PTO-ARCH-DATA-TYPES-FORMAT-E2M1X2

1// PTO-UNIT: {"id":"PTO-ARCH-DATA-TYPES-FORMAT-E2M1X2","surface":"arch","classification":["data-types","formats","e2m1x2"],"depends_on":["PTO-ARCH-DATA-TYPES-FORMAT-DESCRIPTOR"]}2// DOC-BEGIN: operation3// PTO-REQ-HARDWARE-NUMERIC-001: exact E2M1 logical lanes.4
5pure func E2M1X2NumericFormatDescriptor() => NumericFormatDescriptor6begin7    return NumericFormatDescriptor {8        available = TRUE, kind = NumericFormatKind_FixedBinary,9        carrier_bits = 8, lane_bits = 4, lanes_per_carrier = 2,10        sign_bits = 1, sign_bit = 3,11        exponent_bits_min = 2, exponent_bits_max = 2,12        fraction_bits_min = 1, fraction_bits_max = 1,13        exponent_bias_available = TRUE, exponent_bias = 1,14        required_low_zero_bits = 0, required_high_zero_bits = 0,15        has_zero = TRUE, has_signed_zero = TRUE, has_subnormal = FALSE,16        has_infinity = FALSE, has_quiet_nan = FALSE,17        has_signaling_nan = FALSE18    };19end;20
21pure func E2M1X2FiniteDecomposition(value: Word)22    => (boolean, boolean, Word, integer {-1074..1023})23begin24    let lane = value[3:0];25    let exponent = lane[2:1];26    let fraction = lane[0:0];27    if exponent == Zeros{2} then28        if fraction == Zeros{1} then29            return (TRUE, lane[3] == '1', Zeros{PTO_XLEN}, 0);30        else return (TRUE, lane[3] == '1', Zeros{PTO_XLEN} + 1, -1);31        end;32    else return (TRUE, lane[3] == '1',33                 LSL(Zeros{PTO_XLEN} + 1, 1) +34                     ZeroExtend{PTO_XLEN}(fraction),35                 (UInt(exponent) - 2) as integer {-1074..1023});36    end;37end;38pure func ClassifyE2M1X2(value: Word) => NumericValueClass39begin40    return NumericValueClassFromFiniteSign(value[3],41        value[2:0] == Zeros{3}, FALSE);42end;43
44pure func E2M1X2SignedZeroEncodings() => (Word, Word)45begin46    return (Zeros{PTO_XLEN}, Zeros{PTO_XLEN} + 0x8);47end;48// DOC-END: operation49