PTO-ARCH-DATA-TYPES-FORMAT-HF32

1// PTO-UNIT: {"id":"PTO-ARCH-DATA-TYPES-FORMAT-HF32","surface":"arch","classification":["data-types","formats","hf32"],"depends_on":["PTO-ARCH-DATA-TYPES-FORMAT-DESCRIPTOR"]}2// DOC-BEGIN: operation3// PTO-REQ-HARDWARE-NUMERIC-001: exact HF32 encoding and finite values.4
5pure func HF32NumericFormatDescriptor() => NumericFormatDescriptor6begin7    return NumericFormatDescriptor {8        available = TRUE, kind = NumericFormatKind_FixedBinary,9        carrier_bits = 32, lane_bits = 32, lanes_per_carrier = 1,10        sign_bits = 1, sign_bit = 31,11        exponent_bits_min = 8, exponent_bits_max = 8,12        fraction_bits_min = 11, fraction_bits_max = 11,13        exponent_bias_available = TRUE, exponent_bias = 127,14        required_low_zero_bits = 12, required_high_zero_bits = 0,15        has_zero = TRUE, has_signed_zero = TRUE, has_subnormal = TRUE,16        has_infinity = TRUE, has_quiet_nan = TRUE,17        has_signaling_nan = TRUE18    };19end;20
21pure func HF32FiniteDecomposition(value: bits(32))22    => (boolean, boolean, Word, integer {-1074..1023})23begin24    if value[11:0] != Zeros{12} then25        return (FALSE, FALSE, Zeros{PTO_XLEN}, 0);26    end;27    let exponent = value[30:23];28    let fraction = value[22:12];29    if exponent == Ones{8} then30        return (FALSE, FALSE, Zeros{PTO_XLEN}, 0);31    elsif exponent == Zeros{8} then32        if fraction == Zeros{11} then33            return (TRUE, value[31] == '1', Zeros{PTO_XLEN}, 0);34        else return (TRUE, value[31] == '1',35                     ZeroExtend{PTO_XLEN}(fraction), -137);36        end;37    else return (TRUE, value[31] == '1',38                 LSL(Zeros{PTO_XLEN} + 1, 11) +39                     ZeroExtend{PTO_XLEN}(fraction),40                 (UInt(exponent) - (127 + 11))41                     as integer {-1074..1023});42    end;43end;44
45pure func HF32EncodingValid(value: bits(32)) => boolean46begin47    return value[11:0] == Zeros{12};48end;49pure func ClassifyHF32(value: bits(32)) => NumericValueClass50begin51    let exponent = value[30:23];52    let fraction = value[22:12];53    if exponent == Ones{8} then54        if fraction == Zeros{11} then55            if value[31] == '1' then return NumericValue_NegativeInfinity;56            else return NumericValue_PositiveInfinity;57            end;58        elsif fraction[10] == '1' then return NumericValue_QuietNaN;59        else return NumericValue_SignalingNaN;60        end;61    end;62    return NumericValueClassFromFiniteSign(value[31],63        exponent == Zeros{8} && fraction == Zeros{11},64        exponent == Zeros{8} && fraction != Zeros{11});65end;66
67pure func HF32CanonicalNaN() => Word68begin69    return Zeros{PTO_XLEN} + 0x7fc00000;70end;71
72pure func HF32SignedZeroEncodings() => (Word, Word)73begin74    return (Zeros{PTO_XLEN}, Zeros{PTO_XLEN} + 0x80000000);75end;76// DOC-END: operation77