlu;
|
wire iAlu;
|
mIsALU uialu1
|
mIsALU uialu1
|
(
|
(
|
.instr(instr),
|
.instr(instr),
|
.IsALU(iAlu)
|
.IsALU(iAlu)
|
| Line 195... |
Line 197... |
//end
|
//end
|
//endfunction
|
//endfunction
|
|
|
// fnCanException
|
// fnCanException
|
//
|
//
|
// Used by memory issue logic.
|
// Used by memory issue logic (stores).
|
// Returns TRUE if the instruction can cause an exception.
|
// Returns TRUE if the instruction can cause an exception.
|
// In debug mode any instruction could potentially cause a breakpoint exception.
|
// In debug mode any instruction could potentially cause a breakpoint exception.
|
// Rather than check all the addresses for potential debug exceptions it's
|
// Rather than check all the addresses for potential debug exceptions it's
|
// simpler to just have it so that all instructions could exception. This will
|
// simpler to just have it so that all instructions could exception. This will
|
// slow processing down somewhat as stores will only be done at the head of the
|
// slow processing down somewhat as stores will only be done at the head of the
|
| Line 219... |
Line 221... |
case(isn[`INSTRUCTION_S2])
|
case(isn[`INSTRUCTION_S2])
|
`FDIV,`FMUL,`FADD,`FSUB,`FTX:
|
`FDIV,`FMUL,`FADD,`FSUB,`FTX:
|
fnCanException = `TRUE;
|
fnCanException = `TRUE;
|
default: fnCanException = `FALSE;
|
default: fnCanException = `FALSE;
|
endcase
|
endcase
|
`ADDI,`DIVI,`MODI,`MULI:
|
`DIVI,`MODI,`MULI:
|
fnCanException = `TRUE;
|
fnCanException = `TRUE;
|
`R2:
|
`R2:
|
case(isn[`INSTRUCTION_S2])
|
case(isn[`INSTRUCTION_S2])
|
`ADD,`SUB,`MUL,
|
`MUL,
|
`DIV,`MULSU,`DIVSU,
|
`DIV,`MULSU,`DIVSU,
|
`MOD,`MODSU:
|
`MOD,`MODSU:
|
fnCanException = TRUE;
|
fnCanException = TRUE;
|
`RTI: fnCanException = TRUE;
|
`RTI: fnCanException = TRUE;
|
default: fnCanException = FALSE;
|
default: fnCanException = FALSE;
|
endcase
|
endcase
|
`Bcc: fnCanException = TRUE;
|
// Had branches that could exception if looping to self. But in a tight loop
|
`BEQI: fnCanException = TRUE;
|
// it affects store performance.
|
|
// -> A branch may only exception if it loops back to itself.
|
|
`Bcc,`BBc,`BEQI: fnCanException = isn[7] ? brdisp == 11'h7FF : brdisp == 11'h7FE;
|
`CHK: fnCanException = TRUE;
|
`CHK: fnCanException = TRUE;
|
default:
|
default:
|
// Stores can stil exception if there is a write buffer, but we allow following
|
// Stores can stil exception if there is a write buffer, but we allow following
|
// stores to be issued by ignoring the fact they can exception because the stores
|
// stores to be issued by ignoring the fact they can exception because the stores
|
// can be undone by invalidating the write buffer.
|
// can be undone by invalidating the write buffer.
|
`ifdef HAS_WB
|
`ifdef HAS_WB
|
fnCanException = IsLoad(isn);
|
fnCanException = IsMem(isn) && !IsStore(isn);
|
`else
|
`else
|
fnCanException = IsMem(isn);
|
fnCanException = IsMem(isn);
|
`endif
|
`endif
|
endcase
|
endcase
|
end
|
end
|
